How successful have retinoids, such as isotretinoin, been in preventing skin cancer?
Dr. Kraemer: We did a study here a few years ago with Accutane, which was very effective in preventing skin cancer in patients with XP. One patient would get 20 separate primary skin cancers each year for many years, and she was just a teenager. We gave her the oral medicine. Within two years, she was getting two or three cancers a year – a really small number. Unfortunately, when we stopped the medicine, she started getting tumors again, and the medicine itself caused a number of side effects. It made the skin very sensitive to sunlight. It causes birth defects, so people on it can’t get pregnant. Also, it causes calcifications of tendons and ligaments. Accutane is on the market for acne treatment. The people who are treated for acne are treated for just a short time, but patients with XP would have to be treated for a long time. There are thousands of retinoids, and we hope that someday we can find a different retinoid that is equally as effective but less toxic. How does the TN45 li
