Smoking 'raises cancer return risk'
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 7,191 American and Austrian patients who had their prostate glands removed between 2000 and 2011.
Over a period of around 28 months, current smokers had an 80% increased likelihood of cancer returning after surgery than those who had never smoked.
Former smokers were 63% more at risk, but after 10 years free of tobacco their chances of having a cancer recurrence fell to the same level as those who had never smoked.
Lead scientist Professor Shahrokh Shariat, from the University Clinic of Urology at MedUni, Vienna, said: "Our study findings underline the importance of informing a prostate cancer patient about the negative effects of smoking.
"It is never too late to quit smoking. On the contrary, as our study shows, it makes sense to quit, even if you are already suffering from prostate cancer."
Patients whose cancer was known to have spread at the time of diagnosis were excluded from the study. None of the participants had received pre-operative radiotherapy, hormonal therapy or chemotherapy.
The jury is still out on links between smoking and prostate cancer. Some older studies have associated the habit with development of the disease while more recent research has indicated no connection.
"Many questions about prostate cancer and smoking are still unanswered," said Prof Shariat. "Further studies are therefore required to produce satisfactory answers."
Each year around 41,000 men in the UK are diagnosed with prostate cancer and around 11,000 die from the disease.