Smith Benjamin D, Gross Cary P, Smith Grace L, Galusha Deron H, Bekelman Justin E, Haffty Bruce G
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520-8040, USA.
J Natl Cancer Inst. 2006 May 17;98(10):681-90. doi: 10.1093/jnci/djj186.
Recent clinical trials have questioned the necessity of breast radiation therapy for older women with early breast cancer. However, the effectiveness of radiation therapy for older women in the community setting has not been addressed.
We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database from January 1, 1992, through December 31, 1999, to identify 8724 women aged 70 years or older treated with conservative surgery for small, lymph node-negative, estrogen receptor-positive (or unknown receptor status) breast cancer. We used a proportional hazards model to test whether radiation therapy was associated with a lower risk of a combined outcome, defined as a second ipsilateral breast cancer reported by SEER and/or a subsequent mastectomy reported by Medicare claims. All statistical tests were two-sided.
Radiation therapy, compared with no radiation therapy, was associated with a lower risk of the combined outcome (hazard ratio = 0.19, 95% confidence interval = 0.14 to 0.28). Radiation therapy was associated with an absolute risk reduction of 4.0 events per 100 women at 5 years (i.e., from 5.1 events without radiation therapy to 1.1 with radiation therapy) and 5.7 events per 100 persons at 8 years (i.e., from 8.0 events without radiation therapy to 2.3 with radiation therapy) (P < .001, log-rank test). Radiation therapy was most likely to benefit those aged 70-79 years without comorbidity (number needed to treat [NNT] to prevent one event = 21 to 22 patients) and was least likely to benefit those aged 80 years or older with moderate to severe comorbidity (NNT = 61 to 125 patients).
For older women with early breast cancer, radiation therapy was associated with a lower risk of a second ipsilateral breast cancer and subsequent mastectomy. Patients aged 70-79 years with minimal comorbidity were the most likely to benefit, and older patients with substantial comorbidity were least likely to benefit.
近期的临床试验对老年早期乳腺癌女性进行乳腺放射治疗的必要性提出了质疑。然而，在社区环境中放射治疗对老年女性的有效性尚未得到探讨。
我们使用了1992年1月1日至1999年12月31日的监测、流行病学和最终结果（SEER）-医疗保险数据库，以识别8724名年龄在70岁及以上、接受保乳手术治疗的小的、淋巴结阴性、雌激素受体阳性（或受体状态未知）乳腺癌女性。我们使用比例风险模型来测试放射治疗是否与联合结局风险较低相关，联合结局定义为SEER报告的同侧第二原发性乳腺癌和/或医疗保险理赔报告的后续乳房切除术。所有统计检验均为双侧检验。
与未接受放射治疗相比，放射治疗与联合结局风险较低相关（风险比=0.19，95%置信区间=0.14至0.28）。放射治疗与5年时每100名女性绝对风险降低4.0例事件相关（即，未接受放射治疗时为5.1例事件，接受放射治疗时为1.1例事件），8年时每100人绝对风险降低5.7例事件（即，未接受放射治疗时为8.0例事件，接受放射治疗时为2.3例事件）（P<0.001，对数秩检验）。放射治疗最有可能使70 - 79岁无合并症的女性受益（预防一例事件所需治疗人数[NNT]=21至22名患者），而最不可能使80岁及以上有中度至重度合并症的女性受益（NNT = 61至125名患者）。
对于老年早期乳腺癌女性，放射治疗与同侧第二原发性乳腺癌及后续乳房切除术风险较低相关。合并症最少的70 - 79岁患者最有可能受益，合并症严重的老年患者最不可能受益。
