Prostate cancer (PCa) patients are at increased risk for secondary primary malignancies compared with the general population, a study found.
In a study of 20,558 PCa patients in Zurich, Switzerland, 1,718 developed a second primary tumor after their PCa diagnosis, mostly frequently lung and colon cancer (15% and 13%, respectively).
Overall, the likelihood for a secondary primary cancer was 1.11 times greater in PCa patients compared with the general population of men, Mieke Van Hemelrijck, MD, of King’s College London in the U.K., and colleagues reported online in PLoS One (2014;9:e102596). PCa patients were twice as likely as men in the general population to develop kidney and bladder cancer. They also were 2.9 times and 1.7 times more likely to develop primary thyroid and colon cancer, respectively.
The investigators stratified PCa patients by treatment. Men who underwent surgery were 3.6 times more likely develop primary thyroid cancer compared with the male general population. Those who underwent radiotherapy had a 3-fold increased risk of liver. Men treated with androgen deprivation therapy had a 3.1 times and 2.5 times increased likelihood of kidney and bladder cancer, respectively.
“Increased diagnostic activity aftrer PCa diagnosis may partly explain increased risks within the first years of diagnosis, but time-stratified analyses indicated that increased risks remained and even increased over time,” the authors concluded.