bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P6-04-25: Epidermal growth factor receptor as therapeutic target in hormone receptor-positive breast cancer
Authors: Jeong Yisun , Bae Soo Youn , You Daeun , Jung Seung Pil , Choi Hee Jun , Kim Isaac , Lee Se Kyung , Yu Jonghan , Kim Seok Won , Lee Jeong Eon , Kim Sangmin , Nam Seok Jin
Published: March 2020

Background/Aims: Despite effective therapeutic strategies for treating hormone receptor-positive (HR+) breast cancer, resistance to endocrine therapy that is either de novo or acquired still occurs. We investigated epidermal growth factor receptor (EGFR) as a therapeutic target for overcoming endocrine resistance in HR+ breast cancer models. Methods: Using clinical data from 2,166 patients who had HR+ breast tumors and received tamoxifen, we analyzed survival rates. Levels of mRNA and protein expression were analyzed by real-time PCR and western blotting, respectively. Cell viability was analyzed by MTT assays and anchorage-independent growth by soft agar colony-formation assays. Efficacy of tamoxifen and/or gefitinib was analyzed using orthotopic xenograft mouse models. Results: EGFR expression was significantly associated with more advanced stage and higher grade. EGFR expression was different in luminal A-like (Lum A, 1.3%) versus luminal B-like (Lum B, 11.4%) subtypes. On multivariate analyses for survival Lum B subtype EGFR+ tumors showed a hazard ratio (HR) of 5.22 (95% CI, 1.29-21.15, P = 0.020) for overall survival (OS) and HR of 2.91 (95% CI, 1.35-6.28, P = 0.006) for disease-free survival (DFS). Levels of EGFR inversely correlated with ER-α expression. Basal ER-α level was completely blocked by TGFA or EGF treatment. With TGFA pretreatment, ER+ breast cancer cells were resistant to 4-hydroxytamoxifen (4-OHT). Conversely, downregulation of ER-α by TGFA was reversed by gefitinib with recovered sensitivity to 4-OHT. Tumorigenicity of EGFR and ER+ breast cancer cells was significantly decreased by combined tamoxifen and gefitinib. Conclusion: Aberrant EGFR expression was associated with poor prognosis in ER+ breast cancers, especially the Lum B subtype. Loss of ER by EGFR activation induced tamoxifen resistance. Therefore, EGFR could be a therapeutic target for overcoming recurrence of ER+ breast cancer with high EGFR expression.

Citation Format: Yisun Jeong, Soo Youn Bae, Daeun You, Seung Pil Jung, Hee Jun Choi, Isaac Kim, Se Kyung Lee, Jonghan Yu, Seok Won Kim, Jeong Eon Lee, Sangmin Kim, Seok Jin Nam. Epidermal growth factor receptor as therapeutic target in hormone receptor-positive breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-04-25.
Abstract P6-06-17: Assessment of TILs, PDL1 and FOXP3 expression in metaplastic breast cancer: A glimpse into its tumour microenvironment
Authors: Kalaw Emarene Mationg
Published: March 2020

BACKGROUND: Metaplastic breast carcinoma (MBC) encompasses a heterogeneous group of tumours that differentiate into squamous and/or spindle, chondroid, osseous or rhabdoid mesenchymal-looking elements.Tumour cells,among others in the tumour microenvironment express Program Death Ligand 1 (PD-L1); an emerging therapeutic target. Activation of PD-1/PD-L1 pathway in neoplastic cells results in dampening of immune response.FOXP3 is a transcriptional factor for regulatory T-cells associated with immunosuppression. AIMS:We aimed to evaluate the immunohistochemical expression of PD-L1, FOXP3 and tumour infiltrating lymphocytes (TILs) by assessing their expression in tumour and immune stromal cells and correlated this with patient outcome. METHODS:Quantification of TILs according to the 2014 working group was performed for a large cohort of MBC, and control Triple Negative breast cancer (TNBC) cohort. Expression of PD-L1 and FOXP3 was evaluated with immunohistochemistry. PD-L1 expression was recorded in the tumour cells and stromal TILS (sTILs). TILs in direct contact with malignant cells are classed intra-tumoural (iTILs),while sTILs are lymphocytes that do not interact directly with cancer cells. FOXP3 positive iTILs and sTILs were evaluated. Histologic score was calculated and findings compared with the TNBC cohort. RESULTS: No significant associations were found between TILs and World Health Organisation (WHO) MBC subtypes,or number and type of morphologies present in mixed MBCs. However, WHO MBC Types 1 and 4 tend to contain higher amounts of TILs, while WHO Type 6 presents with the least amount of infiltrate, suggesting a restricted immunogenic repertoire. Mixed MBC cases with more than 3 phenotypes present have fewer TILs. Low tumour and high sTILs PD-L1 expression displayed the best clinical outcome (without reaching significance in a Kaplan Meier survival analysis; p value= 0.5780) while FOXP3 iTILs is associated with adverse prognostic outcome (p value=0.0240). CONCLUSIONS: We identified a subset of patients that would likely respond to immunotherapeutics targeting the PD-1/PD-L1 checkpoint. We report the biological significance of FOXP3 and TILs in MBC; wherein, their presence establishes a potential prognostic value.

