• Journal of Gastric Cancer
• /
• v.17 no.3
• /
• pp.212-219
• /
• 2017

Purpose: The aims of this study were to compare the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging manuals on tumor, node, and metastasis (TNM) staging systems and to evaluate whether the 8th edition represents a better refinement of the 7th staging system, when applied for the classification of gastric cancers. Materials and Methods: A total of 5,507 gastric cancer patients, who underwent treatment from January 1989 to December 2013 at a single institute, were included. We compared patient survival rates across the disease groups classified according to the 7th and 8th editions of the AJCC TNM staging systems. Results: Stage migration was observed in 6.4% (n=355) of the patients. Of these, 3.5% (n=192) and 2.9% (n=158) of patients showed a higher stage and lower stage, respectively. According to the 8th edition of the AJCC TNM staging criteria, the 5-year overall survival rates of the patients with stage IIIB and IIIC showed a significant difference (40.8% vs. 20.2%, P<0.001) whereas no significant differences in the 5-year overall survival rates were observed according to the 7th edition criteria (37.6% vs. 33.2%, P=0.381). Conclusions: Restaging stage III cancers according to the 8th edition of the AJCC TNM classification criteria improved survival rate discrimination, particularly, in institutes where the stage III patients were not distinctly categorized.

• Journal of Digestive Cancer Reports
• /
• v.7 no.1
• /
• pp.13-17
• /
• 2019

Stomach cancer is the fifth most common malignancy in the world. The incidence of stomach cancer is declining worldwide, however, gastric cancer still remains the third most common cause of cancer death. The tumor, node, and metastasis (TNM) staging system has been frequently used as a method for cancer staging system and the most important reference in cancer treatment. In 2016, the classification of gastric cancer TNM staging was revised in the 8^th American Joint Committee on Cancer (AJCC) edition. There are several modifications in stomach cancer staging in this edition compared to the 7^th edition. First, the anatomical boundary between esophagus and stomach has been revised, therefore the definition of stomach cancer and esophageal cancer has refined. Second, N3 is separated into N3a and N3b in pathological classification. Patients with N3a and N3b revealed distinct prognosis in stomach cancer, and these results brought changes in pathological staging. Several large retrospective studies were conducted to compare staging between the 7^th and 8^th AJCC editions including prognostic value, stage grouping homogeneity, discriminatory ability, and monotonicity of gradients globally. The main objective of this review is to evaluate the clinical and pathological implications of AJCC 8^th staging classification in the stomach cancer.

• Journal of Gastric Cancer
• /
• v.9 no.4
• /
• pp.159-166
• /
• 2009

Purpose: We evaluated the efficacy and prognostic predictability of the $7^{th}$ UICC TNM classification compared to $6^{th}$ UICC TNM classification in patients with gastric cancer. Materials and Methods: Between June 1992 and December 2006, 1,633 patients with gastric cancer who had undergone gastric surgery and who had been analyzed by the $6^{th}$ UICC method were analyzed using the new $7^{th}$ UICC system. Results: Significant differences in 5-year survival rates were observed for $7^{th}$ UICC N0, N1, N2, N3a, and N3b compared to $6^{th}$ UICC. There were no significant differences in 5-year survival rates between T2 and T3. Distinct survival differences were present between stage III (IIIa, IIIb, and IIIc) and stage IV in $7^{th}$ UICC. Significant differences in 5-year survival rates were not expected for Ia versus Ib, Ib versus IIa, and IIb versus IIIa. The survival rates for the same stages were not homogeneously differentiated by $7^{th}$ UICC except for stage IV. Conclusion: The $7^{th}$ UICC classification system is not better able to predict patient survival compared to 6th UICC in patients with gastric cancer, but is better for accurate prognosis of patients with stage IV gastric cancer.

