Elucidation of the Anatomical Mechanism of Nodal Skip Metastasis in Superficial Thoracic Esophageal Squamous Cell Carcinoma

Abstract

BackgroundLymph node metastasis (LNM) is a standard mechanism of cancer progression in esophageal squamous cell carcinoma (ESCC). We aimed to clarify the anatomical mechanism of skip nodal metastasis to mediastinal zones by analyzing the relationship between LNM to sentinel zones and lymphatic vessel counts in the muscle layer adjacent to the outer esophagus.MethodsWe examined the surgical records of 287 patients with ESCC who underwent potentially curative surgery (three-field lymphadenectomy) and whole esophagi, including pharynges and stomachs from 10 cadavers, to determine the number of lymphatic vessels in the intra-outer longitudinal muscle layer adjacent to the outer esophagus of the cervical (Ce), upper thoracic, middle thoracic (Mt), lower thoracic (Lt), and abdominal esophagi (Ae).ResultsThe frequency of LNM to the middle mediastinal and supraclavicular zones, including the Mt and Ce, respectively, was lower than to the upper and lower mediastinal and abdominal zone in patients with superficial and advanced thoracic ESCC. In cadavers, the lymphatic vessel counts of the intra-outer longitudinal muscle layer in the Mt and Ce were significantly lower than those of the Lt and Ae, suggesting that lymphatic flow toward the outside of the Mt and Ce was not more abundant than to other sites.ConclusionOur anatomical data suggested that the absence of intra-muscle lymphatic vessels in the middle mediastinal and supraclavicular zones causes skip LNM in patients with thoracic ESCC. Thus, standard esophagectomy with lymph node dissection, including distant zones, may be appropriate for treating patients with superficial thoracic ESCC.Electronic supplementary materialThe online version of this article (10.1245/s10434-018-6390-0) contains supplementary material, which is available to authorized users.

Prognostic Evaluation of Nodal Skip Metastasis for Thoracic Esophageal Squamous Cell Carcinoma

“…[17][18][19] In our study a significant difference was found between patients with NSM and non-NSM in tumor location, pT stage, and pN stage (all P < .05), and the rate of NSM was highest in middle thoracic ESCC (43.9%). A recent anatomic study for NSM 20 has provided an explanation for the high incidence of NSM in middle thoracic ESCC: The absence of intramuscle lymphatic vessels in the middle thoracic esophagus makes it more common for tumor cells to metastasize longitudinally from the original region to other anatomic regions. In addition to the anatomic factor the position of middle thoracic ESCC makes tumor cells convenient to metastasize both upward and downward.…”

Development and validation of nomograms to intraoperatively predict metastatic patterns in regional lymph nodes in patients diagnosed with esophageal cancer

“…Esophageal cancer is the eighth most common cancer and the sixth leading cause of cancer-related death worldwide [ 1 ]. It is important for surgeons to determine the accurate patterns of lymph node metastasis in patients with esophageal cancer because lymph node metastasis will affect patient prognosis and decide appropriate treatment strategies [ 2 , 3 ]. However, it is controversial for surgeons to choose the best strategy for lymph node dissection.…”

Lymph node dissection and recurrent laryngeal nerve protection in minimally invasive esophagectomy

“…Another most frequent metastasis site was reported to occur in the paracardia and the left gastric artery LNs; its metastasis rate was between 25% and 60% in the middle-lower thoracic ESCC, but only about 10% in the upper thoracic ESCC. 35 The rate of bilateral recurrent laryngeal LN metastasis was reported to be the highest in the chest and it could be more than 10% even in clinical N0 superficial thoracic ESCC. 36 Therefore, bilateral RLN LNs should be the most important site of lymphadenectomy in the esophagectomy of thoracic ESCC, even in a superficial tumor.…”