Citation Format: Emarene Mationg Kalaw. Assessment of TILs, PDL1 and FOXP3 expression in metaplastic breast cancer: A glimpse into its tumour microenvironment [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-06-17.
Abstract P6-06-18: Promyelocytic leukemia (PML) is induced by tumor-associated macrophages (TAMs) in breast cancer
Authors: Long Meijun , Yang Mei , An Jun , Liu Renbin
Published: March 2020

Introduction: Tumor-associated macrophages (TAMs) are pivotal orchestrators of the tumor microenvironment. Clinical evidences show that density of TAMs increases with lymph node metastasis, which is associated with poor prognosis in breast cancer patients. The underlying mechanism has not been clearly elucidated.

Methods: Transcriptome of MCF-7 cells cocultured with TAMs or monocyte-derived macrophages (MDMs) was analyzed and compared by RNA-seq analysis, which showed that the promyelocytic leukemia (PML) gene was significantly upregulated by TAMs (P<0.001). The upregulation of PML was further verified by qRT-PCR and immunohistochemistry (IHC) in tissue microarrays (TMAs) containing 294 cases of breast cancer tissue with duplicate cores and 28 cases of normal breast tissue with single core. The age, sex, pathological type, histologic grade and stage of the patients were well recorded.

Results: RNA-seq analysis revealed that TAMs significantly upregulated PML expression, which was confirmed by qRT-PCR. Further, the protein level of PML was detected by IHC in TMAs. As expected, 57 cores of benign breast tissue, including normal breast tissue, adjacent normal breast tissue, adenosis and fibrous tissue in invasive ductal carcinoma (IDC) and lobular carcinoma in situ (LCIS), showed absent (80.70%) or low (19.30%) staining scores. In 508 (99.03%) cores of invasive breast cancer tissue, PML expression was positively correlated with lymph node metastasis (P= 0.003). However, no significant associations were observed between PML expression and tumor stage, primary tumor size, histologic tumor grade in IDC, or PML cellular localization.

Conclusion:Recently, PML, upregulated in a subset of breast cancer, has been identified as a breast cancer oncogene. Here, we demonstrated PML expression was induced by TAMs and positively correlated with lymph node metastasis. Thus, we conclude PML mediates TAMs function in breast tumorigenesis and TAMs stimulates the expression of PML in breast cancer.

Citation Format: Meijun Long, Mei Yang, Jun An, Renbin Liu. Promyelocytic leukemia (PML) is induced by tumor-associated macrophages (TAMs) in breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-06-18.
Abstract P6-07-03: The prognostic impact of HECTD1 E3 ubiquitin ligase expression in breast cancer patients
Authors: Uemoto Yasuaki , Kondo Naoto , Wanifuchi-Endo Yumi , Asano Tomoko , Hisada Tomoka , Nishikawa Sayaka , Katagiri Yusuke , Terada Mitsuo , Kato Akiko , Dong Yu , Kato Hiroyuki , Takahashi Satoru , Toyama Tatsuya
Published: March 2020

Background: The epithelial-to-mesenchymal transition (EMT) is fundamental and is required for cancer cells to metastasize. A E3 ubiquitin ligase, HECTD1,wasidentified as a potent regulator of EMT in breast cancer patients. Depletion of HECTD1 was reported to enhance EMT and migration. Here, we investigated the correlation of HECTD1 mRNA expression with prognosis in early breast cancer patients during long-term follow-up.

Materials and methods: A total of 627 invasive breast cancer tissues were analyzed for HECTD1 mRNA expression using a TaqMan PCR system. We also examined correlations between HECTD1 mRNA levels and clinicopathological factors in these samples. The median follow-up period was 10.2 years. Survival curves were analyzed using the Kaplan-Meier method. Cox proportional hazards regression analysis was used for univariate and multivariate analyses of prognostic values.

Results: We identified positive correlations between low HECTD1 mRNA levels and shorter disease-free survival (DFS) and overall survival (OS) in breast cancer patients (P=0.02 and P=0.03, respectively). Low HECTD1 mRNA levels were positively correlated with high tumor grade, ERα and PgR negativity, HER2 positivity, and type of adjuvant therapy. Univariate analysis indicated that low HECTD1 mRNA levels was a factor for poor DFS and OS in breast cancer patients (hazard ratio (HR), 1.43; 95% confidence interval (CI), 1.06-1.95 and HR, 1.49; 95% CI, 1.03-2.17, respectively) (Table 1).

Conclusion: We showed that low HECTD1 mRNA expression may be a predictive factor of poor prognosis in breast cancer patients. HECTD1 could therefore be a candidate biomarker and therapeutic target in breast cancer patients.

Table 1. Univariate Cox regression analysis of HECTD1 mRNA expression associated with prognosis.Patients (n=617)UnivariateDisease-free survivalOverall survivalp valueHR (95%CI)p valueHR (95%CI)HectD1 mRNA expressionhigh3130.021(Reference)0.031(Reference)low3141.43(1.06-1.95)1.49(1.03-2.17)

Citation Format: Yasuaki Uemoto, Naoto Kondo, Yumi Wanifuchi-Endo, Tomoko Asano, Tomoka Hisada, Sayaka Nishikawa, Yusuke Katagiri, Mitsuo Terada, Akiko Kato, Yu Dong, Hiroyuki Kato, Satoru Takahashi, Tatsuya Toyama. The prognostic impact of HECTD1 E3 ubiquitin ligase expression in breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-07-03.
Abstract P6-08-26: Clinical characteristics of breast cancer patients with ATM mutations
Authors: Militello Loredana , Barrera Angelica M Gutierrez , Albarracin Constance , Bedrosian Isabelle , Arun Banu K
Published: March 2020

Background: Pathogenic ATM gene mutations are associated with increased risk of developing several cancers such as lymphoid, gastric, breast, central nervous system, skin, and other cancers. The relative risk of breast cancer is 2.3, with a higher risk seen for women under the age of 50 years. Only few and small studies have reported on the characteristics of breast cancers in women with ATM mutations. Here, we aimed to describe the clinical and pathological characteristics of a single institution largest cohort, to the best of our knowledge, of breast cancer patients with ATM mutations.

