Abstract P4-02-04: Using ultrasound findings to predict high tumor-infiltrating lymphocytes in triple negative breast cancer
Authors: Inagaki M , Ota D , Tsuji M , Kobayashi Y , Mori M , Fukuuchi A 
Published: March 2017

Purpose Previous clinical data showed that high tumor-infiltrating lymphocytes (TILs) indicated a good prognosis in triple negative breast cancer (TNBC) and suggested that TNBC with TILs responded well to immunotherapy. Breast ultrasound is a safe inspection method without any radiation exposure. Therefore, we investigated whether ultrasound findings can predict high TILs in TNBC.

Patients and Methods The TNBC patients who underwent surgery at Mitsui Memorial Hospital, Tokyo, Japan, from 2009 to 2015, including those who underwent neo adjuvant chemotherapy (NAC), were selected for this study. The pre-treatment ultrasound findings were used retrospectively, and we compared the shape, margin, homogeneity of internal echoes, posterior features, and growth pattern of the lesions. Regarding shape, we classified the ultrasound findings as “round”, “oval”, “lobulated”, “irregular”, and “other” in accordance with The Japan Associations of Breast and Thyroid Sonology. Similarly, we classified the margins as "circumscribed" or "well-defined and smooth", "well-defined and rough", "indistinct" and "obscure". We used “homogeneous” and “heterogeneous” internal echoes. In terms of posterior features, we used the “accentuation”, “not changing”, “attenuating” and “shadowing” categories. By referring to previous report, we classified four types of growth patterns, i.e., "growing along the mammary ducts", "expansive growth pattern", "irregularly shaped mass with retracting surrounding tissue" and "other". Two pathologists evaluated stromal TILs, which were located between the cancer nests, by surgical specimens or needle biopsies of those who underwent NAC. Then the TILs were classified into four groups: “absent”, “weak”, “moderate”, and “dense”. “Absent” indicated that there were no lymphocytes in the stroma. “Weak”, “moderate” and “dense” indicated that lymphocytes occupied about 1–40%, 40–75% and 75%–100% area in the stroma, respectively. We analyzed ultrasound findings and TILs with the χ -square test.

Results A total of 97 lesions and 95 female TNBC patients were validated. The median age was 62 years old (range, 32–88 years). Of the total, 37 patients underwent NAC. The degree of “absent” TILs was 5 lesions, “weak” was 58, “moderate” was 22, and “dense” was 12 lesions. In the ultrasound findings, the shape categories “round,” “oval,” and “lobulated” were more "dense" TILs (n=12, 100%) than others (n=47, 55.3%) (p = 0.002). The "circumscribed" and "well-defined and rough" margins were found to be more “dense” TILs (n=11, 91.7%) than the other TILs (n=49, 57.6%) (p=0.020). “Accentuating” posterior echoes were more “dense” and “moderate” TILs (n=23, 67.6%) than “weak” and “absent” TILs (n=25, 39.7%) (p=0.009). The lesions with expansively growing pattern showed higher rate “dense” and “moderate” TILs (n=20, 58.8%) than “weak” and “absent” TILs (n=20, 31.7%) (p=0.010). There were no significant differences in internal echoes.

Conclusion We determined that ultrasound findings of round, oval or lobulated shape, accentuating posterior echoes and expansively growing pattern could predict the presence of high TILs. Thus, the safe, low-cost, and radiation-free ultrasound examination was recommended for predicting high TILs and prognosis.

Citation Format: Inagaki M, Ota D, Tsuji M, Kobayashi Y, Mori M, Fukuuchi A. Using ultrasound findings to predict high tumor-infiltrating lymphocytes in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-04.