Long-term outcomes and prognostic factors in elderly patients with breast cancer: single-institutional experience

Introduction: Despite advances in treatment, there is rising mortality in elderly patients with breast cancer. We aimed to conduct an audit of non-metastatic elderly breast cancer patients to understand the predictors of outcome. Methods: Data collection was done from electronic medical records. All time-to-event outcomes were analysed using Kaplan-Meier method and compared using log-rank test. Univariate and multi-variate analysis of known prognostic factors was also done. Any p-value <= 0.05 was considered statistically significant. Results: A total of 385 elderly (>70 years) breast cancer patients (range 70-95 years) were treated at our hospital from January 2013 to December 2016. The hormone recep-tor was positive in 284 (73.8%) patients; 69 (17.9%) patients had over-expression of HER2-neu, while 70 (18.2%) patients had triple-negative breast cancer. A large majority of women (N = 328, 85.9%) underwent mastectomy while only 54 (14.1%) had breast conservation surgery. Out of 134 patients who received chemotherapy, 111 patients received adjuvant, while the remaining 23 patients received neoadjuvant chemotherapy. Only 15 (21.7%) patients of the 69 HER2-neu receptor-positive patients received adju-vant trastuzumab. Adjuvant radiation was given to 194 (50.3%) women based on the type of surgery and disease stage. Adjuvant hormone therapy was planned using letrozole in 158 (55.6%) patients, while tamoxifen was prescribed in 126 (44.4%). At the median follow up of 71.7 months, the 5-year overall survival, relapse-free survival, locoregional relapse-free survival, distant disease-free survival, breast cancer-specific survival were 75.3%, 74.2%, 84.8%, 76.1% and 84.5%. Age, tumour size, presence of lymphovascular invasion (LVSI) and molecular subtype emerged as independent predictors of survival on multi-variate analysis. Conclusion: The audit highlights the underutilisation of breast-conserving therapy and systemic therapy in the elderly. Increasing age and tumour size, presence of LVSI and molecular subtype were found to be strong predictors of outcome. The findings from this study will help to improve the current gaps in the management of breast cancer among the elderly.