Methods: Patients with breast cancer who presented to the University of Texas MD Anderson Cancer Center Clinical Cancer Genetics clinics and underwent genetic testing for hereditary breast cancer and were found to have an ATM mutation were included. A retrospective review of a prospectively maintained research database was performed for ATM mutation status as well as patient clinical and pathological characteristics. IRB approval was granted for this analysis.

Results: Between 2012 and 2019, a total of 4093 breast cancer patients underwent genetic testing for hereditary breast cancer that included ATM gene testing. The median age of diagnosis of breast cancer was 49.3 (17-89), and median age at genetic testing was 52.1 (18-86). 72% of patients had stage 0-III and 3.2% stage 4 disease. Among patients with ATM pathogenic mutations, 37.7% (10) versus 21.7% (843) of ATM negative patients had a history of multiple primaries of any cancers. The table below shows characteristics of ATM pathogenic mutation carriers versus ATM negative patients.

Conclusion: This is a single institution cohort of breast cancer patients with ATM mutations that show distinct clinical characteristics, such as multiple primary cancers. These findings could have therapeutic implications and should be confirmed in larger cohorts.

Pathogenic Mutation of ATM ATM NegativesVariablesn%n%ERPositive4075.5221757.1Negative11.976019.6Unknown1222.690423.3PRPositive3667.9188448.5Negative59.4107027.6Pos/Neg00.010.03Unknown1222.692623.9Her2Positive1018.958611.3Negative2241.5206257.0Unknown2139.6123314.2Stage059.43178.2I1324.597825.2II1120.8106527.4III713.243611.2IV47.51243.2Unknown1324.596124.8Nuclear GradeI23.82596.7II1935.8111228.7III1120.8115629.8Unknown2139.6135434.9Triple Negative?Yes00.053913.9No3769.8222757.4Unknown1630.2111528.7

Citation Format: Loredana Militello, Angelica M Gutierrez Barrera, Constance Albarracin, Isabelle Bedrosian, Banu K Arun. Clinical characteristics of breast cancer patients with ATM mutations [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-08-26.
Abstract P6-10-11: In vitro chemo interrogation of viable circulating tumor associated cells from breast cancer patients
Authors: Crook Timothy , Akolkar Dadasaheb , Patil Sanket , Mhase Vishakha , Patil Revati , Sims Cynthe , Datta Vineet , Apurwa Sachin , Mane Viwek , Gawai Ashok , Apastamb Madhavi , Srinivasan Ajay , Datar Rajan
Published: March 2020

Background: Chemoresistance in cancer cells is the underlying reason for treatment failure. Real-time monitoring of chemoresistance and response (CRR) is a fundamental but unmet prerequisite of precision oncology. Repetitive invasive biopsies to obtain tumor tissue for in-vitro CRR profiling are neither feasible nor advisable. Circulating Tumor Associated Cells (C-TACs) have been proposed for functional assessment of CRR. In this observational study, we performed CRR profiling on viable C-TACs from breast cancer patients.

Methods: In this 3 arm study, viable C-TACs were harvested from 15 ml of peripheral blood obtained from 242 breast cancer patients using CellWizard™, an epigenetically active media with paradoxical cytotoxicity that selectively kills normal cells and simultaneously confers survival benefit on cells of tumorigenic origin. C-TACs were stained with EPCAM, CK, CD45 and GCDFP. Viable Tumor Derived Cells (TDCs) harvested from freshly biopsied tumor tissue (Arm 1, N=48) and concurrently obtained C-TACs were simultaneously CRR profiled irrespective of whether patient was pre-treated or otherwise. Arm 2 (N=100) included refractory (pre-treated) patients where C-TACs were evaluated for resistance to previously administered drugs. Arm 3 (N=124) included recently diagnosed therapy naïve patients where C-TACs were evaluated for innate chemoresistance.

Results: In Arm 1, CRR profile of C-TACs showed 96.1% concordance with CRR profile of concurrently obtained TDCs. In Arm2, CRR profiling of C-TACs identified chemoresistance due to prior drug exposure in 91.4% of patients. In Arm 3, innate chemoresistance was observed in 42% of patient samples towards commonly used first / second line Standard of Care drugs belonging to various functional categories such as mitotic inhibitors, DNA damaging agents, topo inhibitors and antimetabolites.

Conclusion: This study shows for the first time the feasibility of CRR profiling of C-TACs and its correlation to in-vitro and in-vivo CRR characteristics of the tumor. Adoption of C-TAC based CRR profiling can provide unprecedented real time treatment oversight towards treatment selection and monitoring of drug resistance for personalized treatment of breast cancer patients.

