Adjuvant endocrine therapy for breast cancer

Endocrine therapy is a critical part of adjuvant therapy in women with hormone receptor-positive breast cancer, and has been shown to reduce the risk of recurrence and death from breast cancer. For decades, 5 years of tamoxifen has been the standard treatment. For premenopausal women, it remains so, and we await the results of ongoing trials to define the role of ovarian suppression or ablation with endocrine therapy. If a woman becomes postmenopausal during treatment, consideration should be given to extended adjuvant therapy with an aromatase inhibitor (AI) for another 5 years. In postmenopausal women, trials have shown that AIs are more beneficial than tamoxifen in preventing disease recurrence.They have been compared as upfront treatment for 5 years, as sequential therapy after 2 to 3 years of tamoxifen, and as extended treatment for 5 years after 5 years of tamoxifen. Among the questions still being studied are the optimal duration of extended adjuvant therapy with AIs, how one AI performs compared to another, and whether there is a benefit to intermittent extended adjuvant treatment.     

乳腺癌的辅助内分泌治疗

内分泌治疗是激素受体阳性乳腺癌患者的重要治疗手段.他莫昔芬、阿那曲唑和卵巢功能抑制剂是乳腺癌内分泌治疗中的最常用药物,针对患者疾病分期和绝经状态的小同,内分泌治疗药物的选择不同.内分泌治疗被证实有很好的疗效的同时,也被证实会产生耐药,mTOR抑制剂、CDK4/6抑制剂和纤维母细胞生长因子受体抑制剂将为内分泌治疗耐药患者带来新的希望.     

Controversies in endocrine therapy for breast cancer

Major advances have been made in the treatment of postmenopausal women with hormone-sensitive breast cancer. Although tamoxifen has been the standard endocrine therapy for the past twenty years, the development of a third generation of aromatase inhibitors (Als), which effectively inhibit estrogen synthesis in extragonadal sites, gives us a wider range of choices in endocrine therapy. However, many questions remain with respect to the optimal use of Als. Differences between Als and tamoxifen as well as non-steroidal and steroidal Als in their long-term adverse effects on bone demineralization and lipid metabolism are only starting to emerge. The preferable orders for use of non-steroidal and steroidal Als, Als and pure anti-estrogen in patients with metastatic disease are emerging subjects to be examined, following several studies that showed non-cross reactivity between these types of drug. Neo-adjuvant endocrine therapy is now attempting to apply breast conserving surgery in larger numbers of elderly patients who are not suitable for neo-adjuvant chemotherapy. Moreover, many investigators are currently searching for surrogate markers in neo-adjuvant endocrine treatment that can predict the responsiveness and prognosis with adjuvant endocrine therapy. Further research concomitant with clinical trials may lead to a more reliable endocrine therapy modality in the treatment of breast cancer.     

Evidence-based neoadjuvant endocrine therapy for breast cancer

Breast cancer is the most common malignancy among women in Western countries. The management of patients with nonmetastatic breast cancer with primary endocrine therapy has evolved dramatically in the past decade. Neoadjuvant treatment has been used to turn inoperable tumors into operable tumors and also to downstage tumors. Hormone receptor-positive breast tumors exposed to neoadjuvant chemotherapy have lower rates of pathologic complete response than hormone receptor-negative tumors. Recently, clinical trials showed an increased response rate and a higher rate of breast-conserving surgery with aromatase inhibitors compared with tamoxifen. Exploratory data suggest that predictive markers of response include a higher estrogen receptor expression level and a negative HER2 status. With the introduction of "biologic" agents and surrogate markers like Ki-67, several studies are evaluating which patients are more likely to respond to preoperative hormonal agents. This review summarizes recent data on neoadjuvant endocrine therapy for breast cancer and the implication of predictive markers of response into clinical practice and future research.     

