Profile and survival outcomes among patients with second malignancies following a primary chronic myeloid leukemia: An analysis of the SEER database (1975-2016).

Abstract

e19060 Background: A major concern of cancer survivors is the occurrence of a subsequent cancer. A small proportion of patients with CML develop second cancers. Little is known about these patients. In the present study, we determined the profile and determinants of survival among patients with a primary CML who developed subsequent malignancies. Methods: We utilized the SEER 18 Registry 1975-2016 to conduct a retrospective analysis of patients who developed a subsequent malignancy following a primary CML diagnosis. The outcome of interest was the latency interval between the initial primary CML diagnosis and a subsequent malignancy. Utilizing the cox regression model, we determined the factors associated with the overall survival after controlling for disease stage, treatment modalities, and social determinants of health. Results: There were 2, 312 CML Patients who developed a subsequent malignancy in the study period. Among these patients, 76.3% were non-Hispanic Whites, 9.6% were non-Hispanic Blacks, and 8.7% were Hispanics. 63.0% of the study population were males. The mean age at primary diagnosis of CML was 63.2 ± 15.6 yrs. While the mean age at diagnosis of the subsequent malignancy was 66.9 ± 14.5 yrs. The commonest subsequent malignancies were Acute Myeloid Leukemia (12.9%), Prostate cancers (12.7%), Lung and Bronchi cancers (11.5%), and Breast cancers (5.9%). The mean latency interval for developing a subsequent malignancy following a CML was 3.7± 4.4 years. Significant predictors of reduced survival include increasing age (HR = 1.02; 95% CI 1.01-1.03), Latency interval < 5years (HR = 0.32; 95% CI 0.17-0.60) and Hispanic ethnicity (HR = 1.78; 95% CI 1.09-2.92). Conclusions: Common second malignancies following a primary diagnosis of CML include prostate cancers, lung and bronchi cancers, and breast malignancies. Major predictors of adverse outcomes include advanced age, development of second cancers within 5 years of primary CML diagnosis, and Hispanic ethnicity.