Citation Format: Timothy Crook, Dadasaheb Akolkar, Sanket Patil, Vishakha Mhase, Revati Patil, Cynthe Sims, Vineet Datta, Sachin Apurwa, Viwek Mane, Ashok Gawai, Madhavi Apastamb, Ajay Srinivasan, Rajan Datar. In vitro chemo interrogation of viable circulating tumor associated cells from breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-11.
Abstract P6-10-30: Developing 3D subtyping model for breast cancer patients based on absolute quantitation or ER, PR and Her2 at protein level
Authors: Zhang Jiandi
Published: March 2020

The concept of intrinsic subtypes of breast cancer have been well accepted with several predictor applications based on this concept achieved success in clinical practice. However, all these predictor applications are based on gene expression profiling, and the surrogate assay at protein level is based on immunohistochemistry (IHC), which is known to be associated with inherent problems of subjectivity and inconsistency. Consequently, subtyping of breast cancer patients in clinical practice is limited either by the cost or the inaccuracy (surrogate assay). In this study, we proposed the first predictor model at protein level based on the three-dimensional (3D) distribution of samples using ER, PR and Her2 protein levels as coordinates.

Method: Quantitative dot blot (QDB) method was used as a universal platform to achieve absolute quantitative of ER, PR, Her2 and Ki67 protein levels using total tissue lysates prepared from 2 × 15 um Formalin Fixed Paraffin Embedded (FFPE) slices. Total of 1248 FFPE slices were provided from local hospitals sequentially and non-selectively. The measured tissue biomarker levels were plotted in 3D scatterplot for analysis, in combination with provided clinicopathological parameters and overall survival data.

Results: We observed natural segregation of these samples into three distinct groups to mimic “balls falling from ceiling corner” distribution pattern. This distribution pattern disappeared when the scatterplot was narrowed in a small box of ER<0.2 nmole/g, PR <0.8 nmole/g and Her2<0.3 nmole/g. When the observed Her2 level at 0.3 nmole/g was used as cutoff to convert samples dichotomously, we achieved overall concordance with IHC at 94.8%. In addition, 260 out 271 Her2 positive samples were either with ER<0.2 nmole/g or PR<0.8 nmole/g or both, with 8 more samples at the vicinity of corner group. The model was further evaluated with both the overall recurrence and survival of the patients.

Conclusion: We developed the first 3D predictor model for subtyping of breast cancer patients based on the absolute and quantitative levels of ER, PR and Her2 at protein level. We propose this model the projection of intrinsic types at protein level. The adoption of this predictor model in clinical practice should significantly lower the barrier to allow practicing subtyping of breast cancer patients in daily clinical practice worldwide.

Citation Format: Jiandi Zhang. Developing 3D subtyping model for breast cancer patients based on absolute quantitation or ER, PR and Her2 at protein level [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-30.
Abstract P6-13-07: Cost-effective care for newly diagnosed breast cancer patients: Think globally, act locally
Authors: Tang Annie , Ugarte Shannon , John Rohan , Khoury Amal , Knopf Kevin
Published: March 2020

Conscientious use of scarce health economic resources allows for social distributive justice by avoiding over-treatment of patients to allow for appropriate treatment for a broader patient population. Lower socioeconomic status patients with breast cancer have a worse outcome compared to higher socioeconomic status patients in the United States. In part, this is due to poor access to medical care and a failure of logistical care. We implemented a community based breast cancer multidisciplinary program with weekly meetings to discuss patients, coordinate care, and provide cost-effective care to a medically under-served and vulnerable patient population. Breast surgery and medical oncology providers saw patients together in a co-located space and expedited timely initiation of neoadjuvant and adjuvant chemotherapy / hormone therapy for appropriate patients. The conjoint clinic allowed for rapid temporal integration of care in our safety net hospital / community. A single breast cancer navigator provided rapid identification of patients, coordination through clinics, and assistance with social work and other needs. Weekly 30 minute discussion sessions reviewing all new and relevant follow up patient issues were implemented in lieu of a breast cancer tumor board for efficiency. The relevant published clinical literature was reviewed on an ongoing basis. Cost-effective care was obtained by implementing: 1) avoidance of post lumpectomy radiation for selected patients based on PRIME2 trial results, 2) judicious use of post-mastectomy radiation based on a careful re-analysis of the data, 3) avoidance of adjuvant/neoadjuvant Perjeta in HER2+ patients based on a lack of overall survival, 4) adoption of 6 month schedule of adjuvant Herceptin, 5) avoidance of excessive imaging by following NCCN guidelines and clinical judgment, 6) limiting dose dense chemotherapy to appropriate patients (ER- high risk node negative or node positive), and 7) No Nernyx. Using a cost-effectiveness analysis methodology, we are reviewing costs, effectiveness of interventions, and risks with outcomes measured from side effects, complications, recurrence, and mortality. The improvement in temporal parameters and economic endpoints are being currently monitored retrospectively and prospectively and will be presented.

Citation Format: Annie Tang, Shannon Ugarte, Rohan John, Amal Khoury, Kevin Knopf. Cost-effective care for newly diagnosed breast cancer patients: Think globally, act locally [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-13-07.
Abstract P6-16-03: Surgical management of DCIS during the UK Sloane audit project
Authors: Kirwan Cliona Clare , Stallard Sheila , Mylvaganam Senthurun , Hilton Bridget , Clements Karen , Cheung Shan , Thompson Alistair
Published: March 2020

Introduction

The Sloane Project is a prospective cohort study, including 50% of United Kingdom screen detected ductal carcinoma in situ (DCIS) (2003-2012). We sought to examine the trends in surgical management over time for screen detected DCIS.

