Expression of BMP-7 in human gastric cancer and its clinical significance.

BACKGROUND: Bone morphogenetic protein-7 (BMP-7) is a signalling molecule belonging to the transforming growth factor--superfamily. Recent studies have demonstrated the clinical impact of BMP-7 expression in various human cancers. However, there have been few reports detailing this in gastric cancer. METHODS: We immunohistochemically investigated the expression of BMP-7 in 233 gastric cancer patients to disclose the clinicopathological features of BMP-7-positive gastric cancer. RESULTS: Immunohistochemically, in human gastric cancer, BMP-7 expression was identified in cellular membranes but also in the cytoplasm of cancer cells. Bone morphogenetic protein-7-positive expression was found in 129 of 233 patients (55%). Bone morphogenetic protein-7 expression was correlated with tumour size, nodal involvement, lymphatic invasion, venous invasion and histology (P<0.05). Bone morphogenetic protein-7 expression was significantly correlated with patient postoperative outcome, especially in the undifferentiated group. Multivariate analysis revealed BMP-7 expression as one of the independent prognostic factors next to the depth of invasion and nodal involvement (P<0.01). CONCLUSIONS: From the data collected, it would be appropriate to conclude on the possible regulation of gastric cancer progression by autocrine or paracrine BMP-7 loops. We can use BMP-7 expression as one of the strong predictors of risk of tumour recurrence in gastric cancer.

Cyclooxygenase-2 expression is related to prognosis in patients with esophageal squamous cell carcinoma.

AIM: Esophageal carcinoma is one of the most aggressive malignancies. Many studies have examined various biological factors associated with the malignant potential of esophageal carcinoma. Cyclooxygenase (COX)-2 is overexpressed in various types of human malignancies, including esophageal carcinomas. Although some groups have described COX-2 expression in esophageal adenocarcinoma, few studies have reported COX-2 expression in esophageal squamous cell carcinoma (ESCC). METHODS: We immunohistochemically investigated relationships between COX-2 overexpression in surgical specimens of primary tumors in 228 patients with ESCC. Relationships between COX-2 expression and clinicopathological factors, including prognosis, were analyzed. COX-2 expressions were classified into 4 criteria: Score 0, no staining; Score 1, <10% staining; Score 2, 10-90% staining; and Score 3, >90% staining. RESULTS: Scores of COX-2 immunoreactivity in 228 patients were as follows: Score 0, 21 of 228; Score 1, 71of 228; Score 2, 117 of 228; and Score 3, 19 of 228, respectively. COX-2 expression was significantly correlated with depth of invasion and tumor stage (p=0.03 and p=0.04, respectively). The 5-year survival rate of patients decreased significantly with increased expression of COX-2 (p=0.005). Multivariate regression analysis indicated COX-2 expression as an independent prognostic factor for ESCC. CONCLUSIONS: COX-2 overexpression was significantly correlated with depth of invasion, tumor stage and survival in ESCC. Evaluation of COX-2 expression should be useful for determining tumor properties, including prognosis, in patients with ESCC.

Randomized controlled study on preoperative chemoradiotherapy followed by surgery versus surgery alone for esophageal squamous cell cancer in a single institution.

The purpose of the present study was to compare the clinical results between preoperative chemoradiotherapy followed by surgery (CRT group) and surgery alone (Surgery group) by a randomized controlled study. Twenty-two patients were assigned to the CRT group and 23 to the Surgery group. A total radiation dose of 40 Gy was applied and in the same period, intravenous chemotherapy was performed using cisplatin (7 mg over 2 h) and 5-fluorouracil (5-FU; 350 mg over 24 h). Surgical treatment was performed in 20 patients in the CRT group except for two patients with bone metastasis after CRT. According to histological effects of primary tumors, the number of patient with Grades 1, 2 and 3 was 11, 7 and 3, respectively. Frequency of lymphatic and venous invasion was significantly lower in the CRT group than in the Surgery group. The 5-year survival rate was 57% in the CRT group and 41% in the Surgery group (P = 0.58). According to the histological effect in the CRT group, 5-year survival was 30% for Grade 1, 83% for Grade 2 and 100% for Grade 3 (P = 0.0069). This randomized trial did not demonstrate a statistically significant survival difference between the CRT group and the Surgery group.

