Factors Associated with Time to Progression and Overall Survival in Patients with De Novo Metastatic Breast Cancer: A Colombian Cohort.

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.

Evaluation of the AJCC Eighth-Edition Prognostic Staging System for Breast Cancer in a Latin American Cohort.

BACKGROUND: The staging of breast cancer has been based on tumor size, lymph node involvement, and presence or absence of distant metastases. The American Joint Committee on Cancer (AJCC) staging system in its eighth edition incorporates hormone receptors, human epidermal growth factor receptor 2 (HER2), and histologic grade due to their prognostic importance. In Latin America, however, the impact of the new edition is unknown. This article evaluates the performance of the AJCC eighth-edition staging system in a cohort of patients with breast cancer at a reference center in Colombia. METHODS: The study investigated a descriptive cohort of 912 patients who received complete treatment for non-metastatic invasive breast cancer and had information on the anatomic stage and biologic factors,. All the patients were restaged using the AJCC eighth-edition classification. Changes in clinical stages and differences between the two classifications were compared. RESULTS: The study enrolled 912 patients. Changes in staging occurred for 54.82% (downstaging for 40.3% and upstaging for 14.47%) of these patients. For recurrence-free survival, the C-Index of the eighth-edition AJCC was 0.726, and the AIC was 1323.7, whereas the C-Index of the seventh-edition AJCC was 0.731, and the AIC was 1314.3 (p = 0.99). CONCLUSIONS: The seventh and eighth editions of the AJCC staging system have similar predictive values in our population for recurrence-free survival. Future studies are necessary to evaluate the performance of the AJCC eighth-edition staging system in predicting overall survival.

Pathological Response to Neoadjuvant Chemotherapy and the Molecular Classification of Locally Advanced Breast Cancer in a Latin American Cohort.

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 HER2-negative 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 triple-negative tumors. 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.