A nine-city study, involving about 100 people at risk of developing bladder cancer, is contemplated to see if threetimes-daily doses of the retinoid 13-cis-retinoic acid can keep precancerous conditions from developing into malignancies.Michael B. Sporn, MD, National Cancer Institute, says these synthetic analogs of vitamin A prevented cancer of the lung, breast, and bladder in experimental animals. However he emphasizes: "Megadoses of vitamin A, as can be bought over the counter, should not be taken, since severe damage to the liver may result." And "there is no evidence that retinoids of any type are effective for treatment of invasive, metastatic cancer."
Some 5 million Americans breathe in significant amounts of abestos fibers daily, and it is estimated 40% may die as a result. Now, a mesothelioma treatment research center is being opened at Mt Sinai School of Medicine, New York.James F. Holland, MD, and