Mutaţiile a două gene, scad eficacitatea tratamentului împotriva cancerului mamar

1 Comentariu [+] Adauga un comentariu

#1 Cornelia Vodoiu 26.01.2010 10:32

• Raspunde

Ma ocup de EDUCATIA SI PREVENTIA CANCERULUI, inclusiv a CANCEULUI SPIRITUAL pentru a aduce la lumina FAMILIA ROMANEASCA SI SCOALA ROMANEASCA.
A.« WHAT ARE THE RISK FACTORS FOR DEVELOPING BREAST CANCER ?
A.The most significant risk factors for breast cancer are GENDER and AGE. Men can develop breast cancer, but women are 100 times more likely to develop breast cancer than men. Breast cancer is 400 times more common in women who are 50 years old as compared to those who are 20 years old.
B.Family history.
Another important risk factor is having first degree relatives (mother, sister or daughter ) with breat cancer or male relatives with prostate cancer.
The risk is especially higher if both the mother and sister have had breast cancers, if the cancers in first-degree relatives occurred early in life (before age 50), or if the cancers in these relatives were found in both breasts. Women who have inherited defective BRCA1, BRCA2, p53, and DNA repair genes have an increased risk of developing breast cancer, sometimes at early ages, as discussed previously. But even in the absence of one of the known predisposing genetic defects, a strong family history may signify an increased risk because of genetic or environmental factors that are specific to that particular family. For example, increased risk in families could be due to exposure to similar environmental toxines in some cases.
C.Radiation therapy.
Women with a history of radiation therapy to the chest area as treatment for another cancer (such as Hodgkin ‘s disease or non-Hodgkin’s lymphoma) have a significantly increased risk for breast cancer, particularly if the radiation treatment was received at a young age.
D.Hormonal factors.
Women who started their menstrual periods before age 12, those who have late menopause (after age 55, and those who had their first pregnancy after age 30, or who have never had children have a mildly increased risk of developing breast cancer (less than two times the normal risk). Studies have confirmed that long-term use (several years or more) of hormone therapy (HT) after menopause, particularly estrogens and progesterone combined , leads to an increase risk for development of breast cancer.
E. Lifestyle factors.
Dietary factor such as high-fat diets and alcohol consumption have also been implicated as factors that increase the risk for breast cancer. Cigarette smoking, caffeine intake, antiperspirant use, and stress, do not appear to increase tha risk of breast cancer. ».Edward White, MD, Melissa Conrad Stöppler, MD, William C.Shiel, Jr. MD, FACP, FACR and Dennis Lee, Md – « BREAST CANCER PREVENTION ».
B.[« Future Treatment Choices Could Be Guided By Genes Linked To Breast Cancer Drug Resistance.
Article Date : 25 Jan 2010 -2 :00 PST.
SOURCE : Bill Schaller ; Dana –Farber Cancer Institute.
Researchers at Dana –Farber Cancer Institute have discovered a gene activity signature that predicts a high risk of cancer recurrence in certain breast tumors that have been treated with commonly used chemotherapy drugs.
Despite their resistance to drugs of the ANTHRACYCLINE class , the breast cancers bearing this gene signature will probable still be vulnerable to other types of chemotherapy agents, say scientists in a letter to be published in « Nature medicine », on its Web site and later in a print edition. Thus, the findings could lead to a genetic test of breast cancers to help physicians choose the best initial treatment for an individual patient.
Led by Andrea Richardson , MD, PhD, and Zhigang Charles Wang, MD, PhD, the investigators identified two genes that, when abnormally active, enabled cancer cells to resist the effects of drugs called ANTHRACYCLINES. This class of agents includes DOXORUBICIN, DAUNORUBICIN, and EPIRUBICIN, which are often used an adjuvant therapy in breast cancer. It’s been known that some breast tumors acquire during the course of treatment , altered genes or chromosomes that make them resistant to many cancer drugs. But with one or two exceptions , « No tests are done before treatment begins to predict who’s going to be resistant or sensitive to different compounds », says Richarson. « Most breast cancer patients are initially given the same drugs. »
Exceptions include patients whose tumors are spurred by estrogen and are often less sensitive to any chemotherapy ; hormonal treatment is generally prescribed in that case.
Also, breast cancers found to be HER2 –positive are treated with the antibody TRANSTUZUMAB –another example of « personalized » or tailored therapy ».] SOURCE: Medical News TODAY.

 

Vezi toate »