SAN DIEGO (EGMN) – Adding radiation therapy after lumpectomy reduced the risk of recurrent breast cancer within 10 years by nearly 15% and reduced the overall chance of dying from the disease within 15 years by nearly 4%, results from a large long-term analysis demonstrated.

During a Nov. 1 press briefing at the annual meeting of the American Society for Radiation Oncology, Sarah C. Darby, Ph.D., presented the findings on behalf of the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) that reviewed the medical records of 10,906 women who participated in 17 randomized trials of radiation therapy after breast-conserving surgery with a median follow-up of 9.5 years.

Every 5 years since 1985, the 400-plus members of the EBCTCG worldwide have shared their data, said Dr. Darby, professor of medical statistics at Oxford University’s Clinical Trial Service Unit and Epidemiological Studies Unit. The combination of moderate gains in treatment and screening has led to a halving of breast cancer mortality among women aged 35-69 years in the United States and in the United Kingdom since the late 1980s, she said.

Among all 10,906 women evaluated in the current analysis, Dr. Darby reported that adding radiation therapy reduced the 10-year risk of breast cancer recurrence by 14.6% (from 37.3% to 22.7%) and the 15-year risk of death from the disease by 3.7% (from 25.4% to 21.7%).

Of the 7,334 women with pathology-confirmed node-negative disease, adding radiation therapy reduced the 10-year risk of isolated locoregional recurrence by 15.4% (from 22.5% to 7.1%) and the 10-year risk of any recurrence by 14.5% (from 33.4% to 18.9%).

Certain factors associated with node-negative disease were associated with a greater benefit from radiation therapy. For example, among women with estrogen receptor–positive tumors in trials where tamoxifen use was planned, radiation therapy reduced the 10-year risk of recurrence for women aged 40 years and younger by 35% (from 55% to 20%). At the same time, radiation therapy reduced the 10-year risk of recurrence for women aged 70 and older with low-grade tumors by only 5% (from 11% to 6%).

Of the 1,108 women studied who had pathology-confirmed node-positive disease, radiation therapy reduced the 10-year risk of recurrence by 17.7% (from 64.5 to 46.8%) and reduced their 15-year risk of death by 7.8% (from 51.2% to 43.4%).

Dr. Darby said that she had no relevant financial conflicts to disclose.

Copyright (c) 2010 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

圣地亚哥(EGMN)——一项长期分析结果表明，乳房肿瘤切除术后使用放射治疗能将10年内乳腺癌复发率降低15%，并将15年内总死亡率降低4%。

 

在11月1日美国放射肿瘤学会年会上发布的一条简讯中，Trialists早期乳腺癌试验协作组(EBCTCG, Early Breast Cancer Trialists’ Collaborative Group)的研究者仔细审查了17个随机试验中10,906名妇女在乳腺保守手术后接受放射治疗的情况，该调查随访期平均为9.5年。

 

通过治疗和筛查发现，自从1980年以来，美国和英国年龄在35~69岁之间乳腺癌妇女的死亡率已降低了一半。当前分析中的10,906名妇女在额外增加放射治疗后，10年内乳腺癌复发率风险降低了14.6%(从37.3%降至22.7%)，15年内该症的死亡率降低了3.7%(从25.4%降至21.7%)。7334名妇女通过病理学方法确定了淋巴结阴性疾病，从而使放射治疗将10年内局部单独病灶复发率降低了15.4%(从22.5%降至7.1%)，10年内总复发率降低了14.5%(从33.4%降至18.9)。

 

放射治疗给淋巴结阴性疾病相关的某些因素带来更多好处。例如，在计划使用它莫西芬治疗雌激素受体阳性肿瘤的妇女中，放射治疗能降低40岁以下患者10年复发风险率达35%(从55%降至20%)。与此同时，放射治疗仅减少了70岁以上患者低度恶性瘤10年内复发率达5%(从11%降至6%)。1,108名通过病理学方法确定的淋巴结阳性妇女中，放射治疗能降低10年复发率达17.7%(从64.5%降至46.8%)，15年内死亡率降低7.8%(从51.2%降至43.4%)。

 

研究者表示无相关经济冲突需要披露。

 

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