Shunichi Tsujitani

Less invasive surgery for early gastric cancer based on the low probability of lymph node metastasis

BACKGROUND Less invasive treatment is the current trend in many surgical fields. Most patients with early gastric cancer do not have lymph node metastasis. Thus extensive resection of the stomach and extended lymph node dissection do not appear to be necessary. METHODS In a retrospective study, 890 consecutive patients with early gastric cancer who had undergone standard gastrectomy were assessed for depth of invasion, gross appearance, and maximum diameter of the tumor to examine the possibility of limiting the extent of lymph node dissection. A variety of limited gastrectomies have been developed and now include endoscopic mucosal resection, wedge resection, segmental gastrectomy, limited proximal gastrectomy, and distal hemigastrectomy. RESULTS A retrospective study revealed that extensive lymph node dissection did not improve the survival of patients with early gastric cancer. Endoscopic mucosal resection was suitable for cancers of the depressed type of less than 1 cm in diameter and the elevated type of less than 2 cm in diameter. Wedge, segmental, or limited proximal gastrectomy was suitable for the elevated type of 2 to 3 cm in diameter. The elevated type of more than 3 cm in diameter and the depressed type of 1 to 3 cm in diameter sometimes involved metastasis to group 1 nodes. The depressed type of more than 3 cm in diameter sometimes involved metastasis to group 2 nodes. Thus such cases should be treated by gastrectomy with dissection of potentially metastatic lymph nodes. CONCLUSIONS Limitation of the extent of gastrectomy and lymph node dissection may be possible, depending on the gross appearance and size of the tumor.

The expression of transforming growth factor-β1 is significantly correlated with the expression of vascular endothelial growth factor and poor prognosis of patients with advanced gastric carcinoma

Transforming growth factors β (TGFs β) are involved in a variety of important cellular functions, including cell growth and differentiation, adhesion, migration, extracellular matrix formation, and immune function. Moreover, it has been reported that TGFs β are correlated with angiogenesis. However, the role of TGF‐β as an angiogenic factor in gastric carcinoma is still unclear.

Apoptotic Cell Death in Human Gastric Carcinoma: Analysis by Terminal Deoxynucleotidyl Transferase‐mediated dUTP‐biotin Nick End Labeling

We have examined the occurrence of apoptotic cell death in formalin‐fixed, paraffin‐embedded human gastric carcinoma specimens by the terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP‐biotin nick end labeling (TUNEL) method. The specificity of the TUNEL signals was confirmed by the omission of either TdT or biotinylated dUTP as negative controls, and by pretreatment with DNase I as a positive control. Careful observation of routine hematoxylin and eosin‐stained sections showed a few tumor cells with apoptosis, especially in well‐differentiated carcinomas. Intense TUNEL signals were frequently observed even in ordinary, non‐pyknotic nuclei of tumor cells, and occasionally also in nuclear fragments corresponding to apoptotic bodies. Apoptotic indices (number of apoptotic cells/total number of tumor cells) ranged between 7.7 and 14.5% (mean, 10.9%) in nine well‐differentiated carcinomas and between 2.7 and 7.5% (mean, 4.0%) in five which were poorly differentiated, the mean number being significantly higher in the former (P<0.01). No apparent correlation was found between apoptosis and the expression of proliferating cell nuclear antigen, P53 or Ley in the present study. This high frequency of apoptosis, implying cell loss, may be related to the slow‐growing nature of well‐differentiated carcinomas. Poorly differentiated carcinomas, including scirrhous gastric carcinomas, showed a lower incidence of apoptosis, indicating the existence of an escape mechanism from the process.

Expression of vascular endothelial growth factor correlates with hematogenous recurrence in gastric carcinoma

BACKGROUND It has recently been reported that the microvessel density in a tumor correlates with hematogenous metastasis in gastric carcinoma. The aim of this study was to evaluate the relationship between the expression of vascular endothelial growth factor (VEGF), which was thought to be a potent angiogenesis-promoting factor, and hematogenous recurrence in advanced gastric carcinoma. METHODS The expression of VEGF and the density of the microvessels were examined by immunohistochemistry in patients with advanced gastric carcinoma with serosal invasion who had undergone curative resection. RESULTS The prognosis of patients with a VEGF-negative tumor was significantly better than that of patients with a VEGF-positive tumor. Multivariate analysis by Cox proportional hazards model showed that the expression of VEGF was an independent prognostic indicator. The expression of VEGF provided a significant estimate of relative risk for the development of hematogenous recurrence by multivariate logistic regression analysis. The microvessel count in VEGF-positive tumors was significantly higher than that in VEGF-negative tumors. CONCLUSIONS VEGF is associated with hematogenous recurrence. Assessment of the expression of VEGF may therefore prove valuable in identifying patients with gastric carcinoma at high risk for recurrence who would benefit from adjuvant therapy.

