A new cancer diagnostic system based on a CDK profiling technology

A series of molecular pathological investigations of the molecules that stimulate the cyclin dependent kinases (CDK1, 2, 4, and 6) have led to enormous accumulation of knowledge of the clinical significance of these molecules for cancer diagnosis. However, the molecules have yet to be applied to clinical cancer diagnosis, as there is no available technology for application of the knowledge in a clinical setting. We hypothesized that the direct measurement of CDK activities and expressions (CDK profiling) might produce clinically relevant values for the diagnosis. This study investigated the clinical relevance of CDK profiling in gastrointestinal carcinoma tissues by using originally developed expression and activity analysis methods. We have established novel methods and an apparatus for analyzing the expression and activities of the CDK molecules in lysate of tumor tissue in a clinical setting, and examined 30 surgically dissected gastrointestinal carcinomas and corresponding normal mucosal specimens. We demonstrate here that remarkably elevated CDK2 activity is evident in more than 70% of carcinoma tissues. Moreover, a G1-CDK activity profiling accurately mirrored the differences in proliferation between tumor and normal colonic tissues. Our results suggest that CDK profiling is a potent molecular-clinical approach to complement the conventional pathological diagnosis, and to further assist in the individualized medications.

A case of occult contralateral breast cancer incidentally detected by contrast-enhanced MRI; report of a case with review of literature

We encountered a case of occult contralateral breast cancer, previously undetected by conventional imaging such as mammography (MMG) and ultrasonography (US), but incidentally detected by contrast-enhanced magnetic resonance imaging (CE-MRI). We present it here with a review of the literature. A 67-year-old Japanese woman was referred to our hospital in October 2000 because of a 1.5 cm right breast lump detected in a medical checkup. MMG, US and fine needle aspiration cytology revealed a cancerous lesion during the right breast. No mass lesion was palpable nor was any detected by MMG or US in the left breast. Bilateral breast CE-MRI was performed for more detailed evaluation. Consequently, an occult contralateral breast cancerous lesion was detected incidentally by CE-MRI, with the images showing rapid initial enhancement of time to signal intensity curves. Before surgery, bilateral breast lesions were diagnosed as invasive ductal carcinoma by open biopsy. She underwent bilateral breast conserving surgery with bilateral axillary lymph node dissection. The postoperative course was uneventful and no recurrence has been noted as of January 18th, 2004. CE-MRI of the contralateral breast should be of value as a routine screen in those patients with a known or suspected malignancy in one breast considering the limits of breast cancer detection by such conventional modalities as MMG and US.

Titration of serum p53 antibodies in patients with gastric cancer: a single-institute study of 40 patients

BACKGROUND

Alterations of the p53 tumor suppressor gene are the most commonly observed genetic abnormalities in many different types of human malignancies. The accumulation of mutant p53 often leads to the production of p53 antibody (p53-Ab) in the sera of patients with various cancers. To evaluate the clinical implications of serum p53-Abs in patients with gastric cancer, we compared p53-Abs with conventional tumor markers such as carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9.

METHODS

Serum samples were obtained preoperatively from 40 patients with histologically confirmed gastric adenocarcinoma, including 28 (70%) patients in stage Ia. The serum p53-Abs were assessed by enzyme-linked immunosorbent assay, using a new version of a highly specific, quantitative p53-Abs Kit (MESACUP Kit II).

RESULTS

p53-Abs were detected in 6 (15%) of 40 patients with gastric cancer, including 3 patients with early gastric cancer. Seven (17.5%) of the 40 patients were positive for CEA in serum. However, none of 7 patients with high CEA levels were positive for p53-Abs. No significant correlation of p53-Abs with patient age, sex, pathological parameters, tumor markers such as CEA and CA19-9, or poor survival (P = 0.116) was observed.

CONCLUSION

Although we employed the latest version of the p53-Abs Kit, the sensitivity of serum p53-Ab in gastric cancer patients was relatively low. No correlation was found between the presence of p53-Ab and the staging of cancer or survival. However, serum p53-Ab was detectable in patients with gastric cancer even in the early stages of disease. In addition, it may be independent of CEA and CA19-9.