• Journal of Gastric Cancer
• /
• v.11 no.2
• /
• pp.94-100
• /
• 2011

Purpose: The 7th AJCC tumor node metastasis (TNM) staging system modified the classification of the lymph node metastasis widely compared to the 6th edition. To evaluate the prognostic predictability of the new TNM staging system, we analyzed the survival rate of the gastric cancer patients assessed by the 7th staging system. Materials and Methods: Among 2,083 patients who underwent resection for gastric cancer at the department of surgery, Hanyang Medical Center from July 1992 to December 2009, This study retrospectively reviewed 5-year survival rate (5YSR) of 624 patients (TanyN3M0: 464 patients, TanyNanyM1: 160 patients) focusing on the number of metastatic lymph node and distant metastasis. We evaluated the applicability of the new staging system. Results: There were no significant differences in 5YSR between stage IIIC with more than 29 metastatic lymph nodes and stage IV (P=0.053). No significant differences were observed between stage IIIB with more than 28 metastatic lymph nodes and stage IV (P=0.093). Distinct survival differences were present between patients who were categorized as TanyN3M0 with 7 to 32 metastatic lymph nodes and stage IV. But patients with more than 33 metastatic lymph nodes did not show any significant differences compared to stage IV (P=0.055). Among patients with TanyN3M0, statistical significances were seen between patients with 7 to 30 metastatic lymph nodes and those with more than 31 metastatic lymph nodes. Conclusions: In the new staging system, modifications of N classification is mandatory to improve prognostic prediction. Further study involving a greater number of cases is required to demonstrate the most appropriate cutoffs for N classification.

• Journal of Gastric Cancer
• /
• v.19 no.3
• /
• pp.329-343
• /
• 2019

Purpose: Gastric cancer with lymph node metastasis (LNM) more than 15 (N3b) was defined as stage IV until the 6th AJCC system. However, it has been reclassified as a localized disease (stage IIb or III) since the 7th system. The aim of this study is to demonstrate that the survival of N3b is comparable to cytology-only positive (CY1-only) stage IV and to propose a new TNM system interpreting N3b as an eligibility criterion for receiving more intensive chemotherapy regimens. Materials and Methods: 1,430 patients who underwent gastric cancer surgery at Seoul National University Hospital from 2007 to 2012 were retrospectively analyzed. The 5-year survival rate (5YSR) and 3-year recurrence-free survival (RFS) were evaluated according to the 7th and 8th systems, as well as a new categorization based on N-classification; N0-2 (LNM<7), N3a (LNM 7-15), or N3b (LNM>15). Results: The survival of N3b is comparable to that of CY1-only stage IV (log rank test, P=0.671) and is distinct from that of grossly stage IV (log rank test, P<0.001). The survival of the remaining stage IIIc (T4bN3a) was comparable to those of N3b and CY1-only stage IV. Most N3b patients had significantly shorter 3-year RFS and mean RFS than those with IIb-IIIc, as if N3b itself was a higher TNM stage. Conclusions: In terms of survival, T4bN3a, N3b, and CY1-only stage IV were unified as stage IVa, while grossly stage IV was defined as stage IVb. N3b can be regarded as an eligibility criterion for undergoing more intensive chemotherapy regimens.

• Journal of Gastric Cancer
• /
• v.16 no.4
• /
• pp.207-214
• /
• 2016

Purpose: The utility of N classification has been questioned after the 7th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) was published. We evaluated the correlation between ratio-based N (rN) classification with the overall survival of pathological T4 gastric cancer patients who underwent D2 lymphadenectomy. Materials and Methods: We reviewed 222 cases of advanced gastric cancer patients who underwent curative gastrectomy between January 2006 and December 2015. The T4 gastric cancer patents were classified into four groups according to the lymph node ratio (the number of metastatic lymph nodes divided by the retrieved lymph nodes): rN0, 0%; rN1, ${\leq}13.3%$; rN2, ${\leq}40.0%$; and rN3, >40.0%. Results: The rN stage showed a large down stage migration compared with pathological T4N3 (AJCC/UICC). There was a significant difference in overall survival between rN2 and rN3 groups in patients with pT4N3 (P=0.013). In contrast, the difference in metastatic lymph nodes was not significant in these patients (${\geq}16$ vs. <15; P=0.177). In addition, the rN staging system showed a more distinct difference in overall survival than the pN staging system for pathological T4 gastric cancer patients. Conclusions: Our results confirm that rN staging could be a good alternative for pathological T4 gastric cancer patients who undergo D2 lymphadenectomy. However, before applying this system to gastric cancer patients who undergo D2 lymphadenectomy, a larger sample size is required to further evaluate the usefulness of the rN staging system for all stages, including less advanced stages.