本帖最後由 lsc0019 於 2009-6-3 09:56 編輯
作者：Nick Mulcahy
出處：WebMD醫學新聞
May 19, 2009 — 醫師與他們的乳癌病患經常面對這種兩難局面：在前哨淋巴結切片(SLNB)確認結轉移之後是否要進行完整腋下淋巴廓清術。
一篇有22,278名婦女的新觀察研究認為，答案往往是否定的，特別是微小型的結轉移。該研究線上登載於4月13日的臨床腫瘤期刊。
資深作者、David J. Winchester醫師向Medscape Oncology表示，多數病患可能不需要完整腋下淋巴廓清術。Winchester醫師是伊利諾州北岸大學健康體系一般外科與腫瘤外科主任。
他解釋，在本研究中，完整腋下淋巴廓清術(ALND)並未改善微小型病患之腋下淋巴復發或存活結果。再者，對於這些微小型病患，完整ALND只有小小的助益。
對於微小型結轉移病患，兩個治療組之間的腋下淋巴復發與存活相當。
不過，Winchester醫師等人報告指出，校正兩組間的差異之後再分析發現，相較於單用SLNB，完整 ALND有不顯著的較佳結果趨勢，腋下淋巴復發的風險比為0.58 (95%信心區間[CI]為0.32 - 1.06)，整體存活為0.89(95% CI為0.76 - 1.04)。
Winchester醫師指出，此研究結果仍然會使得醫師不自主的使用完整 ALND。
他在一篇聲明中表示，我們太過信賴手術，本報告指出，就存活率差異或局部復發差異來說，我們或許不需要動這個手術。這是一個與顯著發病率有關的手術。
他表示，舉例來說，完整ALND的水腫風險是30%至40%，SLNB則是2%至5%。
研究作者表示，有時候需要完整ALND與否是個爭議，因而促使美國腫瘤外科醫師學會腫瘤小組(ACOSOG)進行 Z0011試驗比較這兩種方法。不過，在2004年，該試驗進行5年之後，因為新增病患太少而中止。
Winchester醫師等人提出，ACOSOG Z0011的隨境分析顯示，69%的結節陽性病患拒絕納入試驗而繼續接受完整 ALND。他們也表示，即便有另一個比較這兩種方法的前溯臨床試驗，目前的研究結果可以為隨機指派到單用SNLB提供某些平衡點。
【實務上的改變】
Winchester醫師等人使用國家癌症資料庫的臨床結節陰性乳癌女性，且接受SLNB以及在1998至2005年間有結轉移者的資料(n= 97,314)。
除了評估這些女性的結果，新研究的研究者也追蹤部份接受SLNB與完整ALND的病患。
結果指出，有關這些手術的實務有些改變。
主要研究作者、Karl Bilimoria醫師在聲明中表示，對於1998至2005年間的微小型結節疾病，單用SLNB而無完整結剝離者從大約25%增加到45%，至於有更明顯結轉移的病患(宏觀組)，其比例在整個研究期間相當穩定，當年在進行分析時，他是美國外科醫師學會研究員，現在是伊利諾州西北大學Feinberg醫學院外科住院醫師。
特別的是，單用SLNB治療宏觀型疾病的病患數量在這段期間內減少，從24.2%降到16.7%(P< .001)；不過，單用SLNB治療微小型疾病的病患增加，從24.7%增加到45.3% (P< .001)。
Bilimoria醫師推測，單用SLNB治療微小型疾病增加使得醫師有較多有趣的發現，並非每個病患都需要結節剝離。
【後續詳細結果資料】
因為資料庫中追蹤5年的婦女人數有限，結果分析包括一小組婦女(n= 22,278)，且僅限於1998至2000年。該組平均追蹤63個月。
微小型結轉移病患中(n= 2203)，不論校正或未校正臨床-病理特徵、治療與醫院類型，單用SLNB(5個結節以下)與SLNB併用完整 ALND(9個結節以上)之間並無顯著差異。
宏觀型結轉移病患中(n= 20,075)，單一變項分析時，單用SLNB以及SLNB併用完整ALND之間的結果沒有顯著差異(腋下淋巴復發為1.0%vs1.2% [P = .40] ，相對存活為 98.5% vs98.2% [P= .72] ，觀察存活為82.1% vs81.8% [P= .55] )。
不過，如前所述，校正臨床-病理特徵、治療與醫院類型之後進行分析時，對宏觀型疾病來說，相較於SLNB併用完整 ALND，單用SLNB治療傾向有不佳結果，但是沒有顯著差異。
美國外科醫師學會住院醫師計畫臨床獎學金、西北大學Feinberg 醫學院外科支持本研究。
J Clin Oncol. 印刷前線上登載於2009年4月13日。
When Sentinel Lymph Node Biopsy is Enough in Breast Cancer
By Nick Mulcahy
Medscape Medical News
May 19, 2009 — It's a common dilemma for clinicians and their patients with breast cancer: whether or not to perform completion axillary dissection after nodal metastases have been identified by sentinel lymph node biopsy (SLNB).
