Greater adherence to lifestyle recommendations after cancer diagnosis is associated with lower mortality in the UK Biobank

Abstract Background: Research supporting the current recommendation to adhere to a healthy lifestyle following cancer diagnosis is limited. We investigated whether a healthy lifestyle after diagnosis is associated with a lower risk of mortality among those diagnosed with any malignant cancer, and breast, colorectal and prostate cancers. Methods: In 2006-2010, UK Biobank participants (aged 37-73 years) were assessed. Analyses were restricted to those with a malignant cancer diagnosis prior to baseline (n=20,805, including 5,845 breast, 1,943 colorectal and 2,715 prostate cancer cases). Participants were followed for all-cause and cancer-specific death up to November 2022. A lifestyle index was determined based on lifestyle recommendations for cancer prevention. Cox regression was used to examine associations with all-cause and cancer-specific mortality among those with any cancer, and separately for breast, colorectal and prostate cancers, adjusting for relevant confounders. Results: There were 4,328 deaths and 3,354 cancer-specific deaths in the 258,985 person-years of follow up. A higher lifestyle index, representing greater adherence to recommendations, was associated with a lower risk of all-cause mortality (any cancer - highest vs lowest lifestyle index tertile: HR[95%CI]=0.77[0.71,0.83]; breast: 0.75[0.64,0.88]; colorectal: 0.68[0.52,0.89]; prostate: 0.73[0.59,0.89]), and cancer-specific mortality in all populations examined (any cancer: 0.82[0.75,0.89]; breast: 0.88[0.71,1.09]; colorectal: 0.58[0.36,0.94]; prostate: 0.70[0.53,0.93]), although evidence was weaker for cancer-specific mortality among colorectal and breast cancer survivors. Conclusions: Our findings provide evidence to support the recommendation to follow a healthy lifestyle after cancer diagnosis to prolong life. Impact: Clinical guidelines and public health programs promoting a healthy lifestyle to cancer survivors may prolong life.