Prognostic significance of lymph node metastasis in advanced carcinoma of the stomach

Characterization of early gastric cancer and proposal of the optimal therapeutic strategy

BACKGROUND AND AIMS

The optimal protocol of the treatment for early gastric cancer has not been fully established. The current study was designed to elucidate the relationship between the depth of tumors with or without an ulcer and the presence of lymph node metastasis and to establish the optimal and practical therapeutic strategy for patients with early gastric cancer.

PATIENTS AND METHODS

A retrospective analysis of 1051 patients with early gastric cancer treated by gastrectomy with D1 or D2 lymph node dissection was performed. The patients were divided into those with mucosal (M) tumors and those with submucosal (SM) tumors. These 2 groups were subclassified, depending on the coexistence of ulcer or the degree of submucosal invasion, and were characterized in relation to clinicopathologic factors and 5-year prognosis.

RESULTS

The incidence of lymph node metastases from SM tumors (19.8%, 85 of 430) was more frequent than that from M tumors (2.3%, 14 of 621) (P <.001). All M tumors with lymph node involvement, including tumors smaller than 1.5 cm in diameter, had ulceration or ulceration scar in the lesions. SM tumors that had invaded less than 200 microm in depth (SM1a) had significantly less lymph node involvement than those with deeper invasion. The node metastases were confined to epigastric lymph nodes (N1) in both M tumors with ulceration or ulceration scar and SM1a tumors.

CONCLUSIONS

All macroscopic M tumors without ulceration or ulceration scar should be considered for endoscopic mucosal resection. The need for reoperation for a formal gastrectomy with lymphadenectomy or a limited surgical operation will vary depending on the pathologic analysis of endoscopic mucosal resection specimens (depth of invasion, presence of ulceration).

Analysis of the survival period in resectable stage IV gastric cancer

BACKGROUND

Patients with stage IV gastric cancer usually have a poor prognosis, but some patients with resectable cancer survive for more than 5 years. We aimed to study the correlation of protein expression and survival in resectable stage IV gastric cancer.

PATIENTS AND METHODS

Tissue samples of 42 patients with resectable stage IV gastric cancer were stained immunohistochemically for the mutant p53 protein and heat shock protein-27 (hsp27). The correlation between protein expression and clinicopathological factors was investigated. Furthermore, prognostic value of each factor was analyzed.

RESULTS

Univariate analysis showed that pN factors (Japanese classification, P = .028; International Union Against Cancer classification, P = .024), blood vessel invasion (P = .043), hsp27 overexpression (P = .019), and the index of p53 and hsp27 overexpression (P = .0026) had a prognostic influence. Only Lauren classification, however, revealed the prognostic influence in multivariate analysis (P = .046).

CONCLUSIONS

These results suggest that immunostaining of tumor specimens for p53 and hsp27 and clinicopathological analysis may help predict the survival of patients with resectable stage IV gastric cancer.

Lymph node staging in gastric cancer: is location more important than Number? An analysis of 1,038 patients

OBJECTIVE

To compare the impact of staging systems on the survival of 1,038 patients with gastric cancer undergoing resection for cure in a North American center.

SUMMARY BACKGROUND DATA

In 1997, the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer redefined N stage in gastric cancer. The number of involved nodes rather than their location defines N, and a minimum of 15 examined lymph nodes is recommended for adequate staging. In the 1988 AJCC N-staging system, N1 and N2 node metastases were defined as within 3 cm or more than 3 cm of the primary; the 1997 AJCC N stages were defined as N1 = 1 to 6 positive nodes, N2 = 7 to 15 positive nodes, and N3 = more than 15 positive nodes.

METHODS

Between 1985 and 1999, 1,038 patients underwent an R0 resection. Median and 5-year survival rates were compared and the Kaplan-Meier method was used to estimate median survival.

RESULTS

The location of positive nodes did not significantly affect median survival when analyzed by the number of positive nodes. In contrast, the number of positive lymph nodes had a profound influence on survival. The new N categories served as a better discriminator of median survival when 15 or more nodes were examined. Survival estimates for stages II, IIIA, and IIIB were significantly influenced by examining 15 or more nodes.

