[Prognostic significance of the number of dissected lymph nodes in Siewert type Ⅱadenocarcinoma of the esophagogastric junction without lymphatic metastasis].

OBJECTIVE: To investigate the correlation between the number of dissected lymph nodes (LNs) and the prognosis of patients with node-negative Siewert type ⅡAEG.

METHODS: 248 patients with Siewert type Ⅱ AEG treated in our hospital between January 1998 and December 2008 were retrospectively assessed. All cases underwent left transthoracic subtotal esophagogastrectomy with conventional two-field lymphadenectomy, and were histopathologically proved to be without lymph node involvement. The prognostic impact of the number of dissected LNs was analyzed.

RESULTS: The overall median survival time and the 1-, 3-, and 5-year overall survival rates were 64 months, 80.4%, 60.8% and 51.0%, respectively. Cox regression showed that the number of dissected LNs and the depth of tumor invasion were independent prognostic factors. Patients with a high number of negative LNs had better overall survival than patients with a low number of negative LNs (P<0.05). The patients had better long-term survival outcomes with more than 10 LN dissected for cases with pT1 tumor (P<0.001), and so did those with more than 15 LN dissected for cases with pT2-3 tumor (P=0.003, 0.018, respectively).

CONCLUSION: The number of negative lymph nodes and the depth of tumor invasion are independent prognostic factors for node-negative Siewert type Ⅱ AEG, and adequate lymph node dissection can improve the long-term survival.