pN3M0 gastric cancer: the category that allows the sub-classification of stage-IV gastric cancer (IVa and IVb)

Prognostic value of the seventh AJCC/UICC TNM classification of non-cardia gastric cancer

Background

The TNM staging criteria for gastric carcinoma have seen numerous revisions, the most recent of which are reflected in the seventh edition AJCC TNM cancer staging manual.

Methods

A retrospective evaluation of the sixth and seventh TNM classification of gastric cancer on a prospective database, regarding patients operated on for primary gastric cancer, was conducted. The end point of the study was prognosis evaluation in terms of overall survival.

Patients operated on for primary gastric cancer between September 2003 and March 2012 at our Department of Emergency and General Surgery, were consecutively retrieved in this study; a total of 114 patients were considered. Cardia gastric cancers, gastric lymphomas and gastrointestinal stromal tumors (GIST) were excluded. Median and mean follow-up periods were 22.5 and 27.7 months (range 15 days to 5 years). Both TNM6 and TNM7 were used to evaluate our patients. Overall survival and survival rates at different stages were analyzed using the Kaplan-Meier method and differences were determined using a log-rank test. Cox’s proportional hazard model was used to identify significant factors related to prognosis in a multivariate analysis.

Results

Overall survival between the sixth and seventh TNM classification was not significantly different. Both the Kaplan-Meier analysis and the multivariate analysis showed that the major negative prognostic factor was lymphovascular invasion (P < 0.001 in the univariate analysis and P = 0.035 to 0.048 in the multivariate analysis). Stage distribution and stage-related survival changed from the sixth to the seventh edition, especially in T3 stage where median survival for the sixth edition was 720 days versus 1,200 days for the seventh edition. Moreover, differences were shown in the survival rate of N1 versus N2 stages within the seventh TNM.

Conclusions

Even though further studies are needed in order to increase the number of patients studied, the seventh edition seems to provide a more accurate prognosis, especially regarding N1 and N2 tumors, showing that the most important prognostic factor is lymphovascular invasion.

Validation of seventh edition AJCC gastric cancer staging modifications

BACKGROUND AND OBJECTIVES

The seventh edition of the AJCC has more detailed staging categories for gastric cancer than does the sixth edition. The aim of our study was to compare the prognostic accuracies of the sixth and seventh AJCC editions for gastric cancer patients.

METHODS

We analyzed survival rates by category using the sixth and seventh editions of the AJCC in 10,060 patients with gastric cancer who had undergone gastrectomy between 1994 and 2007 at Samsung Medical Center.

RESULTS

Significant differences in prognosis were seen when comparing the new stages of the seventh edition of the AJCC that are subgroups of stages IB, II, IIIA, and IV in the sixth edition. In particular, stage IV of the AJCC sixth edition is divided into stages IIB, IIIA, IIIB, IIIC and IV in the seventh edition, and the 5-year survival rates of these respective stages were 80.2%, 45.3%, 23.5%, 17.2%, and 10.1% (P < 0.001).

CONCLUSIONS

Each category of the AJCC sixth edition has been divided into multiple stages in the AJCC seventh edition, each with a different prognosis. The newly divided subgroups from AJCC sixth edition stage IV showed more accurate outcome classification based on AJCC seventh edition staging stratification.

Evaluation of the 7th UICC TNM Staging System of Gastric Cancer

Since January of 2010, the seventh edition of UICC tumor node metastasis (TNM) Classification, which has recently been revised, has been applied to almost all cases of malignant tumors. Compared to previous editions, the merits and demerits of the current revisions were analyzed. Many revisions have been made for criteria for the classification of lymph nodes. In particular, all the cases in whom the number of lymph nodes is more than 7 were classified as N3 without being differentiated. Therefore, the coverage of the N3 was broad. Owing to this, there was no consistency in predicting the prognosis of the N3 group. By determining the positive cases to a distant metastasis as TNM stage IV, the discrepancy in the TNM stage IV compared to the sixth edition was resolved. In regard to the classification system for an esophagogastric (EG) junction carcinoma, it was declared that cases of an invasion to the EG junction should follow the classification system for esophageal cancer. A review of clinical cases reported from Asian patients suggests that it would be more appropriate to follow the previous editions of the classification system for gastric cancer. In addition, in the classification of the TNM stages in the overall cases, the discrepancy in the prognosis between the different stages and the consistency in the prognosis between the same TNM stages were achieved to a lesser extent as compared to that previously. Accordingly, further revisions are needed to develop a purposive classification method where the prognosis can be predicted specifically to each variable and the mode of the overall classification can be simplified.

