Mycophenolic acid and cancer risk in solid organ transplant recipients: Systematic review and meta-analysis

AIM Mycophenolic acid (MPA) is an immunosuppressive drug commonly used for prophylaxis of graft rejection in solid organ transplant recipients. The main concern with the prolonged use of immunosuppressive drugs is the risk of developing cancer. However, it remains unclear whether the immunosuppressive regimens containing MPA confer an increased degree of cancer risk. The present study aimed to determine the association between MPA exposure and the incidence of cancer in solid organ transplant recipients. METHODS A systematic search was performed on the PubMed, EMBASE and Cochrane Library databases. Relevant articles that had findings on the incidence (or event) of cancer in cohorts with and without MPA exposure were retrieved for data extraction. A meta-analysis was conducted by means of the random-effects model, and the relative risk (RR) and its 95% confidence interval (95% CI) were used as a summary effect measure. RESULTS A total of 39 studies were eligible for inclusion, with 32 studies that enabled meta-analysis. MPA exposure was significantly associated with a lower risk of cancer when compared to azathioprine exposure (RR = 0.66, 95% CI = 0.53-0.81, P < .001) or no exposure to any additional treatments (RR = 0.85, 95% CI = 0.73-0.99, P = .04). There was no significant difference in cancer risk for the comparison between MPA exposure and mammalian target of rapamycin (mTOR) inhibitor exposure (RR = 1.54, 95% CI = 0.96-2.46, P = .07). CONCLUSIONS MPA exposure was not associated with an increased risk of cancer and may even be associated with a lower risk of cancer when compared to azathioprine or no treatment.