Which of the following is best for treating ER positive Ca breast?
Ans. A. Raloxifene. (Ref. Harrison's Medicine 18th/Table. 90-4).Tamoxifen, raloxifene:MechanismSelective estrogen receptor modulators (SERMs) -- receptor antagonists in breast and agonists in bone. Block the binding of estrogen to ER + cells.UseBreast cancer treatment (tamoxifen only) and prevention. Raloxifene also useful to prevent osteoporosis.S/ETamoxifen--partial agonist in endometrium, which*the risk of endometrial cancer; "hot flashes."Raloxifene--no*in endometrial carcinoma because it is an endometrial antagonist.The choice of endocrine therapy in Rx of breast cancer# In most patients, the initial endocrine therapy should be an aromatase inhibitor rather than tamoxifen. For the subset of postmenopausal women who are estrogen receptor-positive but also HER2/neu positive, response rates to aromatase inhibitors are substantially higher than to tamoxifen.# Newer "pure" antiestrogens that are free of agonistic effects are also effective.# Cases in which tumors shrink in response to tamoxifen withdrawal (as well as withdrawal of pharmacologic doses of estrogens) have been reported. Endogenous estrogen formation may be blocked by analogues of LHRH in premeno- pausal women. Additive endocrine therapies, including treatment with progestogens, estrogens, and androgens.Endocrine Therapies for Breast CancerTherapyCommentsCastrationSurgicalLHRH agonistsFor premenopausal womenAntiestrogens Tamoxifen"Pure" antiestrogensSurgical adrenalectomyAromatase inhibitorsHigh-dose progestogensHypophysectomyAdditive androgens or estrogensUseful in pre- and postmenopausal womenResponses in tamoxifen-resistant and aromatase inhibitor-resistant patientsRarely employed second-line choiceLow toxicity; now first choice for metastatic diseaseCommon fourth-line choice after Als, tamoxifen and fulvestrantRarely usedPlausible fourth-line therapies; potentially toxicAlso know:A trial comparing tamoxifen with another selective estrogen receptor modulator, raloxifene, showed that raloxifene is comparable to tamoxifen in cancer prevention. This trial only included postmenopausal women. Raloxifene was associated with more noninvasive breast cancer than tamoxifen; the drugs are similar in risks of other cancers, fractures, ischemic heart disease, and stroke. Because the aromatase inhibitors are even more effective than tamoxifen in adjuvant breast cancer therapy, it is hoped that they would be more effective in breast cancer prevention.
Raloxifene
Exemestane
Leuperide
Bicalutamide
Oncology