Impact of immunohistochemistry-based molecular subtype on chemosensitivity and survival in Hispanic breast cancer patients following neoadjuvant chemotherapy

Abstract

BackgroundNeoadjuvant chemotherapy (NAC) is the standard treatment for patients with locally advanced breast cancer, showing improvement in disease-free survival (DFS) and overall survival (OS) rates in patients achieving pathological complete response (pCR). The relationship between immunohistochemistry-based molecular subtyping (IMS), chemo sensitivity and survival is currently a matter of interest. We explore this relationship in a Hispanic cohort of breast cancer patients treated with NAC.MethodsA retrospective survival analysis was performed on Colombian females with breast cancer treated at Instituto de Cancerología-Clinica Las Américas between January 2009 and December 2011. Patients were classified according to immunohistochemistry-based subtyping into the following five groups: Luminal A, Luminal B, Luminal B/HER 2+, HER2-enriched, and triple-negative breast cancer. Demographic characteristics, recurrence pattern, and survival rate were reviewed by bivariate and multivariate analysis.ResultsA total of 328 patients fulfilled the study’s inclusion parameters and the distribution of subtypes were as follows: Luminal A: 73 (22.3%), Luminal B/HER2−: 110 (33.5%), Luminal B/HER2+: 75 (22.9%), HER2-enriched: 30 (9.1%), and triple-negative: 40 (12.2%). The median follow-up was 41 months (interquartile range: 31–52). Pathological response to NAC was as follows: complete pathological response (pCR) in 28 (8.5%) patients, partial 247 (75.3%); stable disease 47 (14.3%), and progression 6 (1.8%) patients. The presence of pCR had a significant DFS and OS in the entire group (p = 0.01) but subtypes had different DFS in Luminal B (p = 0.01) and triple negative (p = 0.02) and also OS in Luminal B (p = 0.01) and triple negative (p = 0.01).ConclusionspCR is associated with an improved overall survival and disease-free survival rates in this group of Hispanics patients. Advanced stages, Luminal B subtypes, triple-negative tumours and non-pCR showed lower DFS.

Assessment of the predictive role of pretreatment Ki-67 and Ki-67 changes in breast cancer patients receiving neoadjuvant chemotherapy according to the molecular classification: a retrospective study of 1010 patients

“…Most of the above results were in line with previous literature [ 12 , 16 , 19 , 25 ]. However, the HER2 status did not show a statistically significant response in clinical and pathological response in our analysis, which is not consistent with the existing literature.…”

Breast Cancer Precision Medicine in Hispanics/Latinas: Focus on Luminal B Tumors

“…No significant association was found in this study between genetic ancestries established using 80 Ancestry Informative Markers (AIMs) and St. Gallen subtype distribution. Similar results were obtained by Gomez et al in an independent study of a Colombian cohort [24].…”

Breast Cancer in Latinas: A Focus on Intrinsic Subtypes Distribution

“…It is important to emphasize that the studies included in this review are based on different sources of information. Some studies are based on data from population registries (53–55,57,58,60–64,87,88) and, others are hospital/clinic based (66,68–70,72,73,77,78). The population-based studies tend to report lower prevalence of the more aggressive tumors (ranging between 12 to 17%) compared to hospital/clinic-based studies (ranging between 12 to 23%) (Table 2), which is to be expected when the hospitals included in the studies are reference centers and therefore tend to receive patients that could not be adequately served by local hospitals/clinics.…”

“…al. (77) analyzed the distribution of breast cancer intrinsic subtypes in 328 clinic-based patients from Medellin, Colombia diagnosed between January 2009 and December 2010. The mean age at diagnosis for this study was 52.9 years.…”