ABSTRACT
Purpose@#Triple negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer. However, we have often experienced that triple positive breast cancer (TPBC) shows more aggressive clinical features than TNBC. In this retrospective study, we aimed to examine the differences in clinical courses between TNBC and TPBC. @*Methods@#Using medical records and clinical data, we selected patients with breast cancer who met the criteria for the two groups, TNBC and TPBC, based on the expression or absence of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). We then compared these groups with respect to clinical and pathological variables, such as patient age at diagnosis, TNM stage, number of tumors, involvement of resection margin, operation methods, histologic grade (HG), nuclear grade (NG), and lymphatic invasion (LI). We also compared the disease-free (DFS) and overall survival (OS) outcomes between the groups. @*Results@#Seventy patients with TNBC and 91 with TPBC were identified among a total of 628 patients. In univariate analysis, TPBC was significantly more frequently associated with lower HG (p=0.001), lower NG (p=0.003), LI (p=0.001), and a Ki-67 index ≤20% (p<0.001). In multivariate analysis, a lower Ki-67 index (p=0.031) and LI (p=0.022) were identified as significant and independent factors contributing to DFS. In a survival analysis over time, the TPBC showed a worse OS than TNBC 5 years post-treatment for breast cancer. Consequently, the TPBC group had definite worse 10-year DFS (p=0.012) and showed relatively lower OS rate (p=0.058), than the TNBC group. @*Conclusion@#Our results demonstrate considerable differences in long-term post-treatment survival of patients with TPBC and TNBC. Further studies to determine the proper management of both types of breast cancer and an accurate prognostic evaluation method are warranted.