Second primary tumors and their risk factors in patients with primary head and neck tumors

Introduction and objective: The term second primary tumor (SPT) is used to designate a new primary cancer that occurs in a person previously diagnosed with cancer. SPT are considered to occur independently and not as a result of a resurgence or metastasis of the index tumor or first primary tumor (FPT). The aim of this study is to investigate the prevalence, risk factors, location and treatment of STP, as well as time elapsed between tumor occurrence. Method: A retrospective descriptive study was performed including patients diagnosed with SPT between January 2004 and December 2021 at Hospital Universitario de Fuenlabrada. The prevalence and location of SPT, related risk factors, time between the onset of FPT and SPT, treatment of FPT and SPT and their outcome were analyzed. Results: From a total of 360 cases, 73 patients were included in the study because of SPT. 75% were smokers and 46.6% were drinkers. Most of these patients were treated surgically. It was observed that the FPT with the highest development of SPT was the larynx, with supraglottis being the most frequent sublocalization. The most frequent SPT was epidermoid carcinoma of the lung. Conclusions: In our series SPT appear in 20% of head and neck tumors. They are more frequent after laryngeal cancer, the most frequent location being the lung. Both tobacco and alcohol play an important role in their development, shortening the time between the appearance of tumors, in addition to the possibility of recurrence, persistence and metastasis.