Cytogenetic and clinicopathological characterization by fluorescence in situ hybridization on paraffin-embedded tissue sections of twenty-six cases with malignant lymphoma of small intestine

OBJECTIVE

In small intestinal malignant lymphoma (SIML), the correlation between specific chromosomal abnormalities and clinicopathological features remains unclear. The aim of this study was to determine the frequency of chromosomal translocations involving the BCL1, BCL2, c-MYC, BCL6 and MALT1 genes by using fluorescence in situ hybridization directly on paraffin-embedded tissue sections (tissue-FISH).

MATERIAL AND METHODS

Twenty-six cases diagnosed as having SIML between 1996 and 2003 were the subjects of the clinicopathological investigation conducted in this study. Tissue-FISH was performed with specific probes on paraffin-embedded tissue sections as described previously.

RESULTS

The primary site was frequently located at the duodenum (9 cases, 35%). In accordance with the World Health Organization classification, 14 (53%) cases were diagnosed as having diffuse large B-cell lymphoma (DLBCL) and 6 (23%) as marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). Macroscopically, DLBCL and MALT lymphoma displayed various macroscopic features. Cytogenetically, IGH-BCL2 translocation was detected in 3 (21%) out of 14 DLBCL cases, but in none of the MALT lymphomas. BCL6 translocation was detected in 5 (35%) of 14 DLBCL cases and in 1 (17%) of 6 MALT lymphoma cases (17%). API2-MALT1 translocation was detected in 1 (7%) of 14 DLBCL cases and in 1 (17%) of 6 MALT lymphoma cases.

CONCLUSIONS

The duodenum was preferentially involved in SIML. DLBCL and MALT lymphoma showed various macroscopic features. Tissue-FISH analysis disclosed that DLBCL is cytogenetically heterogeneous. Furthermore, our study validated tissue-FISH as an additional promising diagnostic tool for detecting specific chromosomal translocations in NHL.

Single- versus two- layer intestinal anastomosis: a meta-analysis of randomized controlled trials

BACKGROUND

To compare single- with two- layer intestinal anastomosis after intestinal resection: a meta-analysis of randomized controlled trials.

METHODS

Randomized controlled trials comparing single- with two-layer intestinal anastomosis were identified using a systematic search of Medline, Embase and the Cochrane Library Databases covering articles published from 1966 to 2004. Outcome of primary interest was postoperative leak. A risk ratio for trial outcomes and weighted pooled estimates for data were calculated. A fixed-effect model weighted using Mantel-Haenszel methods and a random-effect model using DerSimonian-Laird methods were employed.

RESULTS

Six trials were analyzed, comprising 670 participants (single-layer group, n = 299; two-layer group, n = 371). Data on leaks were available from all included studies. Combined risk ratio using DerSimonian-Laird methods was 0.91 (95% CI = 0.49 to 1.69), and indicated no significant difference. Inter-study heterogeneity was significant (chi2 = 10.5, d.f. = 5, p = 0.06).

CONCLUSION

No evidence was found that two-layer intestinal anastomosis leads to fewer post-operative leaks than single layer. Considering duration of the anastomosis procedure and medical expenses, single-layer intestinal anastomosis appears to represent the optimal choice for most surgical situations.

Predictive value of the time-intensity curves on dynamic contrast-enhanced magnetic resonance imaging for lymphatic spreading in breast cancer

PURPOSE

Dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) has emerged as a promising diagnostic modality in various breast cancer treatments. However, little is known about the correlation between the pattern of time to signal intensity curves (TIC) on the CE-MRI and clinicopathologic features. This study was designed to investigate these correlations and evaluate the predictive value of TIC on CE-MRI in order to identify high-risk patients.

METHODS

Between 2001 and 2003, 101 lesions were evaluated to detect malignancy on CE-MRI in 101 women who were suspected of having breast tumors based on either clinical findings or conventional imaging studies. Moreover, the clinicopathologic findings were compared with the pattern of TIC for the 69 surgically treated malignant lesions.

