Abstract
Background: Frail patients with cancer (Ca) have worse survival. Current methods of assessment of fitness (performance status) for cancer treatment, such as chemotherapy, are time -consuming and often not used by practicing oncologists. The electronic frailty index (SCARF) is derived from a cumulative deficit frailty model and provides a measure of frailty alongside pre-existing conditions. We used this methodology to investigate whether it can predict outcomes of chemotherapy in patients with Ca. Methods: The study conducted data analysis of Ca patients treated with chemotherapy in England, years 2015-2018; stage II-III breast Ca, stage III colon Ca and stage IIIB-IV non-small-cell lung Ca. The data was linked with hospital admissions to calculate 30-day chemotherapy mortality, overall survival and SCARF. Results: The SCARF was calculated for 78,799 patients. The risk of dying within 30 days of chemotherapy in severely frail patients with colorectal cancer >= 70 y.o. was twice that of the <70 y.o. (OR 2.04 -95% CI 1.58-2.64, mild frailty 1.07-95% CI 0.78-1.45); and 6 times higher in breast cancer (OR 5.73-95% CI 2.66-12.32, mild frailty OR 1.45 95% CI 0.78-2.71). Conclusion: The SCARF index predicts poor outcomes from SACT, particularly in breast and colon cancer, and it requires further evaluation.