Cleveland Clinic Cancer Center (Taussig) Outcomes
Leukemia & Myeloid Disorders
Is There an Increased Risk in ALL Patients with First Cancers Treated with Radiotherapy and/or Chemotherapy?
External-beam radiotherapy (RT) and chemotherapy (CT) are commonly used modalities in cancer therapy and have been associated with increased risk of second hematological malignancies, especially myeloid neoplasms. Acute lymphoblastic leukemia (ALL) is typically not considered a treatment-related complication and the risk of ALL in patients treated with chemotherapy and radiation for other cancers is poorly defined. This study interrogated the U.S. Surveillance Epidemiology and End Results (SEER) registry to analyze the risks of ALL in cancer patients treated with RT, CT, or combined modality regimens at the population level.
Standardized Incidence Ratios Based on Radiotherapy (N = 4,851,222)
Standardized Incidence Ratios Based on Chemotherapy (N = 4,851,222)
Standardized Incidence Ratios Based on Chemo and Radiotherapy (N = 4,851,222)
Relative Risks Ratios Compared to Patients Receiving No Cytotoxic Therapy (N = 4,851,222)
Among patients treated for a first cancer, receipt of RT and/or CT was associated with higher relative risks and hazards for developing ALL than those not receiving cytotoxic modalities. Patients with hematologic first cancers (myeloid lineage or plasma cell dyscrasias) had the highest hazards of developing ALL as second cancer. When considering the risk kinetics and subgroup analyses in patients with solid first cancers, RT only or RT + CT, but not CT only, associate with increased risks for ALL. Differentially elevated risks of ALL observed in cancer cohorts based on the treatment modality that was received for a prior cancer suggests a possible biological mechanism that needs to be explored further.