CONCLUSION

The number of positive nodes best defines the prognostic influence of metastatic lymph nodes in gastric cancer. Survival estimates based on the number of involved nodes are better represented when at least 15 nodes are examined.

Reflections and proposals for the standardization of lymphadenectomy for gastric carcinoma

In this paper, I consider: the value of various histological procedures; the feasibility and reproducibility of lymphadenectomies according to the Japanese Research Society for Gastric Cancer; the minimal number of lymph nodes (LNs) which should be resected for each type of lymphadenectomy; and the best way to present the results concerning the LN status. A reproducible lymphadenectomy is proposed for simplified anatomical level I (anterior plane, along the gastric curves) and level II (intermediate plane, along the gastric arteries), without spleno-pancreatectomy for the majority of cases. The LN status must be based on the total number of involved nodes, as recommended by the 1997 UICC classification. These simple, reproducible guidelines offer a basis for the standardization of procedures used for the treatment and classification of gastric carcinomas.

Lymph node dissection for gastric cancer

Complete tumor removal with margins of clearance at the resection lines must be the aim of today's surgical treatment of gastric cancer, and this must be applied even in lymph node dissection. But, over the last few decades, the extent and impact of lymphadenectomy remains controversial. Whereas Japanese centers advocate extensive lymph node dissection as the base of their excellent results, many Western surgeons, supported by actual randomized trials, believe that the potential benefit of such procedures cannot outweigh the risk of increased postoperative morbidity and mortality. However, if lymphadenectomy is restricted to the removal of nodes only, it does not influence the operative risk. Further, the lymph node ratio and number of lymph nodes involved are relevant prognostic parameters. Survival improvement can be achieved in a moderate degree of metastatic involvement of the nodes (pN0,1). Therefore, systematic lymph node dissection should be an integral part of the curative resection sought. Limited or no lymphadenectomy might be indicated in noncurative surgery or in special types of mucosal early gastric cancer, respectively.

Evaluation of the New American Joint Committee on Cancer/International Union against cancer classification of lymph node metastasis from gastric carcinoma in comparison with the Japanese classification

BACKGROUND

A new system for the classification of gastric carcinoma, based on the number of metastatic lymph nodes, has been adopted by the current American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) TNM system (1997). The purpose of this study was to evaluate the rationality of this classification in comparison with the Japanese classification, which is based on the location of positive lymph nodes.

METHODS

The authors analyzed 587 patients who underwent clinically curative gastrectomy with D2 lymphadenectomy for gastric carcinoma and each had 15 or more lymph nodes histologically examined from 1982 to 1992. Multivariate analysis with the Cox proportional hazards model was carried out to determine which classification was more effective.

RESULTS

Within the pN1 or pN2 category of the new AJCC/UICC system, no significant difference in the survival rates existed between n1 patients and n2 patients of the Japanese classification. On the other hand, the survival rates significantly decreased, in the order of pN1, pN2, and pN3 (from greatest to smallest decrease), within the n1 and n2 categories. In multivariate analysis, lymph node involvement by the AJCC/UICC classification was selected as the most significant prognostic determinant, whereas the Japanese lymph node classification was not significantly prognostic. When survival rates were calculated within the pT1, pT2, and pT3-4 categories, no differences existed between pN0 and pN1. There was some discrepancy between the survival rate for each pT and pN category and the corresponding stage.

CONCLUSIONS

The new AJCC/UICC classification for lymph node involvement of gastric carcinoma is basically acceptable and considered superior to the Japanese classification. Further analysis involving a greater number of cases may be necessary to confirm the applicability of this staging system.

Factors correlated with number of metastatic lymph nodes in gastric cancer

OBJECTIVE

We had previously reported a reasonable categorization of the number of positive lymph nodes (LN: 0, 1-4, 5-8, and > 8) as a prognostic indicator. This study was an extension, to see which factors correlated with number of positive lymph nodes.

METHODS

A total of 533 patients with gastric adenocarcinoma, who underwent curative surgery between January 1988 and December 1995, were entered into this study. Patients were divided into four groups according to metastatic LN number (0, 1-4, 5-8, and > 8). Their survival and clinicopathological factors were analyzed.

