Estimation of cancer mortality attributable to excess body weight during 2006-2015 in China

Cancer is one of the most common causes of death. Excess body weight (EBW), a risk factor for cancer, is highly prevalent in China. We aimed to estimate the number and proportion of cancer deaths attributed to EBW and their changes during 2006-2015 in China.

Population attributable fractions in 2006, 2010, and 2015 were calculated with 1) prevalence of overweight/obesity, exacted from the China Health and Nutrition Survey conducted in 8-9 provinces of China in 1997, 2000, and 2004; 2) relative risks for EBW and site-specific cancers, obtained from previous studies; 3) data on cancer deaths in 2006, 2010, and 2015, originated from the Chinese Cancer Registry Annual Report.

In 2015, EBW contributed to 45,918 (3.1% of all) cancer deaths in China, with 24,978 (2.6%) in men and 20,940 (3.8%) in women. By region, the fraction of cancer deaths attributable to EBW ranged from 1.6% (West) to 4.1% (Northeast). Cancers of liver, stomach, and colorectum were the main EBW-attributable cancers. The fractions of cancer deaths attributable to EBW were 2.4% (95%CI: 0.8-4.2%) in 2006, 2.9% (95%CI: 1.0-5.2%) in 2010, and 3.1% (95%CI: 1.0-5.4%) in 2015, respectively, and increased for all gender, region, and cancer site during 2006-2015.

The proportion of cancer deaths attributed to EBW was higher in women and Northeastern China, with an upward trend in the recent decade. A combination of comprehensive and individualized measures is necessary to reduce the prevalence of EBW and related cancer burden in China.