Optimize surveillance of post-kidney transplantation cancer in national healthcare system: age-dependent and tumor-dependent
Po- Chi Liao, Kevin Lu, Kun-Yuan Chiu*
Division of Urology, Department of Surgery, Taichung Veterans General Hospital*
Malignancy after kidney transplantation(KT) is an important factor affect quality of life and overall survival. Viral related tumors appeared more frequent, however, urological malignancy is also crucial in post-KT malignancy. The incidence of malignancy after transplantation increased with duration of follow-up. How to optimize post-transplantation cancer screening is of importance to improve long-term patient outcome. We investigated time trend and occurrence pattern of post-KT malignancy and tried to develop optimal post-transplantation surveillance strategies.
Materials and Methods:
We conducted a nation-wide retrospective population-based cohort study by extracting Taiwan’s national health insurance research data base(NHIRD). Random sample of 1,000,000 subjects were selected and patients underwent renal transplantation from 2000 to 2006 were collected. A 1:2 (KT
group: Non-KT group)patient number propensity score matching comparison were performed for incidence and survival outcome of de novo malignancy.
In total, 9105 patients were enrolled into this study with long-term follow-up. No significant difference between two groups in terms of age, sex and Charlson Comorbidity index(CCI). The incidence of malignancy was higher in KT group than that in non-KT group (Hazard ration(HR)=2.33, 95% Confidence interval(CI):2.04-2.66, p<0.001). The top 3 post-KT malignancy by organ system were, genitourinary(GU) organ(57.5%), digestive organs (21.4%) and bone, connective tissue skin and breast(6.3%). Overall survival and malignancy-free survival are significant lower in KT group than in the general population(p<0.001). With respect to GU malignancy, bladder cancer was diagnosed. Temporal trends unveiled biphasic patterns of urotract malignancy occurrence, especially peak at 2 years and then increasing gradually 8 years after KT.
De novo GU malignancy is the most prevalent in post KT population in Taiwan. Temporal and spatial trends show biphasic patterns of GU malignancy development at post KT 2 and then 8 years later. Due to higher malignancy mortality rate in KT patients, intensive surveillance protocol for cancer, especially urotract malignancy should be established to improve long-term outcome of these patient populations.