RESULTS

In detecting malignancy, the sensitivity, specificity, and accuracy were 78.7%, 88.5%, and 81.2%, respectively, in the 101 breast lesions. Especially for the 69 surgically treated malignant lesions, in comparison with breast cancer tumors with the benign pattern of TIC, the breast cancer tumors with a malignant pattern were found more frequently in lymphatic invasion (P < 0.01) and lymph node metastasis (P < 0.005), although no statistical correlation regarding the histological type, tumor size, vascular invasion, extensive intraductal component, hormone receptor status, or pathological stage was noted between the two groups. According to a logistic regression model, lymph node metastasis was found to be a significant independent variable.

CONCLUSION

The pattern of TIC could be used to predict lymphatic spreading associated with lymph node metastasis prior to surgery as well as to detect malignancy. Therefore, a more detailed evaluation should be made to identify the presence of lymphatic spreading in patients with a malignant pattern of TIC.

Furosemide, a Blocker of Na+/K+/2Cl− Cotransporter, Diminishes Proliferation of Poorly Differentiated Human Gastric Cancer Cells by Affecting G0/G1 State

Furosemide, a blocker of Na(+)/K(+)/2Cl(-) cotransporter (NKCC), is often used as a diuretic to improve edema, ascites, and pleural effusion of patients with cancers. The aim of the present study was to investigate whether an NKCC blocker affects cancer cell growth. If so, we would clarify the mechanism of this action. We found that poorly differentiated gastric adenocarcinoma cells (MKN45) expressed the mRNA of NKCC1 three times higher than moderately differentiated ones (MKN28) and that the NKCC in MKN45 showed higher activity than that in MKN28. A cell proliferation assay indicates that furosemide significantly inhibited cell growth in MKN45 cells, but not in MKN28 cells. Using flow cytometrical analysis, we found that the exposure to furosemide brought MKN45 cells to spend more time at the G(0)/G(1) phase, but not MKN28 cells. Based on these observations, we indicate that furosemide diminishes cell growth by delaying the G(1)-S phase progression in poorly differentiated gastric adenocarcinoma cells, which show high expression and activity of NKCC, but not in moderately differentiated gastric adenocarcinoma cells with low expression and NKCC activity.

Potassium oxonate, an enzyme inhibitor compounded in S-1, reduces the suppression of antitumor immunity induced by 5-fluorouracil

S-1 is an oral formulation combining tegafur (FT), 5-chloro-2,4-dihydroxypyridine (CDHP), and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1. We examined whether Oxo reduces the immunosuppression induced by 5-fluorouracil (5-FU) in the rat. The body weight of rats treated with S-1 (FT + CDHP + Oxo) for seven consecutive days was significantly higher than that of rats treated with a combination of FT plus CDHP (FT + CDHP) for a similar period. The number of peripheral leukocytes was significantly higher in the S-1-treated rats (S-1 group) than that in the FT + CDHP-treated rats (FT + CDHP group). There was no apparent difference between the two treated groups in phenotypic changes of CD3-, CD45-, CD4-, or CD8-positive cells from the spleen or mesenteric lymph nodes. However, the natural killer activities of both spleen cells and mesenteric lymph node cells were significantly higher in the S-1 group than in the FT + CDHP group. Interleukin (IL)-2 production by spleen cells stimulated with concanavalin A was significantly lower in the FT + CDHP group than in the S-1 group. Although IL-2 production by mesenteric lymph node cells in the S-1 group was lower than that in untreated rats, it was higher than that in the FT + CDHP group. These findings suggest that Oxo in S-1 may reduce the suppression of antitumor immunity induced by 5-FU.

Possible involvement of RUNX3 silencing in the peritoneal metastases of gastric cancers

PURPOSE

Our previous results suggested that a lack of RUNX3 function contributed to human gastric carcinogenesis, but the role of RUNX3 in progression and metastasis remains unclear. We examined RUNX3 expression in clinical samples of peritoneal metastases in gastric cancers. Changes in metastatic potential were assessed in animal experiments using stable RUNX3 transfectants of gastric cancer cells. Finally, global expression changes were analyzed using a cDNA microarray.

