Comparison of the UICC/AJCC 1992 and 1997 pN categories for gastric cancerpatients after surgery

Background/Aims: UICC/AJCC 1997 classification changes pN category. We eval uated its prognostic impact. Methodology: A total of 710 patients who underwent a greater than or equal to D2 gastrectomy were recruited. Among them, the data of 319 patients who had involved regional lymph nodes and no evidence of distant metastases wer e used for comparing the 1992 and 1997 pN categories. Results: For 1997 category, 201 patients (64%) were pN1, 75 (23.5%) pN2, an d 43 (13.5%) pN3. For 1992 category, 143 patients (44.8%) were pN1, and 147 (46.1%) pN2. 29 patients (9.1%) with lymph node metastasis to the hepatoduo denal Ligament were distant metastasis. The 1997 pN category was a more pow erful prognostic discriminant (relative risk: 2.086) than the 1992 category . Compared to the 1992 stage classification, the 1997 one had a skewed dist ribution of patients with marked shift of patients of stage IIIA (105-126 p atients), IIIB (116-58 patients), and TV (100-122 patients). The survival d ifference between stage IIIA and IIIB for the 1997 stage classification is narrower than for 1992. Conclusions: The 1997 pN category allows for estimation of prognosis superi or to the 1992 category.