Methods

Trends in type of breast surgery were compared with DCIS radiology, pathology and breast size.

Results

Of 9945 patients with complete data undergoing surgical excision, 2274 (22.9%) underwent mastectomy as their first procedure, of whom 1581 (69.5%) had a simple mastectomy. Among 7877 undergoing attempted breast conserving surgery (BCS), 83 (1%) had therapeutic mammoplasty (TM). The 4:1 attempted BCS:mastectomy ratio remained consistent over time. Of attempted BCS, 882 (11.2%) were ultimately converted to mastectomy (28.9% reconstructed).

Over the decade, preoperative radiological estimation of DCIS remained constant at 26mm, however pathological DCIS size steadily increased from 22.4mm (2003-4) to 25.3 (2011-12). There was no corresponding increase in mastectomy, completion mastectomy or re-excision rates. Mean tumour size excised at BCS was 19.3mm (mean), at TM was 32.4mm and at mastectomy was 39.8mm. The rates of simple mastectomy (vs reconstruction) decreased from 77.7% to 61.2% while there was a small increase in TMs (from 0.2% (2 patients) [2003-4] to 1.7% (15 patients) [2011-12]).

There was a statistically (but small [8%] clinically) significant difference in mean breast volume for BCS compared to mastectomy patients (1068ml vs 988ml respectively, Student’s t-test p<0.0001). Mean breast volume (determined from mammography measurements) increased by 16% over the 9 years (from 1013ml to 1171ml), in parallel with increasing national BMI figures for these age groups.

Conclusion

Breast size and pathological size, but not radiological size of screen detected DCIS increased between 2003 and 2012, but BCS rates remained consistent. Interestingly, breast size had no apparent influence on type of surgery, although the decrease in simple mastectomy suggests breast reconstruction increased over time.

Citation Format: Cliona Clare Kirwan, Sheila Stallard, Senthurun Mylvaganam, Bridget Hilton, Karen Clements, Shan Cheung, Alistair Thompson. Surgical management of DCIS during the UK Sloane audit project [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-16-03.
Abstract P6-16-05: Clinical outcomes achieved with brachytherapy vs whole breast irradiation for ductal carcinoma in situ
Authors: Nguyen Katarina T , Francis David , Chandering Thevaa , Pointer Kelli , Anderson Bethany
Published: March 2020

Purpose: To compare the locoregional control achieved with whole breast irradiation (WBI) and accelerated partial breast irradiation (APBI) in women with ductal carcinoma in situ (DCIS).

Methods: We used an institutional, IRB-approved database to retrospectively identify women with primary DCIS lesions less than 3 cm from 1995 to 2014, who underwent negative-margin breast conserving surgery (BCS) followed by either WBI or APBI. Cox-proportional hazard analysis was performed to estimate risks of in-breast tumor recurrence (IBTR) and regional nodal recurrence (RNR), adjusting for age of patient at diagnosis.

Results: Three-hundred and eighty women were identified. Seventy-nine percent received WBI and 21% underwent APBI. Among women receiving WBI, 15.4% received a sequential lumpectomy cavity boost. APBI was delivered via high-dose-rate (HDR) brachytherapy technique, utilizing either a multi-catheter interstitial or single-entry intracavitary approach. The median follow-up time was 6 years for women who received WBI, and 8.9 years for women who received APBI.

The actuarial 10-year IBTR rate was 9.0% for WBI and 8.75% for APBI (p = 0.94). The actuarial 10-year isolated regional nodal recurrence (RNR) rate was 0% for WBI and 2.5% for APBI. Among women who received WBI, the 10-year IBTR rate was 10.0% without lumpectomy cavity boost and 6.36% with boost (p = 0.40). Increasing age correlated with a lower risk of recurrence, regardless of treatment modality (p = 0.005).

Conclusions: No differences in locoregional control was detected for women with DCIS measuring <3 cm, treated with BCS followed by APBI vs WBI.

Citation Format: Katarina T Nguyen, David Francis, Thevaa Chandering, Kelli Pointer, Bethany Anderson. Clinical outcomes achieved with brachytherapy vs whole breast irradiation for ductal carcinoma in situ [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-16-05.
Abstract PD5-04: Tumor-infiltrating lymphocytes evaluation using machine learning image analysis based on core needle biopsy in HER2-positive breast cancer
Authors: Abe Norie , Matsumoto Hirofumi , Takamatsu Reika , Tamaki Kentaro , Takigami Naoko , Uehara Kanou , Kamada Yoshihiko , Tamaki Nobumitsu , Motonari Tokiwa , Nakada Norihiro , Zaha Hisamitsu , Yoshimi Naoki
Published: March 2020

