Factors associated with increased incidence of head and neck cancers include all of the following EXCEPT:a. Human papillomavirus (HPV) exposure
Human papilloma virus (HPV) is an epitheliotropic virus that has been detected to various degrees within samples of oral cavity squamous cell carcinoma. Infection alone is not considered sufficient for malignant conversion; however, results of multiple studies suggest a role of HPV in a subset of head and neck squamous cell carcinoma. Multiple reports reflect that up to 40 to 60% of current diagnoses of tonsillar carcinoma demonstrate evidence of HPV types 16 or 18. Environmental ultraviolet light exposure has been associated with the development of lip cancer. The projection of the lower lip, as it relates to this solar exposure, has been used to explain why the majority of squamous cell carcinomas arise along the vermilion border of the lower lip. In addition, pipe smoking also has been associated with the development of lip carcinoma. Factors such as mechanical irritation, thermal injury, and chemical exposure have been described as an explanation for this finding. Other entities associated with oral malignancy include Plummer-Vinson syndrome (achlorhydria, irondeficiency anemia, mucosal atrophy of mouth, pharynx, and esophagus), chronic infection with syphilis, and immunocompromised status (30-fold increase with renal transplant).