Effects of clinical treatment decisions on long-term survival outcomes of locally advanced breast cancer with different molecular subtypes based on the SEER database

Abstract

Background: Some patients with breast cancer are diagnosed with locally advanced breast cancer (LABC). At present, there are no obvious reports on LABC radiotherapy, chemotherapy, and breast-conserving benefit population. Method: The cases of LABC confirmed by pathology from 2010 to 2015 were searched through the Surveillance Epidemiology and End Results (SEER) database. Breast cancer-specific survival (BCSS) and overall survival (OS) were estimated by plotting Kaplan-Meier curves. The log rank test (Mantel-Cox) was used to analyze the difference between the groups, and the benefit population of LABC was determined after for age, TNM stage, grade, treatment methods. Results: A total of 34474 LABC patients were included, 22477 (65.2%) were Luminal A, 1418 (4.1%) were Luminal B, 4911 (14.3%) were triple-negative breast cancer, 2461 (7.1%) were HER2-enriched, and 3207 (9.3%) were three positive breast cancer. Kaplan-Meier curves of 5-year OS and BCSS were plotted for LABC patients with different molecular types of breast conserving surgery and mastectomy. Overall the LABC with breast conserving and total mastectomy was 77.8%, 84.6% ,68.4% and 77.2%. Luminal A LABC with breast conserving and total mastectomy was 79.9%,87.5%, 72.3% and 81.5%.Luminal B LABC with breast-conserving and total mastectomy were 79.3% , 83.1%, 70.8% and 77.1%. TNBC LABC with breast-conserving and total mastectomy were 61.0% ,68.4%, 47.5% and 56.2%. HER2-enriched LABC with breast-conserving and total mastectomy were 77.7%, 80.5%, 67.2% and 75.2%. TPBC LABC with breast-conserving and total mastectomy were 84.9%, 91.8%, 75.5% and 82.1%, respectively. Except for the Luminal B LABC BCSS surgery method, there was no significant difference (P=0.058), all the others were statistically significant (P<0.05). Conclusions: This study found that in the selective population, OS and BCSS of patients with LABC undergoing breast conserving surgery were significantly better than those of mastectomy.This study also found that LABC could be considered for highly differentiated, NO stage TPBC without chemotherapy.