Breast Cancer and Vitamin A Lack of this antioxidant may affect why cells turn cancerous (HealthScout) -- Women with breast cancer may not have the protein that lets them use vitamin A properly. This lack may explain why normal breast cells turn cancerous, a new study shows. Their preliminary study shows that in about a quarter of the women with breast cancer, their tumor cells lack CRBP, a protein that helps vitamin A stick to cells, say researchers at Mount Sinai School of Medicine in New York. "The big question is: What does it mean?" says Dr. Rafael Mira-y-Lopez, associate professor in the department of medicine at Mount Sinai in New York City. "And the truth is, it's still very hard to say. What we can't yet tell is whether the lack of this protein CRBP is contributing to the development of cancer or is it a consequence of the cancer." Lopez and his colleagues examined 15 tissue samples taken from women who had breast reductions and compared the tissue to that of 49 breast cancer patients. "What we found is that the protein implicated in vitamin A metabolism is not found in roughly one-quarter of breast cancer patients," Lopez says. CRBP was found in all the normal tissue samples from the breast reductions as well as in 33 of the 35 specimens of normal tissue found next to cancerous tissue. In the cancerous tissues, however, 12 showed no sign of CRBP. The findings will be published in tomorrow's issue of the Journal of the National Cancer Institute. Lopez says, "Vitamin A helps develop cells into their specialized roles -- a breast cell or a lung cell or a brain cell. CRBP assists the body when it converts a form of vitamin A -- retinal -- into its acidic form, and that performs the specialization, called differentiation." Vitamin A is found in fruits and vegetables, as well as in fish, eggs and liver. The researchers have two theories to describe what may be going on, Lopez says. "CRBP may be decreasing . . . the efficiency of vitamin A conversion into retinoic acid," explains Lopez. "If that happens, it could possibly be affecting vitamin A's role as a differentiating agent. That could make the cell invasive or cancerous, but we don't know yet." "Lack of vitamin A could be giving the cells a growth advantage," he says. Then again, the lack of CRBP may mean nothing at all. "It could be a marker for some other kind of chemical function that we do not understand yet," Lopez says. Whatever the reason, Lopez cautions that the study is too small to draw any conclusions. "We need to do more confirmatory studies," he says. "We do not see any therapeutic of drug consequences at this point." Lopez points out that vitamin A is an important factor in other cancers. "The vitamin A receptor is abnormally expressed in cancer of the breast, head and neck and lungs. What we want to do now is find out whether the lack of CRBP is a defect fairly widespread in other cancers." That makes the study important, says Dr. Ethan Dmitrovsky, chairman of the department of pharmacology and toxicology at Dartmouth Medical School in Hanover, N.H. In an editorial accompanying the study, Dmitrovsky and fellow author Michael Spinella say the study's importance lies in its identification of a "tumor-associated abnormality." "This alteration may account for some of the abnormal growth properties found in some breast cancers, " Dmitrovsky says. More research is needed, however. "Future work following treatment with retinoids may lead to strategies, which correct this particular defect," Dmitrovsky adds. "What could happen is that retinoid levels are restored in the cells." That's what Lopez would like to find out. "What we'd like to do is put CRBP back into breast cells that lack the protein and see what happens. Will it change how the cell converts retinol to retinoic acid? Will it have an affect on differentiation?" Lopez asks. What To Do This work is in its preliminary stages, and this study, the experts agree, is too small to draw any conclusions from. All agree more research is needed. Thanks to healthscout.com and Breast Cancer News is brought to you by the The MID HUDSON OPTIONS PROJECT, INC a grassroots Breast Cancer Health Advocacy, Support and Activist Group. 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.