Solid-organ Transplant Does Not Worsen Prostate-cancer Outcomes

By WIll Boggs MD

December 26, 2019

NEW YORK (Reuters Health) - Solid-organ transplantation is not associated with worse prostate-cancer mortality, though it is associated with increased overall mortality, according to a database analysis.

"Our study findings have important implications on decision-making in the transplant candidate," Dr. Stanley Liauw of the University of Chicago told Reuters Health by email. "Some transplant teams might have a strict rule in place requiring no detectable cancer over an established time period. This study challenges that conventional wisdom and suggests that surveillance of any newly diagnosed, low-risk prostate cancer does not appear to compromise cancer mortality."

Population-based studies suggest that immunosuppression like that often used after solid-organ transplantation does not increase the incidence of prostate cancer, but no studies have assessed whether immunosuppression alters the likelihood of dying from the malignancy.

For their study, published in the Journal of the National Cancer Institute, Dr. Liauw and colleagues used data from Surveillance, Epidemiology and End Results (SEER) and Medicare.

They included 620 transplanted men matched to 3,100 nontransplanted men (mean age, 73.3 years). The transplant group was nearly evenly divided among those who had transplants before and after a prostate-cancer diagnosis, respectively.

Among the transplanted men, 55.6% died overall (6.0% of prostate cancer and 49.7% of other causes), with no significant difference in prostate-cancer-specific mortality between transplanted (6.0%) and nontransplanted (7.6%) men.

Ten-year overall mortality was significantly higher in transplanted men (55.7%) than in nontransplanted men (42.4%), however.

In propensity-score-matched analyses, transplanted men had the same risk of dying from prostate cancer as non-transplanted men, but they had an 83% higher risk of dying from other causes and a 65% higher risk of dying overall (both P<0.001).

The risk of overall mortality for transplanted men was elevated for those who had local therapy or no therapy but not for those who had primary hormonal therapy.

Results were similar in an analysis of the 334 men with low-risk features of prostate cancer.

Among transplanted men, survival outcomes did not differ between those transplanted before and those transplanted after their prostate-cancer diagnosis.

"Patients who are candidates for a transplant, but have a low-risk prostate cancer as a result of mandated (prostate-specific antigen) screening, might, therefore, be appropriately managed without immediate treatment of the prostate cancer," Dr. Liauw said. "These patients had about a 3% risk of prostate-cancer mortality at 10-years, regardless of their initial management strategy."

"In the post-transplant patient diagnosed with prostate cancer, our findings suggest that clinicians can offer prostate-cancer therapy consistent with a typical risk/benefit discussion, without a concern for higher rates of mortality due to transplant immunosuppression," he said. "However, men with transplant did have shorter overall survival due to death from other causes, so the impact of transplant on life expectancy should be considered."

"Although this study may be among the largest studies analyzing prostate-cancer outcomes in men with transplant history, methods used to control for differences in cohorts are still subject to unmeasured confounding," he cautioned. "Any clinical decisions regarding prostate-cancer management should be conducted in a multidisciplinary oncology and transplant setting, considering these data in the appropriate clinical context."

SOURCE: Journal of the National Cancer Institute, online November 15, 2019.