Suboptimal use of ovarian function suppression in very young women with early breast cancer: a real-world data study.

PURPOSE: The incidence of breast cancer in young women (BCYW) has increased in recent decades. Malignant disease in this subset is characterized by its aggressiveness and poor prognosis. Ovarian function suppression (OFS) in these patients improves survival especially in hormone receptor-positive (HR +) cases. The Regan Composite Risk (RCR) is a prognostic tool to identify high-risk HR + BC candidates for OFS. Our study sought to characterize a Chilean cohort of early HR + BCYW assessing the use of OFS and its related prognosis and the utility of RCR in our patients. METHODS: This was a retrospective population cohort study that included ≤ 35-year-old early HR + /human epidermal growth factor receptor 2 -negative (HER2-) BC patients treated between 2001 and 2021. Analysis included clinical-pathological characteristics, treatment strategies, and survival. Also, we evaluated the association between RCR and survival. RESULTS: A total of 143 patients were included into our study, representing 2.9% of all early BC cases in our registry. Median age was 31 years old (range: 19-35). Most patients (93%) received endocrine therapy (ET). Of these, 18% received OFS. No survival differences were observed among treatment strategies. Median RCR score for patients treated with CT plus ET was significantly higher vs. ET alone (2.95 vs. 1.91; p = 0.0001). Conversely, patients treated with tamoxifen alone had significantly lower RCR scores vs. OFS (2.72 vs. 3.14; p = 0.04). Higher RCR scores were associated with poorer overall survival. CONCLUSION: Less than 20% of very young women with early HR + /HER2-BC in our cohort received OFS, in most cases, this involved surgical oophorectomy. RCR score was higher in patients that underwent CT and OFS and was associated with survival, regardless of treatment. We confirm the RCR score as a valuable prognostic tool to identify high-risk BC patients who could benefit from OFS.

Better overall survival in patients who achieve pathological complete response after neoadjuvant chemotherapy for breast cancer in a Chilean public hospital.

INTRODUCTION: There is extensive evidence associating the response to neoadjuvant chemotherapy (NeoCT) with breast cancer (BC) survival. However, to the author's knowledge, there is no published data in Chile. The objective of the study is to evaluate whether achieving pathological complete response (pCR) after NeoCT is associated with greater survival and lower risk of recurrence in a Chilean Public Health Service. METHODS: Retrospective analysis of a database. Patients with a diagnosis of Stages I-III BC who received NeoCT between 2009 and 2019 were included. Clinical and pathological information were extracted from the clinical records. BC subtypes were defined using hormone receptor (HR) information (HR: oestrogen and/or progesterone) and epidermal growth factor type 2 (HER2), being divided into four groups: HR+/HER2-, HR+/HER2+, HR-/HER2+, HR-/HER2-. pCR was defined as the absence of invasive cancer in the breast and axilla (ypT0/is N0) after NeoCT. RESULTS: Of 3,092 patients, 17.2% received NeoCT. Of these, 40.2% corresponded to HR+/HER2-, 20.9% HR+/HER2+, 18.2% HR-/HER2+ and 20.7% HR-/HER2-. Overall, 24.8% achieved pCR, being the lowest for HR+/HER2- (10.3%) and the highest for HR-/HER2+ (53.2%). In the multivariable analysis, family history, HER2+ and type of chemotherapy were associated with a greater probability of pCR. With a median follow-up of 40 months, the overall survival and metastasis-free survival (MFS) at 3 years were greater for the group with pCR compared to that which did not achieve it (90.5% versus 76.7%, p = 0.03 and 88.5% versus 71.4%, p = 0.003, respectively). The multivariable analysis confirmed this finding. Brain MFS was similar in both groups. CONCLUSION: NeoCT is associated with greater pCR in aggressive BC subtypes. In those, achieving pCR was associated with better survival in our study. To the author's knowledge, this is the first study which evaluates the relation between pCR and BC subtypes in a Chilean public hospital.