EXPERIMENTAL DESIGN AND RESULTS

Significant down-regulation of RUNX3 through methylation on the promoter region was observed in primary tumors (75%) as well as in all clinical peritoneal metastases of gastric cancers (100%) compared with normal gastric mucosa. Stable transfection of RUNX3 inhibited cell proliferation slightly, and modest transforming growth factor-beta (TGF-beta)-induced antiproliferative and apoptotic effects were observed. Interestingly, it strongly inhibited peritoneal metastases of gastric cancers in animal model (P < 0.01). Furthermore, we did globally analyzed expression profiles of approximately 21,000 genes in parent cells and stable transfectant of RUNX3 using a cDNA microarray. Microarray analysis identified approximately 28 candidate genes under the possible downstream control of RUNX3, some of these genes were considered to be possibly involved in peritoneal metastases, which were related to signal transduction (vav3, TOLL-like receptor, MAPKK, MET, S1 00A1 1, and cathepsin E), apoptosis (caspase 9), immune responses (CD55 and TLR1O), and cell adhesion (sialyltransferase 1 and galectin 4). Some of the genes are involved in the TGF-beta signaling pathway.

CONCLUSION

These results indicate that silencing of RUNX3 affects expression of important genes involved in aspects of metastasis including cell adhesion, proliferation, apoptosis, and promoting the peritoneal metastasis of gastric cancer. Identification of such genes could suggest new therapeutic modalities and therapeutic targets.

Possible inhibition of cancer cell adhesion to the extracellular matrix in NK4-induced suppression of peritoneal implantation

Milky spots (MS), peritoneal lymphoid tissues, expose the extracellular matrix (ECM) due to a defect of mesothelial cells on their surface, which may explain why peritoneal implantation of cancer cells preferentially takes place at MS. We recently reported that adenovirus vector-mediated intraperitoneal production of NK4 strongly suppressed MS-selective implantation of cancer cells and subsequent peritoneal dissemination, without histological evidence of angiogenesis inhibition. The present study was conducted to clarify the mechanisms underlying the suppressive effects of NK4 on peritoneal implantation. In mice intraperitoneally injected with CT26 cells that were genetically modified to produce NK4 (CT26-NK4), peritoneal dissemination was significantly suppressed with survival prolongation. A decreased cell implantation to omental MS was also detected and evaluated by green fluorescence protein (GFP) imaging. In an in vitro adhesion assay, hepatocyte growth factor-stimulated adhesion to ECM components, such as fibronectin and collagen, was inhibited in CT26-NK4 compared to control cells. These results strongly suggest an inhibition of cancer cell adhesion to the ECM in the suppression of peritoneal implantation by NK4.

[A long-term survival case with multiple liver metastases from duodenal gastrointestinal stromal tumor that was drastically reduced by the treatment with imatinib]

Constitutive activation of c-kit receptor tyrosine kinase is a critical factor in the pathogenesis of gastrointestinal stromal tumors. Imatinib mesylate (IM), a selective tyrosine kinase inhibitor, has been shown in clinical studies to work against such tumors. But there is little information on whether a combination of IM and surgical treatment can prolong survival in a case of unresectable multiple liver metastases. We report a case of postoperative recurrence of gastrointestinal stromal tumor (GIST) treated by the tyrosine kinase inhibitor IM and surgical treatment. Therefore, we discuss some important implications. This 37-year-old Japanese man underwent a pancreaticoduodenectomy for GIST of the duodenum in January 2003. The postoperative course was good at first, but 3 months after the initial operation, MRI showed multiple liver metastases. The patient was treated with 400 mg of IM once daily with only weak liver dysfunction as a side effect. The initial response to treatment of CR continued for 18 months. Currently, IM is the first-line therapy for non-resectable GISTs. As the mechanisms of recurrence and resistance to imatinib in GIST remain unclear, they should be intensively performed in the sight of both clinical and molecular biological viewpoints. Further examination in more cases of recurrent GIST is also necessary to estimate the effectiveness of treatment with IM.

