Tuesday, 15 March 2011 08:00
SEATTLE (Feb. 24, 2011) – Full-term pregnancy has long been associated with a reduced risk of breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , but a new study finds that the more times a woman gives birth, the higher her risk of “triple-negative” breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , a relatively uncommon but particularly aggressive subtype of the disease. Conversely, women who never give birth have a 40 percent lower risk of such breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , which has a poorer prognosisThe likely outcome or course of a disease; the chance of recovery or recurrence. than other types of breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. and doesn’t respond to hormoneOne of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory. -blocking therapies such as tamoxifenA drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast) and in women who are at a high risk of developing breast cancer. Tamoxifen is also being studied in the treatment of other types of cancer. It blocks the effects of the hormone estrogen in the breast. Tamoxifen is a type of antiestrogen. Also called tamoxifen citrate. .
These findings, from a study led by Amanda Phipps, Ph.D., a postdoctoral research associate in the Public Health Sciences Division of Fred Hutchinson Cancer Research Center, are published online in the Journal of the National Cancer Institute.
“Unlike most breast cancers, triple-negative tumors don’t depend on hormonal exposures to grow and spread, so our assumption going into the study was that reproductive factors would not be associated with a woman’s risk of this cancer subtype,” Phipps said. “We were surprised by these findings because researchers have known for quite some time that women who have children, especially those who have them at an early age and have multiple full-term pregnancies, have a lower risk of breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. overall.”
While never giving birth appears to be protective against triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , the researchers found that women who remain childless have about a 40 percent higher risk of estrogenA type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions. -receptor-positive breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. – the most common form of the disease, which can be treated with estrogenA type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions. -blocking drugs – as compared to those who have one or more offspring. This higher risk of estrogenA type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones. Estrogens can also be made in the laboratory. They may be used as a type of birth control and to treat symptoms of menopause, menstrual disorders, osteoporosis, and other conditions. -receptor-positive breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. among women who have not had children is well established, and it is thought to be related to the fact that such women do not undergo pregnancy-related changes in the breast that confer a lifelong protective effect.
“The mechanisms by which full-term pregnancy contributes to an increased risk of triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. and a decreased risk of other forms of the disease are not clear,” Phipps said. “We do know that the hormones of pregnancy induce certain changes in the cellular structure of the breast. Overall, those changes seem to make the breast less susceptible to cancer. It is possible, however, that the increased risk of triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. we found in women who had given birth may be due to some abnormal responseIn medicine, an improvement related to treatment. of their breast tissueA group or layer of cells that work together to perform a specific function. to the hormones of pregnancy. Another possibility is that pregnancy somehow makes the breast more susceptible to certain carcinogens even while reducing breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. risk overall,” she said.
For the study, which was based on data from the Women’s Health Initiative, Phipps and colleagues analyzed the detailed reproductive histories of some 150,000 postmenopausal women, more than 300 of whom went on to develop triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. . “This particular study is significant because it is one of the largest studies ever conducted on the impact of reproductive history on triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. ,” Phipps said.
Triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , which refers to any breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. that does not express the genes for estrogen receptorA protein found inside the cells of the female reproductive tissue, some other types of tissue, and some cancer cells. The hormone estrogen will bind to the receptors inside the cells and may cause the cells to grow. Also called ER. (ER), progesterone receptorA protein found inside the cells of the female reproductive tissue, some other types of tissue, and some cancer cells. The hormone progesterone will bind to the receptors inside the cells and may cause the cells to grow. Also called PR. (PR) or Her2A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of HER2/neu to help decide the best type of treatment. HER2/neu is a type of receptor tyrosine kinase. Also called c-erbB-2, human EGF receptor 2, and human epidermal growth factor receptor 2. /neu, accounts for only 10 percent to 20 percent of all breast cancers, and only in the past decade have researchers become aware that this cancer subtype exists. “This research reinforces the notion that breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. is not just one disease,” Phipps said.
“The mechanisms that lead to triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. are likely different from those that lead to other forms of the disease. We still have a lot to learn about what causes this more aggressive form of breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. , but we hope that research like this will help us develop better tools to identify those women at greatest risk.”
It is known that this cancer subtype is more predominant in African American women and it tends to be diagnosed at an earlier age. Researchers also know there is a strong link between geneticInherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells. mutations in the so-called “breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. geneThe functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein. ,” BRCA1A gene on chromosome 17 that normally helps to suppress cell growth. A person who inherits a mutated (changed) BRCA1 gene has a higher risk of getting breast, ovarian, or prostate cancer. , and triple-negative breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. .
“More research is needed to better understand the causes of the most aggressive and lethal forms of breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. . While this study adds to our knowledge base, it should not change women’s approaches to breast cancerCancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare. screening,” Phipps said.
The National Heart, LungOne of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body. and BloodA tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes. Institute of the National Institutes of Health funded the study, which also involved researchers from Albert Einstein College of Medicine, Georgetown University, Harbor-UCLA Medical Center, Stanford University, State University of New York at Stony Brook, the University of Buffalo, the University of Pittsburgh and Wake Forest University.
The More Times a Woman Gives Birth, the Higher Her Risk of Rare But Aggressive 'Triple-Negative' Breast Cancer
No hay comentarios:
Publicar un comentario