Pattern of lymph node metastasis in thoracic esophageal squamous cell carcinoma with poor differentiation

Metastatic patterns of subcarinal, right and left recurrent laryngeal nerve lymph nodes in thoracic esophageal squamous cell carcinoma without neoadjuvant therapy

PURPOSE

This research aimed to clarify the metastatic patterns of subcarinal, right and left recurrent laryngeal nerve lymph nodes in thoracic esophageal squamous cell carcinoma and to investigate appropriate strategies for lymph node dissection.

METHODS

Patients with thoracic esophageal squamous cell carcinoma receiving esophagectomy from December 2020 to April 2024 were retrospectively analyzed. Risk factors for subcarinal, right and left recurrent laryngeal nerve lymph nodes metastasis were determined by chi-square test and multivariate logistic regression analysis. We visualized the metastasis rates of these specific lymph nodes based on the different clinicopathological characteristics. Correlation between subcarinal, right and left recurrent laryngeal lymph nodes metastasis and postoperative complications were also analyzed.

RESULTS

A total of 503 thoracic esophageal squamous carcinoma patients who underwent esophagectomy were enrolled. The metastasis rates of subcarinal, right and left recurrent laryngeal nerve lymph nodes were 10.3%, 10.3%, and 10.9%, respectively. The lymphovascular invasion status and tumor location were the significant predictors for subcarinal and right recurrent laryngeal nerve lymph nodes metastasis, respectively (P < 0.001 and P = 0.013). For left recurrent laryngeal nerve lymph node metastasis, younger age (P = 0.020) and presence of lymphovascular invasion (P = 0.009) were significant risk factors. Additionally, pulmonary infection is the most frequent postoperative complication in patients with dissection of subcarinal, right and left recurrent laryngeal lymph nodes. There was no significant difference in the incidence of anastomotic leakage (P = 0.872), pulmonary infection (P = 0.139), chylothorax (P = 0.702), and hoarseness (P = 0.179) between the subcarinal lymph node dissection cohort and the reservation cohort. The incidence of hoarseness significantly increased in both right (P = 0.042) and left (P = 0.010) recurrent laryngeal nerve lymph nodes dissection cohorts compared by the reservation cohorts, with incidence rates of 5.9% and 6.7%, respectively.

CONCLUSIONS

The metastasis rates of subcarinal, right and left recurrent laryngeal nerve lymph nodes in thoracic esophageal squamous cell carcinoma were all over 10%. The dissection of subcarinal lymph nodes does not increase postoperative complications risk, while recurrent laryngeal nerve lymph nodes dissection significantly increases the incidence of hoarseness. Thus, lymph node dissection of subcarinal lymph nodes should be conducted routinely, while recurrent laryngeal nerve lymph nodes dissection may be selectively performed in specific patients.

Optimal criteria for predicting lymph node metastasis in esophageal squamous cell carcinoma by anatomical location using preoperative computed tomography: a retrospective cohort study

PURPOSE

Predicting lymph node metastasis (LNM) in esophageal squamous cell carcinoma (ESCC) is critical for selecting appropriate treatments despite the low accuracy of computed tomography (CT) for detecting LNM. Variation in potential nodal sizes among locations or patients' clinicopathological background factors may impact the diagnostic quality. This study explored the optimal criteria and diagnostic ability of CT by location.

METHODS

We retrospectively reviewed preoperative CT scans of 229 patients undergoing curative esophagectomy. We classified nodal stations into six groups: Cervical (C), Right-upper mediastinal (U_R), Left-upper mediastinal (U_L), Middle mediastinal (M), Lower mediastinal (L), and Abdominal (A). We then measured the short-axial diameter (SAD) of the largest lymph node in each area. We used receiver operating characteristics analyses to evaluate the CT diagnostic ability and determined the cut-off values for the SAD in all groups.

