Everolimus and malignancy after solid organ transplantation: A clinical update

Malignancy after solid organ remains a major cause of post-transplant mortality. The mammalian target of rapamycin (mTOR) inhibitor class of immunosppressants exerts various anti-oncogenic effects, and the mTOR inhibitor everolimus is licensed for the treatment of several solid cancers. In kidney transplantation, evidence from registry studies indicates a lower rate of de novo malignancy under mTOR inhibition, with some potentially supportive data from randomized trials of everolimus. Case reports and small single-center series have suggested that switch to everolimus may be beneficial following diagnosis of post-transplant malignancy, particularly for Kaposi's sarcoma and non-melanoma skin cancer, but prospective studies are lacking. A systematic review has shown mTOR inhibition to be associated with a significantly lower rate of hepatocellular carcinoma (HCC) recurrence versus standard calcineurin inhibitor therapy. One meta-analysis has concluded that patients with non-transplant HCC experience a low but significant survival benefit under everolimus monotherapy, so far unconfirmed in a transplant population. Data are limited in heart transplantation, although observational data and case reports have indicated that introduction of everolimus is helpful in reducing the recurrence of skin cancers. Overall, it can be concluded that in certain settings, everolimus appears a promising option to lessen the toll of post-transplant malignancy