Whether kidney transplant recipients who were treated for a malignant tumor before transplantation are at an increased risk of developing a tumor posttransplantation has not been adequately quantified and characterized.
We studied more than 270 000 patients on whom pretransplant and posttransplant malignancy data were reported to the Collaborative Transplant Study. More than 4000 of these patients were treated for pretransplant malignancy. The posttransplant tumor incidence in these patients was compared to that in recipients without a pretransplant tumor. Cox regression, considering multiple confounders, was applied.
Significant increases in posttransplant tumor incidence with hazard ratio ranging from 2.10 to 5.47 (all P < 0.001) were observed for tumors in the site-specific pretransplant locations, suggesting tumor recurrences. There were also significantly increased de novo tumors in new locations with hazard ratio ranging from 1.28 to 1.89. Pretransplant basal cell carcinoma of the skin and male genital cancer were associated with significantly increased death-censored graft survival, suggesting impaired immune responsiveness against transplanted kidneys. Time interval from pretransplant tumor occurrence to transplantation and posttransplant mammalian target of rapamycin inhibitor treatment was not found to be of significant relevance in this study.
Patients who experienced a pretransplant tumor are at significant risk of tumor recurrence, regardless of the length of interval between tumor treatment and transplantation. There is also some increased risk for de novo tumors, suggesting impaired immune surveillance. Impaired tumor immunity appears to extend to a lower rate of transplant rejection because patients with pretransplant tumors tended to show improved death-censored graft survival.
1Institute of Immunology, Heidelberg University, Heidelberg, Germany.
Received 13 June 2018. Revision received 11 September 2018.
Accepted 12 September 2018.
The authors declare no funding or conflicts of interest.
C.U., G.O., and B.D. participated in research design, performance of the research, data analysis, and in the writing of the article. C.S. participated in research design and in the writing of the article.
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Correspondence: Christian Unterrainer, MS, Institute of Immunology, Heidelberg University Im Neuenheimer Feld 305 69120, Heidelberg, Germany. (firstname.lastname@example.org).