Rising incidence of obesity-related cancers among younger adults in China: A population-based analysis (2007-2021)

Abstract

Background: Developing countries face an "obesity epidemic," particularly affecting children and younger adults. While obesity is a known risk factor for 12 types of cancer, primarily affecting older populations, its impact on younger generations is understudied.

Methods: This study analyzed data from a population-based cancer registry covering 14.14 million individuals in China (2007-2021). We compared the incidence of obesity- and non-obesity-related cancers and applied an age-period-cohort model to estimate their impacts.

Findings: Among 651,342 cancer cases, 48.47% were obesity related. The age-standardized incidence rates (ASRs) of the 12 obesity-related cancers increased annually by 3.6% (p < 0.001), while ASRs for non-obesity-related cancers remained stable. Obesity-related cancers surged among younger adults, with rates rising across successive generations. The annual percentage of change decreased with age, from 15.28% for ages 25-29 years to 1.55% for ages 60-64 years. The incidence rate ratio for obesity-related cancer was higher in younger generations compared to those born in 1962-1966. We predict that the ASR for obesity-related cancers will nearly double in the next decade.

Conclusions: The rising incidence of obesity-related cancers among young adults poses a significant public health concern. The increasing cancer burden underscores the need for targeted interventions to address the obesity epidemic.

Funding: This work was supported by the National Natural Science Foundation of China (81930019, 82341076) to J.-K.Y.

Keywords: Translation to population health.

Figure 1:. Age-specific annual percent changes, incidence rate ratios and age-specific incidence rates by birth cohort for obesity- and nonobesity-related cancers observed (2007–2021) and predicted (2022–2031).

A, B: Age-specific annual percent change (AAPC) for obesity- (A) and nonobesity-related (B) cancers; Dots and shaded areas represent the net annual percentage changes (% per year) and 95% CIs in incidence from the age-period-cohort models for 14 age groups (5-year increments from age 20 years). C, D: Incidence rate ratio (IRR) for obesity- (C) and nonobesity-related (D) cancers; Dots and shaded areas represent incidence rate ratios and 95% CIs for a given birth cohort relative to the 1964 birth cohort (1962–66; reference). E, F: Age-specific incidence for obesity- (E) and nonobesity-related (F) cancers; Dots denote observed incidence for 5-year age groups. G, H: Observed (2007–2021) and predicted incidence rates (2022–2031) (age-standardized to the Segi standard population) for obesity-related cancers by cancer sites (G) and by 5-year age groups (H).