华陀再世
一个中国医学生(CMG)在美国的生活。。。
乳癌保乳术后接受放射疗法可以使乳腺癌复发的风险减半
(记者萨迪·怀特洛克斯) [英国《每日邮报》网站10月21日报道]
科学家说，放射线疗法大大降低接受过乳房肿瘤切除术的乳腺癌患者肿瘤复发的风险。
牛津大学的研究人员发现，术后放疗能使乳腺癌复发的几率减少50%。
研究人员在10年期间，对1万多名女性的数据进行了评估。这是同类研究中最为深入的研究之一。
研究结果表明，放疗能减少癌症向身体其他部分扩散的可能性，是许多人挽救生命的重要手段。
医生往往在手术后对病人实施利用高能X光的放射线疗法，杀死没有被切除的癌细胞。
此项研究的负责人萨拉·达比教授说：“一些人一直怀疑，是否所有患者都有必要在保乳术后接受放疗。我们的研究结果证实，对几组女性而言，放疗是挽救生命的重要手段。”
放疗经过谨慎的设计，以确保尽可能多地杀死癌细胞，同时保护健康细胞。放疗次数取决于肿瘤的位置、肿瘤大小和类型以及患者的总体健康状况。
此项研究涉及的所有女性以前都有通过乳房肿瘤切除术就可以去除的小肿瘤。
在历时10年的研究期间，患者的病情受到监控，科学家将接受过和没有接受过放疗的女性的状况进行了对比。
达比教授指出，虽然自从研究开始以来，乳腺癌的治疗方法一直在发展，但了解放疗的长期益处将有助于指导今后的治疗。 她还说：“只要有可能，患乳腺癌的女性都接受手术，要么是乳房切除术(切除整个乳房)，要么是保乳手术(只切除部分乳房)。”
达比教授说：“目前的原则是，接受过保乳手术的所有女性都应进行放疗。对于接受了乳房切除术的女性而言，如果肿瘤已扩散至腋下淋巴结但没有扩散至其他地方，放疗是有必要的。”
此项研究结果本周刊登在《柳叶刀》医学期刊上。托马斯·巴克霍尔兹教授评价说：“放疗降低乳腺癌复发的风险，更重要的是，放疗提高总体生存几率。”
他说：“放疗使乳腺癌复发的可能性减少50%，这或许是治疗乳腺癌最有效的方法。”
Breast Cancer Study: Radiation Slashes Recurrence, Saves Lives
Radiation therapy following breast conserving surgery reduced the rate of disease recurrence by half, a large meta-analysis found.
In trials of more than 10,000 women with breast cancer, the use of radiation therapy decreased the risk of recurrence within 10 years from 35% to 19.3%, according to investigators from the Early Breast Cancer Trialists' Collaborative Group (EBCTCG).
That represented an absolute reduction of 15.7% (95% CI 13.7 to 17.7, 2P<0.00001), the investigators reported online in The Lancet.
Because the possibility that microscopic remnants of tumor may remain with breast conserving surgery, radiation has often been used with the aim of preventing recurrences and metastases.
However, the long-term outcomes of these efforts have not been fully chronicled, so the EBCTCG have been following their large cohort of clinical trial participants and periodically updating their outcomes data.
The current report included 17 trials that began before 2000, six of which evaluated the use of radiation therapy after lumpectomy in 4,398 low- and high-risk women.
Four of the trials examined the results of radiotherapy after quadrantectomy or sector resection in 2,399 women. The remaining seven compared radiotherapy following lumpectomy in 4,004 women considered to be at low risk.
This analysis found that not only did radiotherapy reduce the rate of 10-year recurrences, but also decreased the 15-year mortality risk by 3.8% (95% CI 1.6 to 6, 2P=0.00005), the investigators reported.
Women who had radiation therapy after their surgery also had half the annual rate of a first recurrence compared with those not given radiotherapy (RR 0.52, 95% CI 0.48 to 0.56), with the greatest benefit seen during year one (RR 0.31, 95% CI 0.26 to 0.37).
The annual death rate was reduced with the use of radiation therapy by about one-sixth (RR 0.82, 95% CI 0.75 to 0.90).
The investigators also looked at differences depending on whether the women had lymph node positive or negative disease.
Among those who were lymph node negative and had radiotherapy, the annual recurrence rate during the first 10 years fell by about half (RR 0.46, 95% CI 0.41 to 0.51).
This decreased the 10-year recurrence risk to 15.6% from 31%, which represented an absolute risk reduction of 15.4% (95% CI 13.2 to 17.6, 2P<0.00001), the investigators found.
