Prognostic Factors in Geriatric Patients with Metastatic Colon Cancer

Abstract

Backgrounds: Colorectal cancer is an important contributor to cancer morbidity and mortality. Given that many older adult patients often have concomitant diseases and impairments in organ function, they are at increased risk for chemotherapy toxicity. Therefore, it is important to identify prognostic factors in older patients undergoing chemotherapy. Methods: We performed a retrospective chart review of colorectal cancer patients treated at Nagoya Memorial Hospital between 2012 and 2017 and selected those who received chemotherapy for metastatic colon cancer. Overall survival was calculated from the beginning of chemotherapy until death or the most recent follow-up date. We used the Kaplan-Meier method to plot survival curves and performed a statistical comparison using a log-rank test. In addition, multivariate analysis was performed using stepwise Cox proportional hazards models. Finally, a comprehensive geriatric assessment was conducted for older patients. The chart review was approved by the ethics committee of Nagoya Memorial Hospital. Results: The overall survival of metastatic colon cancer patients was not markedly different between patients aged < 65 years (N = 17) and those aged ≥ 65 years of age (N = 37). Neither lesion site nor the RAS status affected survival, whereas the usage of three kinds of cytotoxic agents prolonged longevity. In a multivariate analysis of patients ≥ 65 years of age, the only independent prognostic factor for survival was the functional capacity, as measured by the Tokyo Metropolitan Institute of Gerontology (TMIG) index of competence. Conclusions: A combination of the comprehensive geriatric assessment and TMIG index was useful for predicting the longevity in patients with metastatic colon cancer ≥ 65 years of age.