Predictors of Secondary Lung Cancer Among Hodgkin Lymphoma Survivors: A Nationwide Analysis.

ABSTRACT

PURPOSE: There is insufficient data regarding the incidence rate of secondary lung cancer among Hodgkin lymphoma (HL) survivors and the predisposing factors. METHODS: We analyzed the data from the cohort of patients who had HL between 1973 and 2015 using the Surveillance Epidemiology and End Results database (SEER). Data on patient's age, gender, year of diagnosis with HL, Ann-Arbor stage, Histology, racial groups, date of last follow-up, date of death, and treatment modalities were collected. RESULTS: We identified a total of 56,856 patients with HL; of those, 862 had secondary lung cancer, with an incidence rate of 157 (95%CI 147-168) per 100,000 person-years. The median overall survival from time of HL diagnosis for those with secondary lung cancer was 12.1 years (95% CI 10.7-13) compared to 27.1 years (95% CI 26.5-27.6) for those who did not develop lung cancer (log-rank P-value of <.01). After propensity score weighting, radiation therapy was associated with a higher risk of secondary lung cancer (hazard ratio (HR) 1.23, 95% CI 1.002-1.55) with a P-value of 0.048. Older age at the time of HL diagnosis and male gender were associated with higher risk, with an HR of 1.07 (95% CI 1.062-1.073) and an HR of 1.602 (95% CI 1.33-1.94), respectively. Furthermore, chemotherapy increased the risk only among older age groups. CONCLUSION: Older age at the time of HL diagnosis, male gender, radiation therapy, and chemotherapy only among older age groups were associated with higher risk for secondary lung cancer, with 50% of the cases occurring within 9.1 years following HL diagnosis.