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.

Ductal carcinoma in situ: an overview.

Advances in methods used to diagnose breast cancer have resulted in the increased detection of ductal carcinoma in situ; most of these are detected by screening mammograms and are confirmed by core needle biopsy. Currently, classification schemas are moving toward a molecular approach. Treatment options for patients with ductal carcinoma in situ are multiple and take into consideration end points such as local, regional or distant recurrence, overall survival and quality of life. Treatment methods continue to be controversial and debated in the oncology community. The quality of local control is multifactorial and depends on adequate surgical clearance, biological characteristics of the tumor, clinical presentation and the possibility of radiation therapies.