Weight maintenance and gain were significantly associated with lower risk of all-cause and cancer-related mortality in Korean adults who were newly diagnosed with cancer based on the Korean NHIS-HEALS cohort

The burden of malignant neoplasms is increasing worldwide. Healthy lifestyles such as maintaining a healthy body weight are important to improve survival rate in cancer patients. This study was aimed to test the hypothesis that weight change affects mortality in patients newly diagnosed with cancer. This study was retrospectively designed based on the National Health Insurance Service-National Health Screening Cohort. A total of 1856 subjects aged at least 40 years who received a national health checkup within 6 months before cancer diagnosis was included. Study subjects were classified into 3 categories based on weight change before and after cancer diagnosis: weight loss, maintenance, and gain. Cox proportional hazards regression models were adopted to examine the association between weight change and mortality after adjusting for confounders. Compared to those experiencing weight loss, the adjusted hazards ratios (HRs) (95% confidence intervals [CIs]) for those experiencing weight maintenance were 0.327 (0.189−0.568) for all-cause mortality and 0.431 (0.215−0.867) for cancer-related mortality. The adjusted HRs (95% CIs) for those experiencing weight gain were 0.149 (0.044−0.505) for all-cause mortality and 0.289 (0.080−1.045) for cancer-related mortality. After stratifying according to baseline body mass index (BMI), weight maintenance and gain were negatively associated with all-cause mortality (0.286 [0.138−0.592] for weight maintenance and 0.119 [0.027−0.533] for weight gain) among those with a BMI < 25 kg/m(2). Weight maintenance and gain reduced the risk of all-cause mortality in patients newly diagnosed with any cancer. In addition, weight maintenance was significantly related to cancer-related mortality.