Abstract P2-08-28: Breast cancer in young patients undergoing neoadjuvant chemotherapy - A comparison between very young women (less than 30) and young women (31-40 years) - Experience of a cancer center in Brazil
Authors: Fraianella Lilian , Santos Silvana S , Sanches Solange M , Rocha Caroline GA , De Brot Marina , Makdissi Fabiana BaroniAlves 
Published: March 2020

Introduction Breast tumors (BC) in young patients is frequently diagnosed as a high-grade tumor, at a more advanced stage, hormone receptor negative and Her2 overexpressed. Age is an important risk factor for local recurrence, despite the type of surgery, and is associated to increased risk of metastasis and death. Neoadjuvant Chemotherapy (NeoCT) is the standard of treatment for locally advanced and higher risk tumors (triple negative/TN and HER2 positive). Objectives Observation of BC and prognostic factors in young women submitted to NeoCT in a Brazilian cancer center and to compare age groups (31-40 years of age and below 30 years). Method Retrospective cohort study of women with BC diagnosed at below the age of 40, submitted to NeoCT at a Brazilian cancer center, between 2000-2016. The Residual Cancer Burden (RCB) was used for analysis of the pathological response. P &lt;0.05 was considered statistically significant for Pearson's Chi-square test and Fisher's exact test. Survival analyses were estimated by Kaplan-Meier and the patients were followed for at least 60 months. Results 271 women with BC under the age of 40 were submitted to NeoCT. Of these patients, the age of 217 (80.1%) was between 31-40 years of age, 54 (19.9%) were below 30, and 29.2% had family history of BC or ovarian cancer in first or second degree relatives. Data for clinical staging was 2.2% stage I, 43.1% II, 52.4% III and 2.2% IV (as a single site metastasis). We identified a difference in the stage IV group, with 7.4% (4/54) in the women younger than 30 years and 2.2% (6/217) in the women 31-40 years of age (p 0.035). The most frequent histology was invasive ductal carcinoma, in 87.5% of cases, with histological grades of 2 (35.8%) and 3 (46.9%). Histological subtype revealed 49.1% luminal, 17.7% luminal with 2 superexpressions, 8.1% HER2 and 24.4% TN. We identified a greater proportion of luminal patients in the 31-40 year range (53.9% vs 30.8%) and TN and Her2 in the group younger than 30 years (32.7% and 36.5% vs 22.6% and 23.5%, respectively), p 0.006. Chemotherapy based on anthracyclines and taxanes was used in 76.3% of the cases, with HER2 block when indicated. Dense dose schedules were used in 9.6% of the cases. Complete pathological response (pCR) occurred in 34.7% of the cases, partial response in 45.4%, stable disease in 11.1% and progression during chemotherapy in 1.5% of the cases (2 TN and 2 luminal), not revealing any trend as per age group. Her2 tumors had pCR of 63%, 55% for Her2 luminal, and 53.7% for TN. Conservative surgeries were performed in 78 patients (28.8%) and mastectomies in 193 (71.2%). Sentinel lymph node biopsy was performed in 20.7% of the cases, and lymphadenectomy in 79.3%. 56.9% of patients with conservative surgery and 29.6% of those submitted to mastectomy with pCR. Even with pCR, 94 cases (56.3%) were mastectomized. Of the 251 patients, 37.6% relapsed, 21% distant recurrence, 7% local and 9.1% local and distant, with no variation regarding age group. Of these, 23.1% underwent conservative surgery and 37.4% underwent mastectomy. The response is actually inversely correlated with 15% of patients with pCR, 39.8% of partial responses, 63% of stable diseases and 75% disease progression during treatment. Overall survival was associated to a pathological response, tending to benefit the age range of 31-40 years. Conclusions BC in young patients may have reveal differences as per their age group. In our sample, patients under the age of 30 revealed the most advanced and most aggressive subtypes of BC when compared to women in the 31-40 year group. No distinction was made between NeoCT and relapse, however a survival trend was observed in patients over 30 years of age. No distinction was made between RCB and relapse, but there was a trend of survival in patients over 30 years.

Citation Format: Lilian Fraianella, Silvana S Santos, Solange M Sanches, Caroline GA Rocha, Marina De Brot, Fabiana BaroniAlves Makdissi. Breast cancer in young patients undergoing neoadjuvant chemotherapy - A comparison between very young women (less than 30) and young women (31-40 years) - Experience of a cancer center in Brazil [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 P2-08-28.