健康小屋

　　馬里蘭大學的Randi J. Cohen博士在美國放射腫瘤學會(ASTRO)年會上報告，對於早期乳腺癌患者，年齡大本身並不應當被視爲乳房腫瘤切除術後放療的不利因素。在老年乳腺癌患者中，接受術後放療者的5年、10年總生存率和癌症特異性生存率均高於僅接受乳房腫瘤切除術者。

　　研究者對29949名年齡70~84歲、生存至少1年的臨牀Ⅰ期、雌激素受體陽性乳腺癌患者的數據進行了分析。大約3/4的受試者在乳房腫瘤切除術後接受了放療。

　　結果顯示，接受乳房腫瘤切除術+放療者的5年總生存率爲88.6%，高於未放療組的73.1%(P＜0.0001)。兩組患者的10年總生存率分別爲65.0%和41.7%。兩組患者的5年原因特異性生存率分別爲98.3%和97.4%，10年時分別爲95.5%和93.3%(均P＜0.0001)。乳房腫瘤切除術+放療組患者的中位生存期也長於單純乳房腫瘤切除術組，分別爲13.1年和11.1年。

　　放療是獨立預測因素

　　校正年齡、腫瘤大小、種族、導管組織學、淋巴結和婚姻狀況的多變量分析也顯示，不接受放療者的結局明顯更差，總生存率和原因特異性生存率的危險比(HR)分別爲1.56和1.41。

　　上述結果與早期乳腺癌試驗者協作組(EBCTCG)的一項Meta分析結果很相似。這項Meta分析顯示，加用放療可使10年生存率的絕對值增加3%。而根據本項研究，加用放療可使10年生存率的絕對值增加2.2%。

　　Cohen博士稱，2004年癌症與白血病B組(CALGB)的一項試驗促使她開展了本項研究。這項2004年試驗招募了630例≥70歲的女性早期乳腺癌患者，評價了在乳房腫瘤切除術+阿莫西芬的基礎上加用放療是否能改善乳腺癌特異性生存率。經過中位時間10.5年的隨訪，研究者發現加用放療者的相同乳腺癌複發率降低了6%，但總生存率和無病生存率均無差異。

　　Cohen博士認爲，EBCTCG研究和本項研究中顯示的放療獲益，可能與局部區域控制水平提高有關。本項研究中放療對總生存率的益處可能源於選擇了相對更健康、預期壽命更長的患者接受放療。但她承認，缺乏複發率和激素治療相關數據是本項研究的一大侷限性。

　　獲益程度仍有疑問

　　耶魯大學的Meema Moran博士評論指出：“原因特異性生存率方面的獲益程度不太可能僅僅取決於放療。”她注意到，在EBCTCG研究中，加用放療僅能使這一相對低危的人羣在15年時獲得3%的生存益處，這一益處可能部分來源於治療選擇偏倚。

　　她還指出，由於本項研究未收集局部復發數據，研究者將無乳房切除術生存率作爲復發的替代指標，然而乳房切除率可能因同側復發的治療方式不同(乳房切除術或再次保乳手術)而異。

　　Cohen博士未披露本項研究的資金來源。她自稱無相關利益衝突。Moran博士報告稱爲基因組健康諮詢委員會提供了服務。

　　相關鏈接: Internal Medicine News Digital Network

　　Older Women Lived Longer With Radiotherapy After Lumpectomy

　　BOSTON – A review of data on nearly 30,000 women suggests older age by itself should not be a barrier to radiotherapy after lumpectomy for early-stage breast cancer.

　　Older patients treated with both modalities had higher rates of overall and breast cancer–specific survival at 5 and 10 years compared with women who underwent lumpectomy alone, investigators reported at the annual meeting of the American Society for Radiation Oncology.

　　Courtesy American Society for Radiation Oncology

　　"The improvement in cause-specific survival with the addition or radiation suggests that in healthy, elderly women, adjuvant radiation should be strongly considered as part of their breast cancer treatment," said Dr. Randi J. Cohen, a radiation oncologist at the University of Maryland in Baltimore.

　　The review examined Surveillance, Epidemiology, and End Results (SEER) database records on 29,949 women, who were aged 70-84 years at diagnosis with clinical stage I, estrogen receptor–positive breast cancer and survived at least 1 year. About three-fourths underwent radiation after lumpectomy.

　　Women treated with lumpectomy and radiation had an overall survival rate of 88.6% at 5 years vs. 73.1% among those with no radiation (P less than .0001), Dr. Cohen reported. Overall survival rates at 10 years were 65.0% and 41.7%, respectively.

　　Cause-specific survival rates at 5 years were 98.3% for patients in the radiation plus surgery group and 97.4% for those with no radiation. At 10 years, the respective rates were 95.5% and 93.3% (P less than .0001 for both comparisons).

　　The median length of survival also was greater with the addition of radiotherapy – 13.1 years vs. 11.1 years with lumpectomy alone.

　　Radiation Was Independent Predictor

　　In multivariate analysis that controlled for age, tumor size, race, ductal histology, lymph nodes and marital status, hazard ratios also showed significantly worse outcomes without radiation – 1.56 in the overall survival analysis and 1.41 in the cause-specific survival analysis.

　　The results are similar to those in a meta-analysis from the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), said Dr. Cohen. That study showed an absolute benefit for adding radiation of 3% at 10 years, compared with 2.2% at 10 years in the current study.

　　Dr. Cohen said the review was prompted by questions raised in a 2004 study from the Cancer and Leukemia Group B (CALGB). In that trial, investigators looked at whether adding radiation to lumpectomy plus tamoxifen would have an effect on overall or breast cancer–specific survival in 630 women 70 years and older with early-stage disease. They found that at a median follow-up of 10.5 years, there was an absolute reduction of 6% in same-breast tumor recurrence with radiation, but no difference overall of disease-free survival.

　　In the much larger EBTCG study and the current study, however, the disease-specific survival advantages with the addition of radiation were likely related to greater locoregional control. Dr. Cohen said that the overall survival advantage in her study was probably due to selection of healthier patients with longer predicted life expectancy for radiotherapy.

　　She noted, however, that the study was limited by a lack of data on recurrence rates or hormonal therapy.

　　Strength of Benefit Questioned

　　"It’s highly unlikely that the magnitude of the benefits of cause-specific survival can be attributed to just radiation alone," said Dr. Meema Moran, the invited discussant. She noted that in EBCTCG study, there was only about a 3% benefit at 15 years in a seemingly low-risk population with shorter follow-up. The favorable survival in the meta-analysis may therefore be partly attributable to treatment selections bias, said Dr. Moran, a radiation oncologist at Yale University in New Haven, Conn.