A new observational study of 22,278 women suggests that the answer is frequently no, especially if the nodal metastases are microscopic. The study was published online April 13 in the Journal of Clinical Oncology.
A full axillary dissection may not be necessary for most patients.
"A full axillary dissection may not be necessary for most patients," senior study author David J. Winchester, MD, told Medscape Oncology. Dr. Winchester is chief of the Division of General Surgery and Surgical Oncology at NorthShore University HealthSystem in Evanston, Illinois.
He explained that, in the study, completion axillary lymph node dissection (ALND) did not improve outcomes in either axillary recurrence or survival for patients with microscopic disease. Furthermore, there may only be a small benefit with regard to those outcomes with completion ALND for those with macroscopic disease, he suggested.
In patients with macroscopic nodal metastases, axillary recurrence and survival were comparable between the 2 treatment groups.
However, after the analysis was adjusted for differences between the 2 groups, there was a nonsignificant trend toward better outcomes for completion ALND than for SLNB alone — hazard ratio for axillary recurrence was 0.58 (95% confidence interval [CI], 0.32 - 1.06) and for overall survival was 0.89 (95% CI, 0.76 - 1.04), Dr. Winchester and colleagues report.
Still, the study results should cause clinicians to not automatically use completion ALND, noted Dr. Winchester.
We have relied upon that operation too much.
"We have relied upon that operation too much, and this paper points out that we may not need to do it in terms of a survival difference or a regional recurrence difference. This is an operation associated with significant morbidity," he said in a statement.
For instance, the risk for edema is 30% to 40% with completion ALND, and 2% to 5% with SLNB, he said.
The need for completion ALND has been debated for some time, and led to theAmerican College of Surgeons Oncology Group (ACOSOG) Z0011 trial comparing the 2 approaches, say the study authors. However, the trial was suspended after 5 years, in 2004, due to low patient accrual.
An ad hoc analysis of ACOSOG Z0011 showed that 69% of node-positive patients who refused to enroll went on to undergo completion ALND, Dr. Winchester and coauthors comment. They also say if there is ever another prospective clinical trial comparing the 2 approaches, then the current study's results could provide some "equipoise" for random assignment to SNLB alone.
Shift in Practice
Dr. Winchester and colleagues used data obtained from the National Cancer Data Base on women with clinically node-negative breast cancer who underwent SLNB and who had nodal metastases from 1998 to 2005 (n?= 97,314).
In addition to evaluating outcomes in these women, the investigators of the new study tallied the proportion of patients undergoing SLNB and completion ALND.
The results indicate that there has been a shift in practice patterns concerning the procedures.
"For microscopic nodal disease from 1998 to 2005, the proportion of patients undergoing [SLNB] alone without a completion nodal dissection increased considerably, from about 25% to 45%, whereas for patients with more substantial nodal metastases (the macroscopic group), the proportion stayed fairly constant over the time course of the study," said study lead author Karl Bilimoria, MD, MS, in a statement. He was an American College of Surgeons Research Fellow at the time the analysis was performed, and is now a surgical resident at the Feinberg School of Medicine of Northwestern University in Evanston, Illinois.
Specifically, the proportion of patients who underwent SLNB alone for macroscopic disease declined during the study period, from 24.2% to 16.7%; (P?< .001); however, the proportion of patients who underwent SLNB alone for microscopic metastases increased, from 24.7% to 45.3% (P?< .001).
Dr. Bilimoria speculated that the increase in the use of SNLB alone for microscopic disease arose as physicians "anecdotally found that nodal dissection is not necessary in all patients."
Outcomes Data in Further Detail
Because there was a limited number of women with 5-year follow-up in the database, the outcomes analysis comprised a smaller group of women (n?= 22,278) and was limited to the years 1998 to 2000. The group had a median follow-up of 63 months.
In patients with microscopic nodal metastases (n?= 2203), there was not a significant difference in outcomes between SLNB alone (5 or fewer nodes) and SLNB with completion ALND (9 or more nodes) — either unadjusted or adjusted for differences in clinico-pathologic characteristics, treatment, and hospital type.
In patients with macroscopic nodal metastases (n?= 20,075), on univariate analysis, there was not a significant difference in outcomes between SLNB alone and SLNB with completion ALND (1.0% vs1.2% [P = .40] for axillary recurrence, 98.5% vs98.2% [P?= .72] for relative survival, and 82.1% vs81.8% [P?= .55] for observed survival).
However, as noted above, after the analysis was adjusted for differences in clinico-pathologic characteristics, treatment, and hospital type, there was a nonsignificant trend toward worse outcomes with SLNB alone than with SLNB with completion ALND for macroscopic disease.
The study was supported by the American College of Surgeons Clinical Scholars in Residence program and the Department of Surgery, Feinberg School of Medicine, Northwestern University.
J Clin Oncol. Published online before print April, 13 2009. |
|
