Lymph node metastases in gastric cancer: correlation between new and old UICC TNM classification

The 5th edition of TNM classification (1997) grades lymph node involvement in gastric cancer by the number of metastatic lymph nodes. Their prognostic significance as defined by the new (5th edn., 1997) and old (4th edn., 1987) TNM classification was evaluated and survival in pN categories between both versions was compared. It was demonstrated in our analysis that comparison of old and new TNM systems is possible. Categories pN1 and pN2 contain patients selected by different criteria in both versions of TNM classification but with similar survival probabilities. Anatomic location of lymph nodes as described in the 4th edn. and number of involved nodes in the 5th edn. of TNM classification have about the same prognostic value in categories pN1 and pN2. The advantage of the 5th edn. is the identification of a group of patients (pN3, >15 involved lymph nodes) with significantly poor prognosis, which, in our series, includes 15% of R0 resected patients with lymph node metastases.