Expression of osteopontin in oesophageal squamous cell carcinoma.

Osteopontin is a multifunctional 34 kDa extracellular matrix protein with a cell-binding domain. It is involved cell adhesion and cell migration and is therefore considered to influence tumorigenesis and/or metastasis. The purpose of the present study was to evaluate the clinical significance of Osteopontin expression in oesophageal squamous cell carcinoma (ESCC). In the present study, we immunohistochemically investigated the relationship between Osteopontin expression and clinicopathological factors including prognosis in surgical specimens of primary tumours in 175 patients with ESCC. Osteopontin was expressed in 48% of 175 patients. Osteopontin expression was significantly correlated with lymph node metastasis, lymphatic invasion, and stage (P=0.0015, 0.037 and 0.033, respectively). Tumours with expressing Osteopontin exhibited more lymph node metastasis, lymphatic invasion and advanced stage than the tumour with negative Osteopontin expression. Five-year survival rate was better in patients with negative Osteopontin expression than in those with positive Osteopontin expression (P=0.035). However, multivariate analysis revealed that Osteopontin expression was not an independent prognostic factor. As our findings suggest that Osteopontin may play an important role in progress of ESCC, the evaluation of Osteopontin expression is useful for predicting the malignant properties of ESCC.

The role of salvage surgery for recurrence of esophageal squamous cell cancer.

AIM: A consensus treatment strategy for recurrent esophageal squamous cell cancer (ESCC) has not been established. The purpose of the present study was to analyse the mode of recurrence, and evaluate the role of surgical salvage treatment in recurrence of ESCC. METHODS: Recurrence was detected in 131 of 367 consecutive patients with ESCC. We retrospectively analysed the mode of recurrence and treatment for recurrence. Recurrence was divided into four types; lymph node, hematogeneous, mixed and local. Treatments were classified into four groups; chemotherapy alone (C group), radiation therapy +/- chemotherapy (R group), surgery +/- other therapy (S group), and no therapy (N group). RESULTS: Of the 131 recurrences, the number of patients with lymph node, hematogeneous, mixed and local recurrence was 43, 44, 40 and 4, respectively. The number of patients in the C, R, S, N groups was 35, 35, 24 and 37, respectively. Of the 24 patients who received surgical treatment for recurrence, the number of patients with lymph node, hematogeneous, mixed and local recurrence was 11, 6, 6 and 1, respectively. The number of lesions in hematogeneous recurrence was 2 or less. The survival rate from recurrence to death in the C, R, S and N groups was 0, 3.9, 6.7 and 0%, respectively. A statistically significant difference was found in these groups (p < 0.0001). CONCLUSIONS: Salvage surgery is one of the useful treatment tools for resectable metastatic lesions. In such cases, the number of lesions, recurrent sites and effectiveness of chemotherapy and/or radiotherapy should be carefully evaluated.

Mirthful laughter differentially affects serum pro- and anti-inflammatory cytokine levels depending on the level of disease activity in patients with rheumatoid arthritis.

OBJECTIVES: To examine the effect of mirthful laughter in rheumatoid arthritis (RA), we evaluated the levels of serum cytokines before and after patients experienced mirthful laughter. METHODS: Forty-one patients with RA and 23 healthy subjects were enrolled. They listened to 'Rakugo', a traditional Japanese comic story, to induce mirthful laughter. We measured serum IL-6, IL-1beta, TNF-alpha, IL-4 and IL-1 receptor antagonist (IL-1Ra) concentrations before and after patients listened to the story. The RA subjects were divided into two groups. One was designated the 'difficult-to-control RA' group (CRP > or =1.0 mg/dl); The other group was regarded as the 'easily controlled RA' group (CRP <1.0 mg/dl). RESULTS: The basal levels of serum IL-6 and TNF-alpha in the RA patients were significantly higher than those in the healthy group. After experiencing mirthful laughter, the levels of serum IL-6 decreased significantly in the RA group but not in the healthy subjects. Interestingly, the level of serum TNF-alpha decreased only in the easily controlled RA group. Serum IL-4 concentration in the RA group was significantly higher than that in healthy subjects before the story. After the story, the level of serum IL-4 significantly decreased in the RA group, especially in the difficult-to-control RA group. In contrast, serum IL-1Ra concentration was statistically higher in the RA group than that in healthy subjects before the story, and a further increase was observed after the story, especially in the easily controlled RA group. CONCLUSIONS: Our findings suggest that mirthful laughter affects the levels of serum pro- and anti-inflammatory cytokines differentially, depending on the RA disease activity.

