Limited Impact of Breast Cancer and Non-breast Malignancies on Survival in Older Patients with Early-Stage Breast Cancer: Results of a Large, Single-Centre, Population-Based Study

Aims: To analyse the disease-free survival and overall survival in older adults with breast cancer after breast-conserving therapy, focusing on the relevance of non-breast malignancy (NBM) with respect to survival rates. Materials and methods: Analyses were based on 1205 women aged 65 years and older with breast cancer treated with breast-conserving therapy between 1999 and 2015. Patients were divided into three age categories: 65–70, 71–75 and >75 years. Multivariate survival analysis was carried out using Cox regression analysis. Results: The two youngest age categories showed excellent results, with a 12-year disease-free survival of 84.6 and 86.3%, respectively. We noted a 17.2% incidence of NBM, particularly for colon cancer and lung cancer. Most (72.9%) occurred after a diagnosis of breast cancer. Of those 72.9%, about 50% died as a result of NBM within 2 years of the diagnosis of NBM. The overall 12-year NBM-specific survival was 92.0%. The 12-year overall survival was 60.0% for all and for the three abovementioned age categories was 73.3, 54.4 and 28.4%, respectively. The cause of death for all was predominantly non-malignancy-related morbidity. Conclusion: The impact of breast cancer on life expectancy was limited, in particularly for women aged 65–75 years. The relevance of NBM on survival was limited.