[A case report of esophageal cancer with tracheoesophageal fistula--improving the quality of life by using a covered self-expandable metallic stent]

We present the case of a 64-year-old male who was diagnosed with esophageal cancer with tracheal invasion and distant lymph node metastases, and he received chemoradiation therapy. The therapy resulted in complete remission. However, he was unable to eat anything because of missed swallowing caused by a large tracheoesophageal fistula. The placement of a covered self-expandable metallic stent (SEMS) improved his quality of life and palliated dysphagia for 3 months. Stenting in the cervical or upper esophagus may cause discomfort. However, the placement of a covered SEMS is one of the useful palliative treatments for esophageal cancer with tracheoesophageal fistula.

[Multiple hepatocellular carcinomas successfully treated by combined therapies]

We report a case of advanced multiple hepatocellular carcinomas (HCC), successfully treated by combination therapies of transarterial chemoembolization (TAE), operation and radiofrequency ablation therapy (RFA). A 59 year-old man was detected with an increased serum alpha-fetoprotein (AFP) level and an ultrasonography (US) revealed three nodules of HCC at the right lobe in August 1998. He was successfully treated with a combination therapy of TAE and percutaneous ethanol injection therapy (PEIT) at the beginning. However, HCC had recurred quite often. TAE had been repeated for twelve times before right trisegmentectomy was performed in November 2002. Thirteen months after the operation, CT revealed a new lesion at subsegment 3, which was treated by RFA. Furthermore, a metastatic single lesion had appeared at the left lung, which was resected. He has still been well for 82 months since the first detection of HCC.

[The effects of direct hemoperfusion using the filtration column filled with the adsorption fiber for immunosuppressive substances on cell-mediated immunity in tumor-bearing rats]

The patients with advanced cancer often lose their anti-tumor immune responses due to the increase of some immunosuppressive substances in the blood, such as cytokines and proteins derived from cancer cells or immune cells. We developed the adsorption fiber in transforming growth factor (TGF)-beta for the treatment to remove immunosuppressive substances and investigated the effects of direct hemoperfusion using the filtration column filled with this adsorption fiber in tumor-bearing rats. On day 0, KDH-8 tumor cells (1 x 10(6) cells/rat) were implanted subcutaneously into the back of WKAH/Hkm rats. On day 21 after tumor implantation, the rats underwent the direct hemoperfusion with this filtration column for 60 minutes. On day 28, the rats were sacrificed and the natural killer (NK) activities of their spleen cells were examined. As a result, the rats that underwent this treatment showed a significant increase in their NK activities compared with those of rats who underwent direct hemoperfusion with an empty column or had no treatment. Therefore, we indicated the possibility of a new immunotherapy technique against cancer using a direct hemoperfusion column filled with an adsorption fiber for immunosuppressive substances.

[Analysis of Reg IV expression in peritoneal dissemination of gastric cancer using real-time RT-PCR]

We had performed a global analysis of the gene expression of gastric cancer cell lines established from malignant ascites to identify the novel markers for the detection of micro-metastasis in peritoneal cavity. One of the up-regulated genes is Reg IV, which is a member of the Reg gene family belonging to calcium dependent lectin (C-type lectin) gene superfamily. But the role of Reg IV in peritoneal dissemination is still unclear. We have examined the potential of Reg IV as a novel marker for the detection of peritoneal micro-metastases of gastric cancer. Reg IV expression was examined by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Mean Reg IV mRNA expression levels in surgically resected specimens (n = 41) were more than 20-times higher than those in normal mucosa from those patients. Furthermore, Reg IV mRNA expression level in the peritoneal wash was strongly higher in peritoneal metastasis compared to those without peritoneal metastasis. These results suggest that Reg IV may be involved in peritoneal dissemination of gastric cancers and Reg IV would be a potential novel marker for peritoneal dissemination of gastric cancers.

Results of total gastrectomy with extended lymphadenectomy for gastric cancer in elderly patients

BACKGROUND AND OBJECTIVES

The incidence of gastric cancer, in people over 70 years of age, has increased remarkably. Aggressive lymphadenectomy with gastrectomy has been reported to improve survival in patients with gastric cancer. Because complication rates following gastrectomy increase with advancing age, we sought to determine whether this procedure was merited in elderly patients with gastric cancer.

