乳癌的荷爾蒙治療

Hormone Therapy for Breast Cancer

饒坤銘(Kun-Ming Rau)

《中華民國癌症醫學會雜誌》 24卷2期 (2008/04) Pp. 127-131

https://doi.org/10.6588/JCOS.2008.24.2.8

摘要

乳癌的發生與成長，有一部份與女性荷爾蒙的不斷刺激有關。在此類的乳癌，若能阻斷女性荷爾蒙的作用，就能有效的抑制乳癌的成長與復發。決定乳癌細胞是否受女性荷爾蒙調控，有賴病理切片分析女性荷爾蒙接受器－尤其是雌性素接受器(estrogen receptor, ER)是否有表現。停經後女性的乳癌，有2/3是ER陽性；反之停經前女性的乳癌，只有1/3是ER陽性。針對乳癌患者的荷爾蒙治療機轉，可分三個方向：第一是減少女性荷爾蒙的分泌量，此類藥物有停經前婦女適用的促性腺成長激素類似物(GnRH agonist)，以及停經後婦女適用的芳香環轉化酶抑制劑(Aromatase inhibiter, AI)。第二是去競爭性阻止女性荷爾蒙與ER結合，此類藥物最具代表性的就是tamoxifen。第三則是直接破壞ER，最新的藥物為Fulvestrant。這些藥物，各有優缺點，也各有適用的年齡，但前提是腫瘤一定要為ER陽性。至於藥物使用的時機，包括術後的輔助性治療，以及發生轉移時的緩和性治療。前者以減少復發為主要目標，後者以控制病情惡化，延長患者壽命為主。Tamoxifen固然是治療停經前婦女所謂”gold standard”，但目前更多的研究與進展則是在停經後病患使用AI做為輔助性治療，現在普遍接受的看法是一開始就使用AI五年，或接續於tamoxifen後使用至五到十年，都比單獨使用tamoxifen五年能更有效減少復發，甚至能延長病患整體存活時間。面對越來越多的資訊，臨床醫師應熟知各項藥物使用的條件、時機與順序，尤其是在藥物長期使用所引發之副作用的診斷與處理方式，以確實能控制疾病、減少復發，並改善患者生活品質。

關鍵字

乳癌 ； 荷爾蒙治療 ； 雌性素受體 ； 芳香環轉化酶抑制劑

並列摘要

A part of breast cancers depend on stimulus from estrogen for their growth. In such cases, once we can block the effect from estrogen, we can effectively inhibit the growth and recurrence of breast cancers. Only hormone receptor, especially estrogen receptor (ER) positive cancer cells can be stimulated by estrogen. There are about 2/3 postmenopausal patients' breast cancers are ER positive; on the contrast, only 1/3 premenopausal patients' breast cancers are ER positive. Hormone therapy, in such cases, can work at 3 different mechanisms. The first mechanism is to decrease estrogen production. Drugs of this kind include gonadotropin releasing hormone agonist (GnRH agonist) for premenopausal women and aromatase inhibitors (AIs) for postmenopausal women. The secondary mechanism is to competitively inhibit estrogen binding to ER, the most important drug is tamoxifen. The third mechanism is to destroy ER directly, such as Fulvestrant. These drugs work through different mechanisms and on different patient population whose cancer cells must be ER positive. They can be used as adjuvant therapies after surgery, in order to decrease disease recurrence. They also can be used as palliative therapies in order to delay disease progression then to prolong life. Although tamoxifen is now the gold standard for premenopausal women, most of recent studies and reports focused on AIs as adjuvant therapies for postmenopausal women. It is now widely accepted that AIs, either upfront use for 5 years, or sequential use with tamoxifen for total 5 to 10 years, are more effective than tamoxifen alone on disease recurrence and even overall survival. Since there is so much information, clinicians should be familiar with all these drugs’ indication, effects and especially, the diagnosis and managements of side effects which might happen after long-term use, so that we can really decrease disease recurrence, delay disease progression and improve quality of life for our patients.

並列關鍵字

breast cancer ； hormone therapy ； estrogen receptor ； aromatase inhibiter