Second primary tumors in head and neck squamous cell carcinoma patients: A cross-sectional study.

Abstract

5588 Background: Head and neck squamous cell carcinoma (HNSCC) patients (pts) are at elevated risk of developing a second primary tumor (SPT). Here we aimed to study the frequency of SPTs and those characteristics related to an increased probability of SPT occurrence. Methods: It is a cross-sectional study in pts diagnosed with SCC primary located in oral cavity, oropharynx, hypopharynx or larynx, treated in two Brazilian institutions, with an index tumor diagnosed from Jan/2000 to Jan/2009. All pts were followed according the current recommendations, including clinical visits, imaging and endoscopic procedures. A SPT was defined following the Warren and Gates criteria (Am J Cancer 51:1358,1932), and they were classified as synchronous or metachronous if detected less or more than six months after the diagnosis of the index tumor, respectively. Results: 38 out of 318 HNSCC pts (12%) were diagnosed with 41 SPTs in their follow-up, being 12 synchronous (29%) and 29 metachronous (71%), all classified as SCC. Regarding the index tumor, it was primary located in oral cavity (114 pts, 36%), oropharynx (87 pts, 27%), larynx (83 pts, 26%) and hypopharynx (34 pts, 11%), and staged as I-II (30%) or III-IV (67%). The SPTs were located more frequently in oral cavity (27%), lungs (27%), oropharynx (15%) and esophagus (12%) and staged as I-II (44%) or III-IV (42%). Among the 29 metachronous SPTs, 12 (41%) were diagnosed in the first two years of follow-up, 11 (38%) between two and five years, and 6 (21%) after five years. Considering all the studied HNSCC pts and index tumor characteristics, including primary site, persistence of tabacco and alcohol habits, and treatment, none was identified as related to an increased probability of developing a SPT. In the median follow-up of 40 mo., the median overall survival was not reached in all 318 HNSCC pts. No difference in overall survival was observed between those pts diagnosed or not with a SPT (HR 0.35, p=0.555). Conclusions: We found a 12% incidence of SPTs in these HNSCC pts. At diagnosis, SPTs were located more frequently in oral cavity and lungs, in advanced stages, and may occur even after five years after the index tumor. More efficient primary and secondary preventive strategies of SPTs must be developed.