Relationship between pathological response and molecular subtypes in locally advanced breast cancer patients receiving neoadjuvant chemotherapy

Abstract

Background: More than half of patients with breast cancer were diagnosed with locally advanced stages of the disease (54%). This study aimed to explain the pathological response received with neoadjuvant chemotherapy (NACT) according to the molecular classi cation of breast cancer in patients with locally advanced tumors.Methods: One hundred one patients with locally advanced breast cancer treated with neoadjuvant chemotherapy were analyzed. Patients were classi ed into ve molecular subtypes based on the pro le of the estrogen receptor, progesterone receptor, HER2, and Ki-67. We determined associations between pathologic complete response and molecular subgroups.Results: Most patients had luminal A tumors (n:28, 27.7%). The overall rate of pathological complete response (pCR) was 34.7% (n:35). Tumors that presented the highest rate of pCR were pure HER2positive, at 60% (n:6; OR, 3.2; 95% CI, 0.8-12.2). According to logistic regression analysis, the factors affecting pCR were HER2 positivity and clinically positive axilla before NACT. Luminal A tumors had a signi cantly lower pCR rate. (7.1%,p: 0.001). Despite the low pCR rate, luminal A tumor survival was the best subgroup (p< 0.001). However, there was no difference between EFS and OS according to pCR in any molecular subgroups.Conclusion: Pathological complete response is directly related to the subtypes of breast cancer. A high rate of complete pathological response is observed in the pure HER2-positive group. However, EFS and OS were not statistically signi cant in patients with and without pCR.

Investigation of efficacy of two different chemotherapy protocols used in neoadjuvant chemotherapy in clinical stages II–IV canine malignant mammary tumours

“…In TNBC patients, the pCR was found to be in the range of 23.2%-44.4%. 33,[35][36][37] In this study, CR was found to be 21.43% (3/14) in the AC group. The effects of molecular subtypes in this group on CR were found to be 33.33% for triple-negative and 22.22% for Luminal A.…”

“…32 pCR is directly related to subtypes of HBC, and research is ongoing into the use of molecular subtypes in HBC to predict the clinical efficacy of NAC. 33 pCR rate was found to be very low in ER-positive and HER2-negative patients in HBC, and it was observed that the best responses to NAC were obtained in HER2-positive patients, followed by triple-negative breast cancer (TNBC) patients. 34 The pCR rates in Luminal A and B subtypes are expressed as 0.3%-6% and 8.3%, respectively.…”

“…This was followed by the triple-negative molecular subtype. 33,[35][36][37] These differences are thought to be due to the breed, the small number of dogs, the different tumour grades, especially the chosen chemotherapy protocol, and the non-use of anti-HER2 agents in the treatment. These results are the first clinical data evaluating the response to NAC treatment according to molecular subtypes in CMT.…”

Clinical factors affecting the long-term survival of breast cancer patients

“…BC subtypes have direct effects on the pathological complete response. 41 However, the molecular subtype data in this study could not be presented because the older patient data from between 1977 and 2005 did not include information on molecular subtypes. In future research, the molecular subtypes should also be given more attention.…”

X-box binding protein 1 (XBP1): a potential role in chemotherapy response, clinical pathologic features, non-inflamed tumour microenvironment for breast cancer

“…According to statistical data, locally advanced BC accounted for approximately 54%, whose tumour is greater than 5 cm in size, possibly with the involvement of regional lymph nodes, chest walls, or skin [ 2 ]. Neoadjuvant chemotherapy is the standard treatment for locally advanced BC [ 3 ]. However, only 10–40% of BC patients demonstrate pathological complete response that is a prognostic indicator for long-term disease-free and overall survival [ 4 , 5 ].…”