- 期刊
乳癌基因檢測之臨床應用與倫理考量
Clinical Utilization and Ethical Considerations of Breast Cancer Genetic Testing
摘要
BRCA 1與BRCA 2具有修補DNA及調控細胞生長週期的重要功能，此二基因的突變帶原者被發現終其一生其罹患乳癌的機會可高達80%以上。BRCA 1/2基因的突變甚少發生於一般人，而是與人種和家族有關。因此，BRCA1/2的基因檢測並不被列於一般常規檢驗項目，而只建議用於乳癌高風險族群。檢測結果的判斷，必須根據被檢者的乳癌風險評估資料；檢測的結果不僅代表著個人罹患乳癌的可能性，更影響著個人及家族未來的健康醫療計畫。結果的告知極可能引發受檢者對罹患乳癌的焦慮與害怕。故基因檢測需要一個嚴謹的、持續性的、多次性的諮詢過程，以達到正確危險因子評估，詳實的訊息告知，並藉此支持被檢者選擇最適合的乳癌風險降低策略。目前被認為有利於降低乳癌風險的策略有四；1.良好的生活型態；2.定期篩檢；3.預防性藥物處置，例如：Tamoxifen或Raloxifene；4.預防性乳房／卵巢手術切除。其中藥物性處置和外科切除手術，已被報告可大幅度減少乳癌發生機率；但是，這些正面效益的報告多不是來自隨機分派臨床試驗。更重要的是，不論是藥物使用或手術的執行皆有可能發生短期的合併症或長期副作用的危險。乳癌基因資訊的揭發和風險降低策略的執行所帶來的利與弊，不僅是醫療處置的討論，更牽涉著對醫療倫理包括良善與不傷害、自主以及隱私權保護原則的挑戰，是身為醫護人員的我們不可忽略的重要臨床議題。
並列摘要
The genes of BRCA 1 and BRCA 2 play an essential role in DNA repair and cell cycle regulation. Mutation of these two genes is associated with an 80% lifetime risk of developing breast cancer. BRCA 1/2 gene mutation rarely occurs in general population, but is race and family related. Thus, genetic testing of BRCA1/2 mutation is not considered as routine test. Instead, it is recommended for high-risk groups for breast cancer. Understanding of the breast cancer risk factors in the particular individual is a crucial basis in the interpretation of testing results, for the results not only disclose the possibility of developing breast cancer, but also the need for future plans of the subject as well as his /her family regarding their healthcare. This information, undoubtedly, can cause a certain degree of anxiety and fear for the subject and the family. Consequently, genetic counseling sessions are needed in order to achieve a comprehensive assessment of risk factors, provision of accurate information, and to support and help the subject to choose the best risk-reducing strategies. Four strategies have been recommended to reduce the risk of developing breast cancer: 1. Life style modification, 2. Screening, 3. Prophylactic pharmacological interventions, e.g.: Tamoxifen or Raloxifen, and 4. Prophylactic surgery. Among these, pharmacological interventions and surgery have been proven to significantly reduce the risk of breast cancer. Nevertheless, majority of the evidences are not reported from randomized controlled trials. Furthermore, both medical and surgical strategies may result in acute complications or long term adverse effects. The pros and cons of uncovering the genetic information and formulating risk-reducing strategies do not just mean a simple discussion of medical treatment, but also post a medical ethics challenge including beneficence and do no harm, respect for autonomy, privacy and so on. As healthcare providers, these issues must be taken into consideration when we encounter patients with breast cancer.