Criteria for the Optimal Extent of Lymph Node Dissection for Gastric Carcinoma: Number of Harvested Lymph Nodes or Properly Dissected Relevant Lymph Node Stations? Standard or Personalized Extent?

Ramiz Bayramov, Professor at Department of Oncology, Azerbaijan Medical University, Baku, Azerbaijan
2020 Journal of Oncology Research Review & Reports  
Gastric cancer is one of the leading causes of cancer-related deaths worldwide accounting for more than 8.0% of the total deaths from all causes of malignancy. Although the prognosis for advanced gastric carcinoma has improved with the introduction of effective neoadjuvant and adjuvant chemotherapy surgical eradication of the tumor with its lymphatics remains the primary therapeutic modality for resectable tumor. With respect to surgical procedure, dissection of the regional lymph nodes is
more » ... ded an important part of radical intent surgery for gastric carcinoma. However, there are significant differences in the extent of lymph node dissection preformed by surgeons in different part of the world. Gastric carcinoma can spread early to surrounding lymph nodes. As the primary tumor invades more deeply through the wall of the stomach, the risk of lymph node metastasis increases. Comprehensive investigations have shown that the stomach has a sophisticated lymphatic flow, and gastric carcinoma follows various spreading patterns according to the tumor location and biology. Lymphatic spread occurs via the submucosal and subserosal lymphatic plexuses depending on the depth of invasion through the wall of the stomach. It means that lymphatic spread can happen at early stage and intensify at more advanced T stages. Cancer cells fallen into lymphatic flow firstly encounter the local lymph nodes (sentinel lymph nodes) and are trapped and grow in them. From metastatic local lymph nodes cancer cells can be further carried to the regional lymph nodes located on antegrade lymph flow. The lymphatic drainage of the stomach follows its arterial supply. Although most lymphatics ultimately drain into the celiac nodal station, lymph drainage sites can include the splenic hilum, suprapancreatic nodal groups, porta hepatis, and gastroduodenal areas depending on the stage of gastric carcinoma. Studies have shown that tumors located in particular parts of the stomach rarely metastasized outside their designated drainage pattern. Lymphatic drainage tends to be centripedal toward the celiac trunk and the lymph nodes located on this route are the regional lymph nodes. In the stomach, as in other organs, the very presence of cancer can alter the normal lymphatic drainage. Obstructed by cancer cells lymphatic vessels can divert the lymph drainage so that metastases appear in unexpected nodes that can be named extraregional lymph nodes. With other words extraregional lymph nodes are the nodes that normally are located not on the antegrade lymphatic flow. So obturated by cancer cells normal lymphatics can form collateral lymphatics, producing a shift in the drainage pattern. Theoretically, removal of a wide range of lymph nodes can improve the chance for cure in patients with gastric carcinoma. With other words eradication of the primary tumor without removing of lymph nodes with cancer cells cannot present a chance for cure. Extended lymph node dissection, however, could be irrelevant when no lymph nodes are affected, when the cancer has developed into systemic disease, or the dissection increases morbidity and mortality substantially. Determination of gastric cancer cases with absolutely unaffected lymph nodes and microscopically systemic disease is impossible before and during surgery. It means that probability of both absence of lymphatic spread and presence of occult hematogenous metastases cannot approve the surgery without removal of the local and regional lymph nodes. Early in the 1960s, D2 dissection was introduced and later adopted as standard therapeutic modality in Japan for management of gastric carcinoma. Despite the first opinions of Western surgeons extracted from the results of the appropriate studies in the late 1990s about that lymphadenectomy is purely a staging rather than a therapeutic tool, after 15 year-follow up of the famous Dutch study it has been demonstrated that locoregional recurrence rate is significantly lower in patients treated with D2 lymphadenectomy in comparison with the patients who underwent D1 dissection, showing a survival benefit with the extended dissection. Therefore nowadays D2 lymph node dissection is the standard surgical procedure in the management of gastric carcinoma and is accompanied by not higher morbidity and mortality rates in the high-volume centers. Gastric cancer can develop lymphogenic metastases at any T stage of the tumor. Even at T1 stage the frequency of lymph node metastasis accounts for up to 18%. Negative results of pathologic examination following sentinel lymph node biopsy does
doi:10.47363/jonrr/2021(2)119 fatcat:5keglgzc7vhnbg6nwgpclgqtci