Cancer risk for kidney transplant recipients not affected by drug choice

Kidney transplant recipients are known to have a higher risk of cancer, compared to the general population, due to the need to take immunosuppressive drugs to prevent organ rejection. Results published from a significant, long-term study suggest that no single medication appears to increase this cancer risk.

Evaluating data from 1983 in a randomised trial, researchers were able review trends among 481 patients over 20 years – providing the strongest evidence to date on the issue. A total of 226 patients in the trial developed at least one cancer. By 20 years post transplant, 27% of patients developed non-skin cancer and 48% of patients developed skin cancer – no one treatment had a greater effect on cancer risk.

"We found that no particular immunosuppressive drug regimen appears to increase the risk of cancer among kidney transplant patients," said lead author Dr Martin Gallagher, the George Institute.

"What we did find is that the cancer risk is driven by many factors that are known at the time of transplantation such as age and smoking history, so that patients at especially high risk can be targeted at this time," he added.

The results, which were published in the Journal of the American Society of Nephrology, reported that non-skin cancer was associated with increasing age and smoking history; skin cancer was associated with increasing age, non-brown eye color, fairer skin, and a functioning transplant. Therefore, patients at especially high risk can be monitored more closely and use preventive measures to protect against cancer.

"Much debate has focused on the effects of various agents and dose regimens, but our analysis would suggest that cancer risk is driven by total immune suppression rather than specific medications."

More than 11,000 Australians have received a kidney transplant in the last forty years. Kidney transplant survival rates are about 90% in the first year and over 75% in five years, which mean that most kidney recipients can look forward to many years of productive life. However, it is known that patients with a kidney transplant have a 2.5–3 times higher risk of cancer than the general population.

(Source: The George Institute: Journal of the American Society of Nephrology: May 2010)