Breast cancer hormone receptor status

Toremifene is another commercially available SERM for the treatment of breast cancer. It exhibits similar efficacy and tolerability to tamoxifen in the metastatic setting. Cross-resistance to toremifene has been demonstrated in patients with tamoxifen-refractory disease.51 Therefore, toremifene appears to be an alternative to tamoxifen in postmenopausal patients with positive or unknown hormone-receptor status with metastatic breast cancer. 

The use of CL as a prognostic indicator has been best studied in breast cancer. Most studies measured CL from tumor extracts and correlated high levels of CL with a decrease in relapse-free survival. CL appears to be an independent prognostic marker in both node-negative and nodepositive breast cancer, especially when combined with other prognostic markers such as CB, CD, node status, and steroid hormone receptor status. 

It is apparent from clinical and laboratory experiments and observation that the spread of breast cancer via the bloodstream occurs early in the course of the disease. This results in patients relapsing with systemic metastatic disease following local curative therapy. The likelihood of later development of metastatic disease is related to the size of the primary tumor, presence of lymph node involvement and number of nodes affected, and a number of additional pathologic prognostic factors, which include proliferative capacity, nuclear grade, hormone receptor status, and presence or absence of oncogenes and other protein products. Systemic adjuvant therapy is commonly... 

The relationship between hormone receptor status and the effect of adjuvant tamoxifen in early breast cancer remains controversial. TAM has been considered to be the hormonal agent of first choice for management of postmenopausal women with metastatic breast cancer (II, 12). Recent studies (B4, VI) showed that response to tamoxifen was significantly related to ERP levels, but no benefit was observed among ERP negative patients. The relationship to PRP alone was of... 

The measurement of ER has become a standard assay in the clinical management of breast cancer. The presence of ERa identifies those breast cancer patients with a lower risk of relapse and better clinical outcome. Receptor status also provides a guideline for those tumors that may be responsive to hormonal intervention. But only about half of ER-positive patients respond to hormonal therapies. Of those who respond initially, most will eventually develop an estrogen unresponsive disease following a period of treatment even though ERa is often still present. Mutant receptors and constitutively active r eceptors as well as hormone-independent activation of the ERa are discussed. The involvement of ER 3 isoforms is under investigation. 

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... 

Winer EP, Hudis C, Burstein HJ, et al. American Society of Clinical Oncology technology assessment on the use of aromatase inhibitors as adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer Status report 2004. J Clin Oncol 2005 23 619-629. 

Idoxifene has been evaluated as a breast cancer treatment for postmenopausal patients [296, 297]. In one study, 321 postmenopausal patients with unknown receptor status or hormone receptor-positive metastatic breast cancer were randomized to receive either tamoxifen or idoxifene as first-line endocrine therapy for their advanced disease. Complete plus partial response rates were 9 and 13% for tamoxifen and idoxifene, respectively. The median time to progression was slightly higher for idoxifene (140 versus 166 days), but these differences were not statistically significant. Morbidity was similar for both groups. The authors concluded that in postmenopausal women with metastatic breast cancer idoxifene had similar efficacy and toxicity to tamoxifen [298]. However, idoxifene has not been developed further because of concerns about uterine prolapse [299]. This side-effect is not seen with tamoxifen. 

There is no doubt that patients who are both ERP+/PRP+ have a higher response to endocrine therapy at relapse. There are a substantial number of patients having either one or the other positive receptor status who also respond to hormonal therapy. It has been stated that ERP+ lesions are most likely to spread to bone, whereas those that are ERP- are more likely to develop visceral metastases, especially in liver or brain (Kl). Most breast cancers exhibit significant steroid receptor heterogeneity at a cellular level in both positive and negative cells, but in negative cells can be shown to be highly proliferative (Bl). 

B13. Browder, H., Keller, J., White, J. M., Losada, M., Kianka, J., and Hunter, H., Prognostic value of receptor and disease status in response to hormonal therapy and time to progression in metastatic breast cancer. Proc. Anna. Meet. Am. Soc. CliiL Oncol. 5, 59 (1986). 

Approximately two-thirds of primary breast cancers are ER -i- [45]. Oestrogen receptor status is important, as it determines whether or not the patient can benefit from hormonal therapy and also provides information on the history of the cancer, since ER -i- patients show a longer disease-free interval and total survival than ER - patients. About 60% of ER -I- patients and 10% of ER- patients may respond to hormonal therapy [45, 46]. Patients with ER - tumours have very little chance of remission with endocrine therapy ablative procedures are avoided and replaced by cytotoxic therapy [47]. 

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