Purpose: To evaluate tumor-infiltrating lymphocytes (TILs) quantitatively in breast cancer and to verify the utility of machine learning image analysis in TIL assessment. Methods: Stromal TILs in 105 Human epidermal growth factor receptor 2 (HER2)-positive invasive breast cancers, diagnosed from patients treated with neoadjuvant anti-HER2 therapy, were evaluated by image analysis of hematoxylin and eosin-stained slides from core needle biopsies. TIL level was determined as the number of TILs per square millimeter of stromal tissue. Associations of TIL level with clinicopathological parameters, pathological response, and clinical outcomes were assessed. Results: Median TIL level were 1287/mm2 (range, 123 - 8101/mm2). Higher TIL level was associated with higher histological grade (P = 0.02), estrogen receptor (ER) negativity (P = 0.036), and pathological complete response (pCR) (P< 0.0001). According to analysis of the receiver operating characteristic curve, a threshold TIL level of 2420/mm2 stroma best discriminated pCR from non-pCR. In multivariate analysis, high TIL levels (>2420/mm2) were significantly associated with pCR (P< 0.0001). On Kaplan-Meier analysis, prognosis was not associated with high or low TIL levels. However, high TIL levels tended to be associated with better prognosis in the HER2+/ER+ subgroup (P = 0.131), but not in the HER2+/ER- subgroup. Conclusions: A machine learning image analysis algorithm could assess TIL level as the number of TILs per square millimeter, contrary to semiquantitative evaluation. TIL level derived from this method could offer an independent predictor of pCR.

Citation Format: Norie Abe, Hirofumi Matsumoto, Reika Takamatsu, Kentaro Tamaki, Naoko Takigami, Kanou Uehara, Yoshihiko Kamada, Nobumitsu Tamaki, Tokiwa Motonari, Norihiro Nakada, Hisamitsu Zaha, Naoki Yoshimi. Tumor-infiltrating lymphocytes evaluation using machine learning image analysis based on core needle biopsy in HER2-positive breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD5-04.
Abstract PD7-03: Adaptive kinome reprogramming in endocrine therapy resistant metastatic breast cancer
Authors: Dustin Derek , Gu Guowei , Chan Doug , Beyer Amanda , Edwards David , Ellis Matthew , Fuqua Suzanne
Published: March 2020

Background: Approximately half of women with estrogen receptor (ER)-positive breast cancer who undergo adjuvant endocrine therapy (ET) develop disease progression and metastasis. Studies have revealed that up to 40% of metastatic patients develop tumors bearing a mutation in ESR1 which is associated with therapeutic resistance and poor prognosis. Studies have shown that cancers can undergo kinome reprogramming in response to therapy and acquired genetic alterations within the tumor. We hypothesize that expression of ESR1 mutations induces kinome reprogramming, which presents novel potential therapeutic targets to selectively treat ESR1 mutant metastatic breast cancer.

Methods: We performed Kinobeads Precipitation (KiP) using broad specificity kinase inhibitors to capture and quantify by MS the level of active kinases in MCF-7 ESR1 wild-type and ESR1 Y537S mutant cells. We performed targeted siRNA screens and immunoblots to validate the hyperactivity of several of these kinases. Specific kinase inhibitors are being used to test their effects on proliferation and invasion in vitro, and in ex vivo organoid growth assays. Xenograft models are being used to evaluate the effects of the inhibitors on primary tumor growth and distant metastasis.

Results: KiP analysis revealed hyperactivation of growth factor receptors, the PI3K/Akt/mTOR pathway, and MAPK pathway, in Y537S mutant cells. We tested specific inhibitors of these pathways, and have shown that the mutant cells have reduced proliferation when these pathways are targeted. We developed organoid growth assays using primary and metastatic tumors from xenograft and PDX models and found that ET in combination with these selected targeted kinase inhibitors decreased the growth of organoids. We are currently testing inhibitors in combination with ET in vivo, and preliminary results demonstrate a significant inhibition of primary tumor growth and distant metastasis. These results suggest that selective inhibition of hyperactivated “reprogrammed” kinase pathways can restore ET sensitivity in ESR1m tumors, and may show promise for use in ER-positive metastatic breast cancer patients.

Citation Format: Derek Dustin, Guowei Gu, Doug Chan, Amanda Beyer, David Edwards, Matthew Ellis, Suzanne Fuqua. Adaptive kinome reprogramming in endocrine therapy resistant metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD7-03.
Abstract PL2: The role of radiotherapy combined with immunotherapy in oligometastatic cancer
Authors: Weichselbaum RR , Hellman S
Published: March 2020

In 1995 Samuel Hellman and I advanced the hypothesis that many cancers represent a spectrum of disease from purely localized to widespread, highlighting a disease state we termed “oligometastasis.” We proposed that oligometastasis represented an intermediary state between localized and widespread disease that was amenable to cure by metastasis-directed therapies. We also hypothesized that tumor clones that escape systemic therapies, now termed “oligoprogressors,” might be targets for ablation by focal treatments. I will present data supporting the basis and classification of (oligo)metastatic disease, as well as clinical trial results from patients, including those with breast cancer, that informs us regarding future clinical strategies. A decade ago our group noted that large radiation doses used in stereotactic radiotherapy employed in clinical trials of oligometastatic tumors induced immunogenic cell death, which has led us to investigations into the potential interaction between radiotherapy and immunotherapy. I will also present basic and clinical data from investigations into combined radio-immunotherapy treatment and suggest how these investigations might improve treatment of patients.

Citation Format: RR Weichselbaum, S Hellman. The role of radiotherapy combined with immunotherapy in oligometastatic cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PL2.
Abstract TS1-1: Advanced enabling technologies for cancer proteomics
Authors: Liu T
Published: March 2020

Mass spectrometry-based proteomics is a promising technology in characterization of human proteome at a genome scale, facilitating proteogenomic characterization of cancer specimens. Recent advances in mass spectrometry instrumentation, sample handling platforms, and proteomic analysis strategies allow for not only large-scale, comprehensive proteome profiling, but also focused systems biology studies, biomarker verification, as well as analysis of protein expression and phosphorylation in very small populations of cells. This will lead to significantly improved understanding of aberrant regulatory and signal transduction networks underlying cancer for translational applications.