These lymph node negative women also had a decrease in mortality over 15 years, to 17.2% from 20.5%, which was an absolute risk reduction of 3.3% (95% CI 0.8 to 5.8, 2P=0.005).
Women who were lymph node positive and received radiation therapy experienced a five-fold decrease in recurrences during the first year, from 26% to 5.1% (RR 0.20, 95% CI 0.14 to 0.29), according to the investigators.
Mortality also was reduced in lymph node positive women who had radiotherapy (RR 0.79, 95% CI 0.65 to 0.95, 2P=0.01).
Further analyses of patient subgroups determined that absolute reduction in recurrences was significantly associated with age (2P=0.0002), tumor grade (2P<0.00001), and estrogen receptor status and use of tamoxifen (2P=0.003).
Finally, the investigators calculated that among the entire cohort, by year 15 one death was prevented for every four recurrences prevented at year 10.
They noted that the risk reduction was less in the most recent trials with the wider use of tamoxifen.
"However, even for women with [lymph node negative] disease in the recent low-risk trials, the predicted absolute 10-year recurrence reduction with radiotherapy exceeded 10% in most women and exceeded 20% in some women," they observed.
In a comment accompanying the meta-analysis, Thomas A. Buchholz, MD, of the University of Texas MD Anderson Cancer Center in Houston, observed, "These results confirm that radiation is effective in eradication of much of the microscopic locoregional disease that might still be present after surgery."
"The data reinforce the important role that radiotherapy has in management of breast cancer, and the fact that the benefits of radiation are complementary to the advances in both surgery and systemic treatment is particularly rewarding," Buchholz wrote.
论文摘要：
Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10 801 women in 17 randomised trials
Early Breast Cancer Trialists' Collaborative Group (EBCTCG)‡
The Lancet, Early Online Publication, 20 October 2011 DOI: 10.1016/S0140-6736(11)61296-8.
Background
After breast-conserving surgery, radiotherapy reduces recurrence and breast cancer death, but it may do so more for some groups of women than for others. We describe the absolute magnitude of these reductions according to various prognostic and other patient characteristics, and relate the absolute reduction in 15-year risk of breast cancer death to the absolute reduction in 10-year recurrence risk.
Methods
We undertook a meta-analysis of individual patient data for 10 801 women in 17 randomised trials of radiotherapy versus no radiotherapy after breast-conserving surgery, 8337 of whom had pathologically confirmed node-negative (pN0) or node-positive (pN+) disease.
Findings
Overall, radiotherapy reduced the 10-year risk of any (ie, locoregional or distant) first recurrence from 35·0% to 19·3% (absolute reduction 15·7%, 95% CI 13·7—17·7, 2p<0·00001) and reduced the 15-year risk of breast cancer death from 25·2% to 21·4% (absolute reduction 3·8%, 1·6—6·0, 2p=0·00005). In women with pN0 disease (n=7287), radiotherapy reduced these risks from 31·0% to 15·6% (absolute recurrence reduction 15·4%, 13·2—17·6, 2p<0·00001) and from 20·5% to 17·2% (absolute mortality reduction 3·3%, 0·8—5·8, 2p=0·005), respectively. In these women with pN0 disease, the absolute recurrence reduction varied according to age, grade, oestrogen-receptor status, tamoxifen use, and extent of surgery, and these characteristics were used to predict large (≥20%), intermediate (10—19%), or lower (<10%) absolute reductions in the 10-year recurrence risk. Absolute reductions in 15-year risk of breast cancer death in these three prediction categories were 7·8% (95% CI 3·1—12·5), 1·1% (—2·0 to 4·2), and 0·1% (—7·5 to 7·7) respectively (trend in absolute mortality reduction 2p=0·03). In the few women with pN+ disease (n=1050), radiotherapy reduced the 10-year recurrence risk from 63·7% to 42·5% (absolute reduction 21·2%, 95% CI 14·5—27·9, 2p<0·00001) and the 15-year risk of breast cancer death from 51·3% to 42·8% (absolute reduction 8·5%, 1·8—15·2, 2p=0·01). Overall, about one breast cancer death was avoided by year 15 for every four recurrences avoided by year 10, and the mortality reduction did not differ significantly from this overall relationship in any of the three prediction categories for pN0 disease or for pN+ disease.
Interpretation
After breast-conserving surgery, radiotherapy to the conserved breast halves the rate at which the disease recurs and reduces the breast cancer death rate by about a sixth. These proportional benefits vary little between different groups of women. By contrast, the absolute benefits from radiotherapy vary substantially according to the characteristics of the patient and they can be predicted at the time when treatment decisions need to be made.
Funding
Cancer Research UK, British Heart Foundation, and UK Medical Research Council.
