Bridging the age gap in breast cancer - analysis of the influence of age, comorbidity and frailty on the types of surgery performed in older women with operable breast cancer

Background: The Bridging the Age Gap in Breast Cancer study is a multicentre retrospective cohort study examining the management of older patients with breast cancer. This study aimed to examine the selection criteria for breast cancer surgery in patients over 70 and the adverse events risk in this population. We present data on the impact of age, comorbidity, frailty and dementia on breast surgical choices. Materials and Methods: Baseline information on age, comorbidities (Charlson Comorbidity Index), frailty (activities of daily living, ADL and instrumental ADL) and cognitive function (MMSE) was collected across 56 UK breast units from women >70 with early breast cancer. These were correlated with breast and axillary surgery rates and types, using Chi squared. Results: Between 2013-2018, 3460 women with operable breast cancer were recruited; 2792 (80.7%) were treated surgically. There were 62 bilateral tumours, giving a total of 2854 surgical events. Median age was 76 (range 70-95). Age was a significant predictor of mastectomy (mastectomy rate 70-74 years: 29.9%, 75-79: 41.1%, 80-85: 50.4% and 85+: 59.9% P<0.01) and no axillary surgery (70-74 years: 1.4%, 75-79: 1.5%, 80-84: 4.8% and 85+: 8.6% P<0.01). Frailty (ADL or IADL) and increasing Charlson Comorbidity Index (CCI) were all significant predictors of no axillary surgery (ADL normal 2.4%, frail 3.6% P<0.05, IADL normal 1.9%, frail 6.6% P<0.01, CCI-3 1.0% CCI-4 1.4% CCI-5 3.0% CCI>5 7.5% P<0.01) and mastectomy (ADL normal 38.8%, frail 43.7% P<0.05, IADL normal 38.2%, CCI-3 34.4%, CCI-4 44.6% CCI-5- 40.5% CCI>5 6 44.7% P<0.01). Impaired cognitive function was not a predictor for mastectomy or axillary surgery, but numbers were small. Conclusions: Older age, ill health and frailty deter standard axillary surgery but are linked to more extensive breast surgery. The higher mastectomy rate with older age may reflect the lack of screening in older groups and consequent larger tumour sizes.