Effects of mirthful laughter on growth hormone, IGF-1 and substance P in patients with rheumatoid arthritis.

OBJECTIVE: Growth hormone (GH) plays an ancillary role in the regulation of immune function. GH has been shown to be associated with joint symptoms such as pain and swelling. On the other hand, mirthful laughter has favorable effects on the neuroendocrine-immune system. We evaluated the levels of serum GH, insulin-like growth factor-1 (IGF-1) in RA patients and evaluated the effect of mirthful laughter on GH and IGF-1. METHODS: We compared with the levels of serum GH, IGF-1 and substance P (SP) in patients with RA and healthy subjects (control group) before and after exposure to "Rakugo", a traditional Japanese comical story that induces mirthful laughter. RESULTS: The basal level of serum GH in the RA group was significantly higher than in the control group. After experiencing mirthful laughter, the level of serum GH in the RA group significantly decreased, approaching that in the control group. The serum IGF-1 level was lower in the RA group than in the control group. There was no significant difference in the level of serum SP between the RA group and the control group. CONCLUSION: The basal level of serum GH in the RA group was significantly higher than in the control group, and the level of serum GH significantly decreased after experiencing mirthful laughter These results suggest that the homeostasis of GH in patients with RA is disturbed, and the increased serum GH levels in RA patients may be associated with their stress condition.

Lymphatic invasion using D2-40 monoclonal antibody and its relationship to lymph node micrometastasis in pN0 gastric cancer.

The monoclonal antibody D2-40 is a specific lymphatic endothelial markers and D2-40 staining have been applicable to evaluate lymphatic invasion in various malignant neoplasms. In the present study, we investigated lymph node micrometastasis determined by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) in all dissected lymph nodes obtained from 80 patients with node-negative gastric cancer, and analysed the relationship between micrometastasis and clinicopathological findings including lymphatic invasion of the resected primary tumour using D2-40 immunohistochemical staining. The incidence of micrometastasis determined by IHC and RT-PCR was 11.3% (nine out of 80) and 31.3% (25 out of 80), respectively. Although haematoxylin-eosin (HE) staining revealed lymphatic invasion in 11.3% (nine out of 80) of patients, D2-40 staining uncovered new invasion in 23.8% (19 out of 80) of patients. In the diagnosis of HE and D2-40 staining, the incidence of micrometastasis was significantly higher in patients with lymphatic invasion than in those without lymphatic invasion (P=0.0150 and P<0.0001, respectively). Micrometastasis correlated more closely with D2-40 than with HE staining. We demonstrated a high incidence of micrometastasis and lymphatic invasion and a correlation between them even in pN0 gastric cancer. When planning less invasive treatment, the presence of such occult cancer cells should be considered.

The predictive value of p53, p53R2, and p21 for the effect of chemoradiation therapy on oesophageal squamous cell carcinoma.

