Treatment Modality and Second Primary Tumors of the Head and Neck

Introduction: Second primary tumors (SPTs) in head and neck cancer are thought to occur from premalignant lesions that are present at the time of the primary tumor diagnosis. The association of the modality used to treat the primary lesion with SPT occurrence is not clear. Objective: The aim of the study was to assess the incidence of SPTs in patients with head and neck malignancies, according to treatment modality. Methods: We conducted a retrospective cohort study. All patients who were treated at Soroka Medical Center between 2000 and 2013 for a head and neck squamous cell carcinoma were assessed. Data analysis included tumor site of the primary and second primary and treatment modality of the primary tumor. In addition, demographics as well as habits were recorded as well. Results: Of the 184 patients included in the cohort, SPT developed in 31 patients (17%) with a median time to diagnosis of 4.3 years. Smoking was reported in 74% of those with SPT and 78% of those without. The most common site for SPT was the lungs, with 13 cases, 42% of the total SPTs. Among patients who developed an SPT, for 12 of those with an index tumor in the oral cavity or oro-hypopharynx, 8 (67%) developed an SPT in the same location; for 18 of those with an index tumor in the larynx, 11 (61%) developed a SPT in the lungs and bronchi (p = 0.001). On multivariate analysis, the treatment modality used was not found to be associated with the occurrence of SPTs and the radiotherapy showed no protective or harmful effect (HR 0.64 p = 0.24). Conclusion: Treatment modality used for head and neck cancer does not seem to be associated with the occurrence of SPTs.