Chemotherapy for solid tumors is associated with an increased risk of therapy-related myelodysplastic syndromes or acute myeloid leukemia (tMDS/AML), according to a retrospective analysis.
Long-term, population-based cohort data showed the risk of tMDS/AML was significantly elevated after chemotherapy for 22 solid tumor types.
The relative risk of tMDS/AML was 1.5- to 39.0-fold greater among patients treated for these tumors than among the general population.
Lindsay M. Morton, PhD, of the National Institutes of Health in Rockville, Maryland, and her colleagues reported these findings in JAMA Oncology.
“We undertook an investigation to quantify tMDS/AML risks after chemotherapy for solid tumors in the modern treatment era, 2000-2014, using United States cancer registry data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program,” the investigators wrote.
They retrospectively analyzed data from 1619 patients with tMDS/AML who were diagnosed with an initial primary solid tumor from 2000 to 2013.
Patients were given initial chemotherapy and lived for at least 1 year after treatment. Subsequently, Dr. Morton and her colleagues linked patient database records with Medicare insurance claim information to confirm the accuracy of chemotherapy data.
“Because registry data do not include treatment details, we used an alternative database to provide descriptive information on population-based patterns of chemotherapeutic drug use,” the investigators noted.
The team found the risk of developing tMDS/AML was significantly increased following chemotherapy administration for 22 of 23 solid tumor types, excluding colon cancer.
The standardized incidence ratio (SIR) for tMDS/AML ranged from 1.5 to 39.0, and the excess absolute risk (EAR) ranged from 1.4 to 23.6 cases per 10,000 person-years.
SIRs were greatest in patients who received chemotherapy for malignancy of the bone (SIR=39.0, EAR=23.6), testis (SIR, 12.3, EAR=4.4), soft tissue (SIR=10.4, EAR=12.6), fallopian tube (SIR=8.7, EAR=16.0), small cell lung (SIR=8.1, EAR=19.9), peritoneum (SIR=7.5, EAR=15.8), brain or central nervous system (SIR=7.2, EAR=6.0), and ovary (SIR=5.8, EAR=8.2).
The investigators also found that patients who were given chemotherapy at a young age had the highest risk of developing tMDS/AML.
“For patients treated with chemotherapy at the present time, approximately three-quarters of tMDS/AML cases expected to occur within the next 5 years will be attributable to chemotherapy,” the investigators said.
They acknowledged a key limitation of this study was the limited data on patient-specific chemotherapy and dosing information. Given these limitations, Dr. Morton and her colleagues said, “the exact magnitude of our risk estimates, including the proportions of excess cases, should therefore be interpreted cautiously.”
This study was supported by the Intramural Research Program of the National Institutes of Health, National Cancer Institute, and the California Department of Public Health. The authors reported no conflicts of interest.