METHODS

We performed a retrospective analysis of 202 patients who underwent total gastrectomy with extended lymphadenectomy for gastric carcinoma. Postoperative complication rates were compared between patients over and under 70 years of age.

RESULTS

The 10-year survival rates of patients under and over 70 years of age following total gastrectomy with extended lymphadenectomy were not significantly different. Although medical comorbidities in each group were similar, pulmonary dysfunction was significantly more common following total gastrectomy in patients over 70 years than in patients under 70 years. Moreover, logistic regression analysis revealed that patient's age was the only variable that independently correlated with the presence of postoperative complications.

CONCLUSIONS

The prognosis of the gastric cancer patients over 70 years of age was similar to that of younger patients after total gastrectomy with extensive lymphadenectomy. However, pulmonary dysfunction was significantly more common in patients over 70 years old.

Recurrent chromosomal rearrangements at bands 8q24 and 11q13 in gastric cancer as detected by multicolor spectral karyotyping

AIM: To identify chromosomal translocations specific to gastric cancer (GC), spectral karyotyping (SKY) analysis was performed on established cell lines and cancerous ascitic fluids.

METHODS: SKY analysis of 10 established cell lines and seven cancerous ascitic fluid samples identified recurrent chromosomal breakpoints and translocations in GC, several of which involved chromosomal loci of oncogenes or tumor suppressor genes.

RESULTS: A total of 630 chromosomal breaks were identified. Chromosome no.8 was the most frequently involved in rearrangements (65 breaks), followed by chromosomes no.11 (53), no. 1 (49), no. 7 (46), no. 13 (37), no. 3 (36), no. 17 (33), and no. 20 (29). Frequent breakpoints were detected in 8q24.1 (30 breaks), 11q13 (29), 13q14 (16), 20q11.2 (14), 7q32 (13), 17q11.2 (13), 18q21 (12), 17q23 (9), 18q11.2 (9). SKY analysis identified a total of 242 chromosomal rearrangements including 190 reciprocal and non-reciprocal translocations. The recurrent combinations of chromosomal bands involved in translocations were 8q24.1 and 13q14 (3 cases), 8q24.1 and 11q13 (3), 11q13 and 17q11.2 (2), and 18q11.2 and 20q11.2 (2). Our study validated the ability of SKY to characterize in detail the chromosomal rearrangements in solid tumors and derived cell lines. Moreover, fluorescence in situ hybridization helped to identify the insertions, translocations, and homogeneously staining regions of MYC and CCND1 gene loci.

CONCLUSION: The non-random co-localization of certain cytogenetic bands suggests the importance of chromosomal translocations in gastric carcinogenesis, by serving as landmarks for the cloning of GC causing genes.

Phase I study of a combination of s-1 and weekly paclitaxel in patients with advanced or recurrent gastric cancer

OBJECTIVE

A phase I study of weekly intravenous paclitaxel combined with a fixed dose of S-1, a dihydropyrimidine-dehydrogenase-inhibitory oral fluoropyrimidine, was conducted for patients with advanced or recurrent gastric cancer (ARGC). Endpoints of this study were to examine the toxicity profile OF this regimen and to determine the recommended dose (rd) of paclitaxel.

METHODS

S-1 was fixed at a dose of 80 mg/m(2) per day and was administered for 2 weeks (days 1--14) followed by a 2-week rest. Two dose levels of paclitaxel (level 1: 60 mg/m(2), level 0: 50 mg/m(2)) were studied. Paclitaxel was infused over 1 h on days 1, 8, and 15. Plasma sampling was performed to characterize the pharmacokinetics and pharmacodynamics of paclitaxel in some patients. Fifteen patients were enrolled (6 patients in level 1, and 9 patients in level 0). Dose-limiting toxicities were defined as grade 4 hematological (including grade 3 febrile neutropenia) and grade 3 non-hematological (except anorexia, nausea, vomiting and depilation) toxicities.

