Epidemiological Risk Factors for Colorectal Adenomas

Colorectal adenomas are benign mucosal proliferations that represent a pivotal stage in the adenoma–carcinoma sequence. Epidemiological investigations have identified a constellation of non-modifiable factors—such as advancing age and family history of colorectal cancer—and modifiable determinants, including obesity, central adiposity, metabolic dysfunction and lifestyle behaviours. Elevated body mass index (BMI) and waist-to-hip ratio (WHR) reflect adiposity that promotes systemic inflammation and insulin resistance, both of which have been linked to adenoma initiation. Metabolic syndrome components—dyslipidaemia, hyperglycaemia and hypertension—further compound risk by altering cell proliferation and apoptosis pathways. Lifestyle elements such as smoking, excessive alcohol intake, sedentary habits and diets rich in red and processed meats have been shown to interact synergistically with metabolic factors. Conversely, physical activity, high-fibre diets and maintenance of healthy weight confer protective effects. The global burden of colorectal adenomas underscores the need for integrated risk stratification, combining demographic, clinical and behavioural data to guide personalised surveillance and prevention strategies.

Research from Nature Portfolio

Recent studies have refined risk prediction for individuals with a negative index colonoscopy by developing and validating a nomogram that incorporates baseline age, BMI, physical activity and first-degree family history of colorectal cancer. Using LASSO-Cox and multivariate Cox proportional hazards regression, a four-covariate model achieved superior discrimination of adenoma-free survival, with robust calibration and decision-curve performance, enabling cost-effective identification of high-risk subjects. In a large Chinese cohort, a combined cross-sectional and retrospective approach quantified the prevalence and incidence of colorectal polyps, revealing that regular smoking and alcohol intake independently predict polyp formation. Stratified analyses indicated that smoking was particularly associated with rectal and small polyps. These findings reinforce the role of modifiable lifestyle factors and support region-specific prevention efforts.

Epidemiological Risk Factors for Colorectal Adenomas publication trend

The graph below shows the total number of articles in epidemiological risk factors for colorectal adenomas across all publications each year (not limited to Nature Index journals).

Technical terms

Body mass index (BMI): A ratio of weight (kg) to height (m²) used to classify underweight, normal weight, overweight and obesity.

Waist-to-hip ratio (WHR): A measure of central adiposity calculated by dividing waist circumference by hip circumference.

LASSO-Cox regression: A penalised regression technique that selects predictive covariates for time-to-event data by shrinking coefficients towards zero.

Nomogram: A graphical tool that integrates multiple prognostic variables to estimate an individual’s probability of a clinical event.

Odds ratio (OR): A statistic that quantifies the strength of association between an exposure and an outcome in case-control studies.

References

1. Interaction of Colorectal Neoplasm Risk Factors and Association with Metabolic Health Status Focusing on Normal Waist-to-Hip Ratio in Adults. Cancers (2024).
2. Derivation and validation of a nomogram incorporating modifiable lifestyle factors to predict development of colorectal adenomas after negative index colonoscopy. Scientific Reports (2024).
3. Prevalence and risk factors for colorectal polyps in a Chinese population: a retrospective study. Scientific Reports (2020).
4. Combined Effect of Healthy Lifestyle Factors and Risks of Colorectal Adenoma, Colorectal Cancer, and Colorectal Cancer Mortality: Systematic Review and Meta-Analysis. Frontiers in Oncology (2022).