Physical activity at baseline and risk of prostate cancer grade reclassification on active surveillance: results from...

For men with low-risk prostate cancer (PCa) on active surveillance (AS), there remain limited and conflicting data regarding whether physical activity may influence disease progression evidenced by grade reclassification (GR). Furthermore, it is unclear whether physical activity affects the risk independently of other lifestyle factors such as diet and smoking.

This is a prospective cohort study of men diagnosed with Grade Group (GG) 1 PCa undergoing AS. Patients completed diet and physical activity questionnaires upon AS enrollment. Physical activity level was evaluated as metabolic equivalent of task hours per week (MET-h/wk), and diet quality as energy-adjusted Healthy Eating Index (E-HEI) score. Multivariable competing risk regressions were utilized to examine the association of baseline physical activity level with GR to ≥GG2 and to ≥GG3, adjusting for established clinicopathological risk factors, diet quality, and smoking history.

We included 828 men with a median follow up of 6.4 years (quartiles: 4.0-9.1). In multivariable regression models adjusted for covariates, increased baseline physical activity levels (3 to <9 MET-h/wk versus <3: subdistribution hazard ratio [SHR] 0.18, 95% confidence interval [CI] 0.05-0.61; 9 to <18 MET-h/wk versus <3: SHR 0.26, 95% CI 0.10-0.68; ≥18 MET-h/wk versus <3: SHR 0.31, 95% CI 0.12-0.80) were associated with significantly decreased risks of GR to ≥GG3. Increased physical activity levels were associated with non-significant decreases in GR to ≥GG2. An increased E-HEI score was also significantly associated with decreased GR to ≥GG3, and non-significant reduction in GR to ≥GG2. Smoking history was not associated with either GR outcome.

In a large prospective cohort with longitudinal follow-up of men pursuing AS for GG1 PCa, increased baseline physical activity levels, compared to a sedentary lifestyle defined as <3 MET-h/wk, was independently associated with a lower risk of progression to ≥GG3 disease.