The previously common post-kidney transplant Kaposi sarcoma has become non-existent for a decade: an Egyptian experience

Background De novo malignancy is a worrying complication after kidney transplantation; the type of which may vary due to factors such as the prevalence of viral infection and race. Kaposi sarcoma used to be the most common malignancy among our patients constituting more than one-third of cancers. Nevertheless, we noticed that Kaposi sarcoma has not been observed for a long period. Therefore, we conducted this study to explore such observation. Methods Data of all kidney transplant recipients were retrieved and retrospectively analyzed. Their total number was 3126 patients. Their mean age was 28.71 ± 10.97 years and of them, 823 (26.3%) were females. The pattern of Kaposi sarcoma throughout the last decade as well as the preceding three decades was studied. The possible relation between the disappearance of Kaposi sarcoma and three paradigm shifts in our practice, namely the use of mTOR inhibitors, steroid-free regimen and CMV prophylaxis was explored. Results Since 2010, no new cases of Kaposi sarcoma have been observed. In addition, patients who have been transplanted after 2006 did not develop such malignancy. Patients who received CMV prophylaxis and/or were maintained on mTOR inhibitor or steroid-free regimens have not developed Kaposi sarcoma. Moreover, CMV prophylaxis had a statistically significant difference when compared to a homogenous group without CMV prophylaxis. However, Kaplan–Meier analysis of patients of the three policies and their counterpart groups showed comparable results. Conclusion Kaposi sarcoma, which was previously the most common malignancy, is no longer observed for almost a decade among our kidney transplant recipients. m-TOR inhibitors, steroid-free regimen and CMV prophylaxis policy are possible contributing factors. Nevertheless, only CMV prophylaxis policy had a statistically significant relation to the disappearance of Kaposi sarcoma.