Incidence of Multiple Primary Cancers. III. Cancers of the Respiratory and Upper Digestive System as Multiple Primary Cancers<xref ref-type="fn" rid="FN2">2</xref>

Abstract

During 23,802 patient-years of observation, 518 cancers of other sites developed in 9,415 patients with prior squamous cell cancers of the respiratory or upper digestive tract or other cell types of lung carcinoma. Only patients with index cancers of the nasal cavity, paranasal sinuses, and nasopharynx did not develop excess cancers. Of the excess cancers, 73% occurred in other upper digestive or respiratory sites, 20% in the skin, and 7% in other organs or tissues. Lip cancer patients were at greatest risk of developing skin and intraoral cancers. The increases in relative risk for esophageal cancer were greater in patients with lingual, palatine, or pharyngeal carcinomas than in those with other types of intraoral cancer.