The p53 family regulates cell-cycle arrest, triggers apoptosis or is involved in repair of DNA damage. In the present study, we analysed the expression of some p53 family proteins and their responses to chemoradiation therapy (CRT) in cases of oesophageal squamous cell carcinoma (ESCC). We immunohistochemically investigated the relationship between p53, p53R2, and p21 expression in biopsy specimens of untreated primary tumours and their clinical and histological responses to CRT in 62 patients with ESCC. Chemoradiation therapy consisted of 5-fluorouracil plus cisplatin and 40 Gy of radiation. The rates of clinical and histological responses (complete or partial) to CRT were 71.0% (clinical) and 52.8% (histological). The rate of positive expression was 43.5% for p53, 37.1% for p53R2, and 54.8% for p21 expression. Statistically significant correlations were found between p53 or p53R2 expression and favourable response to CRT (P=0.0001 or 0.041 clinical, P=0.016 or 0.0018 histological, respectively). Furthermore, in p53-negative tumours, CRT was more effective in tumours with p53R2 negative expression than those with p53R2 positive expression (P=0.0014). We demonstrated that the negative expression of p53 and p53R2 expression was closely related to the effect of CRT and should predict the CRT outcome in patients with ESCC.

Rapid immunohistochemical detection of lymph node micrometastasis during operation for upper gastrointestinal carcinoma.

BACKGROUND: The intraoperative diagnosis of lymph node micrometastasis (LNM) may help guide the area of appropriate lymph node dissection. This study aimed to evaluate the rapid immunohistochemical detection of LNMs using frozen sections during operation for gastro-oesophageal cancer. METHODS: Rapid immunostaining with anticytokeratin (AE1/AE3) antibody was compared with conventional immunostaining. A total of 210 lymph nodes obtained from 47 patients with oesophageal squamous cell carcinoma and from 32 with gastric adenocarcinoma were examined during operation. Lymph nodes were frozen, sectioned, and examined by histological and immunohistochemical methods. RESULTS: It took 30 min to complete the rapid immunostaining procedure; the expression of cytokeratin by rapid immunostaining was similar to that by conventional immunostaining. The incidence of lymph node metastasis detected by histological and immunohistochemical examination was 17 and 23 per cent respectively. LNM was solely detected in 12 lymph nodes by immunostaining: three micrometastases and nine with tumour cell microinvolvement. CONCLUSION: : Intraoperative rapid immunostaining is a simple and useful technique for detecting LNMs. Further study should investigate the role of rapid immunostaining during cancer surgery to select appropriate areas for lymphadenectomy.

Invariant chain expression in gastric cancer.

Invariant chain (Ii) is a chaperone molecule that inhibits the binding of endogenous antigens to HLA class II. The tumor cell with overexpressed Ii chain is thought to escape attacking cytotoxic lymphocytes by suppressing the host immune. However, the relationship between Ii expression by the tumor and clinicopathological factors in gastric cancer remains unclear. We studied 126 patients with gastric cancer who had undergone curative gastrectomy at Kagoshima University Hospital between 1988 and 1997. In order to detect Ii and HLA-DR expression by tumor cells, immunohistochemical staining with anti-CD74 and anti-HLA-DR antibodies were performed by avidin-biotin peroxidase complex method. The 126 patients studied were divided into two groups based on Ii expression. Ii and HLA-DR were expressed both on the surface and in the cytoplasm of tumor cells and tumor infiltrating lymphocytes. A total of 48 patients were identified as Ii positive, while the remaining 78 patients were Ii negative. Ii expression negatively correlated with the depth of invasion of the tumor as well as the patients' clinical stage. Ii expression was negatively correlated with HLA-DR expression. Patients with Ii negative expression had significantly better surgical outcomes than those with Ii positive expression (P<0.05). Ii expression in gastric cancer affected surgical outcome and Ii expression was negatively correlated with depth of invasion and HLA-DR expression. Ii expression in gastric cancer may be a prognostic factor related to suppressive effects on host immune responses to tumor cells.

Intravenous chlorhexidine gluconate causing acute respiratory distress syndrome.

