title: Head and neck squamous cell carcinoma in Iranian patients and risk factors in young adults: a fifteen-year study.
abstract: BACKGROUND
  Head and neck squamous cell carcinoma (HNSCC) is the 8th most common cancer worldwide. Although older age, male gender, smoking and alcohol consumption are known risk factors, an increasing number of HNSCC patients are without typical risk factors. Our aim was to define demographics of HNSCC in Iran and the potential risk factors related to Iranian ethnicity and lifestyle.
  
  
  METHODS
  We conducted a cross-sectional analytical study on 262 patients with primary SCC of the larynx, hypopharynx or tongue referred to our pathology department during 1995-2010. Patients' demographics, tumor characteristics and risk factors such as smoking, alcohol consumption and anemia were analyzed and compared in two groups of patients: over 40 years (older group) and 40 years or less (young group); Chi-square and Mann-Whitney analytical tests were employed.
  
  
  RESULTS
  5.7% of patients were young adults. The male to female ratio was 1.5 in the younger group and 5.6 in the older group. In young adults, 40% of tumors were located in larynx and 40% in the tongue. Age >40 was significantly associated with laryngeal location (P<0.001). History of smoking and drinking was significantly associated with age >40 and SCC of larynx in both age groups. Cervical lymph node involvement was significantly correlated with SCC of tongue (P<0.001), however, considering young adults only, SCC of hypopharynx was most frequently accompanied by lymph node involvement (60%). The most prevalent tumor among men was SCC of larynx whereas SCC of hypopharynx was the most prevalent tumor among women (61%), of whom 18.2% were ≤40.
  
  
  CONCLUSIONS
  The incidence of HNSCC among young adults seems to be higher in Iran compared to other countries. Reduction in exposure to known risk factors, especially tobacco smoking in forms of cigarettes and bubble pipes, and search for other causative agents of HNSCC in young population is recommended.
authors.affiliation: Department of Pathology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Negar
authors.initials: N
authors.lastname: Mafi
authors.forename: Maryam
authors.initials: M
authors.lastname: Kadivar
authors.forename: Niloufar
authors.initials: N
authors.lastname: Hosseini
authors.forename: Sara
authors.initials: S
authors.lastname: Ahmadi
authors.forename: Ali
authors.initials: A
authors.lastname: Zare-Mirzaie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D000077195:Squamous Cell Carcinoma of Head and Neck; D055815:Young Adult