乳腺癌内分泌治疗的进展

内分泌治疗是激素受体阳性乳腺癌综合治疗的重要组成部分,其疗效已得到广泛的认可.随着新的内分泌药物的出现,乳腺癌的内分泌治疗也取得了新的进展.目前,三苯氧胺对绝经前患者仍是内分泌治疗的标准用药,但对绝经后患者应用芳香化酶抑制剂会有更大的效益.芳香化酶抑制剂及药物去势等多个大型的临床研究还正在进行并备受关注.本文概述乳腺癌的内分泌治疗并着重介绍近期的进展.     

luminal型乳腺癌新辅助内分泌治疗的研究进展

luminal型乳腺癌的激素受体呈阳性表达,因此,临床上内分泌治疗具有重要地位。新辅助内分泌治疗可能使luminal型乳腺癌降期,也能提高保留乳房率,并能为术后系统治疗提供有效的生物学信息。由于绝经前与绝经后luminal型乳腺癌的新辅助内分泌治疗策略存在较大区别,同时内分泌治疗药物的选择及使用时间仍在不断研究及探索中,笔者就luminal型乳腺癌新辅助内分泌治疗的研究进展进行综述。     

Adjuvant endocrine therapy for operable breast cancer

A brief resume of adjuvant endocrine therapy for operable breast cancer is given. This was first suggested in the 1930's but has only become accepted in the last 10-15 years. The reason for the lack of survival benefit in the first randomised trial, which began in 1948 in Manchester, was thought to be due to the increasing use of hormone therapy for metastases. Revival of interest came with the survival gain reported in the Toronto ovarian trial and the success in post-menopausal patients of the non-toxic anti-oestrogen tamoxifen. The different dose schedules used in the various large tamoxifen trials could explain the confusingly variable results in the literature. Combined analysis of trial results indicates that CMF is the adjuvant therapy of choice for pre-menopausal patients but this therapy may in part be acting through the ovaries. The Scottish and NATO trials have an overall survival advantage from adjuvant tamoxifen, even in pre-menopausal patients, and both have shown results to be independent of oestrogen receptor (ER) status. Whether the extra 3 years given in Scotland adds an additional benefit over the more commonly used 2-year course is uncertain. A statistically invalid look at selected data in the Scottish trial suggests that, in ER positive cases, post-relapse tamoxifen may have as great an effect on total survival as adjuvant use, a finding similar to that suggested by the first ovarian ablation trial and one requiring continued review.     

Adjuvant endocrine therapy for early breast cancer

Breast cancer is the most common cancer among women and about 80% of breast cancers express hormone receptors. Tamoxifen has been the most important form of adjuvant endocrine therapy over the last 25 years. The third generation aromatase inhibitors (AIs) are a new class of drugs challenging the central role of tamoxifen as adjuvant endocrine treatment in postmenopausal women with hormone receptor-positive breast cancer. Their effectiveness has been demonstrated in first line therapy as well in neoadjuvant setting with a statistically significant superiority over tamoxifen. Here we considered the role of adjuvant AIs in early stage breast cancer with an analysis reviewing the main adjuvant trials. We considered efficacy, side effects, optimal timing, duration of the therapy and whether specific subgroups may achieve particular benefit. In conclusion the upfront use of adjuvant anastrozole or letrozole is superior to tamoxifen with a good relative toxicity profile. Tamoxifen will continue to have a role where recurrence risk is low or if AI is poorly tolerated. Issues including the timing of administration (up-front or sequential), the duration of the therapy and the role of biomarkers such as PgR and HER2 in optimal selection remain unresolved.     