RESULTS

Optimal cut-offs were 6.5 mm (M), 6 mm (C, L, and A), and 5 mm (U_R and U_L). Diagnostic abilities differed among locations, and U_R had the highest sensitivity. A multivariate analysis showed poor differentiation to be an independent risk factor for a false-negative diagnosis (p = 0.044).

CONCLUSIONS

Optimal criteria and diagnostic abilities for predicting LNM in ESCC varied among locations, and poor differentiation might contribute to failure to detect LNM.

Impact of 18F-FDG-PET/CT on the identification of regional lymph node metastases and delineation of the primary tumor in esophageal squamous cell carcinoma patients

PURPOSE

In patients undergoing chemoradiation for esophageal squamous cell carcinoma (ESCC), the extent of elective nodal irradiation (ENI) is still discussed controversially. This study aimed to analyze patterns of lymph node metastases and their correlation with the primary tumor using 18F‑fludeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans.

METHODS

102 ESCC patients with pre-treatment FDG-PET/CT scans were evaluated retrospectively. After exclusion of patients with low FDG uptake and patients without FDG-PET-positive lymph node metastases (LNM), 76 patients were included in the final analysis. All LNM were assigned to 16 pre-defined anatomical regions and classified according to their position relative to the primary tumor (above, at the same height, or below the primary tumor). In addition, the longitudinal distance to the primary tumor was measured for all LNM above or below the primary tumor. The craniocaudal extent (i.e., length) of the primary tumor was measured using FDG-PET imaging (LPET) and also based on all other available clinical and imaging data (endoscopy, computed tomography, biopsy results) except FDG-PET (LCT/EUS).

RESULTS

Significantly more LNM were identified with 18F‑FDG-PET/CT (177 LNM) compared to CT alone (131 LNM, p < 0.001). The most common sites of LNM were paraesophageal (63% of patients, 37% of LNM) and paratracheal (33% of patients, 20% of LNM), while less than 5% of patients had supraclavicular, subaortic, diaphragmatic, or hilar LNM. With regard to the primary tumor, 51% of LNM were at the same height, while 25% and 24% of lymph node metastases were above and below the primary tumor, respectively. For thirty-three LNM (19%), the distance to the primary tumor was larger than 4 cm. No significant difference was seen between LCT/EUS (median 6 cm) and LPET (median 6 cm, p = 0.846) CONCLUSION: 18F‑FDG-PET can help to identify subclinical lymph node metastases which are located outside of recommended radiation fields. PET-based involved-field irradiation might be the ideal compromise between small treatment volumes and decreasing the risk of undertreatment of subclinical metastatic lymph nodes and should be further evaluated.

Distribution of Lymph Node Metastases in Esophageal Carcinoma Patients Undergoing Upfront Surgery: A Systematic Review

Metastatic lymphatic mapping in esophageal cancer is important to determine the optimal extent of the radiation field in case of neoadjuvant chemoradiotherapy and lymphadenectomy when esophagectomy is indicated. The objective of this review is to identify the distribution pattern of metastatic lymphatic spread in relation to histology, tumor location, and T-stage in patients with esophageal cancer. Embase and Medline databases were searched by two independent researchers. Studies were included if published before July 2019 and if a transthoracic esophagectomy with a complete 2- or 3-field lymphadenectomy was performed without neoadjuvant therapy. The prevalence of lymph node metastases was described per histologic subtype and primary tumor location. Fourteen studies were included in this review with a total of 8952 patients. We found that both squamous cell carcinoma and adenocarcinoma metastasize to cervical, thoracic, and abdominal lymph node stations, regardless of the primary tumor location. In patients with an upper, middle, and lower thoracic squamous cell carcinoma, the lymph nodes along the right recurrent nerve are often affected (34%, 24% and 10%, respectively). Few studies describe the metastatic pattern of adenocarcinoma. The current literature is heterogeneous in the classification and reporting of lymph node metastases. This complicates evidence-based strategies in neoadjuvant and surgical treatment.