RESULTS

A total of 16,457 LNs, with an average of 30.9 per specimen, were removed, of which 1686 (10.2%) showed metastases. The 5-yr cumulative survival rate decreased as the number of metastatic LNs increased, ie., 91.3% for LN 0; 67.4% for LN 1-4; 37.2 for LN 5-8, and 14.1% for LN > 8. Multivariate analyses showed that depth of cancer invasion (odds ratio: 2.4), gross appearance (odds ratio: 1.9), size (odds ratio: 1.9), and location (odds ratio: 1.4) of tumor were four independent factors correlated with the number of metastatic LNs. Number of metastatic LNs increased with advanced Japanese nodal stage and UICC-TNM stage.

CONCLUSIONS

Depth of tumor invasion, and gross appearance, size, and location of tumor were four pathological factors independently correlated with number of metastatic LNs in gastric cancer.

Gastric cancer in Asia: progress and controversies in surgical management

Considerable controversy surrounds the management of gastric cancer and this has largely overshadowed recent progress in our understanding of the epidemiology and molecular pathogenesis of the disease, and improvements in diagnostic and staging techniques. Differences identifiable in the molecular pathogenesis of the 'intestinal' and 'diffuse' types of gastric cancer may help to unravel the biological behaviour of variants and ultimately influence therapeutic strategies. Endoscopic ultrasound is well established as being accurate for T staging and the introduction of laparoscopy, with or without ultrasound, is obviating unnecessary laparotomy in non-bleeding, non-obstructed patients. Controversies in surgery encompass the role of laparoscopic surgery in early gastric cancer, the extent of lymphadenectomy including para-aortic nodal dissection, resection of en bloc contiguous organ involvement, pancreatosplenectomy, left upper abdominal evisceration, and modes of reconstruction (pylorus-preserving gastrectomy, pouch formation) to enhance quality of life. Whereas adjuvant chemotherapy does not impact favourably on survival, emphasis has now shifted to neoadjuvant (induction) chemotherapy to downstage the disease. Preoperative regional chemotherapy and intra-operative hyperthermic chemotherapy or irradiation may prove to be of benefit in patients with resectable disease, but some scepticism still exists as to the usefulness of biological response modifiers (e.g. OK432, PSK) for adjuvant treatment. Ethical issues relating to cultural differences in Asia sometimes mitigate against adequate trial design (e.g. a surgery-alone control group or a no adjuvant therapy treatment group may be considered inappropriate) and this has understandably hindered acceptance in Western countries of the value of current management practices in Asia. These issues and the need for ongoing well-conducted randomized trials with prospective subset analysis are now being addressed.

Prognostic factors in a series of 297 patients with gastric adenocarcinoma undergoing surgical resection

BACKGROUND

Gastric cancer has a poor prognosis. The aim of this study was to determine the influence of several clinicopathological variables on outcome in a series of 297 Western patients undergoing surgical resection for gastric adenocarcinoma.

METHODS

The results were analysed retrospectively and prognostic factors were identified in a univariate and Cox proportional hazards regression model. Mean patient age at the time of operation was 61.9 years; 65.7 per cent were men. Mean follow-up was 7.8 (range 1-15) years. Of the 297 patients undergoing surgery, 70 per cent had subtotal gastrectomy, 26.3 per cent underwent total gastrectomy and 3.7 per cent had proximal gastrectomy.

RESULTS

The overall survival rate was 38.9 per cent at 5 years. In th univariate analysis, survival-related factors were weight loss (P < 0.05), abdominal mass (P < 0.01), dysphagia (P < 0.001), type of gastrectomy (subtotal gastrectomy versus total gastrectomy, P < 0.001), intention of resection (curative versus palliative resection, P < 0.001), tumour site (P < 0.001), histopathological grade (low versus high grade, P < 0.05), tumour diameter less than 3 cm (P < 0.001), degree of gastric wall invasion (P < 0.001), degree of lymph node invasion (P < 0.001) and stage of the neoplasia (P < 0.001). Other variables had no significant influence. In the multivariate analysis, degree of gastric wall invasion, lymph node invasion, tumour size and dysphagia at presentation were the only independent prognostic variables.

CONCLUSION

From these data it was possible to derive a prognostic index with which patients could be classified as at low, intermediate or high risk.