Chapter 1 - Epidemiology, Risk factors and Pathogenesis of Squamous Cell Tumours
Tobacco: Approximately 90% of patients with HNSCC have a history of tobacco use.
Compared to non-smokers, tobacco users have a 4–5-fold increased risk for cancer in the oral cavity, oropharynx and hypopharynx and a 10-fold increased risk of laryngeal cancer.
Risk of HNSCC is related to the frequency, intensity and duration of tobacco consumption; association is dose-dependent.
adapted from Doll et al, BMJ 2004;328:1519
Smoking cessation may reduce risk of HNSCC. Risk decreases with time since smoking cessation.
Smokeless (chewing) tobacco increases the risk of cancer of the oral cavity. In India and Sudan, 50%–60% of oral cavity cancers are attributed to smokeless tobacco.
It is estimated that tobacco smoking increases the risk of HPV infection and persistence; therefore it may contribute to development of HPV-positive OPC.
Alcohol: Alcohol use independently increases the risk of HNSCC, with 1%–4% of cases attributed to alcohol alone. It specifically increases the risk of hypopharyngeal cancer.
It acts synergistically with tobacco, resulting in an approximately 35-fold increase in HNSCC risk in heavy smokers (>2 packs/day) and drinkers (>4 drinks/day).
Gender, age: Men have a 2- to 5-fold greater risk of HNSCC than women. HNSCC risk also increases with age, with a median age of diagnosis in the late 60s and 70s.
Revision Questions
- What percentage of patients with HNSCC have a history of tobacco use?
- Which type of head and neck cancer has the strongest association with tobacco?
- How much is the risk of HNSCC increased by the combined effect of tobacco and alcohol?
