Pattern of Distribution of Lymph Node Metastases in Individual Stations in Middle and Lower Gastric Carcinoma

SIMPLE SUMMARY: Gastric cancer (GC) is a malignancy with great heterogenicity, and applying the same standard to all patients in different conditions may lead to treatment bias. D2 lymphadenectomy is the elective procedure for surgical treatment of GC. Middle- and lower-third GC show a different lymphatic spread than proximal tumors. This study has limitations. The retrospective nature of this study is a potential source of intrinsic biases. Our results must be interpreted with caution because they represent only a group of patients with distal GC. However, the present study shows that the primary tumor location is related to the location of nodal metastases. The knowledge of the localization of the tumor could lead to a tailored lymphadenectomy in the case of small tumors, in consideration of the absence of involvement of stations 7 to 12 in distal T1 cancers. On the other hand, in advanced GC, both circular and longitudinal localization should be considered to concentrate the lymphadenectomy on the most interesting individual stations and, in selected cases, extending the nodal dissection also to stations that are not routinely included in the D2 lymphadenectomy. ABSTRACT: (1) Background: Lymph node (LN) dissection is the cornerstone of curative treatment of GC. The pattern of distribution of LN metastases is closely related to several factors. The aim of this study is to evaluate the factors determining the distribution of nodal metastases in a population of N+ distal GC patients undergoing gastrectomy and D2 lymphadenectomy. (2) Methods: The medical charts of 162 N+ GC patients who underwent surgical resection over a 15-year period were retrospectively analyzed. Clinical, pathological and anatomical characteristics were evaluated to identify the factors affecting the patterns and prevalence of metastases in individual LN stations. (3) Results: LN metastasis is correlated with the depth of the tumor and to diffuse-type tumors. A higher number of metastatic nodes was documented in patients with middle-third tumors (8.2 ± 7.3 vs. 4.5 ± 5.0 in lower-third tumors, p = 0.0001) and in patients with tumors located on the lesser curve. Station 4 showed the highest rate of metastases (53.1%). Concerning stations 7 to 12, station 8 showed the highest metastasis rate (28.4%). Metastases at stations 1, 2, 4 and 7 to 11 were dominant in middle-third cancer, whereas stations 5 and 6 were dominant in lower-third cancers. Station 4, 5, 6, 10 and 11 metastases were dominant when the cancer was located on the greater curve, whereas stations 1, 2, 7, 8 and 12 were dominant in lesser-curve cancers. (4) Conclusions: The study documented that in patients with distal GC, the distribution of nodal metastases at individual stations is closely related to primary tumor location.