Comparison of the 6th and 7th editions of the UICC TNM staging system for gastric cancer: results of a Chinese single-institution study of 1,503 patients

AIM

To evaluate the prognostic efficacy of the 7th edition tumor-node-metastasis (TNM) classification compared with the 6th edition in gastric cancer patients.

METHODS

A total of 1,503 gastric cancer patients undergoing surgical resection were staged using the 6th and 7th edition staging systems. Homogeneity, discriminatory ability, and monotonicity of gradients of the two systems were compared using linear trend χ(2), likelihood ratio χ(2) statistics, and Akaike information criterion (AIC) calculations.

RESULTS

Significant differences in 5-year survival rates were observed for the T, N, and M subgroups using the 7th edition system, except for stage N2 and N3 patients in the 6th edition system. There were no significant differences in survival between IB and IIA in the 7th edition system. Patients with stage IV disease due to T4/N3 in the 6th edition system who were downstaged to stage III in the 7th edition system had significantly better survival than those who remained at stage IV. The 7th edition system had higher linear trend and likelihood ratio χ(2) scores, and smaller AIC values compared with those for the 6th edition, which represented the optimum prognostic stratification.

CONCLUSIONS

Our study suggests that the 7th edition system performs better than the 6th edition in several aspects.

Subclassification of stage IV gastric cancer (IVa, IVb, and IVc) and prognostic significance of substages

BACKGROUND

Although the prognosis of stage IV gastric cancer is poor, some patients with stage IV gastric cancer had a long-term survival after gastrectomy. The objective of this study was to subclassify stage IV gastric cancer according to survival differences, evaluate the prognosis by substage, and identify the factors associated with patient survival in each substage.

METHODS

The data from 1,176 patients who underwent gastric resection for stage IV gastric cancer between 1988 and 2007 at Tumor Hospital of Harbin Medical University were reviewed retrospectively. The patients were divided into three substages according to the survival differences: stage IVa (T1-2N3M0), stage IVb (T3N3M0 and T4N1-2M0), and stage IVc (T4N3M0 and TanyNanyM1). The clinicopathological characteristics as well as survival of the patients were evaluated retrospectively by substage.

RESULTS

There were no significant differences in survival among T3N3M0, T4N1M0, and T4N2M0 groups (p = 0.884) and between T4N3M0 and TanyNanyM1 groups (p = 0.192). The 5-year survival rates in stage IVa (T1-2N3M0), stage IVb (T3N3M0 and T4N1-2M0), and stage IVc (T4N3M0 and TanyNanyM1) were 22.7%, 9.9%, and 2.2%, respectively (p < 0.001). Multivariate analysis showed the following independent prognostic factors for survival: subclassification, operation type, number of retrieved lymph nodes, curability, and chemotherapy for stage IV gastric cancer; curability, chemotherapy, and number of retrieved lymph nodes for stage IVa and IVb; chemotherapy and operation type for stage IVc. For 406 patients with curative resection in stage IVa and IVb, hematogenous recurrence (35.9%) was the dominant recurrence pattern in stage IVa, whereas the most common patterns of recurrence were peritoneal (40.8%) and locoregional recurrence (31.8%) in stage IVb.

CONCLUSIONS

Subclassification of stage IV gastric cancer into IVa (T1-2N3M0), IVb (T3N3M0 and T4N1-2M0), and IVc (T4N3M0, TanyNanyM1) may be helpful to predict the outcome and determine the therapeutic strategies for patients with stage IV gastric cancer.

Metastatic lymph node in gastric cancer; is it a real distant metastasis?

BACKGROUND

Currently, the TNM staging system is a widely accepted method for assessing the prognosis of the disease and planning therapeutic strategies for cancer. Of the TNM system, the extent of lymph node involvement is the most important independent prognostic factor for gastric cancer. The aim of our study is to evaluate the survival and prognosis of gastric cancer patients with LN#12 or #13 involvement only and to assess the impact of anatomic regions of primary gastric tumor on survival in this particular subset of patients.

METHODS

Among data of 1,008 stage IV gastric cancer patients who received curative R0 gastrectomy, a total of 79 patients with LN#12 (n = 68) and/or #13 (n = 11) were identified. All patients performed gastrectomy with D2 or D3 lymph node dissection.

