Second primary esophageal or lung cancer in patients with head and neck carcinoma in Taiwan: incidence and risk in relation to primary index tumor site

BackgroundSecond primary cancer is prevalent in patients with head and neck cancer (HNC), for which esophagus and lung are the most usual sites, associated with an extremely poor prognosis. However, information regarding the actual risk of second primary esophageal or lung cancer in South-east Asia, the betel-quid chewing area, has been restricted to data from single-institutions. We have therefore conducted a population-based study to evaluate the incidence, risk, and developmental time of second esophageal or lung cancer in HNC patients.