Background. The majority of patients with breast cancer in Colombia are admitted into oncological centers at locally advanced stages of the disease (53.9%). The aim of this study was to describe the pathological response obtained with neoadjuvant chemotherapy (NACT) according to the molecular classification of breast cancer in patients with locally advanced tumors treated within the National Cancer Institute (NCI) Functional Breast Cancer Unit (FBCU) in Bogotá, Colombia. Materials and Methods. This was an observational, descriptive, historical cohort study of patients with locally advanced breast cancer treated within the NCI FBCU. Results. We included 414 patients who received NACT and surgical management. Most patients had luminal B HER2negative tumors (n = 134, 32.4%). The overall rate of pathological complete response (pCR) ypT0/ypN0 was 15.2% (n = 63). Tumors that presented the highest rate of pCR were pure HER2, at 40.5% (n = 15; odds ratio [OR], 6.7); however, with a follow-up of 60 months, only the triple negative tumors presented a statistically significant difference for event-free survival (EFS; median recurrence time, 18 months; range, 1-46) and overall survival (OS; median follow-up, 31 months; range 10-57). The molecular subtype that most recurrences presented was luminal B HER2 negative, at 38.3% (n = 28). The majority of recurrences (93.2 %; n = 68; OR, 5.9) occurred in patients in whom no pathological response was obtained (Chevallier 3 and 4). Conclusion. Pathological response in locally advanced tumors is related to the molecular subtype of breast cancer, finding higher pCR rates in pure HER2 and triple-negative tumors. A direct relationship was found between disease recurrences and the pathological response, evidencing greater tumor recurrence in patients who did not respond to NACT (Chevallier 3 and 4). EFS and OS were greater in patients with pCR, with statistical significance only in triplenegative tumors. The Oncologist 2019;24:e1360-e1370 Implications for Practice: This research article is of scientific interest, because it describes the clinical and pathological features and analyzes the correlation between pathological response to neoadjuvant chemotherapy and the molecular classification of locally advanced breast cancer in patients treated in the National Cancer Institute in Bogotá, Colombia. It was found that pathological response is related to the molecular subtype of breast cancer. In addition, there is a direct relationship between disease recurrences and pathological response. The survival results were greater in patients with pathological complete response. Global Health and CancerAccording to data from GLOBOCAN 2018, 13,380 new cases of breast cancer were diagnosed in Colombia within that year (an incidence of 44.1 per 100,000 people), being 13.1% of the total of patients diagnosed with cancer in the country. Among the female population, cases of breast cancer rank first in incidence, at 24.8%. Mortality in both sexes has a rate of 11.9 per 100,000 people, representing 3,702 dea...

Purpose About 10% of breast cancer (BC) is diagnosed in stage IV. This study sought to identify factors associated with time to progression (TTP) and overall survival (OS) in a cohort of patients diagnosed with de novo metastatic breast cancer (MBC), from a single cancer center in Colombia, given that information on this aspect is limited. Methodology An observational, analytical, and retrospective cohort study was carried out. Time to progression and OS rates were estimated using the Kaplan–Meier survival functions. Cox models were developed to assess association between time to progression and time to death, using a group of fixed variables. Results Overall, 175 patients were included in the study; 33.7% of patients had luminal B HER2-negative tumors, 49.7% had bone involvement, and 83.4% had multiple metastatic sites. Tumor biology and primary tumor surgery were the variables associated with TTP and OS. Patients with luminal A tumors had the lowest progression and mortality rates (10 per 100 patients/year (95% CI: 5.0-20.0) and 12.6 per 100 patients/year (95% CI: 6.9-22.7), respectively), and patients with triple-negative tumors had the highest progression and mortality rates (40 per 100 patients/year (95% CI: 23.2-68.8) and 44.1 per 100 patients/year (95% CI: 28.1-69.1), respectively). Across the cohort, the median TTP was 2.1 years (95% CI: 1.6; the upper limit cannot be reached) and the median OS was 2.4 years (95% CI: 2-4.3). Conclusions In this cohort, patients with luminal A tumors and those who underwent tumor surgery given that they presented clinical benefit (CB) after initial systemic treatment, had the lowest progression and mortality rates. Overall, OS was inferior to other series due to high tumor burden and difficulties in accessing and continuing oncological treatments.

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El 16.9% de las pacientes con cáncer de mama, que ingresan a la Unidad Funcional de Mama y Tejidos Blandos del Instituto Nacional de Cancerología (INC), se presentan con enfermedad metastásica. El desarrollo de las terapias blanco ha modificado radicalmente el enfoque terapéutico en este grupo de pacientes. Se realizó una búsqueda de la literatura seleccionando los ensayos clínicos controlados y aleatorizados fase 3, las revisiones sistemáticas y los metaanálisis, sobre el tratamiento sistémico para el cáncer de mama metastásico con receptores hormonales positivos (RH+) y receptor HER2 negativo (HER2).Se pusieron filtros a la búsqueda para identificar únicamente los artículos publicados a noviembre de 2020 y en idioma inglés. Posteriormente, se socializó la revisión de la evidencia al interior de las Unidades Funcionales (UF) de Mama y Tejidos Blandos y Oncología clínica. Finalmente, se realizó una discusión académica en la cual se establecieron los cambios en el abordaje terapéutico de las pacientes con cáncer de mama luminal, HER2 negativo, metastásico. En los últimos años, el conocimiento de la biología molecular del cáncer de mama ha permitido el desarrollo de múltiples terapias blanco (iCDK4/6, iPI3KCA, inhibidores del mTOR), que combinadas con la terapia hormonal, mejoran los desenlaces oncológicos de las pacientes con enfermedad metastásica (supervivencia libre de progresión y supervivencia global).