CASE REPORT: A 67-year-old man undergoing a colectomy for colon cancer was unintentionally administered 0.8 mg of chlorhexidine gluconate intravenously and subsequently developed acute respiratory distress syndrome. The operation was discontinued immediately. Respiratory failure progressed despite three cycles of plasma exchange beginning on day 1. Extracorporeal membrane oxygenation for 72 h beginning on day 3 was associated with dramatic improvement. The patient showed complete recovery of intellectual function and subsequently underwent a colectomy with lymph node dissection for colon cancer. CONCLUSION: For acute respiratory distress syndrome secondary to chlorhexidine gluconate intoxication, consideration should be given to the treatment of initial respiratory distress and subsequent pneumonia. The benefit of extracorporeal membrane oxygenation and plasma exchange may merit further investigation.

Preserved Smad4 expression in the transforming growth factor beta signaling pathway is a favorable prognostic factor in patients with advanced gastric cancer.

The signals of the transforming growth factor beta (TGF-beta) superfamily are conveyed through cell surface serine/threonine kinase receptors to the intracellular mediators known as Smads. Activation of Smads causes their translocation from the cytoplasm to the nucleus, where they function to control gene expression. The present study analyzed the expression of Smad4 and TGF-beta1 to determine their prognostic significance in advanced gastric cancer. Of 249 cases of advanced gastric cancer, 41 had invaded the muscular layer, 114 had invaded the subserosal layer, and 94 had invaded the serosa. Anti-Smad4 and TGF-beta1 antibodies were used for immunohistochemical staining. Reduced expression of Smad4 was 75.1%, whereas positive expression of TGF-beta1 was 39.6% in gastric cancer. Smad4 expression was related to the depth of tumor invasion (P < 0.05), and TGF-beta1 expression correlated with tumor gross type (P < 0.05). Postoperative survival analysis indicated that patients who had a tumor with reduced Smad4 expression had a poorer clinical outcome than those with preserved expression (P < 0.05). Furthermore, in patients with TGF-beta1-positive tumors, survival rate was significantly better in patients with preserved Smad4 expression than in those with reduced Smad4 expression (P < 0.05). According to multivariate analysis, Smad4 expression acted as an independent prognostic factor. Smad4 expression, particularly in the TGF-beta pathway, is an effective predictor of outcome for patients with advanced gastric cancer.

Detection and prediction of micrometastasis in the lymph nodes of patients with pN0 gastric cancer.

BACKGROUND: The clinicopathologic significance of micrometastasis (MM) and tumor cell microinvolvement (TCM) in regional lymph nodes as identified by immunohistochemical staining for cytokeratin expression was evaluated in patients with node-negative gastric cancer. METHODS: MM was defined as tumor cells with stromal reaction, and TCM was defined as individual tumor cells without stromal reaction. We investigated 1761 lymph nodes obtained from 67 gastric cancer patients whose diagnosis showed no lymph node metastasis by routine histological examination. The depth of tumor invasion was T1 (submucosa) in 33 patients and T2 (muscularis propria and subserosa) in 34 patients. The lymph nodes were examined immunohistochemically for the presence of tumor cells using anti-cytokeratin AE1/AE3 monoclonal antibody. Both the biopsy tumor specimens obtained prior to surgery and the resected primary tumors were immunostained with E-cadherin (E-cad) monoclonal antibody. RESULTS: Thirty (1.5%) of the 1761 lymph nodes showed MM and/or TCM. MM with or without TCM was found in 10 patients, and TCM alone was found in 4 patients; 6 (18.2%) of the 33 patients with T1 tumor and 8 (23.5%) of the 34 patients with T2 tumor had occult lymph node metastasis. The 5-year survival rate was worse among those with MM with or without TCM, than among those without MM. Nearly all of the patients with MM and/or TCM had reduced or negative E-cad expression in the primary tumor. CONCLUSIONS: We demonstrated that the incidence of MM and/or TCM in the lymph nodes of patients with gastric cancer is quite high, and that such metastasis is associated with the prognosis of patients with pN0. Examination of E-cad expression in biopsy tumor specimens may be useful for predicting MM and/or TCM.

Clinical importance of preoperative carcinoembryonic antigen and carbohydrate antigen 19-9 levels in gastric cancer.

