Second Cancer Incidence, Risk Factor, and Specific Mortality in Head and Neck Squamous Cell Carcinoma

ObjectiveSecond primary malignancies (SPMs) are common in patients with head and neck squamous cell carcinoma (HNSCC) and have a negative impact on their survival. This study aimed to evaluate risk factors for SPM occurrence and cause-specific mortality in Asian HNSCC patients.Study DesignA retrospective cohort study.SettingUniversity teaching hospital.SubjectsNine hundred and thirty-seven patients without previous cancer history who were treated between 2000 and 2009 and followed for at least 2 years.MethodsConfirmation of SPMs was performed by histopathology. The cumulative probability of a SPM among survivors of index HNSCC was calculated using a competing risk model. Univariate and multivariate analyses were utilized to determine factors predictive of SPM occurrence and cause-specific mortality.ResultsOf 937 patients, cumulative incidence of SPMs was 7.2% at 0 to 6 months (synchronous), 17.9% at 5 years, and 23.1% at 10 years after index tumor diagnosis. In multivariate analyses, old age (>60 years) (...