SECONDARY LUNG CANCER AMONG SURVIVORS OF ADOLESCENT AND YOUNG ADULT CANCER: A POPULATION-BASED STUDY.

Abstract

Background: Survivors of adolescent and young adult cancer (AYA, age 15 to 39 years at diagnosis) are at increased risk for second malignant neoplasms (SMNs) of which lung cancer is the most lethal. Factors contributing to lung SMN development and outcomes are not well-characterized.

Methods: Survivors of AYA cancer diagnosed between 1998 and 2020 were identified in the California Cancer Registry (n=251,632). Pearson's chi-square and Fisher's exact tests were used to determine associations between sociodemographic and cancer characteristics with SMN status. Multivariable Cox proportional hazard regression, adjusting for age, time from primary diagnosis, race/ethnicity, insurance, primary cancer site, stage, and treatment, evaluated associations between these characteristics and lung SMN incidence and mortality.

Results: A total of 675 (0.7%) survivors were diagnosed with lung SMN, of whom 487 (72.1%) died. Median time from primary diagnosis to lung SMN was 13.0 years (IQR 4.0-20.0 years). Nearly half (46.5%) of survivors with lung SMN had metastatic disease. Non-Hispanic Black survivors were more likely than non-Hispanic White survivors to develop lung SMN (adjusted hazard ratio [aHR] 1.47, 95% confidence interval [95%CI] 1.13-1.91) but not more likely to die from lung SMN (aHR 0.84, 95%CI 0.56, 1.27). Primary cancer treatment with both chemotherapy and radiation was associated with greater likelihood of lung SMN (aHR 1.41, 95%CI 1.11-1.80) compared to receiving neither.

Conclusions: Lung SMN has a long latency and high mortality among survivors of AYA cancer.

Impact: More research is needed regarding lung cancer prevention, education, and early detection, particularly among survivors at higher risk.