Multiple Primary Malignancies in Head and Neck Cancer: A University Hospital Experience Over a Five-Year Period

Introduction With an estimated incidence of 2%-4% per year, the development of a second primary malignancy (SPM) in patients with head and neck tumors (HNTs) is not a rare event. The present study aimed to (i) assess the frequency of SPMs in patients with HNTs treated in a university hospital over a five-year period and (ii) provide a demographic characterization of these patients. Methods Retrospective single-centre study of patients with more than one primary tumor (including at least one HNT) diagnosed between January 1, 2015, and December 31, 2019. Data were retrieved from patients' clinical records and anonymized for analysis purposes. Results A total of 53 out of 824 (6.43%) patients with multiple primary malignancies were identified, 18 of which synchronous and 35 metachronous. The median follow-up was 25 months. Thirteen patients were diagnosed with more than one HNT. Forty patients were diagnosed with at least one HNT and one non-HNT. The most frequently diagnosed non-HNT SPMs were lung cancer (n=17) and esophageal cancer (n=8). The five-year survival rate was 53% for patients with multiple HNSCCs and 47% for patients with at least one non-HNT (log-rank p=0.729). The median overall survival was 14 months for synchronous and 58 months for metachronous SPMs (log-rank p=0.002). Conclusion Findings from this study highlight the importance of long-term follow-up of HNT patients for early detection of SPMs, increasing the chance of providing treatment with curative intent and improving patient outcomes and survival.