Abstract
The utility of para-aortic lymph node dissection was evaluated in a histological study for metastasis in gastric cancer. Para-aortic lymph nodes were dissected from 91 cases of gastric cancer, and metastasis in para-aortic lymph node was histologically confirmed in 21 cases (23.1%). In all cases with para-aortic lymph node metastasis, the depth of invasion was to the serosa (S2) and gastric cancer histological type was moderately or poorly differentiated adenocarcinoma or mucinous carcinoma. All 21 cases with para-aortic lymph node metastasis were associated with n1 (+) and n2 (+) metastasis, but 9 (42.9%) of them were not associated with n3 (+) metastasis. The rates of the metastasized lymph nodes to the total number of n1 (+) and n2 (+) in 21 cases with para-aortic lymph node metastasis were significantly greater than those in other cases without para-aortic lymph node metastasis (p<0.01). Prognosis was poor in cases with para-aortic lymph node metastasis. We would suggest that para-aortic lymph node dissection should be performed in cases with level of serosal invasion of S2 or deeper, as well as in cases without serosal invasion (S0, S1) in which N2 (+) metastasis was found. However, this dissection should not be performed in cases in which metastasized para-aortic lymph nodes constitute a large proportion to the total number of metastasized n2 lymph nodes. It is thought that the number of metastasized n2 lymph nodes may be an indicator for para-aortic lymph node metastasis.
