科學(xué)家說，放射線療法大大降低接受過乳房腫瘤切除術(shù)的乳腺癌患者腫瘤復(fù)發(fā)的風(fēng)險,。

牛津大學(xué)的研究人員發(fā)現(xiàn),，術(shù)后放療能使乳腺癌復(fù)發(fā)的幾率減少50%。研究人員在10年期間,，對1萬多名女性的數(shù)據(jù)進行了評估,。這是同類研究中最為深入的研究之一。研究結(jié)果表明,，放療能減少癌癥向身體其他部分?jǐn)U散的可能性,，是許多人挽救生命的重要手段。醫(yī)生往往在手術(shù)后對病人實施利用高能X光的放射線療法,，殺死沒有被切除的癌細(xì)胞,。

此項研究的負(fù)責(zé)人薩拉·達比教授說：“一些人一直懷疑，是否所有患者都有必要在保乳術(shù)后接受放療,。我們的研究結(jié)果證實,，對幾組女性而言，放療是挽救生命的重要手段,。”放療經(jīng)過謹(jǐn)慎的設(shè)計,，以確保盡可能多地殺死癌細(xì)胞，同時保護健康細(xì)胞,。放療次數(shù)取決于腫瘤的位置,、腫瘤大小和類型以及患者的總體健康狀況。

此項研究涉及的所有女性以前都有通過乳房腫瘤切除術(shù)就可以去除的小腫瘤,。在歷時10年的研究期間,，患者的病情受到監(jiān)控，科學(xué)家將接受過和沒有接受過放療的女性的狀況進行了對比,。達比教授指出,，雖然自從研究開始以來，乳腺癌的治療方法一直在發(fā)展,，但了解放療的長期益處將有助于指導(dǎo)今后的治療,。她還說：“只要有可能,，患乳腺癌的女性都接受手術(shù)，要么是乳房切除術(shù)(切除整個乳房),，要么是保乳手術(shù)(只切除部分乳房),。”

達比教授說：“目前的原則是，接受過保乳手術(shù)的所有女性都應(yīng)進行放療,。對于接受了乳房切除術(shù)的女性而言,，如果腫瘤已擴散至腋下淋巴結(jié)但沒有擴散至其他地方，放療是有必要的,。”

此項研究結(jié)果本周刊登在《柳葉刀》醫(yī)學(xué)期刊上,。托馬斯·巴克霍爾茲教授評價說：“放療降低乳腺癌復(fù)發(fā)的風(fēng)險，更重要的是,，放療提高總體生存幾率,。”

他說：“放療使乳腺癌復(fù)發(fā)的可能性減少50%，這或許是治療乳腺癌最有效的方法,。”（生物谷 Bioon.com）

doi:10.1016/S0140-6736(11)61629-2
PMC:
PMID:
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)‡

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.