淋巴结转移率和数量分级与胃癌预后及病理因素关系的研究

Relationship between metastatic rate and amount of lymph nodes and prognosis of gastric cancer

目的分析淋巴结转移率(rN)和数量分级与胃癌预后及病理因素的关系。方法对比分析341例胃癌患者rN分级和1997年第5版TNM分期的淋巴结分级标准(pN)与患者预后及反映胃癌生物学行为的病理因素的关系。结果rN分级中,rN1组术后5年生存率为69.9%,rN2组为45.7%,rN3组为10.6%,3组患者术后生存率差异有统计学意义(χ2=14.38,P均<0.05);在同一pN分级组中,再按rN分级比较5年生存率差异亦有统计学意义,而在同一rN分级组中,再按pN分级比较5年生存率差异均无统计学意义;COX模型分析表明,rN分级是反映胃癌预后最主要的独立指标;淋巴结转移率分级与肿瘤大小、浸润深度及大体类型间的差异有统计学意义(P均<0.05);rN分级与日本胃癌规约中的淋巴结转移分站有相关性。结论rN分级可更好的指导胃癌的治疗和预后判断,有助于完善胃癌的TNM分期体系。

Objective to investigate the relationship between metastatic rate and amount of lymph nodes and prognosis of gastric cancer. Methods The clinical data of 672 patients of gastric cancer with 22.7 regional metastatic lymph nodes on average were analyzed retrospectively. The patients were divided into 3 groups according to the TNM staging system （ 1997, 5^th edition） ： pN0 （ without metastatic lymph node）, pN1 group （with 1～6 metastatic lymph nodes）, pN2 group （with 7～15 metastatic lymph nodes）,and pN3 group （with more than 215 metastatic lymph nodes）, or into 4 groups according to the lymph node metastasis rate： rN0 group （without metastasis of lymph node）, rN1 group （with a lymph node metastasis rate 0 〈 10% ） , rN2 group （ with a lymph node metastasis rate of 10% ～ 30% ）, and rN3 group with a lymph node metastasis rate 〉 30% ）. The 5-year survival rates of different groups in these 2 classification systems and the relationship between metastatic rate and amount of lymph nodes and prognosis of gastric cancer were analyzed. Results According to the lymph node metastasis grading system there were 93 patients in the pN0 group, 201 in the pN1 group, 108 in the pN2 group, and 32 in the pN3 group with the 5-year survival rates of 90.3% , 65.2% , 37.0% , and 18.9% respectively （ X^2 = 12.56, P 〈 0.01 ）.According to the lymph node metastasis system 93 patients were in the rN0 group, 183 in the rN1 group, 92 in the rN2 group, and 66 in the rN3 group , with the 5-year survival rates of 90.3%, 69.9% , 45.7% , and 10.6% respectively （X^2 = 14.38, P 〈 0.01 ）. If the cases in the same pN group were re-divided according to the lymph node metastasis rate, there were significant differences in the 5-year survival rate among the new rN groups （ X^2 = 5.26, P = 0.21 ）, and there was a great difference in the distribution of prognosis among different groups. However, if the cases in the same group rN group were re-divided according to the amounts of metastatic lymph nodes, there was no significant difference in 5-year survival rate among different new pN groups （X^2 =0.14, P =0.932）. Multivariate COX model analysis showed that the influencing factors of the prognosis were rN grading, pN grading, infiltration depth of cancer, gross type, and size of the cancer,arranged according to the degree of closeness （ P 〈 0.05 ） ; lymph nose metastasis rate was closely related with the size, infiltration depth, and gross type of the cancer （ P 〈 0.05 ）. In the same metastasis rate, the 5-year survivals rate decreased along with the increase of the amount of metastatic lymph nodes, and vice versa （ X^2 = 8.22, P = 0. 004 ; X^2 = 4.52, P = 0. 033 ）. Condnsion The staging system based on metastatic lymph node rate is more predictable the number of metastatic lymph nodes for the prognosis of gastric cancer.