Apoptosis occurs more frequently in metastatic foci than in primary lesions of human colorectal carcinomas: analysis by terminal-deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labeling.

We examined the occurrence of apoptotic cell death in 15 advanced colorectal carcinomas with lymph‐node and/or liver metastases by terminal‐deoxynucleotidyl‐transferase (TdT)‐mediated dUTP‐biotin nick end labeling (TUNEL). TUNEL‐positive cells were used to quantify the apoptotic index (AI: percentage of TUNEL‐positive cells in carcinomatous cells). Similarly, Ki‐67‐positive cells were used to quantify Ki‐67 labeling (Kl: percentage of Ki‐67‐positive cells in carcinomatous cells) as a proliferative index. The mean AIs of primary colorectal carcinomas, lymph‐node and liver metastases were 3.5%, 5.6% and 6.2% respectively. There was a significant group difference between primary carcinomas and lymph‐node or liver metastases. The mean Kls of primary colorectal carcinomas, lymph‐node and liver metastases were 51.8%, 60.1% and 61.7% respectively. There was a significant group difference between primary carcinomas and lymph‐node or liver metastases. In addition, there was a close positive relationship between the AI and MI per specimen. There was no apparent correlation between AI or MI and the expression of nuclear p53 of cancer cells. These results suggested that cell proliferation and loss (apoptosis) were more frequent in metastatic foci than in primary lesions, and that apoptosis might reflect not only cell loss but also the proliferative activity of human colorectal carcinomas.

Significant correlation between micrometastasis in the lymph nodes and reduced expression of E-cadherin in early gastric cancer

Background. E-cadherin has been recognized as an impor-tant factor associated with tumor metastasis. However, the relationship between micrometastasis in the lymph nodes and the expression of E-cadherin in the primary tumor in gastric cancer remains unclear.Methods. Two consecutive sections of 4522 lymph nodes from 162 patients with early gastric cancer were prepared for simultaneous hematoxylin and eosin (H&E) and cytokeratin (CK) staining. Sections of primary tumors from 135 of these patients were prepared for E-cadherin immunostaining.Results. The incidence of lymph node involvement was significantly increased, from 6.8% (11/162 patients) by H&E staining, to 27% (43/162 patients) by CK immunostaining (P < 0.0001). Micrometastasis in the lymph node was found in 32 of 151 (21%) patients who had no lymph node metastasis evidenced by H&E staining. Micro-lymph node metastasis was frequently found in tumors with a diameter more than 1.0 cm, of those that were poorly differentiated, deeply invaded, showed lymphatic on vascular invasion, and in those that showed reduced expression of E-cadherin. Loss of expression of E-cadherin in the primary tumor was closely correlated with micro-lymph node metastasis. Patients with tumors with micro-lymph node metastasis detected by CK immunostaining had a significantly lower 5-year survival rate (P < 0.01) than those without such metastases.Conclusion. Tumors more than 1.0 cm in diameter and those that exhibit poor differentiation, deep invasion (i.e., to the submucosa), lymphatic or vascular invasion, and reduced expression of E-cadherin are risk factors for lymph node metastasis in early gastric cancer. Thus, it is recommended that cancers confined to the mucosa (m-cancers) that are more than 1.0 cm in diameter should not be treated with limited surgery without lymphadenectomy.

