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

Abstract

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...

<p>The Evaluation of Magee Equation 2 in Predicting Response and Outcome in Hormone Receptor-Positive and HER2-Negative Breast Cancer Patients Receiving Neoadjuvant Chemotherapy</p>

“…24,25 Luminal breast cancer subtype had lower response to NAC when compare to other subtypes. 26,27 Although there were higher proportion of T4 breast cancer recruited in this current study, the rate of pCR in the current study was similar to the recent report of clinically node-positive breast cancer receiving NAC. 25 However, approximately 70% of the patients received neoadjuvant AC regimen which resulted in lower response when compare to the addition of taxane-based regimen.…”

Human Plasma Metabolomics for Biomarker Discovery: Targeting the Molecular Subtypes in Breast Cancer

“…Breast cancer (BC) is currently the most common malignancy in women, both in developed and less developed countries, and the leading cause of cancer-related deaths among women worldwide, with a high incidence rate [ 1 , 2 ]. Every breast cancer subtype is characterized by intrinsic molecular features and metastatic lesions, and their natural heterogeneity leads to a high diversity in prognosis and clinical responses to available medical treatments, even for patients with similar diagnosis, histology and stage of disease [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ].…”

Predictive and Prognostic Roles of Pathological Indicators for Patients with Breast Cancer on Neoadjuvant Chemotherapy

“…HR-positive patients have relatively more favorable outcome, although they are less responsive to NACT than TNBC and HER2 + tumors [82]. Indeed, it is widely accepted that patients with TNBC and HER2-enriched tumor showed higher pCR rates than luminal subtype [83848586]. Prat et al [83] evaluated the recurrence risk based on BC subtype and confirmed the independent predictive and prognostic value of intrinsic subtype at diagnosis for patients after NACT.…”

“…The correlation between pCR and survival is significant in partial patients based on molecular subtypes. Díaz-Casas et al [84] reported longer EFS and OS in patients who achieved pCR, which was statistically significant only in patients with TNBC. In a study involving 13,939 patients, pCR was demonstrated to be significantly associated with 5-year OS in patients with luminal B, HER2 + , and TNBC (93.0%, 94.2%, and 90.6%, respectively, HER2 + vs. TNBC, p = 0.016) [87].…”