RESULTS

In 79 patients with LN#12/13 involvement, the estimated one-, three- and five-year survival rate was 77.2%, 41.8% and 26.6% respectively. When we compared the patients with LN#12/13 involvement to those without involvement, there was no significant difference in OS (21.0 months vs. 25.0 months, respectively; P = 0.140). However, OS was significantly longer in patients with LN#12/13 involvement only than in those with M1 lymph node involvement (14.3 months; P = 0.001). There was a significant difference in survival according to anatomic locations of the primary tumor (lower to mid-body vs. high body or whole stomach): 26.5 vs. 9.2 months (P = 0.009). In Cox proportional hazard analysis, only N stage (p = 0.002) had significance to predict poor survival.

CONCLUSION

In this study we found that curatively resected gastric cancer patients with pathologic involvement of LN #12 and/or LN #13 had favorable survival outcome, especially those with primary tumor location of mid-body to antrum. Prospective analysis of survival in gastric cancer patients with L N#12 or #13 metastasis is warranted especially with regards to primary tumor location.

Prognosis of pN3 stage gastric cancer

PURPOSE

The aim of this study was to determine the prognosis of pN3 stage gastric cancer patients after they have undergone curative resection, and we also wanted to identify the prognostic factors according to the clinico-pathologic features.

MATERIALS AND METHODS

Between January 2000 and December 2004, we retrospectively reviewed the medical records of the patients with histologically confirmed pN3 stage gastric cancer. They underwent both gastrectomy and lymphadenectomy with a curative aim. We categorized the pN3 stage patients into 2 groups; one with pN3 only (pN3M0) and the other with pN3 combined with M1 stage (pN3M1) that included peritoneal seeding, hepatic metastasis or para-aortic LN metastasis.

RESULTS

Out of 467 patients with stage IV gastric adenocarcinoma who received surgery, 260 patients underwent curative resection and they were pathologically staged as N3. Among these 260 patients, 78 patients were classified as the pN3/M1 stage. For all the patients, the median follow-up period was 19 months (range: 1~108 months) and the median overall survival time was 16.2 months (95% CI, 14.1~18.3%). The 5-year survival rate of the pN3/M0 group was significantly higher than that of the pN3/M1 group (12.6% vs. 2.6%, respectively, p<0.0001). The identified predictor for a worse prognosis was an advanced T4 stage (HR: 3.38, 95% CI, 1.4~8.3, p=0.008) for the pN3 patients.

CONCLUSION

The survival for the pN3 gastric cancer patients after curative gastrectomy was significantly longer in the pN3/M0 group as compared to that of the pN3/M1 group. An advanced T stage was a predictor for a poor prognosis for the pN3 patients. Therefore, diverse treatment strategies for these heterogeneous pN3 gastric cancer patients are needed for improving their survival.

Prognostic influence of sub-stages according to pTNM categories in patients with stage IV gastric cancer

BACKGROUND AND OBJECTIVES

The prognosis for patients with stage IV gastric cancer is still very poor. The purpose of this study was to evaluate the surgical outcome and prognosis, and to determine the prognostic influence of sub-stages of stage IV gastric cancer.

METHODS

From 1992 to 2002, 287 patients histologically diagnosed with stage IV gastric cancer underwent gastrectomy at the Department of Surgery, Ruijin Hospital, China. Regarding TNM categories, we separated them into T1-3N3M0, T4N1-2M0, T4N3M0, and TanyNanyM1 groups. We compared the clinicopathological characteristics as well as the survival in these groups.

RESULTS

There were largest proportions of patients who underwent extended lymphadenectomy and curative gastrectomy in T1-3N3M0 group followed by T4N1-2M0, T4N3M0, and TanyNanyM1 groups. The survival rate of patients with sub-stage IVa (T1-3N3M0 and T4N1-2M0) tumors was significant higher than that of patients with sub-stage IVb (T4N3M0 and TanyNanyM1) tumors (P = 0.008). Multivariate analysis showed that sub-stage with the highest risk ratio (1.454), and the surgical curability were independent prognostic factors in patients with stage IV gastric cancer.

CONCLUSIONS

Sub-stages IVa (T1-3N3M0 and T4N1-2M0) and IVb (T4N3M0 and TanyNanyM1) may predict patients' prognosis more accurately. Curative resection should be performed whenever possible in patients with stage IV gastric cancer.