Prostate Cancer Outcomes Following Solid-Organ Transplantation

A SEER-Medicare Analysis

Stanley L. Liauw; Sandra A. Ham; Lauren C. Das; Sonali Rudra; Vignesh T. Packiam; Matthew Koshy; Ralph R. Weichselbaum; Yolanda T. Becker; Adam S. Bodzin; Scott E. Eggener

Disclosures

J Natl Cancer Inst. 2020;112(8):847-854. 

In This Article

Abstract and Introduction

Abstract

Background: Immunosuppressive regimens associated with organ transplantation increase the risk of developing cancer. Transplant candidates and recipients with prostate cancer are often treated, even if low-risk features would ordinarily justify active surveillance.

Methods: Using SEER-Medicare, we identified 163 676 men aged 66 years and older diagnosed with nonmetastatic prostate cancer. History of solid organ transplant was identified using diagnosis or procedure codes. A propensity score-matched cohort was identified by matching transplanted men to nontransplanted controls by age, race, region, year, T-stage, grade, comorbidity, and cancer therapy. Fine-Gray competing risk models assessed associations between transplant status and prostate cancer-specific mortality (PCSM) and overall mortality (OM).

Results: We identified 620 men (0.4%) with transplant up to 10 years before (n = 320) or 5 years after (n = 300) prostate cancer diagnosis and matched them to 3100 men. At 10 years, OM was 55.7% and PCSM was 6.0% in the transplant cohort compared with 42.4% (P < .001) and 7.6% (P = .70) in the nontransplant cohort, respectively. Adjusted models showed no difference in PCSM for transplanted men (hazard ratio = 0.88, 95% confidence interval = 0.61 to 1.27, P = .70) or differences by prostate cancer therapy. Among 334 transplanted men with T1-2N0, well or moderately differentiated "low-risk" prostate cancer, PCSM was similar for treated and untreated men (hazard ratio = 0.92, 95% confidence interval = 0.47 to 1.81).

Conclusions: Among men aged 66 years and older with prostate cancer, an organ transplant is associated with higher OM but no observable difference in PCSM. These findings suggest men with prostate cancer and previous or future organ transplantation should be managed per usual standards of care, including consideration of active surveillance for low-risk cancer characteristics.

Introduction

Immunosuppression, whether acquired or iatrogenic, is associated with an increased risk of developing solid tumors.[1] Consequently, candidates for solid organ transplantation commonly undergo screening for certain cancers, and patients who are posttransplant may be subject to more rigorous screening, treatment, or posttreatment surveillance related to heightened concerns for cancer progression.[2] Prostate cancer, commonly diagnosed after prostate-specific antigen (PSA) screening, can therefore present a clinical challenge for patients who are pre-transplant or posttransplant, especially because of the wide heterogeneity in disease characteristics and risk of progression. Healthy patients with low-risk prostate cancer are ideal candidates for active surveillance, whereas those with high-risk cancers have a 20%–40% risk of cancer mortality at 15 years after local therapy.[3,4]

There are no widely accepted guidelines regarding prostate cancer screening or treatment in the transplant population, and practice patterns widely vary.[5] Most studies evaluating prostate cancer outcome following previous transplant include very small cohorts treated with a single modality of local therapy.[6–11] Larger population-based studies suggest immunosuppression does not increase the incidence of prostate cancer;[2,12–14] however, no population-based studies to our knowledge have assessed whether immunosuppression alters the likelihood of dying from prostate cancer. To obtain a large sample size with increased power, we studied men in the Surveillance, Epidemiology, and End Results (SEER)-Medicare population who had prostate cancer diagnosed before or after solid organ transplantation. Our hypothesis was that immunosuppression following transplantation would not adversely influence the rate of prostate cancer mortality compared with men without a history of transplantation. Our secondary aim was to compare outcomes by therapies for transplant and nontransplant patients.

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