Evaluating Myelodysplastic Syndrome Risks in NET Patients Planned for Peptide Radionuclide Therapy

Radiopharmaceuticals is currently used for the treatment of metastatic cancer date. While radiopharmaceuticals are generally well tolerated, one of its most devastating long-term toxicities is the development of therapy related myeloid neoplasms (t-MN), an umbrella term for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). PRRT (Receptor Radionuclide Therapy) is a targeted radiopharmaceutical therapy (RPT) used to treat neuroendocrine tumors. RPTs use drugs to attack cancer cells while reducing harm to healthy tissue. PRRT delivers high doses of radiation to tumors in the body to destroy or slow their growth and reduce disease side effects.

While PRRT is generally well tolerated, one of its long-term side effects is the development of therapy related myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The identification of genetic changes that lead to the development of MDS and AML during PRRT is a growing area of research. It is now known that the genetic changes that lead to progression into AML typically occur through many years of pre-leukemic hematopoietic stem cell clonal evolution, before development of late mutations that lead to malignant disease. The short interval between exposure to PRRT and appearance of MDS and AML would suggest some patients are already at high risk of developing AML and are potentially detectable. The ability to identify individuals predisposed to developing MDS/AML could improve patient selection for PRRT and design strategies to mitigate the development of MDS/AML.

This research proposes to study the genetic changes that occur pre-PRRT and post-PRRT using blood samples obtained from a patient population at Princess Margaret Hospital. Cohort A will consist of 20 patients that have had PRRT within the past 4 years. Cohort B will consist of 20 patients planned for PRRT. Cohort C will consist of 1-5 patients post PRRT, diagnosed with t-MN.