Cancer Incidence After Kidney Transplantation in Saudi Arabia

Abstract

In the current era of renal transplantation the patient and graft survival are continuously improving. However there are some factors that are counterbalancing the effect of such success. One such factor is post renal transplant malignancies (PRTxM). The longer the patient survival is with functioning allograft, the higher is the risk of developing malignancy. In this present study we describe our experience of PRTxM among 2981 renal transplants performed in our centre. Material and Methods We performed retrospective analysis of prospectively collected data of 2981 renal transplant performed at King Faisal Specialist Hospital and Research Centre KSA between 1981 and 2016 with a median follow-up period of 153 months. We studied incidence and outcome of PRTxM among these patients. Statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS 21). Non-variables were analyzed using the T-Test, and variables were analyzed by means of the Fisher exact test and Chi square test. We also analyzed for relative risk ratio among different factors. Survival analysis was conducted using Kaplan-Meier survival graphs and log-rank testing was used where differences in survival were significant. In general, a P value of <0.05 was considered statistically significant for the purpose of our study. Results Overall there was 4.2% (n=125) incidence of post renal transplant malignancies recorded in our patients with equal distribution among pediatric and adult recipients [RR 1.0106; 95% CI 0.5927 to 1.7231; P = 0.96921. The median time from transplant to malignancy was 53 months. Non-cutaneous carcinomas (n=42) were the commonest malignancy followed by PTLD (n=33) [Table I]. The incidence of PTLD was higher in pediatric group as compared to adults [RR 3.4667; 95% CI 1.2050 to 2.4504; P <0.0001]. Likewise the incidence of non-cutaneous carcinoma was higher in adult as compared with pediatric population [RR 2.343; 95% CI 1.2204 to 2.042; P <0.0001]. The overall mortality was 7.45% during the median follow-up period of 153 months. Patients with malignancy had higher mortality rate of 29.24% as compared to 6.64% in non-malignancy group [P= <0.0001] [Figure I] Death with functioning graft (DWFG) was significantly more in malignant group [P=<0.0001]. Conclusion The overall rate of malignancy remain low(4.2%) when compared to the international rat, this is in spite of high rate of follow up. Viral driven cancer were more common when compared to national rates, however non cutaneous carcinoma were comparable to local standardized rate. Mortality was significantly higher with cancer development and PTLD was common among pediatric patients particularly EBV negative.