Epidemiology of post-transplant malignancy in Asian renal transplant recipients: a population-based study.

OBJECTIVE

Using Taiwan's National Health Insurance Research Database, this large population-based study was conducted to explore the incidences and risk factors of post-transplant malignancy in Asian renal transplant recipients.

PATIENTS AND METHODS

A total of 642 patients who firstly underwent renal transplant between January 1, 2000 and December 31, 2008 were identified from a 2 million cohort. The primary endpoint was a subsequent hospitalization with a primary diagnosis of malignancy (ICD-9-CM code: 140.xx-239.xx) after renal transplantation. All patients were followed until the occurrence of endpoints or the end of the study (December 31, 2010), whichever came first. Adjusted risks of post-transplant cancer were analyzed using Cox proportional hazards regression model. All models were adjusted for baseline characteristics, comorbid diseases, transplant year, and exposure to immunosuppressive agents.

RESULTS

Among 642 renal transplant patients, 54 cancers (8.4 %) were identified. The median time between transplant and cancer diagnosis was 46.2 (range 8.5-107.4) months. Cancers of kidney and other unspecified urinary organs was the most common cancer sites, accounted for 18.5 % of the malignancies diagnosed. The next most common cancer sites were trachea, bronchus, and lung (14.8 %), bladder (13.0 %), liver and intrahepatic bile ducts (11.1 %), colon (5.6 %), and prostate (5.6 %). Age at transplantation was a statistically significant risk factor of post-transplant cancer in our study. Increased risks of post-transplant cancer were observed in patients who received immunosuppression agents (cyclosporine (HR 1.26, 95 % CI 0.58-2.77, p = 0.5603), tacrolimus (HR 1.99, 95 % CI 0.66-6.00, p = 0.2197), and mycophenolate (HR 1.00, 95 % CI 0.40-2.45, p = 0.9874)) although the estimates were not statistically significant.

CONCLUSIONS

Our population-based cohort study offers additional insight into post-transplant cancers in Asian population. Further studies are warranted to assess the association between specific immunosuppression agents and post-transplant cancers.