Although serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 are commonly measured before surgery for gastric carcinoma, this clinical significance is not fully understood. We evaluated a total of 549 patients with gastric cancer who underwent gastrectomy. Levels of CEA and CA19-9 were measured preoperatively in all patients. We retrospectively analyzed correlations between CEA or CA19-9 and clinicopathologic features, and estimated the prognostic utility of the tumor markers by analyzing clinicopathologic characteristics of the carcinoma as a function of seropositivity or negativity of the antigens in combination or by raising the levels. The positivity rates of CEA (> or =5 ng/mL) and CA19-9 (> or =37 U/mL) were 19.5% and 18%, respectively. Serum CEA and CA19-9 positivity significantly correlated with depth of invasion, hepatic metastasis, and curativity. Forty-nine patients positive for both CEA and CA19-9 had significantly higher frequencies of lymph node metastasis, deeper invasion by the tumor, lower rates of curative resection (p < 0.01), and higher rates of hepatic metastasis (p < 0.05) than 377 patients with normal levels of CEA and CA19-9. Surgical outcomes of patients who were CEA- and CA19-9-positive were poorer than those of patients with normal CEA and CA19-9 levels (p < 0.01). Significant correlation was found between serum CEA and CA19-9 level (p < 0.001, r = 0.24). Doubling the threshold level of serum positivity to 10 ng/mL (CEA) and 74 U/mL (CA19-9) improved the prognostic value of these factors. However, multivariate analysis using Cox's hazards model revealed that only CEA positivity using the doubled threshold value (10 ng/mL) (p = 0.04, hazard ratio = 1.7), nodal involvement (p = 0.01, hazard ratio = 1.9), and depth of invasion (p = 0.02 hazard ratio = 1.5) significantly predicted prognosis. Carcinoembryonic antigen positivity using the doubled threshold level (10 ng/mL) was an important prognostic factor in patients with gastric cancer.

Hereditary protein S deficiency associated with rheumatoid arthritis: a case report of pulmonary embolism after total hip arthroplasty.

Abstract A 57-year-old woman with RA of 10 years' duration presented with a history of right coxalgia. Three weeks after total hip arthroplasty, the patient developed an acute pulmonary embolism. The results of screening for hypercoagulable states revealed a protein S (PS) deficiency, and all PS values, i.e., total PS antigen, free PS antigen, and PS cofactor, were lower than the normal ranges, showing that the patient had type I PS deficiency. She had no past history of embolism or deep venous thrombosis. The values of three PS-related parameters were also lower than normal in her daughter. The responsible mutation may be located on exon 15 of genomic PS DNA, as indicated by polymerase chain reaction. We therefore diagnosed hereditary PS deficiency.

Effects of combinations of anti-rheumatic drugs on the production of vascular endothelial growth factor and basic fibroblast growth factor in cultured synoviocytes and patients with rheumatoid arthritis.

OBJECTIVE: To examine whether different combinations of disease-modifying anti-rheumatic drugs (DMARDs), including bucillamine (BUC), gold sodium thiomalate (GST), methotrexate (MTX), salazosulphapyridine (SASP) and dexamethasone (DEX; a steroid), act by inhibiting the production of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in cultured synoviocytes, causing a decrease in their serum concentrations in patients with rheumatoid arthritis (RA). METHODS: The VEGF and bFGF concentrations in cultured synoviocytes and peripheral blood from patients with RA were measured by enzyme-linked immunosorbent assay and their serum concentrations were measured at two time points. RESULTS: BUC and GST inhibited VEGF production even when given alone, and a combination of BUC, GST and MTX with DEX also inhibited VEGF production. None of the DMARDs or DEX inhibited bFGF production when given alone, but a combination of SASP and GST inhibited the production of bFGF in cultured synoviocytes. Serum VEGF concentrations were significantly decreased 6 months after the commencement of medication compared with their concentrations before medication. CONCLUSION: Our results show that the effects of a combination of DEX with any two of BUC, GST, SASP and MTX on the production of VEGF and bFGF in cultured synoviocytes and on the serum concentrations of VEGF in patients with RA may be based on synergistic or additive effects of the drugs.

