Boston, MA (October 16, 2002) – Use of topical tazarotene, a vitamin A derivative, has significant potential for the prevention of basal cell carcinoma in people predisposed to the disease, according to a study presented at the American Association for Cancer Research's (AACR) first annual Frontiers in Cancer Prevention Research meeting. The study was designed to see if topical treatment with this retinoid would prevent the development of skin cancer in mice predisposed to the disease who were exposed to UV radiation. The researchers found an 85 percent inhibition of both tumor number and size in the tazarotene-treated mice compared to mice administered a placebo. Tazarotene is currently on the market for the treatment of acne and psoriasis.
"Oral retinoids have been shown to shrink tumors in patients with skin cancer, however, they usually are not tolerable for long periods of time," according to Ervin Epstein, Jr., MD, clinical professor and research dermatologist, Department of Dermatology, University of California School of Medicine, San Francisco, and lead investigator of the study. "Newer topical retinoids, like tazarotene, may provide a safer alternative for cancer prevention in those at risk."
The mice used in this study are research models for people with basal cell nevus syndrome (BCNS), an inherited syndrome with multiple defects involving the skin, nervous system, eyes, endocrine glands, and bones, leading to predispositions for developing large numbers of basal cell carinomas. People with BCNS inherit one defective gene of the Hedgehog signaling repressor gene PATCHED 1, which is important in the development of a range of tissues; it is now known that disruption of this pathway can result in the formation of several tumor types.
Basal cell carcinomas (BCC), the most common malignancy in humans, typically occurs in areas of chronic sun exposure. BCC is usually slow growing and rarely metastasizes, but it can cause significant local destruction and disfigurement if neglected or treated inadequately. Prognosis is excellent with proper therapy.
An estimated cancer one million new cases of skin cancer will be diagnosed in United States and an estimated 9,600 cancer deaths (7,400 from melanoma, 2,200 from other forms of skin cancer) will occur in 2002, according the American Cancer Society. The rate of melanoma mortality in men has recently increased, but has been stable for women, and the incidence of skin cancer is 10 times higher in Caucasians than in African-Americans. The five-year survival rate for melanoma is 89 percent; about 82 percent of melanomas are diagnosed at a localized stage.
Founded in 1907, the American Association for Cancer Research (AACR) is a professional society of more than 19,000 laboratory and clinical scientists engaged in cancer research in the United States in more than 60 other countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals (Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention).