Risk factors and prognostic implications of upper or middle mediastinal lymph nodes metastasis and recurrence in...

The risk factors for upper and middle mediastinal lymph node (UMMLN) metastasis and the prognostic value of mediastinal lymphadenectomy (MLA) in patients with esophagogastric junction cancer (EGJC) remain unclear. This study aims to identify predictors for UMMLN metastasis or recurrence in EGJC with an esophageal invasion length (EIL) of >2 cm to ≤4 cm, and to clarify the histology specific prognostic impact of mediastinal dissection.

We retrospectively reviewed patients who underwent radical resection for stage II-IV EGJC with an EIL of >2 cm to ≤4 cm between 2000 and 2022. Risk factors for UMMLN involvement, defined as pathological metastasis or locoregional recurrence within 3 years, were evaluated. Postoperative outcomes were compared according to UMMLN involvement and histological subtype.

Among 43 patients with adenocarcinoma (AC) and 45 with squamous cell carcinoma (SCC), the proportion undergoing UMMLN dissection was similar. UMMLN involvement was identified in 20 patients (17 pathological metastases and 3 locoregional recurrences). Esophagus-predominant tumors [odds ratio (OR) 9.24, 95% confidence interval (CI): 1.11-77.2; P=0.04] and clinical N2 or higher (OR 3.7, 95% CI: 1.07-12.8; P=0.04) were independently associated with UMMLN involvement. However, the wide CI reflects a high degree of uncertainty, likely due to the limited number of events. Among patients with SCC, total MLA resulted in comparable survival rates between those with and without pathological UMMLN metastases, while patients with AC and UMMLN metastases had poor long-term outcomes.

Nodal status and histological type, together with tumor epicenter, may help guide the indications for, and prognostic benefit from, UMMLN dissection in EGJC with an EIL of >2 cm to ≤4 cm. Nonetheless, the risk factors for UMMLN involvement remain to be completely elucidated, and further investigation is needed.