Smoking can almost double the risk of prostate cancer returning after surgery, a study has found.
Ex-smokers were also at greater risk of recurring cancer, but not those who quit the habit 10 years or more before having their prostate glands removed.
The findings, published in the journal European Urology, make it seem more likely that there is a link between smoking and prostate cancer.
Previous research has shown that smokers are more likely to die from the disease, but the results of other studies have been inconclusive.
The new investigation looked at data from 7191 American and Austrian patients who had their prostate glands removed between 2000 and 2011.