放射治疗对老年导管原位癌女性患者的疗效
Effectiveness of radiation therapy in older women with ductal carcinoma in situ.
作者信息
Smith Benjamin D, Haffty Bruce G, Buchholz Thomas A, Smith Grace L, Galusha Deron H, Bekelman Justin E, Gross Cary P
机构信息
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA.
出版信息
J Natl Cancer Inst. 2006 Sep 20;98(18):1302-10. doi: 10.1093/jnci/djj359.
BACKGROUND
For women with ductal carcinoma in situ (DCIS), radiation therapy after conservative surgery lowers the risk of recurrence. However, emerging evidence suggests that radiation therapy confers only a marginal absolute benefit for older women with DCIS. In a cohort of older women with DCIS, we sought to determine whether radiation therapy was associated with a clinically significant benefit.
METHODS
Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database from January 1, 1992, through December 31, 1999, we identified 3409 women aged 66 years or older treated with conservative surgery for DCIS. A proportional hazards model tested whether radiation therapy was associated with a lower risk of a combined outcome, defined as a subsequent ipsilateral in situ or invasive breast cancer reported by SEER and/or a subsequent mastectomy reported by Medicare claims. The 5-year event risk was determined for patients without and with high-risk features, which were defined as at least one of the following: age 66-69 years, tumor larger than 2.5 cm, comedo histology, and/or high grade. All statistical tests were two-sided.
RESULTS
Radiation therapy was associated with a lower risk for each component of the combined outcome (hazard ratio = 0.32, 95% confidence interval [CI] = 0.24 to 0.44). For high-risk patients, the 5-year event risk was 13.6% without radiation therapy versus 3.8% with radiation therapy (difference = 9.8%, 95% CI = 6.5 to 13.2; P<.001). For low-risk patients, the 5-year event risk was 8.2% without radiation therapy versus 1.0% with radiation therapy (difference = 7.2%, 95% CI = 3.6 to 10.9; P<.001). Among healthy women aged 66-79 years, the number needed to treat with radiation therapy to prevent one event in 5 years was 11 for high-risk patients and 15-16 for low-risk patients.
CONCLUSION
For older women with DCIS, radiation therapy appears to confer a substantial benefit that remains meaningful even among low-risk patients.
背景
对于导管原位癌（DCIS）女性患者，保乳手术后进行放射治疗可降低复发风险。然而，新出现的证据表明，放射治疗对老年DCIS女性患者仅带来边际绝对获益。在一组老年DCIS女性患者中，我们试图确定放射治疗是否具有临床显著获益。
方法
利用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，我们识别出3409名年龄在66岁及以上因DCIS接受保乳手术的女性。一个比例风险模型测试了放射治疗是否与较低的联合结局风险相关，联合结局定义为SEER报告的后续同侧原位或浸润性乳腺癌和/或医疗保险理赔报告的后续乳房切除术。确定了无高危特征和有高危特征患者的5年事件风险，高危特征定义为以下至少一项：年龄66 - 69岁、肿瘤大于2.5 cm、粉刺样组织学和/或高级别。所有统计检验均为双侧检验。
结果
放射治疗与联合结局的各组成部分风险较低相关（风险比 = 0.32，95%置信区间[CI] = 0.24至0.44）。对于高危患者，未进行放射治疗的5年事件风险为13.6%，而进行放射治疗为3.8%（差异 = 9.8%，95%CI = 6.5至13.2；P <.001）。对于低危患者，未进行放射治疗的5年事件风险为8.2%，而进行放射治疗为1.0%（差异 = 7.2%，95%CI = 3.6至10.9；P <.001）。在66 - 79岁的健康女性中，高危患者5年内预防1例事件所需的放射治疗人数为11人，低危患者为15 - 16人。
结论
对于老年DCIS女性患者，放射治疗似乎带来了显著获益，即使在低危患者中也仍然有意义。
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