Breast tumors hormone receptors

Adjuvant endocrine therapy reduces the rates of relapse and death in patients with hormone-receptor-positive early breast cancer tumors. Adjuvant chemotherapy reduces the rates of relapse and death in all patients with early-stage breast cancer. 

Initial therapy of metastatic breast cancer in women with hormone-receptor-positive tumors should consist of hormonal therapy. 

An NIH Consensus Development Conference Statement22 advises that adjuvant hormonal therapy should be recommended to women whose tumors contain hormone-receptor protein regardless of age, menopausal status, involvement of axillary lymph nodes, or tumor size. They also support a benefit of adjuvant chemotherapy for most women with lymph node metastases or with primary breast cancers larger than 1 cm in diameter (both node-negative and node-positive).22... 

Tamoxifen can be used in both premenopausal and postmenopausal women with metastatic breast cancer who have tumors that are hormone-receptor-positive. The toxicities of tamoxifen are described in the section on adjuvant endocrine therapy. The only additional toxicity that one might expect to find in the setting of metastatic breast cancer (specifically bone metastases) is a tumor flare or hypercalcemia, which occurs in approximately 5% of patients following the initiation of any SERM therapy and is not an indication to discontinue SERM therapy. It is generally accepted that this is a positive indication that the patient will respond to endocrine therapy. 

Fulvestrant is a new agent approved for the second-line therapy of postmenopausal metastatic breast cancer patients who have tumors that are hormone-receptor-positive. Studies examining the role of fulvestrant in the treatment of metastatic breast cancer have compared this agent with anastrozole. Given anas-trozole s mechanism of action, only postmenopausal women were eligible for these trials. There is no biologic reason why fulvestrant should not produce similar outcomes in premenopausal... 

Cytotoxic chemotherapy is eventually required in most patients with metastatic breast cancer. Patients with hormone-receptor-negative tumors require chemotherapy as initial therapy of symptomatic metastases. Patients who respond initially to hormonal manipulations eventually cease to respond and go on to require chemotherapy. The median duration of response is 5 to 12 months, but some patients will have an excellent response to an initial course of chemotherapy and may live 5 to 10 years or longer without evidence of disease. In general, median survival of patients after treatment with commonly used drug combinations for metastatic breast cancer is 14 to 33 months. The median time to response has ranged from 2 to 3 months in most studies, but this period depends in large part on the site of measurable disease. The median time to appearance of response is between 3 and 6 weeks in patients whose disease is primarily in the skin and lymph nodes, 6 to 9 weeks in patients with metastatic lung involvement, 15 weeks in patients with hepatic involvement, and nearly 18 weeks in patients with bone involvement. Thus it is often the case that an immediate response to therapy is not... 

The successful response of breast cancers to tamoxifen or progestin treatment depends on the presence of high-affinity receptors for estrogen, progesterone, or both. Fewer than 10% of mammary tumors that lack detectable ER levels will respond to hormonal therapies. Determination of hormone receptor levels in tumor samples is highly recommended before selecting a therapy. 

Anasfrozole (Arimidex) [Anrineoplasric/Nonsteroidal Aromatase Inhibitor] Uses Breast CA postmenopausal w/ met breast CA, adjuvant Rx postmenopausal early hormone-receptor(+) breast CA Action Selective nonsteroidal aromatase inhibitor, X circ estradiol Dose 1 mg/d Caution [D, ] Contra PRG Disp Tabs SE D, HTN, flushing, T bone/tumor pain, HA, somnolence Interactions None noted EMS May cause vag bleeding during 1st few wks of Tx OD May cause N/V, abd discomfort, and bloody stools symptomatic and supportive... 

When tamoxifen 20 mg/day was compared with equieffective doses of anastrozole in 668 patients with advanced breast tumors that were hormone receptorpositive or of unknown receptor status, tamoxifen produced too high a rate of thromboembolism and vaginal bleeding to be considered the treatment of choice (51,52). 

KLK5 mRNA from breast Q-RT-PCR Overexpressed in younger, pre-/perimenopausal patients with smaller, steroid hormone receptor-positive tumors Associated with a longer OS Predictive value Higher hK3 levels associated with a poor response to tamoxifen therapy Unfavorable prognosis [93]... 

Thrombosis and pulmonary embolism have been described with tamoxifen (27,28) the number of cases is smaU, but the association would not be unexpected in view of what is known about the effects of other sex hormones. The primary condition might be responsible, at least in part, for the occurrence of such complications. Tamoxifen does reduce antithrombin III but not to a degree at which a major risk would be expected, and other measurable effects on the coagulation process seem to be shght When tamoxifen 20 mg/day was compared with equief-fective doses of anastrozole in 668 patients with advanced breast tumors that were hormone receptor-positive or of unknown receptor status, tamoxifen produced too high a rate of thromboembolism and vaginal bleeding to be considered the treatment of choice (29,30). 

Most hormone-sensitive cancers will express hormone receptors that can be assayed on biopsy specimens. This allows the clinician to predict whether an individual patient is likely to benefit from hormonal therapy. For example, it is now standard to measure estrogen receptor (ER) and progesterone receptor (PR) content in breast cancer tissue. Patients with ER- or PR-positive tumors are more likely to respond to antiestrogen therapy compared with patients who lack these hormone receptors. 

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