A prospective pilot study of extended (D3) and superextended para-aortic lymphadenectomy (D4) in patients with T3 or T4 gastric cancer managed by total gastrectomy☆

BACKGROUND Japanese surgeons have been actively performing extended lymphadenectomy (D2, removal of perigastric nodes and nodes along the left gastric, common hepatic, celiac and splenic arteries; or D3, D2 plus removal of nodes in the hepatoduodenal ligament, in the retropancreatic space and along the vessels of the transverse mesocolon). In recent years interest has expanded to superextended lymphadenectomy (D4) of nodes around abdominal aorta (para-aortic lymph nodes from aortic hiatus to aortic bifurcation). Because the therapeutic value of this D4 procedure remains controversial, we initiated a prospective study to compare D3 and D4 lymphadenectomy. METHODS Seventy patients with T3 or T4 gastric cancer and without macroscopic metastasis to the para-aortic nodes treated by potentially curative total gastrectomy were randomized to D4 (group A, n = 35) and D3 (group B, n = 35) lymphadenectomies. RESULTS Metastases to para-aortic nodes were found in 4 patients. Postoperative survival after D4 resection was not statistically significant between the groups. Postoperative morbidity for group A was greater. In group A 4 patients had postoperative retention of intra-abdominal fluid (lymphorrhea) and 4 others had prolonged diarrhea. One patient in each group died of postoperative complications. CONCLUSIONS Surgical treatment of microscopic disease in grossly normal para-aortic lymph nodes may generate occasional long-term survivors. Selecting appropriate candidates who might benefit from D4 resections needs to be refined. On the basis of this study, a nationwide study should be considered.

Serum concentration of CD44 variant 6 and its relation to prognosis in patients with gastric carcinoma

The expression of variant isoforms of CD44 is correlated with the ability of tumor cells to metastasize in some clinical carcinomas. In this study, the serum concentration of soluble splice isoforms of CD44 that shared exon variant 6 (sCD44v6) were measured and the histologic expression of CD44v6 in tumors from patients with gastric carcinoma examined.

Distinct recurrence pattern and outcome of adenocarcinoma of the gastric cardia in comparison with carcinoma of other regions of the stomach

BackgroundCarcinoma arising in the cardioesophageal junction is a distinct clinical entity compared with tumors located in other regions of the stomach. The prognosis for adenocarcinoma of the upper stomach is considered to be relatively poorer than carcinomas of the more distal stomach. We have therefore investigated patients with carcinoma of the gastric cardia in order to evaluate the underlying cause of this poor prognosis.Materials and MethodsClinicopathologic features and postoperative prognosis of 101 patients with carcinoma of the cardia were evaluated and compared with findings on 1884 patients with tumors in other regions of the stomach.ResultsTumors of the cardia had a mean size of 6.8 cm, which was significantly larger than the mean size of 5.9 cm for tumors found in the middle- and lower third of the stomach. The incidence of serosal invasion, lymph node metastasis, and lymphatic and blood vessel invasion was higher in association with adenocarcinoma of the cardia than with adenocarcinoma in remaining parts of the stomach. In the analysis of patients who had undergone curative resection, the 5-year survival rates were 61.6, 79.1, and 82.6% in patients with carcinoma of the cardia, upper one-third, and remaining middle- and lower one-third of the stomach, respectively, and the differences were statistically significant. Multivariate analysis indicated that adenocarcinoma of the gastric cardia is an independent prognostic factor. With regard to the site of recurrence, both lymph node and hematogenous recurrence were observed more frequently in the cardia than in the remaining parts of the stomach.ConclusionsOur data indicate that the prognosis of patients with adenocarcinoma of the gastric cardia is extremely poor. To improve their prognosis, new treatments in addition to gastrectomy with extensive lymph node dissection are needed.

Expression of cyclo-oxygenase-2 is correlated with high intratumoral microvessel density and low apoptotic index in human esophageal squamous cell carcinomas

Abstract. Cyclo-oxygenase (COX) is a key enzyme in the conversion of arachidonic acid to prostanoids. COX-2 expression has been found in many malignancies. This study analyzed the correlation between COX-2 expression and angiogenesis or apoptosis in human esophageal carcinomas. The study examined the expression of COX-2 in six esophageal carcinoma cell lines and in 100 esophageal squamous cell carcinomas, comparing intratumoral microvessel density (IMVD) and apoptotic index (AI) by immunohistochemistry and TUNEL methods. COX-2 was variably expressed in all the cell lines examined. COX-2 immunoreactivity was observed mainly in the cytoplasm of carcinoma cells. Significantly higher mean IMVD and lower AI were noted in the 51 strong COX-2 expressing cases than in the 49 weak cases. IMVD and AI were negatively correlated. COX-2 expression was higher in the tumors with lymphatic invasion than in the others. These data indicate that COX-2 expression is associated with increased intratumoral microvessels and suppression of tumor cell apoptosis. Thus COX-2 might play an important role in the angiogenesis and regulation of apoptosis in esophageal squamous cell carcinomas.