Having psoriasis is associated with an increased risk of cancer, a new review of studies concludes.
Researchers, writing in JAMA Dermatology, combined data from 58 studies and found that, over all, compared with people without the condition, psoriasis of any degree of severity was associated with an 18 percent increased risk for cancer, and severe psoriasis with a 22 percent increase. Cancer mortality was elevated in all cases of severe psoriasis.
For some specific types of cancer, the risk was even higher. For example, they found that severe psoriasis was associated with more than 11 times the risk for squamous cell carcinoma (a skin cancer), about double the risk for esophageal and liver cancer, and a 45 percent increased risk for pancreatic cancer.
Any degree of psoriasis, severe or not, was significantly associated with colorectal cancer, non-Hodgkin’s lymphoma, and cancers of the kidney and pancreas, among others.
The reason for the connection is unclear, but there is a known link between chronic inflammation and cancer, and this may help explain the association.
Alex M. Trafford of the University of Manchester, the lead author, said people with psoriasis tend to smoke more, weigh more and drink more alcohol, factors not accounted for in all of the studies.
“Carrying on a healthy lifestyle,” he said, “could potentially make a big difference in this risk.”