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.     

Adjuvant endocrine treatment in early prostatic cancer

Adjuvant endocrine treatment of prostatic cancer is not an established method at present. With our knowledge of the mechanisms of endocrine dependence of human prostate cancer and of available clinical data, a beneficial effect on survival seems unlikely. It has been shown by several investigators that endocrine treatment has a more favorable effect on the primary tumor than on distant metastases, and local progression under endocrine management is seen less frequently than progression to distant metastases. Studies in patients with lymph node positive but otherwise locally confined prostate cancer have shown that time to progression can be delayed by a factor of 3 with early adjuvant endocrine treatment. Radical surgery and radiotherapy may be facilitated by preceding endocrine measures. There is, however, no evidence at present that initially inoperable tumors may become accessible to radical surgery or that preceding endocrine treatment improves the results of radical surgery. Such an effect appears to be unlikely unless one assumes that prostate cancer cells growing outside the prostate will disappear completely or retract into that organ, hypotheses that are not supported by clinical or experimental observations. It is unknown at present whether very early adjuvant treatment may prevent the progression and the promotion of focal disease to clinical prostate cancer. This possibility should be made a subject of future research.     

绝经前和围绝经期乳腺癌辅助内分泌治疗

回顾绝经前和围绝经期早期乳腺癌术后辅助内分泌治疗,综述第3代芳香化酶抑制剂(AI)联合药物性卵巢去势在术后辅助治疗中的应用.     

Adjuvant endocrine therapy for premenopausal women with early breast cancer

Adjuvant endocrine therapy is a pivotal component of treatment for premenopausal women with early-stage hormone receptor-positive breast cancer. Currently, the standard endocrine therapy for premenopausal women is tamoxifen; a role for ovarian suppression or ablation has also been identified. Uncertainty remains about the optimal use of endocrine therapy in this setting. The role of ovarian suppression with tamoxifen or aromatase inhibitor, the optimal duration of adjuvant endocrine therapy and the utility of biomarkers and pharmacogenetic studies to select therapy are questions worthy of further investigation.     

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.     

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.     

Adjuvant treatment for early breast cancer: the Ludwig breast cancer studies

The Ludwig Breast Cancer Study Group conducted four concomitant trials involving adjuvant chemotherapy and endocrine therapy. In Ludwig I, adjuvant combination chemotherapy was used with or without prednisone to treat premenopausal and perimenopausal women with metastases in 1-3 axillary lymph nodes. The impact of adding low-dose, continuous prednisone (7.5 mg/day) to an adjuvant, chemotherapy regimen of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) was investigated in a randomized trial of 491 premenopausal and perimenopausal patients with operable breast cancer and metastases in 1-3 axillary lymph nodes. As a consequence of lower hematologic toxicity, a significantly higher dose of CMF could be administered with added prednisone (P less than 0.0001). However, at the 4-year median follow-up, no significant improvement was observed in disease-free survival (DFS) (73% vs. 77%; P = 0.35) or overall survival (OS) (both 86%; P = 0.73). Induced amenorrhea was associated with a longer DFS for younger patients, those who received lower CMF doses, and those with tumors that were estrogen receptor (ER) positive. In Ludwig III, adjuvant therapy was administered to younger postmenopausal women in a study of chemotherapy plus endocrine therapy versus endocrine therapy alone versus mastectomy alone. In this randomized trial of 463 postmenopausal women 65 years of age or younger with axillary node metastases, treatment with the combination of CMF plus low-dose prednisone and tamoxifen (CMFp + T), was compared to endocrine therapy alone (p + T) or to no further treatment after total mastectomy and axillary clearance. At a median follow-up of 4 years, the DFS was 61% for the CMFp + T group, compared with 48% for the p + T group (P = 0.01) and 31% for the observation group (P less than 0.0001). The 4-year OS rates were not statistically different (76%, 67%, and 68%, respectively; P = 0.30). Treatment with CMFp + T reduced local, regional, and distant metastases and was equally effective in improving DFS in patients with ER-positive or ER-negative tumors. In Ludwig II, chemotherapy was given with or without oophorectomy in premenopausal and perimenopausal patients with metastases in 4 or more axillary nodes.(ABSTRACT TRUNCATED AT 400 WORDS)     

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 hormonal therapy in early breast cancer

For many years, tamoxifen has been the gold standard adjuvant hormonal therapy with the greatest impact in early breast cancer for both pre- and postmenopausal women. Tamoxifen-based adjuvant endocrine therapy and chemotherapy have together contributed substantially to the reduction in breast cancer mortality that has occurred in recent years. Over the past few years, the role of aromatase inhibitors has grown in prominence and they are now on the threshold of supplanting tamoxifen as the new gold standard adjuvant therapy for postmenopausal women with estrogen-receptor-positive disease. With extended use of oral antihormones such as tamoxifen, the role of ovarian suppression on the other hand has become less clear in the adjuvant setting. This article reviews the most important data regarding the various adjuvant hormonal treatments in the management of early breast cancer and will also give a brief overview of the role of these agents in the neoadjuvant setting.     

Adjuvant targeted therapy in early breast cancer

For this review, the authors appraised the evidence for adjuvant trastuzumab therapy in early breast cancer. There was level 1 evidence to support the routine use of 1 year of adjuvant trastuzumab in conjunction with chemotherapy for women with human epidermal growth factor receptor 2 (HER‐2)‐positive early breast cancer. The relative benefits of concurrent versus sequential administration remained unclear; however concurrent administration permitted the earliest possible intervention with trastuzumab with possible superiority. There was evidence to support the use of trastuzumab in both lymph node‐positive and high‐risk lymph node‐negative patients, and preliminary data suggested that all patient subgroups that were eligible for the trials benefit equally from trastuzumab. Adjuvant trastuzumab was associated with a risk of cardiotoxicity, the long‐term impact of which remains largely unknown. Routine cardiac risk assessment considering left ventricular ejection fraction, age, and prior history of cardiac events is recommended along with the selection of trastuzumab‐based regimens that minimize cardiotoxicity. Trastuzumab acquisition costs for 1 year of therapy were the largest component of treatment costs. Cancer 2009. © 2009 American Cancer Society.