胃癌淋巴結切除：東方與西方各國的激烈辯論

作者：Nick Mulcahy  
出處：WebMD醫學新聞

　　October 8, 2009 (賓州費城) — 根據國際胃腸道腫瘤協會年會中的一名發表者所述，東方與西方各國的外科醫師大部份都同意如何執行胃癌的兩個主要手術：胃切除與胃重建。
　　
　　南韓首爾Yonsei大學醫學院外科的Sung Hoon Noh醫師表示，不過，胃部手術的第三種主要方法─淋巴結切除術，在東西方各國醫師間卻有著激烈論辯。
　　
　　東方的外科醫師偏好較廣泛的淋巴結切除，而西方的醫師偏好較不廣泛的切除。Noh醫師表示，雙方對於自己的方法都有其理由，最主要的是，東方的外科醫師對於廣泛與複雜D2切除的經驗多很多。
　　
　　他相信，每個醫學中心的最佳方法終究得依照腫瘤、病患、外科醫師的技術等治療因素而定。
　　
　　在東方或西方，D2淋巴結切除適合由就醫量高的中心或技巧熟練的外科醫師進行。不過，在西方，有許多就醫量低的中心，或許比較適合較不廣泛的D1手術以及化學放射療法。
　　
　　【影響胃部手術結果的因素】
　　Noh醫師向與會聽眾表示，相較於西方國家，東方國家的術後發病率、死亡率、胃癌手術後的長期存活率都有詳盡的文獻記載。
　　
　　Noh醫師認為，在東西方都有許多因素，包括分期的差異，會影響手術結果。
　　
　　在東方，常規的檢查或篩檢計畫比較普遍，早期胃癌的發生率較高。相對的，西方國家診斷的通常是比較後期的胃癌與食道胃接合處腫瘤。
　　
　　根據Noh醫師表示，東西方病患特徵的差異也會影響結果。在東方，病患大多是50至60歲，很少過重(身體質量指數(BMI) >30 kg/m2者為3%–4%)，有共病症的人數還好。不過，在西方，病患傾向超過65歲，通常過重(BMI >30 kg/m2者為10%–30%)，有共病症的人數較多。
　　
　　東方的外科醫師有較多經驗是因為胃癌較常見。在東亞，每100,000人口影響超過40人，而在北美，每100,000人口影響不超過10人。
　　
　　Noh醫師指出，胃癌的治療，日本平均每個醫院一年進行50到500例淋巴結切除，在韓國，為100到1500例。在西方，平均每醫院每年進行不到200例手術。
　　
　　【D2與D1淋巴結切除比較】
　　Noh醫師解釋，因為東西方胃癌病患、腫瘤分期、手術經驗等差異，東方比較偏好較廣泛的D2淋巴結切除術的這個結果或許不令人驚訝。
　　
　　Noh醫師表示，例如，荷蘭一篇1989至1993年的研究中，331名病患接受D2淋巴結切除，併發症比率為43%、術後死亡率為10%(N Engl J Med. 1999;340:908-914)。不過，南韓Yonsei大學在2002年的研究中，646名病患接受D2淋巴結切除，併發症比率為17.6%、術後死亡率為0.6%。
　　
　　Noh醫師表示，總結來說，許多因素造成東方的外科醫師偏好廣泛的D2淋巴結切除，這項手術可以安全地進行，提供較佳的局部控制，因此改善存活率，且與較準確的病理分期有關。
　　
　　Noh醫師解釋，相對的，西方多數的外科醫師偏好D1淋巴結切除。他們的論點是，缺乏完全支持D2優於D1手術的證據。再者，D2不夠安全；在西方的試驗中有較高的術後發病率和死亡率。
　　
　　重要的是，Noh醫師表示，西方的外科醫師可能提出「Southwest Oncology Group American Intergroup 0116」 這項研究，認為有限的淋巴結切除合併化學放射治療，可以消除那些可用D2手術切除之殘留的淋巴結轉移(N Engl J Med. 2001;345:725-730)。
　　
　　Noh醫師宣告沒有相關財務關係。
　　
　　國際胃腸道腫瘤協會年會。摘要0945。發表於2009年10月3日。

Gastric Cancer Lymph Node Dissection: "Hotly Debated" Between East and West

By Nick Mulcahy
Medscape Medical News

October 8, 2009 (Philadelphia, Pennsylvania) — Surgeons in Western and Eastern countries largely agree on how to execute 2 major aspects of surgery for gastric cancer — gastric resection and reconstruction — according to a presenter here at the annual meeting of the International Society of Gastrointestinal Oncology.

