Anatomical location-based nodal staging system is superior to the 7th edition of the American Joint Committee on Cancer staging system among patients with surgically resected, histologically low-grade gastric cancer: A single institutional experience

Efficacy of Lymph Node Location-Number Hybrid Staging System on the Prognosis of Gastric Cancer Patients

BACKGROUND

Lymph node metastasis location and number significantly affects the prognosis of patients with gastric cancer (GC). This study was designed to examine a new lymph node hybrid staging (hN) system to increase the predictive ability for patients with GC.

METHODS

This study analyzed the gastrointestinal treatment of GC at the Harbin Medical University Cancer Hospital from January 2011 to December 2016, and selected 2598 patients from 2011 to 2015 as the training cohort (hN) and 756 patients from 2016 as the validation cohort (2016-hN). The study utilized the receiver operating characteristic curve (ROC), c-index, and decision curve analysis (DCA) to compare the prognostic performance of the hN with the 8th edition of AJCC pathological lymph node (pN) staging for GC patients.

RESULTS

The ROC verification of the training cohort and validation cohort based on each hN staging and pN staging showed that for each N staging, the hN staging had a training cohort with an AUC of 0.752 (0.733, 0.772) and a validation cohort with an AUC of 0.812 (0.780, 0.845). In the pN staging, the training cohort had an AUC of 0.728 (0.708, 0.749), and the validation cohort had an AUC of 0.784 (0.754, 0.824). c-Index and DCA also showed that hN staging had a higher prognostic ability than pN staging, which was confirmed in the training cohort and the verification cohort, respectively.

CONCLUSION

Lymph node location-number hybrid staging can significantly improve the prognosis of patients with GC.

Prognostic Value of the Anatomic Region of Metastatic Lymph Nodes in the Current TNM Staging of Gastric Cancer

Purpose

The numeric N stage has replaced the topographic N stage in the current tumor node metastasis (TNM) staging in gastric carcinoma. However, the usefulness of the topographic N stage in the current TNM staging system is uncertain. We aimed to investigate the prognostic value of the topographic N stage in the current TNM staging system.

Materials and Methods

We reviewed the data of 3350 patients with gastric cancer who underwent curative gastrectomy. The anatomic regions of the metastatic lymph nodes (MLNs) were classified into 2 groups: perigastric and extra-perigastric. The prognostic value of the anatomic region was analyzed using a multivariate prognostic model with adjustments for the TNM stage.

Results

In patients with lymph node metastasis, extra-perigastric metastasis demonstrated significantly worse survival than perigastric metastasis alone (5-year survival rate, 39.6% vs. 73.1%, respectively, P<0.001). Extra-perigastric metastasis demonstrated significantly worse survival within the same pN stage; the multivariate analysis indicated that extra-perigastric metastasis was an independent poor prognostic factor (hazard ratio=1.33; 95% confidence interval=1.01–1.75). The anatomic region of the MLNs improved the goodness-of-fit (likelihood ratio statistics, 4.57; P=0.033) of the prognostic model using the TNM stage.

Conclusions

The anatomic region of MLNs has an independent prognostic value in the numeric N stage in the current TNM staging of gastric carcinoma.

Comparison of the sixth, seventh, and eighth editions of the American Joint Committee on Cancer Tumor-Node-Metastasis staging system for gastric cancer: A single institution experience

In 2018, the eighth edition of the American Joint Committee on Cancer Tumor-Node-Metastasis classification and staging system was implemented. Few reports were made comparing the performance of different editions of the American Joint Committee on Cancer (AJCC) system. Therefore, this study aimed to examine the prognostic predictability from the sixth to the eighth editions of the AJCC staging system for gastric cancer.A total of 414 patients with gastric cancer who underwent surgery at Changhua Christian Hospital from January 2007 to December 2017 were enrolled in the study. To identify the prognostic factors for gastric cancer death, univariate and multivariate analyses were performed. The homogeneity and discrimination abilities of the sixth to eighth editions of the staging system were compared using the likelihood ratio chi-square test, linear trend chi-square test, and Akaike information criterion.The sixth edition of the staging system had the lowest Akaike information criterion value, suggesting a better prognostic stratification than other editions. From the result of the likelihood ratio chi-square test, the T and N staging systems of the seventh and eighth editions had better homogeneity and discriminatory ability than the sixth edition. The eighth edition had better prognostic performance in patients at stage III compared with the seventh edition.The AJCC seventh and eighth editions had improved prognostic predictability of the T and N factors compared with the sixth edition. However, the overall staging performance of the eighth edition is not superior compared to the sixth edition. Further studies with larger sample size should be conducted to compare the performance of different editions of the AJCC staging system for different ethnic populations.