A RETROSPECTIVE ANALYSIS OF 4,466 LUMINAL BREAST CANCER TREATED IN A REFERENCE CENTER

Abstract

Objective: The aim of this study was to evaluate HER2-negative estrogen receptor and or progesterone receptor positive
and describe treatments and overall survival (OS) of patients treated in a reference center. Methods: We enrolled retrospectively 5,510 patients in Perola Byington’s database from 2010 to 2021. After excluding patients without minimal complete records, a total of 4,855 were analyzed and clinical and pathological data were collected (date of diagnosis, first treatment, type of treatment, stage, type of surgery, disease-free survival, and OS). This study was approved by our ethics
committee. Results: Most of our patients were diagnosed in stages I (26.9%) and II (38.2%). There was 23.4% in stage III,
only 3.1% in stage IV, and 5.7% in stage 0, and in 2.6% the information was incomplete. The mean age at diagnosis was
57.6 years. We identified 4,761 (86.4% of 5,510) patients who underwent 4,848 surgical procedures. Of the total, 47.2% were
mastectomies, 50.9% were sectorectomy, and 1.9% were adenectomy or adenomastectomy. Immediate reconstruction
was done in 470 patients (69.8% underwent reconstruction with an expander, 22.3% with flap rotation and 7.9% with
implants). The mean and median time between diagnosis and the beginning of treatment were analyzed; in the sample, it
was observed that patients who were diagnosed in stages I, II, and IV had the same mean of 2.6 months, but stage IV had
the lowest median 1.9 months. OS for patients diagnosed in stages I and II did not reach the median in the available period;
for patients in stages III and IV, a median of 80.4 and 41.2 months of OS were identified, respectively. Conclusion: These
are the first results of this large cohort of luminal patients treated in the public service of a referral center. Most patients
are diagnosed in stage I or II and more than half undergo conservative surgery. Immediate reconstruction is not routinely
performed. Stage III survival is 80.4 months and stage IV survival is 41.2 months in this analysis.