title: Second respiratory and upper digestive tract cancers after oral cancer.
abstract: Between 1958 and 1975, 377 patients with squamous cell carcinoma of the floor of the mouth were treated. 123 new cancers (not recurrences) developed in 101 (27%) of these patients after treatment. 82 (67%) were squamous cell carcinomas of the respiratory and upper digestive tracts, one-third of these being in the mouth. These tumors developed at a constant rate of 3.6% per year and led to excess mortality of 5.2% per year. Men with oral cancer have a relative risk of 13.4 for new tumours in the upper respiratory and upper digestive tracts compared with the general population; in females the relative risk for all sites is 82.6. All patients with mouth cancer should thus be examined regularly because of this high risk of new cancers.
mesh_terms: D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000150:complications; D002294:Carcinoma, Squamous Cell / Q000150:complications*; D004938:Esophageal Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000453:epidemiology; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000150:complications*; D009378:Neoplasms, Multiple Primary / Q000453:epidemiology*; D010610:Pharyngeal Neoplasms / Q000453:epidemiology; D012142:Respiratory Tract Neoplasms / Q000453:epidemiology*; D012189:Retrospective Studies; D012306:Risk; D012737:Sex Factors; D014029:Tobacco Use Disorder / Q000150:complications; D014067:Tonsillar Neoplasms / Q000453:epidemiology