Swain Sandra M, Wilson John W, Mamounas Eleftherios P, Bryant John, Wickerham D Lawrence, Fisher Bernard, Paik Soon, Wolmark Norman
National Cancer Institute, Bethesda, MD, USA.
J Natl Cancer Inst. 2004 Apr 7;96(7):516-23. doi: 10.1093/jnci/djh097.
Tamoxifen reduces the risk for contralateral breast cancer by approximately 30%-50%, with benefits probably limited to women with estrogen receptor (ER)-positive primary disease. In a retrospective analysis of data from National Surgical and Adjuvant Breast and Bowel Project trials B-18, B-22, and B-25, we determined whether the ER status of primary breast cancer predicts the ER status of a subsequent contralateral breast cancer and whether tamoxifen treatment affects this relationship. In these trials, tamoxifen at 20 mg/day had been administered only to women aged 50 years or older, rather than to those determined by the ER status of their primary tumor, allowing an assessment of the treatment's effects in ER-negative disease.
Among the 5513 eligible patients, 176 patients developed a contralateral breast cancer. The ER status of the primary and contralateral tumor was determined and cross-classified for women who did not receive tamoxifen (i.e., those aged 49 years or younger) and for women who did (i.e., those aged 50 years or older). ER data were available for 110 evaluable invasive contralateral breast cancers.
Among patients who did not receive tamoxifen (n = 62), 89% with an ER-positive primary cancer had an ER-positive contralateral breast cancer and 70% with an ER-negative primary breast cancer had an ER-negative contralateral breast cancer (odds ratio for the association between primary and contralateral ER status = 14.8, 95% confidence interval = 3.8 to 74.3; P<.001). Among patients who received tamoxifen (n = 48), 56% with an ER-positive primary cancer had an ER-positive contralateral breast cancer and 78% with an ER-negative primary cancer had an ER-negative contralateral breast cancer (odds ratio = 3.4, 95% confidence interval = 0.53 to 39.2; P =.25).
The ER status of the primary breast cancer was associated with that of the contralateral breast for patients not receiving tamoxifen. Patients with an ER-positive primary cancer who received tamoxifen had a lower concordance rate with fewer ER-positive contralateral breast cancers, which may be a result of tamoxifen treatment.
他莫昔芬可使对侧乳腺癌风险降低约30%-50%，其益处可能仅限于雌激素受体（ER）阳性原发性疾病的女性。在对国家外科辅助乳腺和肠道项目试验B-18、B-22和B-25的数据进行的回顾性分析中，我们确定原发性乳腺癌的ER状态是否可预测后续对侧乳腺癌的ER状态，以及他莫昔芬治疗是否会影响这种关系。在这些试验中，仅对50岁及以上的女性给予每日20 mg的他莫昔芬，而非根据其原发性肿瘤的ER状态给药，从而能够评估该治疗对ER阴性疾病的效果。
在5513例符合条件的患者中，176例发生了对侧乳腺癌。确定未接受他莫昔芬治疗的女性（即49岁及以下者）以及接受他莫昔芬治疗的女性（即50岁及以上者）原发性和对侧肿瘤的ER状态，并进行交叉分类。有110例可评估的浸润性对侧乳腺癌的ER数据可用。
在未接受他莫昔芬治疗的患者（n = 62）中，原发性癌症ER阳性的患者中有89%对侧乳腺癌ER阳性，原发性乳腺癌ER阴性的患者中有70%对侧乳腺癌ER阴性（原发性和对侧ER状态之间关联的比值比 = 14.8，95%置信区间 = 3.8至74.3；P <.001）。在接受他莫昔芬治疗的患者（n = 48）中，原发性癌症ER阳性的患者中有56%对侧乳腺癌ER阳性，原发性癌症ER阴性的患者中有78%对侧乳腺癌ER阴性（比值比 = 3.4，95%置信区间 = 0.53至39.2；P =.25）。
对于未接受他莫昔芬治疗的患者，原发性乳腺癌的ER状态与对侧乳腺癌的ER状态相关。接受他莫昔芬治疗的原发性癌症ER阳性患者的一致性率较低，对侧ER阳性乳腺癌较少，这可能是他莫昔芬治疗的结果。
