Association between development of lower lip cancer and tobacco habits.

Tobacco use is considered to increase the risk of tumor induction. The purpose of this case-controlled investigation was to assess the association of tobacco habits and development of squamous cell carcinoma of the lower lip. Sixty-one patients treated for lower lip cancer, aged between 42 and 90 years, were studied. Age- and sex-matched healthy controls showed a similar exposure to tobacco in years and a comparable distribution of tobacco habits. Although the mean exposure factor (duration times exposure) was greater in the tumor group, no intimate correlation between lip cancer and tobacco was demonstrated. However, an increased, although small, occurrence of herpes labialis lesions was found in cancer patients. The hypothesis is presented that smokers experiencing recurrent herpes simplex virus 1 (HSV-1) infections are more liable to tumor initiation, which issue will be subjected to a future study.