A study published in June 2011 by researchers at the Harvard School of Public Health and University of California, USA examined 5,366 men diagnosed with prostate cancer over two decades and found that those who smoked faced a 61% higher risk of cancer recurrence and death.

http://www.france24.com/en/20110621-smokers-face-higher-prostate-cancer-death-risk
http://www.medicalnewstoday.com/articles/229303.php