Treatment and survival outcomes in older women with primary breast cancer: A retrospective propensity score-matched analysis.

PURPOSE: Changes in biological features and functional status make management decisions in older women with primary breast cancer complicated. We aimed to provide an overview of the clinicopathological characteristics and survival outcomes of older breast cancer patients based on the current treatment strategies. METHODS: Female patients diagnosed with primary invasive breast cancer at Fudan University Shanghai Cancer Centre from 2008 to 2016 were included. Patients were divided into a younger group (<65 years) and older group (≥65 years). Propensity score matching was utilised to generate balanced cohorts. RESULTS: A total of 13,707 patients met the study criteria. Compared with younger patients, older patients had a higher Charlson Comorbidity Index (p < 0.001), less lymph node metastasis (p = 0.009), more advanced tumour stage (p = 0.038), and a larger proportion of estrogen receptor-positive (p < 0.001) and epidermal growth factor receptor 2-negative (p < 0.001) tumours. Older patients were likely to receive mastectomy and axillary lymph node dissection in addition to a lower proportion of adjuvant chemotherapy. Adjuvant chemotherapy (HR [hazard ratio] 0.69, p = 0.039) was independently correlated with better overall survival in the older patients. This survival benefit (HR 0.58, p = 0.041) was confirmed in matched cohorts. Among the older patients with larger tumours (HR 0.48, p = 0.038) and more lymph node involvement (HR 0.44, p = 0.040), adjuvant chemotherapy was associated with a significant survival benefit. CONCLUSION: Older breast cancer patients showed less aggressive biological characteristics, intensive surgical and moderate medical preferences. The addition of adjuvant chemotherapy should be considered for older patients, especially for patients with large tumours and more lymph node involvement.