Second primary malignancy of the aerodigestive tract in patients treated for cancer of the oral cavity and larynx.

BACKGROUND We aimed to identify patterns and predictors of second primary malignancy (SPM) of the aerodigestive tract (SPMADT) in patients with squamous cell carcinoma of the oral cavity (SCCOC) and larynx (SCCL). METHODS One thousand two hundred fifty-seven patients from two existing databases were studied: 595 with SCCOC (1986-1995) and 662 with SCCL (1984-1998). The primary endpoint of interest was development of SPMADT, defined as a second primary neoplasm of the head and neck, esophagus, or lung. RESULTS The 5-year SPMADT rate was 8% in the SCCL versus 10% in the SCCOC subgroup. Lung SPM was more common in the SCCL group; head and neck SPM was more common in the SCCOC group. Smokers had a fivefold increased risk, whereas alcohol use was associated with a twofold increased risk of SPMADT. CONCLUSIONS The rates of SPMADT after treatment of SCCOC and SCCL are comparable, but the patterns are different. Smoking and alcohol use are independent predictors of SPMADT development.