Malignancy in renal transplant recipients at Charlotte Maxeke Johannesburg academic hospital: 1990-2010
Date
2016
Authors
Ziki, Joyce Tukayi
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Abstract
Introduction
Post transplant malignancy (PTM) is a recognized long term complication in renal transplant recipients. Many studies have been conducted on this group of patients over the last 50 years to assess the impact of various immunosuppressant drug regimens, geographical locations, ethnicity, and age at the time of transplant on the risk of developing a PTM. The incidence of PTM has been shown from these studies to vary from 3% to 11%. Many inconsistencies exist in these studies, but the one common finding is that the incidence of malignancy is increased in renal transplant recipients compared to the general population.
Aims and Objectives
The objectives of this study were to determine the incidence of PTM at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in the period from 1990 to 2010; to calculate the mean time to diagnosis of PTM; determine the association of PTM and immunosuppressive drug regimens and identify risk factors associated with developing a malignancy post renal transplant.
Methods
The study design was a retrospective review of the medical records of patients transplanted between 01/01/1990 and 31/12/2010 at CMJAH, South Africa. All recipients above 18years of age transplanted during this study period were included in the review. All recipients who rejected, died or were transferred to other centres within six months of transplantation were excluded. A total of 668 records were included in this study for analysis. Information retrieved from the files included patient demographics (age at transplantation; gender; ethnic group, year of transplantation), aetiology of end-stage renal disease, the source of graft, the number of times treated for rejection, oncogenic viruses diagnosed, immunosuppressant regimens and outcomes of the recipients. For those recipients who developed a malignancy,
the time from transplantation to diagnosis of cancer was calculated and the histological diagnoses documented.
Results
The incidence of PTM in this study was 7.0% (95% CI 5.2-9.4) for the era under review. The cumulative incidence of cancer from transplantation increased with follow-up time. The mean time to diagnosis of malignancy was: 3.4 years, 6.6 years, 7.4 years and 8.1 years for Kaposi Sarcoma (KS), post transplant lymphoproliferative disorder (PTLD), skin and solid organ malignancy, respectively. The distribution of post transplant malignancy (PTM) was skin cancers 44.7%; KS 23.4%; PTLD 14.9%; solid organ tumours 17.0 %. The recipients who developed cancer were significantly older at transplantation with a mean age of 42.9 years compared to those without PTM whose mean age was 36.3 years. Age and year of transplantation period 1996-2000 were independent risk factors for developing a malignancy in this cohort.
Discussion
There was no change in the incidence of PTM at CMJAH, occurring in 7% of the transplant recipients in the period of review (1990-2010) compared to 7.0% reported for the period 1966-1989, despite the change in the demographic patterns of the patients, immunosuppressive regimens and improved surveillance for cancers. No individual immunosuppressant drug appears to pose a risk for cancer significantly, instead, the prolonged general state of immune suppression in this group of patients seems to be the main risk factor of note. Recipients transplanted at an older age and those with long post renal transplantation follow-up should be closely monitored and routine surveillance for cancers done.
Description
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Medicine in the Department of Internal Medicine
Johannesburg, August 2016