Three different studies appearing in the Journal of the National Cancer Institute alone have come to three different conclusions about this particular vitamin. Mixed Results for Vitamin A A well-publicized study in the May 17, 2000 issue of the Journal of the National Cancer Institute found that a gene believed to suppress the growth of breast cancer tumors appears to be switched off in the early stages of the disease. But a two-pronged treatment that includes a form of vitamin A (called retinol) may help to reactivate this tumor-suppressing gene and thus prevent tumor growth. Dr. Martin Widschwendter from the University of Innsbruck, Austria and colleagues identified a gene called RAR-beta-2 that is believed to stop the growth of several types of tumors, including breast cancer tumors. But when this gene is inexplicably turned off, the tumors appear to grow unencumbered. The Austrian researchers found that a substance identical to vitamin A (a retinol-like substance called ATRA), when mixed with a demethylating agent, can turn RAR-beta-2 back on. In theory, this would then have a suppressing effect on the growth of cancerous tumors. However, while their studies on laboratory animals have shown promise, they acknowledge that ATRA is still far too toxic for use in humans. Nonetheless, the researchers suggest that retinol-like substances such as ATRA have significant potential for preventing and eliminating breast and other cancers. The Other Side of the Coin Conversely, another study published in the June 21, 2000 issue of the Journal of the National Cancer Institute found that a combination of vitamin A and an antioxidant called N-acetylcysteine does not halt the spread of smoking-related cancers. It was hoped that taking supplements of the two agents, which work differently but have shown individual promise in smaller studies, would help prevent cancer in the lungs, head and neck. Over a two-year period, Dr. Nico van Zandwijk of The Netherlands Cancer Institute in Amsterdam and colleagues provided vitamin A and N-acetylcysteine supplements to more than 2,500 cancer patients who smoked or had a history of smoking. After a follow-up period of four years, they found that neither supplement, whether taken alone or in combination with each other, had any significant effect on survival or cancer recurrence. A third study published in late 1999 in the Journal of the National Cancer Institute came to two different conclusions. Dr. Umberto Veronesi from the Istuto Nazionale Tumori in Milan and colleagues found that another substance that is molecularly similar to vitamin A, fenretinide, has no significant effect in preventing a second breast tumor from occurring in postmenopausal women with breast cancer. (In fact, it may actually increase the risk.) However, fenretinide in premenopausal women appeared to lower their risk of a second breast cancer. "We have been in certain ways surprised because we didn’t expect such a difference in the sense that this drug is very active in very young women," said Veronesi. But after menopause, he noted, "it appears to exert the opposite effect." In fact, his team’s findings suggest that postmenopausal women had a slightly greater risk of a second breast cancer when fenretinide was taken. Thanks to Johns Hopkins journal article (Artemis) http://www.med.jhu.edu/breastcenter/artemis/ Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.