Mammalian target of rapamycin inhibition after solid organ transplantation: can it, and does it, reduce cancer risk?

Area of Science:

• Immunology
• Oncology
• Pharmacology

Background:

• Mammalian target of rapamycin (mTOR) inhibitors (sirolimus, everolimus) are established immunosuppressants for organ transplant recipients.
• These mTOR inhibitors possess antiproliferative properties, suggesting potential chemopreventive capabilities.
• The use of mTOR inhibitors may be particularly relevant for transplant recipients with pre-existing malignancies, such as hepatocellular carcinoma or cholangiocarcinoma.

Purpose of the Study:

• To review the role of mTOR pathway biochemistry in chemoprevention.
• To explore the potential clinical application of mTOR inhibitors in preventing post-transplant malignancies.
• To identify selected patient populations who may benefit from mTOR inhibitor-based immunosuppression for malignancy prevention.

Main Methods:

• Literature review focusing on mTOR pathway biochemistry.
• Analysis of studies on mTOR inhibitors' antiproliferative effects.
• Examination of clinical data regarding malignancy incidence in transplant recipients on mTOR inhibitors.

Main Results:

• The mTOR pathway's antiproliferative mechanisms are central to its chemopreventive potential.
• mTOR inhibitors demonstrate efficacy in preclinical and clinical settings for cancer prevention.
• Evidence suggests a possible role in preventing de novo or recurrent malignancies post-transplantation.

Conclusions:

• mTOR inhibitors offer a unique chemopreventive strategy in organ transplantation.
• Their clinical use may be beneficial for selected patients, especially those with a history of cancer.
• Further research is warranted to optimize mTOR inhibitor-based immunosuppression for malignancy prevention in transplant recipients.