[Study of para-aortic lymph node metastasis of gastric cancer subjected to superextensive lymph node dissection].

Para-aortic lymph nodes (n4), were dissected out to the technical extreme (superextensive lymph node dissection) from 129 gastric cancer cases, and were subjected to the histological study for metastasis. Following observations led us to the conclusions in reference to the significance of n4 node dissections on curability of surgery. 1) Among 25 cases with n4(+) metastasis n3 was free [n3(-)] in 11 cases (44.0%). 2) ps(+) cancer presented high rate of n4(+) (31.5%). 3) n4(+) occurred irrespective of the location of the cancer, with particularly high rate of occurrence among CMA and cancers. 4) The rate of the metastasized lymph nodes to the total number of the n4 lymph nodes, was found low (34.9%) in cases with n3(-), and high (90.1%) with n3(+). 5) The cumulative survival rate of the cases with n4(+) was found significantly high with n3(-), as compared to n3(+) cases. The lymphatic drainage from the stomach seems more direct and/or more abundant to the n4 than to the n3 nodes. Such observation coincides with our experience that the n4 nodes are involved in metastasis in earlier timing and in higher incidence than n3 nodes. These results warn the present evaluation of curability in which the n4 node dissection is not performed. It is our opinion that the thorough dissection extended to the n4 nodes (superextensive lymph node dissection) is warranted, particularly in order to improve the curability of n3(-)-n4(+) cases.