On Sept. 20, 1990, results from the first chemoprevention trial to show efficacy (vitamin A analogue against mouth and throat tumors) were reported.

Patients with head-and-neck cancers who are free of disease after local therapy remain at high risk for both recurrent and second primary tumors. Retinoids have proved efficacious in the treatment of premalignant oral lesions and are promising agents for the prevention of epithelial carcinogenesis.

Daily treatment with high doses of isotretinoin is effective in preventing second primary tumors in patients who have been treated for squamous-cell carcinoma of the head and neck, although it does not prevent recurrences of the original tumor. The study results were published in The New England Journal of Medicine.