RESULTS

Three of 6 patients in level 1 developed grade 4 neutropenia or grade 3 febrile neutropenia, and 1 of them also showed grade 3 diarrhea, which settled the maximum-tolerated dose at this level. At level 0, 2 of 9 patients developed grade 4 neutropenia or grade 3 febrile neutropenia, and the RD of paclitaxel for this protocol was set at this level. Pharmacologic studies demonstrated the persistence of significant serum paclitaxel levels over 24 h after drug administration at both levels. Objective responses according to Response Evaluation Criteria in Solid Tumors were observed in 3 of 6 patients who had measurable disease.

CONCLUSION

A combination of S-1 and weekly paclitaxel was feasible and well tolerated, and is suggested to produce a worthwhile response in ARGC. These results warrant further investigation, and a phase II study has already been started.

Small bowel non-Hodgkin's lymphoma remaining in complete remission by surgical resection and adjuvant rituximab therapy

A 44-year-old man was referred to our hospital with intermittent abdominal pain. Because distention of fluid- and gas-filled loops of small intestine was proved by X-ray, the patient was diagnosed as having small bowel obstruction. A laparotomy revealed a segmental stenosis in the jejunum, which showed diffuse thickening of the intestinal wall. Some mesenteric lymph nodes were swollen. Pathological examination was defined. We diagnosed diffuse large B-cell lymphoma based on the pathological findings of diffuse transmural infiltration of large lymphoid cells and flow-cytometric analyses. Rituximab was administered as adjuvant therapy at weekly doses of 375 mg/m². Four cycles were performed every 6 mo and he remained CR. Rituximab may be effective as adjuvant therapy.

Monoclonal antibody A7-superparamagnetic iron oxide as contrast agent of MR imaging of rectal carcinoma

Superparamagnetic iron oxide (SPIO)-based colloid has been used clinically as a tissue-specific magnetic resonance contrast agent. We coupled monoclonal antibody A7 (Mab A7), which reacts specifically with human colorectal carcinoma, to Ferumoxides (SPIO) and examined the accumulation of this conjugate in xenografted tumours in nude mice. We examined in vitro immunoreactivity of Mab A7 coupled to Ferumoxides and its in vivo distribution in nude mice with human colorectal carcinoma. Magnetic resonance imaging of tumour-bearing nude mice was performed 72 h after injection of A7-Ferumoxides. A7-Ferumoxides retained binding activities that were nearly identical to intact Mab A7. More of the radiolabelled A7-Ferumoxides accumulated in the tumour than normal mouse IgG-Ferumoxides from 12 h onwards after injection (P<0.05). Both A7-Ferumoxides and normal mouse IgG-Ferumoxides disappeared from blood linearly over time. The accumulation levels in normal tissue decreased linearly over time but were lower than levels in tumours from 6 h. In magnetic resonance T2-weighted imaging of the tumour-bearing nude mice, signal intensity was reduced at the margin of the tumour by injection of A7-Ferumoxides. Mab A7 coupled to Ferumoxides is potentially suitable as a magnetic resonance contrast agent for detecting local recurrence of rectal carcinoma.

Comparison of serum aberrant methylation and conventional tumor markers in gastric cancer patients

BACKGROUND/AIMS

This study was designed to compare a methylation-specific polymerase chain reaction (MSP) assay for three genes [p16, E-cadherin, and retinoic acid receptor beta (RARbeta)] and conventional serum tumor markers using blood samples from gastric cancer patients.

METHODOLOGY

Preoperative blood samples obtained from 63 consecutive patients with gastric cancer were subjected to MSP and conventional serum marker assays.

RESULTS

MSP assay detected hypermethylation of p16 in 17 patients (27%), E-cadherin in 15 patients (24%), and RARbeta in 11 patients (17%). Altogether, 32 patients (51%) showed hypermethylation in serum samples. By contrast, only 21 (33%) patients exhibited elevations of serum carcinoembryonic antigen or carbohydrate antigen 19-9. There was no correlation between MSP results and conventional tumor markers.

CONCLUSIONS

The detection rate for MSP was higher than that of conventional tumor markers in serum of gastric cancer patients. Both assays can serve as complementary markers that allow for selection of cases requiring more intensive screening or aggressive postoperative treatment.