However, the third major aspect of gastric surgery, lymph node dissection, is the "most hotly debated" surgical topic between the East and West, said Sung Hoon Noh, MD, PhD, from the Department of Surgery at Yonsei University College of Medicine in Seoul, South Korea.

Surgeons in the East favor more extensive lymph node dissection, whereas those in the West favor less extensive dissection. Each side has its reasons for their approach, not the least of which is that surgeons in the East have far more experience with the more extensive and complex D2 dissections, said Dr. Noh.

Ultimately, the best approach at any center is determined by tumor, patient, and treatment factors, including a surgeon's skill, he believes.

In the East or West, D2 lymph node dissections are appropriate at high-volume centers or for skilled surgeons. However, in the West, where there are many low-volume centers, the less extensive D1 procedures, along with chemoradiation, might be more appropriate.

Factors That Affect Gastric Surgery Outcome

The superior outcomes in postoperative morbidity, mortality rates, and long-term survival after gastric cancer surgery for Eastern countries, compared with Western countries, have been well documented, Dr. Noh told the meeting.

There are a variety of factors that affect surgical outcome in the East and West, including the difference in stage, suggested Dr. Noh.

In the East, where routine check-ups or screening programs are more common, there is a higher incidence of early-stage gastric cancers. In contrast, diagnosis in the West is often of more advanced gastric cancer and of esophagogastric junction tumors.

Differences in patient characteristics affect outcomes in the 2 areas, according to Dr. Noh. In the East, patients tend to be 50 to 60 years of age, are rarely overweight (3%–4% with a body mass index [BMI] >30 kg/m2), and have a moderate number of comorbidities. However, in the West, patients tend to be older than 65 years, are often overweight (10%–30% with a BMI >30 kg/m2), and have a high number of comorbidities, he said.

Surgeons in the East have much more experience because gastric cancer is much more common. In Eastern Asia, it affects more than 40 men per 100,000 population, whereas in North America, the number is less than 10 men per 100,000 population.

Dr. Noh indicated that, in the treatment of gastric cancer, an average hospital in Japan will do 50 to 500 lymph node dissections a year, and in Korea, 100 to 1500. In the West, an average hospital will do a few to 200 procedures a year.

D2 vs D1 Lymph Node Dissection

Given the differences in gastric cancer patients, tumor stage, and surgical experience in the East and West, it is perhaps not surprising that outcomes with the more extensive D2 lymph node dissection are more favorable in the East, Dr. Noh explained.

For instance, in a Dutch trial that took place from 1989 to 1993, 331 patients who underwent D2 lymph node dissection had a 43% complication rate and a 10% postoperative mortality rate (N Engl J Med. 1999;340:908-914). However, in a 2002 study at Yonsei University in South Korea, 646 patients who underwent a D2 dissection had a 17.6% complication rate and a 0.6% postoperative mortality rate, said Dr. Noh.

In summary, the extended D2 lymph node dissection that is favored by surgeons in the East is supported by a number of factors, said Dr. Noh. The procedure can be performed safely, provides better local control and thus improved survival rates, and is associated with more accurate pathologic staging, he said.

In contrast, most surgeons in the West favor D1 lymph node dissection, Dr. Noh explained. Their argument is that evidence is lacking to fully support the superiority of D2 over D1 surgery. Furthermore, D2 is not safe enough; it has high postoperative morbidity and mortality in Western trials, he said.

Importantly, Dr. Noh said that surgeons in the West can point to the Southwest Oncology Group American Intergroup 0116 study, which suggested that limited lymph node dissection with chemoradiation could eliminate the residual lymph node metastases that could be removed by D2 (N Engl J Med. 2001;345:725-730).

Dr. Noh has disclosed no relevant financial relationships.

International Society of Gastrointestinal Oncology annual meeting. Abstract 0945. Presented October 3, 2009.