Citation Format: T Liu. Advanced enabling technologies for cancer proteomics [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr TS1-1.
Abstract TS2-1: CTC Clusters, Cancer Stemness, and New Treatment Strategies
Authors: Liu H
Published: March 2020

Circulating tumor cells (CTCs) seed metastases which eventually kill most of the breast cancer patients; however, CTCs have not been effectively targeted partially due to the unclear cellular and molecular mechanisms. Emerging evidence and our studies demonstrate that CTCs are detectable as singles as well as multicellular clusters in cancer patients; and presence of the latter is associated with unfavorable progression-free survival (PFS) and poor overall survival (OS). Compared to single CTCs, CTC clusters show enriched stemness properties, including enhanced tumorigenic potential and polyclonal metastases, more efficient mammosphere formation, and upregulated expression of CD44 and stemness-related signaling pathways. Using intravital multiphoton microscopic imaging of patient-derived-xenograft (PDX) models and mouse tumor models, we found that clustered tumor cells in migration and circulation resulted from aggregation of individual tumor cells rather than collective migration and cohesive shedding. Molecularly, the intercellular CD44-CD44 homophilic interactions are essential for the multicellular CTC aggregation, recruitment of downstream PAK2, and activation of the FAK signaling. Depletion of CD44 or antibody-mediated blockade of CD44 interactions effectively prevent tumor cell aggregation and abolish polyclonal metastases. In addition to CD44, we have identified other surface receptors and adhesion molecules which also contribute to CTC cluster formation. Our studies highlight that CTC clusters, whose presence is correlated with a poor prognosis of breast cancer patients, can serve as a liquid biopsy-based biomarker as well as novel therapeutic targets of polyclonal metastasis.

Citation Format: H Liu. CTC Clusters, Cancer Stemness, and New Treatment Strategies [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr TS2-1.
Abstract TS2-2: Biology, Vulnerabilities and Clinical Implications of CTC Clusters
Authors: Aceto N
Published: March 2020

CTC clusters have recently emerged as key players in the metastatic process. With a combination of microfluidic technologies and single cell-resolution molecular analysis applied to breast cancer patients and mouse models, we gained fundamental insights into the biology, vulnerabilities, and clinical implications of CTC clusters. For instance, we found that their physical features enable molecular changes that promote stemness and metastasis, allowing us to define new treatments to suppress their metastatic potential. Further, we investigated CTC heterogeneity at the single cell level, revealing fundamental interactions that occur between CTCs and immune cells and that accelerate metastasis formation. Thus, our findings support a model whereby CTCs form multicellular aggregates with each other as well as with immune cells to expand their metastatic potential, providing a new rationale for targeting these interactions in breast cancer.

Citation Format: N Aceto. Biology, Vulnerabilities and Clinical Implications of CTC Clusters [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr TS2-2.
NF-κB–Activated miR-574 Promotes Multiple Malignant and Metastatic Phenotypes by Targeting BNIP3 in Thyroid Carcinoma
Authors: Zhang Zhe-Jia , Xiao Qian , Li Xin-Ying
Published: March 2020

Thyroid cancer is the most common endocrine malignancy, and miR-574 is significantly upregulated in thyroid cancer. However, the role and underlying mechanism of miR-574 in thyroid cancer development are poorly understood. In this study, we showed that NF-κB/p65 signaling pathway was activated and miR-574 was upregulated in thyroid cancer cells. p65 directly bound to the promoter of miR-574 and activated miR-574 transcription. Functionally, miR-574 inhibited apoptosis, promoted proliferation and migration of thyroid cancer cells, and stimulated thyroid cancer–induced tube formation of endothelial cells. On the molecular level, miR-574 inhibited the expression of BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) by binding to 3′-UTR of BNIP3. miR-574 also downregulated the expression of apoptosis-inducing factor (AIF), while elevated the levels of MMP2, MMP9, and VEGFA. In vivo, miR-574 promoted xenograft growth, which was associated with reduced apoptosis and enhanced angiogenesis. NF-κB/miR-574 signaling presents multiple oncogenic activities on thyroid cancer development by directly regulating the BNIP3/AIF pathway. Therefore, targeting NF-κB/miR-574 signaling may reduce the aggressiveness of thyroid cancer.

Implications:

miR-574, directly regulated by NF-κB/p65, promotes tumorigenesis of thyroid cancer via inhibiting BNIP3/AIF pathway.
Abstract A100: Downregulation of type 1 interferon receptor (IFNAR1) regulates the balance of regulatory T cells (Tregs) and cytotoxic T lymphocytes (CTLs) in tumor microenvironment
Authors: Zhang Hongru , Gui Jun , Ortiz Angelica , Fuchs Serge
Published: March 2020

Solid tumors are infiltrated by not only CD8+ effector T cells (CTLs) exerting tumoricidal function, but also by regulatory T cells (Tregs), which are a key barrier to antitumor immunity (1). In the tumor microenvironment, the type 1 interferon (IFN) signaling is downregulated due to proteolytic degradation of IFNAR1 (2). Reduced IFNAR1 levels in tumor stroma are important for establishing the immune privileged niche to support tumor development and progression (3). IFN pathway plays complex and controversial roles in regulating immune responses ([4-7). In this study, we show that loss of IFNAR1 leads to changes in the activities of Tregs and CTLs. Genetic stabilization of IFNAR1 (Ifnar1S526A, SA) recruits more CTLs in the tumor microenvironment; however, it does not change the frequency of Tregs. In addition, in SA tumor tissues, the CTLs appear to exhibit a greater tumoricidal activity. Furthermore, we find that SA Treg lost their inhibitory function and SA CTLs are resistant to Treg-mediated immune suppression. In all, we discuss putative mechanisms underlying these phenotypes that IFN pathway regulates the balance of Treg and CTL activities in the tumor microenvironment.

