Objective: To evaluate the influence of persistent tobacco and alcohol use on the risk of a second metachronous neoplasm in the aerodigestive tract in head and neck squamous cell carcinoma (HNSCC) patients.
Methods: A matched case-control study was carried out in 514 patients with HNSCC. Case patients developed a second metachronous neoplasm in the aerodigestive tract after treatment of an index HNSCC. A patient free of second neoplasm was individually matched to every case patient by location of the index tumor, tumor stage, sex, previous tobacco and alcohol consumption, age, general health status, and treatment. Data about persistence in tobacco and alcohol consumption after treatment of the index tumor was collected retrospectively. A validation study was carried out to confirm the adequacy of this retrospective information.
Results: Persistent tobacco smoking and alcohol drinking after treatment of a HNSCC contributed to the risk of appearance of second neoplasm. The odds ratio of a second neoplasm for patients who continued to smoke was 2.9 (95% CI OR 1.8-4.1), and for patients who continued to use alcohol it was 5.2 (95% CI OR 3.3-7.9). There was a strong association between persistence of tobacco and alcohol use after treatment of the HNSCC index tumor. According to the attributable risk estimation, persistent tobacco and alcohol consumption would be responsible for one-third of the second neoplasms in the patients with a HNSCC index tumor.
Conclusions: Persistence of tobacco and alcohol use after treatment of a HNSCC had a significant influence on the appearance of a second neoplasm in the aerodigestive tract. Cessation of tobacco and alcohol use should be a major goal after treatment of a HNSCC.