35 Associations between transport modes and site-specific cancers: A Systematic review and meta-analysis

TL;DR

This study reviews how different transport modes affect cancer risks, finding that active transport like walking or cycling may reduce the risk of certain cancers.

Contribution

The paper provides a systematic review and meta-analysis linking transport modes to site-specific cancer risks.

Findings

150 minutes of weekly active transport reduces endometrial cancer risk by 7%.

Cycling is linked to lower overall cancer incidence and mortality compared to motorized transport.

Evidence for cancer risk reduction is limited to breast, colorectal, and endometrial cancers.

Abstract

Transport choices may influence cancer risks through their effects on physical activity levels, sedentary time, and environmental pollution. This review synthesizes existing evidence on the associations of specific transport modes with risks of site-specific cancers.

Relevant literature was searched up to 17th February 2023 in PubMed, Embase, and Scopus, and results were meta-analyzed for cancer sites where two or more studies were identified.

27 eligible studies (11 cohort, 15 case-control, and 1 case-cohort) were identified, which reported the associations with 10 site-specific cancers (breast, endometrial, colorectal, testicular, prostate, ovarian, lung, renal, liver, gallbladder and biliary tract). In meta-analysis, 10 Metabolic Equivalent of Task hour increment in transport-related physical activity per week (∼ 150 minutes of walking or 90 minutes of cycling for commute) was associated with a 7% reduction in risk for endometrial cancer (95% CI: 0.89 – 0.98), 5% reduction for colorectal cancer (95% CI: 0.91 – 0.99) and 2% reduction for breast cancer (95% CI: 0.89 – 0.996). Compared to motorized modes, cycling was associated with a lower risk of overall cancer incidence and mortality.

Active transport appears to reduce cancer risk, but evidence for cancer sites other than colorectum, breast, and endometrium is currently limited.