Effect of neoadjuvant chemotherapy for lymph node micrometastasis and tumor cell microinvolvement in the patients with esophageal carcinoma.

Micrometastasis (MM) and tumor cell microinvolvement (TCM) in the lymph node were immunohistochemically evaluated using the cytokeratin (CK) antibody between a surgery group (n=20; 929 lymph nodes) and a chemotherapy group (n=20; 1052 lymph nodes). The incidence of MM+/-TCM in the surgery and chemotherapy groups was 50.0 (10/20) and 55.0% (11/20), respectively. Limiting the analysis to TCM alone revealed that the incidence in the chemotherapy group (10.0%; 2/20) was significantly lower than that in the surgery group (40.0%; 8/20; P=0.032). Preoperative chemotherapy in this regime was not effective, except for some patients with TCM alone.

Clinical impact of intratumoral natural killer cell and dendritic cell infiltration in gastric cancer.

Intratumoral natural killer cells (NKC) and dendritic cells (DC) may affect the clinical features of various gastrointestinal cancers. However, the relationship between intratumoral NKC and DC remains unclear. We examined 169 patients with gastric cancer who underwent gastrectomy at Kagoshima University Hospital. Immunohistochemical staining of CD57 and S-100-protein was performed to evaluate NKC and DC infiltration, respectively. A total of 25 areas containing pericancerous tissue were selected for determining the number of NKC and DC under high power microscopy (x400). Patients were classified into two groups according to NKC and DC population. Intratumoral lymphocytic infiltration was also calculated in 15 areas with a high power (x400) objective. The degree of NKC and DC infiltration was gradually decreased according to the progression of nodal involvement. Patients with many NKC infiltration had a lower positivity of lymph node metastasis and lymphatic invasion than patients with little NKC infiltration. DC infiltration was also negatively correlated with depth of invasion, lymph node metastasis and curativity. DC infiltration was positively correlated with lymphocytic infiltration (P=0.01. r=0.6). The 5-year survival rates of patients with many NKC infiltration and patients with DC many infiltration were 75 and 78%, respectively, both of which were significantly better than that of patients with little NKC and DC infiltration (P<0.05). NKC may be activated without DC or intratumoral lymphocytes. Intratumoral NKC may act as an independent immunologic effector against tumor cells, unlike DC.

Intranodal antitumor immunocyte infiltration in node-negative gastric cancers.

The status and role of immunocytes and dendritic cells in regional lymph nodes in patients with gastric cancer are examined in this study. Forty-nine patients with gastric cancer who underwent curative resection were enrolled in the present study. These patients had no lymph node metastases according to a histological examination. The infiltration of natural killer (NK) cells, dendritic cells, and MIB-1-positive immunocytes was investigated. Based on the Japanese Classification of Gastric Carcinoma, regional lymph nodes were divided into three compartments: (a) compartment 1 (lymph node station numbers 1-6); (b) compartment 2 (lymph node station numbers 7-12); and (c) compartment 3 (lymph node station numbers 14 and 16). Dendritic cells and MIB-1-positive immunocytes infiltrated compartment 1 lymph nodes in increased numbers compared with the lymph nodes of compartments 2 or 3 (P < 0.05). Conversely, intranodal NK cell infiltration did not differ significantly among the three compartments. The incidence of intranodal dendritic and MIB-1-positive cell infiltration in patients with submucosal gastric cancer was significantly higher than in patients with tumors that invaded beyond the muscularis propria. The decreased expression of these immunological markers correlated well with recurrent disease, regardless of tumor depth. The immunocyte level is higher in lymph nodes near the primary tumor (compartment 1) than in those that are distant from the tumor (compartments 2 and 3). This pertains to all three markers, i.e., NK, dendritic, and MIB-1-positive cells. Unlike dendritic and MIB-1-positive cells, intratumoral infiltration of NK cells did not correlate well with either lymph node compartment or the depth of tumor invasion. The degree of NK cell infiltration may be directly associated with antitumor effects, especially in compartment 1. A decrease in all three markers is associated with tumor recurrence.