Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancer is the most frequent female malignant disease in developed countries. Various approaches are being developed for breast cancer prevention. Medical prevention called chemoprevention is reviewed. Prior to any intervention estimation of breast cancer risk is mandatory. For practical reasons distinction of two risk groups is useful. In the high risk group inherited gene mutation showing high penetrance may be suspected, while in the medium risk group hormonal factors play an important role. The antiestrogen tamoxifen has been extensively investigated in breast cancer and also tested for the prevention of breast cancer. The results of four randomized tamoxifen prevention studies have been published. In the largest, American trial the number of invasive or "in situ" breast cancers was halved by tamoxifen. Particularly estrogen receptor positive and relatively good prognosis breast cancers were reduced. Similar results were obtained in the "International Breast Intervention Study". Tamoxifen has been registered for breast cancer prevention for high risk individuals in the United States. The Italian and English ("Royal Marsden Hospital") studies did not prove significant preventative effect for tamoxifen that may be explained by the characteristics of the study protocols and study populations. Increased rates of endometrial cancer, thromboembolic events and cataract were observed under tamoxifen treatment, especially over the age of 50. Prevention has an increased importance in gene mutation carriers. Besides prophylactic mastectomy and close surveillance tamoxifen and bilateral oophorectomy or the use of gonadotropin releasing-hormone analogs seem efficient in this group. Various new chemoprevention strategies are under testing. Raloxifene and the aromatase inhibitors show advantage in menopausal women, the retinoid fenretinide and the gonadotropin releasing-hormone analogs seem promising for premenopausal individuals. The use of these agents are investigated in clinical trials. It is likely that not one single method will be applied for breast cancer prevention in the future. Preferably individual prevention strategies based on individual risk assessment will be developed.
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PMID:[Breakthrough in breast cancer chemoprevention]. 1272 84

Tamoxifen and raloxifene are both selective estrogen receptor modulators (SERMs). The medicines can block estrogen mediated breast cancer growth and development but will also maintain bone density in postmenopausal women and lower circulating cholesterol. Tamoxifen has remained the antihormonal therapy of choice for the treatment of ER positive breast cancer for the last 30 years. However, although adjuvant tamoxifen produces profound increases in disease-free and overall survival in patients with ER positive breast cancer, concerns about drug resistance, blood clots and endometrial cancer have resulted in a change to the use of aromatase inhibitors for the treatment of postmenopausal women. Nevertheless, tamoxifen remains the antihormonal treatment of choice for premenopausal women with ER positive breast cancer and for risk reduction in premenopausal women who are at high risk for developing breast cancer. The risk of endometrial cancer and thromboembolic disorders during tamoxifen therapy is not elevated in premenopausal women. It is important to note that aromatase inhibitors or raloxifene should not be used in premenopausal women. Raloxifene is used to prevent osteoporosis in postmenopausal women and, unlike tamoxifen, does not increase the risk of endometrial cancer. However, raloxifene does reduce breast cancer risk by 50-70% in both low risk and high risk postmenopausal women. Comparisons of raloxifene with tamoxifen show equal efficacy as a chemopreventive for breast cancer but there is a reduction in thromboembolic disorders, fewer endometrial cancers, hysterectomies, cataracts and cataract surgeries in women taking raloxifene. Overall, SERMs continue to fulfill their promise as appropriate medicines that target specific populations for the treatment and prevention of breast cancer.
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PMID:SERMs for the treatment and prevention of breast cancer. 1744 Aug 19

In the Study of Tamoxifen and Raloxifene (STAR) trial, postmenopausal women at increased risk of breast cancer received either oral tamoxifen (20 mg/day) or raloxifene (60 mg/day) over 5 years. There were an equal number of cases of invasive breast cancer in women assigned to tamoxifen and raloxifene. There were fewer cases of noninvasive breast cancer in the tamoxifen group than in the raloxifene group (risk ratio [RR]: 1.40; 95% confidence interval [CI]: 0.98-2.02). There were more cases of uterine cancer with tamoxifen than with raloxifene (RR: 0.62; 95% CI: 0.35-1.08). Thromboembolic events occurred less often in the raloxifene group (RR: 0.70; 95% CI: 0.54-0.91) and there were fewer cataracts and cataract surgeries in the women taking raloxifene (RR: 0.79; 95% CI: 0.68-0.92). The STAR trial has shown that raloxifene is as effective as tamoxifen in reducing the risk of invasive breast cancer and has a lower risk of adverse events but a nonstatistically significant higher risk of noninvasive breast cancer. The risk of other cancers, fractures, ischemic heart disease and stroke is similar for both drugs.
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PMID:The NSABP Study of Tamoxifen and Raloxifene (STAR) trial. 1910 6