Higher Body Mass Index Is a Simple Favorable Non-cancer Prognostic Marker for Japanese Elderly Colorectal Cancer Patients after Curative Resection

Abstract

Objectives: In elderly colorectal cancer (CRC) patients, preoperative surgical indications can be controversial in some cases depending on the patient's physical condition. In comparison with younger patients, both cancer-specific survival (CSS) and non-CCS (NCSS) have an impact on the prognosis and both CSS and NCSS should be considered in the preoperative assessment. We aimed to investigate the impact of body mass index (BMI) on CSS and NCSS in Japanese elderly CRC patients. Methods: We retrospectively collected data from 471 Japanese elderly patients (80 years) with stage I-III CRC who underwent curative surgery from 1998 to 2017. A Kaplan-Meier survival analysis with propensity score matching (PSM) and a multivariate Cox regression analysis were performed. Results: After PSM, 123 higher BMI (23) and 123 lower BMI (<23) cases were matched. The higher BMI group had significantly better survival than the lower BMI group regarding NCSS and overall survival (OS; P < .001 and P < .001, respectively). The multivariate survival analysis further confirmed that the higher BMI group had significantly better survival than the lower BMI group regarding CSS, NCSS, and OS (P = .027, P < .001, and P < .001, respectively). Conclusions: In Japanese elderly patients with stage I-III CRC who underwent curative surgery, preoperative higher BMI was a significant and simple favorable prognostic predictor, especially for NCSS and OS.

Keywords

• body mass index
• colorectal cancer
• elderly
• non-cancer-specific survival
• octogenarian