左半结肠癌淋巴结转移规律的临床分析

Clinical analysis on lymph node metastasis pattern in left-sided colon cancers

目的探讨左半结肠癌淋巴结转移规律，为手术方式的选择及淋巴结清扫范围提供依据。方法回顾性分析福建医科大学附属协和医院结直肠外科2000年1月至2014年10月期间收治的556例左半结肠癌患者的临床资料。其中，横结肠近脾曲及结肠脾曲癌41例（脾曲组），降结肠癌73例（降结肠组），乙状结肠癌442例（乙状结肠组）。T1期29例，T2期63例，T3期273例，T4期191例。均行D3根治术或全结肠系膜切除术（CME）。将肠旁淋巴结定义为第1站，肠系膜淋巴结为第2站，肠系膜根部及肠系膜上下动脉周围淋巴结为第3站，比较不同部位及不同浸润深度肿瘤各站淋巴结的转移情况。结果全组淋巴结总转移率49．6％（276／556），其中脾曲组、降结肠组和乙状结肠组患者的淋巴结转移率分别为53．7％（22／41）、52．1％（38／73）和48．9％（216／442），差异无统计学意义（P〉0．05）。第1、2和3站淋巴结转移率分别为47.3％（263／556）、16．9％（94／556）和5．8％（32／556），差异有统计学意义（X。287．54，P=0．000）。T，、T2、T，、T4期组的第1、2和3站淋巴结转移率分别为13．8％（4／29）、0和0，25．4％（16／63）、4．8％（3／63）和3．2％（2／63），45．8％（125／273）、14．7％（40／273）和4．8％（13／273）以及61．8％（118／191）、13．1％（25／191）和8．9％（17／191）。脾曲组No．222与No．232[14．6％（61／41）比12．2％（5／41），X^2=0．11，P=1．000]以及No．223与No．253[7．3％（3／41）比2．4％（1／41），X^2=1．05，P=0．6161转移率相近；降结肠组No．232转移率15．1％（11／73）高于No．222[2．7％（2／73），X^2=6．84，P=0．017]，No．253比No．223转移率稍高，但差异无统计学意义[4．1％（3／73）比0，X^2=3．06，P=0．245]。而脾曲组No．222和No．223转移率均高于降结肠组和乙状结肠组（X^2=5．69，P=0．025；Fisher确切概率法，P=0．044）；但No．232（乙状结肠组为No．242）转移率3组间差异无统计学意义（X^2=0．90，P=0．660）；No．253转移率3组间差异也无统计学意义（X^2=1．14，P=0．611）。结论T1期左半结肠癌可行D2根治术，T2-4期则应行D，根治术。横结肠近脾曲及结肠脾曲肿瘤D，根治术应清扫到No．223和No．253；降结肠肿瘤D，根治术应清扫到No．222和No．253；乙状结肠肿瘤D3根治术应清扫到No．253。

Objective To investigate the pattern of lymph node metastasis in patients with left- sided colon cancer in order to provide evidences for the choice of operation mode and the range of lymph node clearance. Methods Clinical data of 556 cases with left-sided colon carcinoma undergoing surgical treatment in Department of Colorectal Surgery, Fujian Medical University Union Hospital from January 2000 to October 2014 were retrospectively analyzed. Among these patients, cancer of splenic flexure and transverse colon close to splenic flexure （splenic flexure group） was found in 41 cases, descending colon cancer in 73 cases （descending colon goup） and sigmoid colon cancer in 442 cases （sigmoid colon group）, respectively; T1 was found in 29 cases, T2 in 63 cases, T3 in 273 cases, T4 in 191 cases. All the patients underwent D3 radical operation or complete mesocolic excision （CME）. Para-bowel lymph node was defined as the first station, mesenteric lymph node as the second station, and lymph node in root of mesentery and around upper and inferior mesenteric arteries as the third station. Metastasis was compared among these 3 stations with regard to different sites and tumor invasions. Results The total lymph node metastasis rate was 49.6%（276/556）. The lymph node metastasis rates of splenic flexure, descending colon and sigmoid colon groups were 53.7% （22/41）, 52.1% （38/73） and 48.9% （216/442） respectively without significant difference （P 〉 0.05 ）. The lymph node metastasis rates of the first, second, and third stations were 47.3%（263/556）, 16.9%（94/556） and 5.8%（32/556） respectively with significant difference （X^2= 287.54, P= 0.000）. In the first, second and third station, the lymph node metastasis rate was 13.8%（4/29）, 0 and 0 in T1; 25.4%（16/63）, 4.8%（3/63） and 3.2%（2/63） in T2; 45.8%（125/273）, 14.7%（40/273） and 4.8%（13/273） in T3; 61.8%（118/191）, 26.7%（25/191） and 8.9%（17/191） in T4 respectively. In splenic flexure group, metastasis rates were similar between No.222 and No.232 [ 14.6% （61/41） vs. 12.2%（5/41）, X^2= 0.11, P= 1.000] and between No.223 and No.253 [7.3% （3/41） vs. 2.4% （1/41）, X2= 1.05, P= 0.616]. In descending colon group, metastasis rate of No.232 was higher as compared to No.222 [15.1%（11/73） vs. 2.7% （2/73）, X^2=6.Sd, P〈0.017]; metastasis rate of No.253 was slightly higher as compared to No.223 without significant difference [4.1%（3/73） vs. 0, X^2=3.06, P = 0.245]. Metastasis rates of No.222 and No.223 in splenic flexure group were significantly higher than those in descending colon and sigmoid colon groups （X^2= 5.69, P= 0.025; Fisher exact test, P= 0.044）; While such rates of No.232 （No.242 for sigmoid colon group） and No.253 were not significantly different among 3 groups respectively （X^2 = 0,90, P = 0.660; X^2 = 1.14, P = 0.611）. Conclusions Left-sided colon cancers in T1 should undergo I）2 radical operation, while cancers in T2 to Td should undergo D3 radical operation. The D3 radical operation for splenic flexure cancers and cancers of transverse colon close to splenic flexure should clear No.223 and No.253. The D3 radical operation for descending colon cancer should clear No.222 and No.253. The D3 radical operation for sigmoid colon should clear No.253.