Pattern of Lymph Node Metastases and Recurrence in Thoracic Small Cell Esophageal Carcinoma: A Single-Institution Experience.

BACKGROUND: To study the patterns of lymph node metastases (LNMs) and associated factors, prognostic factors and failure patterns in primary thoracic small cell esophageal carcinoma (SCEC) after curative esophagectomy. METHODS: We retrospectively reviewed thoracic SCEC patients who underwent curative esophagectomy with R0 resection at Fudan University Shanghai Cancer Center. The associations between clinicopathological variables and LNM patterns were evaluated using logistic regression. The prognostic impacts on cancer-specific survival (CSS) and disease-free survival (DFS) were assessed using Cox regression models. RESULTS: Overall, 100/147 patients (68.0%) had LNMs (401/3560 lymph nodes, 11.3%). The frequency of LNM was 8.8% in the neck, 27.9% in the upper mediastinum (Um), 23.1% in the middle mediastinum (Mm), 15.6% in the lower mediastinum (Lm), and 35.4% in the abdomen. Patients with upper thoracic tumors (Ut) predominantly had LNMs in the Um (75.0%); patients with lower thoracic tumors (Lt) most frequently exhibited abdominal LNMs (48.0%); and patients with middle thoracic tumors (Mt) displayed a more diffuse pattern of LNMs (Mm 31.5, Um 30.3, and abdomen 28.1%). Recurrent nerve and perigastric lymph nodes had the highest metastasis/recurrence rates. Notably, lymphovascular invasion (55.1%) strongly correlated with nodal metastasis and worse DFS/CSS. Advanced stage and four or fewer chemotherapy cycles predicted poorer DFS and CSS. CONCLUSIONS: The lymphatic metastatic pattern of SCEC adheres to esophageal anatomical characteristics and tumor location. Compared with esophageal squamous cell carcinoma, SCEC displays greater lymphatic aggressiveness, with higher propensity for abdominal LNMs. Therefore, extended lymphadenectomy, particularly involving recurrent nerve and abdominal lymph nodes, combined with ≥ 4 cycles of adjuvant chemotherapy, is recommended.