Evaluating prognostic value and stage migration effects using a positive lymph node ratio in adenocarcinoma of the esophagogastric junction

BACKGROUND: Adenocarcinoma of the esophagogastric junction (AEG) is increasing worldwide. Lymph node metastasis is an important clinical issue in AEG patients. This study investigated the usefulness of a positive lymph node ratio (PLNR) to stratify prognosis and evaluate stage migration. METHODS: We retrospectively analysed 117 consecutive AEG patients (Siewert type I or II) who received a lymphadenectomy between 2000 and 2016. RESULTS: A PLNR cut-off value of 0.1 most effectively stratified patient prognosis into two groups (P < 0.001). Also, prognosis could be clearly stratified into four groups: PLNR = 0, 0 < PLNR < 0.1, 0.1 ≤ PLNR < 0.2, and 0.2 ≤ PLNR (P < 0.001, 5-year survival rates (88.6%, 61.1%, 34.3%, 10.7%)). A PLNR ≥ 0.1 significantly correlated with tumour diameter ≥ 4 cm (P < 0.001), tumour depth (P < 0.001), greater pathological N-status (P < 0.001), greater pathological Stage (P < 0.001), and oesophageal invasion length ≥ 2 cm (P = 0.002). A PLNR ≥ 0.1 was a poor independent prognostic factor (hazard ratio 6.47, P < 0.001). The PLNR could stratify prognosis if at least 11 lymph nodes were retrieved. A 0.2 PLNR cut-off value discriminated a stage migration effect in pN3 and pStage IV (P = 0.041, P = 0.015) patients; PLNR ≥ 0.2 might potentially diagnose a worse prognosis and need meticulous follow-up post-surgery. CONCLUSION: Using PLNR, we can evaluate the prognosis and detect higher malignant cases who need meticulous treatments and follow-up in the same pStage. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12885-023-10689-6.