People with prostate cancer dramatically increase their chances of dying from the disease if they smoke, research has found.
The study team, at the Harvard School of Public Health in Boston, the US, also linked aggressive tumours to smoking at the time of diagnosis.
Published in the Journal of the American Medical Association, the study was the largest ever examination of the effects of smoking on prostate cancer.
It involved 5,300 men who were diagnosed with the disease between 1986 and 2006.
The researchers, led by Dr Stacey Kenfield, found that those patients who were smokers had a 61% increased risk of dying from the disease than non-smoking sufferers. In addition, the smokers had a similarly increased risk of cancer recurring.
The team also found that among patients diagnosed with cancer which had not yet spread, smokers had an 80% increased risk of dying.
But the death rates from prostate cancer for former smokers was the same as those for non-smokers after they had quit the habit for at least a decade.
Dr Kenfield said: “We found similar results for both prostate cancer recurrence and prostate cancer mortality.
“These data taken together provide further support that smoking may increase risk of prostate cancer progression.”