Citation Format: Hongru Zhang, Jun Gui, Angelica Ortiz, Serge Fuchs. Downregulation of type 1 interferon receptor (IFNAR1) regulates the balance of regulatory T cells (Tregs) and cytotoxic T lymphocytes (CTLs) in tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A100.
Abstract A107: Microfluidics and oncoimmunology: New in vitro models to study solid tumor immunotherapy
Authors: Ayuso Jose M. , Virumbrales-Munoz Maria , McMinn Patrick H. , Rehman Shujah , Fitzgerald Cate M. , Beebe David J. , Skala Melissa C.
Published: March 2020

Immunotherapies against solid tumors face daunting challenges compared with hematologic cancers. In solid tumors, immune cells and antibodies need to extravasate from the vasculature, find the tumor cells, and migrate through a dense mass of normal and tumor cells where nutrients are depleted and waste products build up. All these factors pose significant obstacles for solid tumor immunotherapy, commonly leading to immune exhaustion and compromising the immune response. Thus, finding effective immunotherapies against solid tumors requires in vitro models that accurately capture the tumor complexity. In this work, we present microfluidic models for solid tumor immunotherapy and show how they mimic the tumor architecture in an unprecedented way compared with other traditional in vitro models based on Petri dishes. Breast cancer cells were cultured as a dense mass and embedded in a 3D collagen hydrogel into a microfluidic device. Endothelial cells were cultured in lateral flanking lumens to mimic the blood vessels, allowing the perfusion of therapeutic antibodies or effector immune cells (e.g., natural killer cells). Antibody and immune cell extravasation, diffusion, migration, and tumor clearance were evaluated in the model, showing the NK cell capacity to detect the presence of the tumor hundreds of microns away. Once inside the tumor mass, real-time microscopy revealed natural killer cells were able to destroy tumor cells at the tumor periphery and, more importantly, also at the innermost layers. The combination of antibodies and natural killer cells led to an enhanced cytotoxicity, showing the potential of the model to evaluate new immunotherapy combinations. Finally, tumor, endothelial, and NK cells were retrieved at different locations of the tumor (e.g., tumor margin vs. tumor core) and at different time points to show how these different cell populations adapted to the continuously evolving tumor microenvironment.

Citation Format: Jose M. Ayuso, Maria Virumbrales-Munoz, Patrick H. McMinn, Shujah Rehman, Cate M. Fitzgerald, David J. Beebe, Melissa C. Skala. Microfluidics and oncoimmunology: New in vitro models to study solid tumor immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A107.
Abstract A14: Neoepitope-specific CD8+ T cells in adoptive T-cell transfer
Authors: Kristensen Nikolaj Pagh , Heeke Christina , Tvingsholm Siri A. , Bjerregaard Anne-Mette , Draghi Arianna , Bentzen Amalie Kai , Andersen Rikke , Donia Marco , Svane Inge Marie , Hadrup Sine Reker
Published: March 2020

Adoptive T-cell therapy (ACT) relies on expansion of tumor-infiltrating lymphocytes and infusion into patients following lymphodepletion, which have yielded complete responders in up to 25% of treated patients suffering from metastatic melanoma. However, a large proportion of patients have no clinical benefit (50-60%). Previous studies have found that clinical outcome correlates with tumor mutational and putative neoantigen load. Furthermore, expression of core antigen-presentation pathways including MHC class I genes in tumors correlates with clinical benefit. Based on these findings, we hypothesize that the presence of neoepitope-specific CD8+ T cells within the infusion product of ACT is a key determinant of clinical benefit. We apply in silico prediction of neoepitopes along with DNA-barcoded dextran multimer libraries to screen for personal neoepitope-specific CD8+ T cells. We show persistence of neoepitope-specific CD8+ T cells within patient peripheral blood for up to 24 months after therapy. Furthermore, we show an almost complete lack of neoepitope-specific CD8+ T cells within the infusion products of patients with progressive disease. However, patients with stable disease and long-term responses only have a modest increase in the number of targeted neoepitopes, as wells as the total frequency of neoepitope-specific CD8+ T cells. For future experimentation, we therefore aim to include more patients as well as study the phenotypical differences within the pool neoepitope-specific CD8+ T cells, the ultimate goal being a better understanding of what parameters from neoepitope-specific CD8+ T cells correlate with clinical efficacy of ACT.

Citation Format: Nikolaj Pagh Kristensen, Christina Heeke, Siri A. Tvingsholm, Anne-Mette Bjerregaard, Arianna Draghi, Amalie Kai Bentzen, Rikke Andersen, Marco Donia, Inge Marie Svane, Sine Reker Hadrup. Neoepitope-specific CD8+ T cells in adoptive T-cell transfer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A14.