The Incidence, Risk, and Overall Survival of First and Second Primary Head and Neck Malignancies in the Eastern Province, Saudi Arabia

Abstract

Abstract Background: The mean survival time of head and neck cancers (HNC) differs according to patient and tumor characteristics. Treatment with radiotherapy or chemotherapy, genetic susceptibility, and environmental factors can contribute to the risk of developing second primary malignancy (SPM). Objective: Our purpose is to determine the rate of first primary malignancy and SPM among HNC patients, identify risk factors that may lead to the development of SPM, and analyze predictors of overall survival. Subjects and Methods: This is a single-center, retrospective study that included patients who were diagnosed with a head and neck and nonhead and neck SPM and visited the head and neck clinic between 2010 and 2020. Patients diagnosed with thyroid cancer or head and neck lymphoma, treated outside the facility, or lost to follow-up were excluded from the study. Data about demographics, diagnosis-related information, therapeutic approach, tumor recurrence, and the status of the patient and the tumor after the latest hospital visit were collected. Results: Thirty-seven (6.13%) cases were diagnosed with SPM with a median age of 61 years and a median time to diagnosis of 30.1 months from the first malignancy. Nearly half of the SPM patients were males (54.05%), smokers (51.35%), and underwent radiotherapy to treat the first cancer (51.35%). Laryngeal cancer carries the highest risk of the development of SPM of all SPM cases, followed by oral cavity cancers. The overall survival in patients with metachronous SPM is better than synchronous malignancies, with a median survival time of 149 months. Conclusion: The development of an SPM in patients with HNC is associated with decreased overall survival. Male gender, hypertension, and primary cancer site were significant risk factors for SPM.