32P Ageing Biomarkers in an Elderly Breast Cancer Population: Correlation with Comprehensive Geriatric Assessment (CGA)

ABSTRACT Introduction With increasing life expectancy in the western population, the field of geriatric oncology has been expanding rapidly over the last years. The concept that treatment of cancer in the older person is possible, and can be beneficial even at high age, has been confirmed. However, potential benefit of treatment must be balanced against risks of toxicity and decline in functionality and quality of life. This balance is influenced by the patient’s biological age and life expectancy. CGA can reflect biological age to a certain extent, but with potential limitations in terms of validity, sensitivity and reliability. Better ageing markers are therefore needed, to refine selection of patients for therapy. Methods We retrospectively analyzed a panel of potential ageing biomarkers in blood samples collected at diagnosis from 162 breast cancer patients (≥70 years of age) for whom CGA at the same time point was also available. Patients were divided into 3 categories (Fit-Vulnerable-Frail) on the basis of CGA, using Balducci’s definition. Analyzed biomarkers were circulating levels of IL-6, MCP-1 (CCL2), RANTES (CCL5) and mean leukocyte telomere length. The first three markers were determined by ELISA on serum/plasma, telomere length was determined by RT-PCR on leukocyte DNA. Results Mean levels of circulating IL-6 correlated with levels of frailty (Mean for Fit: 4,40 pg/mL, SEM 1.96 versus Mean for Frail 7.02, SEM 1.77; p = 0.018). Mean telomere length decreased with increasing frailty, although not statistically significant (Mean T/S ratio for Fit: 1.15, SEM 0.14 versus Mean T/S ratio for Frail: 0.92, SEM 0.05; p = 0.99). No correlation between frailty and mean circulating levels of MCP-1 or RANTES could be demonstrated. Conclusion Plasma levels of circulating IL-6 are correlated significantly with the level of frailty determined by CGA in older breast cancer patients. We also saw a decrease of telomere length with increasing frailty, although not statistically significant. IL-6 and telomere length mandate further investigation as markers of biological age in cancer patients, and also as predictors for treatment toxicity and outcome, in order to improve appropriate treatment selection. Disclosure All authors have declared no conflicts of interest.