Selecting adjuvant endocrine therapy for breast cancer

This year alone, more than 215,000 women in the United States will be diagnosed with, and over 40,000 will die from, invasive breast cancer. Recently, mortality from female breast cancer has declined despite an increase in its incidence. This decline corresponds with improved screening for prompt tumor detection, and advances in the treatment of early disease. Of these, endocrine therapy has played a prominent role. For women with estrogen receptor (ER)-positive and/or progesterone receptor (PR)-positive breast cancers, endocrine therapy has proven to be a major component of adjuvant therapy, but it is not effective in women whose breast cancers lack ERs and PRs. The selective estrogen-receptor modulator (SERM) tamoxifen has been well established as safe and effective in the adjuvant care of both pre- and postmenopausal women with hormone-receptor-positive early breast cancer. For premenopausal women, ovarian suppression is an important option to be considered. Additionally, the aromatase inhibitors have recently demonstrated utility in postmenopausal women. The ideal sequencing of treatment with tamoxifen and/or an aromatase inhibitor is the subject of several ongoing studies. Factors involved in selecting an appropriate endocrine regimen have grown considerably over the past decade. It is becoming more important for those caring for women with breast cancer to fully understand the available endocrine treatment options and the prognostic and predictive factors available to help select the most appropriate treatment. The goal of this article is to assist clinicians in making decisions regarding adjuvant hormonal therapy and to provide information regarding available clinical trials. To achieve this, the therapeutic options for hormonal therapy will be reviewed, as will prognostic and predictive factors used in making decisions. Finally, four cases illustrating these difficult decisions will be discussed, with recommendations for treatment.     

Predictors of response to second-line endocrine therapy for breast cancer

This study reports on factors predicting response tosecond-line endocrine therapy in 250 patients with breastcancer for which they were assessable for responseby the International Union Against Cancer (UICC) criteria.Clinical details relating to first-line endocrine therapy wereavailable for all patients. We have not includedin this study patients who received first-line endocrinetherapy but did not or have not yetproceeded to second-line hormone therapy – e.g. diedfrom rapidly progressive disease, started chemotherapy for rapidlyprogressive disease, or remained in long-term remission onfirst-line endocrine therapy.One hundred and fifty nine patients (72%) achievedremission (objective response and static disease [OR +SD]) on first-line endocrine therapy with a medianduration of 19 months. For second-line endocrine therapythe remission rate was 53% (132/225) with amedian duration of 15 months. Tumour grade andoestrogen receptor status of the primary tumour wereshown to be independent predictors of response tosecond-line endocrine therapy while response to first-line endocrinetherapy was a predictor of the duration ofresponse to second-line endocrine therapy. In the sub-groupof patients who showed OR or SD toboth first and second-line therapies, there was nocorrelation between the time to progression (TTP) onfirst and second-line therapies.     

How to improve endocrine therapy of breast cancer

The characteristics of endocrine therapy have made it a standard therapy in metastatic breast cancer. Principles for endocrine therapy in the advanced situation are discussed. Recent overviews have shown a definite, although limited effect also in the adjuvant situation. Three possible ways for further improvement of endocrine therapy are discussed. Firstly, the relevance of results with endocrine therapy in advanced disease for the adjuvant situation is challenged. It is suggested that the most meaningful parameter to look for in the metastatic situation might still be the response rate. Secondly, the question is raised of more reliable predictors of effect of endocrine therapy. A possible model for testing in a neoadjuvant setting in operable cancers is suggested. Thirdly, selection criteria for drugs used in endocrine treatment are discussed, in relation to proven efficacy and short-term and long-term toxicity. As endocrine therapy in the future will probably be more frequently used in patients with better prognosis, the aspect of long-term toxicity will be of major concern.     

Response to endocrine therapy and breast cancer differentiation

Summary The purpose of this study was to determine whether aspects of tumour differentiation are associated with response to endocrine therapy in patients with advanced breast cancer. The features studied were the histological type, grade, and elastosis content of the primary tumours, and the disease-free interval. Statistically significant associations were observed between response to endocrine therapy and histological grade and disease-free interval. In addition, statistically significant associations were observed between histological grade and elastosis and disease-free interval. It is concluded that tumours which are more highly differentiated have a better chance of responding to endocrine therapy.