Impact of total retrieved lymph nodes on staging and survival of patients with gastric cancer invading the subserosa

Abstract 

Purpose

To investigate the impact of total retrieved lymph nodes (tLNs) on staging and survival in patients with pT2b gastric cancer according to the nodal status.

Methods

Clinicopathological characteristics and prognostic outcomes of 392 patients with pT2b gastric cancer between 1980 and 2005 were retrospectively investigated based on the nodal status.

Results

The number of metastatic lymph nodes (mLNs) was highly correlated with the number of tLNs (P<0.001). The overall 5-year and 10-year survival rates were 39.0% (153/392) and 17.9% (70/392), respectively. The survival rates in patients with pN0 cancers did not differ significantly from that in patients with pN1 cancer when the tLNs were 25 or less. However, the survival rate in patients with N0 cancers was significantly greater than that in patients with pN1 cancers when the tLNs were more than 25 (64.3% vs. 36.9%, χ²=4.339, P=0.037). Moreover, both 5- and 10-year survival rates differed significantly among patients with pN1, pN2 and pN3 gastric cancer regardless of tLNs. Multivariate analysis revealed that age, tumor focus number, tumor location, and mLN, but not tLNs, were independent prognostic predictors in patients with pT2b gastric cancer.

Conclusions

To improve the accuracy of staging, no less than 15 tLNs should be pathologically examined in patients with pN1–3, and 25 tLNs for the patients with N0. More tLNs may not be associated with a better prognosis in pT2b disease because the extent of lymph node dissection is pre-defined for the operation.

Keywords: Gastric cancer, Total retrieved lymph nodes, Lymph node metastasis, T category, Prognosis