Clinical significance of molecular subtypes of breast cancer in patients aged over 60 years

Abstract

Objective To retrospectively analyze the distribution percentage points of molecular subtypes of breast cancer and investigate its guiding significance in the prognosis and personalized therapy in patients with breast cancer aged over 60 years. Methods A retrospective analysis of all patients with invasive breast cancer aged over 60 years from January 2009 to June 2014 in Breast Center of Beijing Hospital was performed.Based on the immunohistochemical methods recommended in the St.Gallen International Expert Consensus Report 2013, the molecular subtypes of breast cancer in these patients were identified.All patients were followed up every 6 months after operation until December 2014.Clinical pathological characteristics and prognosis indexes in different molecular subtypes of breast cancer were evaluated. Results Totally 770 patients aged over 60 years with invasive breast cancer met the criterion.The luminal A, luminal B, human epidermal growth factor receptor 2(HER2)over-expression, triple- negative subtypes accounted for 29.1%(224 cases), 47.5%(366 cases), 6.5%(50 cases)and 16.9%(130 cases)of patients, respectively.The luminal A subtype of breast cancer had larger tumor size, more lymph node metastasis and more late TNM stage as compared with other subtypes(all P<0.01). Univariate and multivariate analysis showed that aged ≥80 years and the triple- negative molecular subtype were the independent poor prognostic factors for breast cancer(both P<0.05). The luminal A subtype of breast cancer had relatively good prognosis, while the triple- negative subtype had relatively poor prognosis. Conclusions Molecular subtypes have a significant prognostic effect on breast cancer in patients aged over 60 years, which suggests molecular subtype can be considered as a reference indicator in personalized therapy.Patients aged over 80 years has poor prognosis due to less rational treatment.The reasonable and target treatment based on the molecular subtype of breast cancer should be provided for patients aged over 80 years in clinical medicine. Key words: Breast neoplasms; Molecular subtype; Prognosis