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Recently, the treatment of advanced gastric cancer by continuous infusion of 5-fluorouracil (5-FU) with low-dose cisplatin (CDDP) has improved efficacy without severe toxicities. The possible effectiveness of 5-FU+low-dose CDDP for colorectal cancer (CRC) is intriguing. One hundred fifty-five patients with far-advanced CRC including at least one measurable lesion were enrolled in a prospective randomized clinical trial funded by the Japanese Foundation for Multidisciplinary Treatment of Cancer. These patients were assigned to the two arms to assess the value of low-dose CDDP when added to a continuous intravenous infusion of 5-FU at a dose of 300 mg/m(2)/24 hrs in a one-week cycle consisting of 5 days of treatment and 2 days of rest for at least 12 weeks. CD-DP was given intravenously at a dose of 3 mg/m(2) on days 1-5 and days 8-12, and then at a dose of 7 mg/m(2) twice a week. Three patients were excluded from the trial. The response rate in the 5-FU+low-dose CDDP arm (n=75) was significantly higher than that in the 5-FU arm (n=77) (25.3% vs. 11.7%; P = 0.037). There was no significant difference in the median overall survival time between the 5-FU+low-dose CDDP arm and the 5-FU arm (479 and 491 days, respectively). Grades 3/4 toxicities occurred infrequently in both arms. The quality of life was almost the same between the arms. Low-dose CDDP improved the response rate while keeping toxicities within clinically acceptable limits. However, this combined treatment did not confer a survival advantage over treatment with continuous infusion of 5-FU alone for patients with far-advanced CRC; that might be attributable to the short CDDP administration setting of 12 weeks.

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Lymph-node metastasis is an important indicator in the diagnosis of colon cancer. In order to determine the genes involved in metastasis, genomic copy-number aberrations in the primary tumours and lymph-node metastases were analysed in 12 patients using comparative genomic hybridization. This method detects genomic copy-number changes at the chromosomal level and the identification of the regions of aberration on any chromosome. Copy-number gains at 6p12 and losses at 8p12 were observed in a greater number of the primary tumours than in the metastases. These aberrations appear to be involved in lymph-node metastasis of colon cancer, and may allow measurement of the risk of lymph-node metastasis from a given colon cancer.

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Several clinical cohort and case-control studies have suggested a link between diabetes and colon cancer. Otsuka Long-Evans Tokushima Fat (OLETF) rats spontaneously develop type 2 diabetes mellitus and Long-Evans Tokushima Otsuka (LETO) rats are non-diabetic. The relationship between type 2 diabetes mellitus and colon cancer was examined in these rats. The carcinogen 1,2-dimethylhydrazine was administered subcutaneously once weekly for 10 weeks, and the animals were killed and necropsied in week 29. All OLETF rats and 80% of the LETO rats developed cancer. The number of colon cancers per rat was significantly greater in the diabetic than in the non-diabetic rats. Although the tumours tended to be larger in diabetic rats, the difference was not statistically significant. No significant differences were observed in the depth of invasion or histological type of cancer in the two groups. Type 2 diabetes mellitus may enhance the generation and growth of colon cancer.

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Colorectal cancer is thought to be more common in men than in women. The chromosomal locations of DNA gains and losses in surgical specimens of colorectal tumours were detected by comparative genomic hybridization and were compared by gender. Five chromosomal regions, 7p, 8p, 8q, Xp and Xq, contained multiple gains that were significantly more common in males than in females, and within these regions, the differences were significant for Xp21, Xp11.3, Xp11.4 and Xq26. Regions 1p, 3q, 11q, 12p, 12q and 15q contained multiple sites of gain that were significantly more common in females than in males. Tumours from male and female patients showed significantly more losses at 11p and 15q, and at 4q and Xq, respectively. The fact that gains in X-chromosomal regions were detected with a significantly higher frequency in tumours from male patients suggests that the difference between the genders might be explained by X-chromosomal inactivation.

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Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may influence the chemosensitivity of colorectal cancers to fluorouracil (5-FU) by increasing intracellular 5,10-methylenetetrahydrofolate. The effect of this polymorphism on the expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) and thymidine phosphorylase (TP) in colorectal cancer was investigated. The MTHFR C677T polymorphism was analysed and TS, DPD, OPRT and TP mRNA expression was measured in tumour and adjacent normal mucosal tissue. In all patients, the genotypes of the tumour and normal tissues were identical. No differences were found in the expression of TS, DPD or TP mRNA by genotype in either tumour or normal tissue. Although the OPRT mRNA level in tumour tissue was not associated with the genotype, normal mucosa with the TT genotype showed a significantly higher OPRT mRNA level than mucosa with other genotypes. The MTHFR C667T polymorphism is not associated with intratumoural expression of TS, DPD, OPRT or TP.

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Steroids inhibit primary wound healing and delay the formation of granulation tissue, but it has been controversial whether long-term steroid treatment by itself increases the risk of abdominal wound dehiscence. The aim of this study was to determine whether the pre-operative dose and post-operative total dose of steroids influence abdominal wound dehiscence. Of 28 patients who had surgery while receiving long-term steroid treatment, seven had abdominal wound dehiscence and 21 did not have dehiscence. The two groups differed significantly in the post-operative dose of steroids (404.3 +/- 147.1 and 135.6 +/- 118.7 mg, respectively) and the duration of wound healing (57.3 +/- 18.0 and 12.4 +/- 3.8 days), but no other differences were found. Abdominal wound dehiscence may be influenced by the post-operative rather than the pre-operative steroid dose.

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BACKGROUND: Flat-type colorectal tumors are rare, but are known for their unusual flat morphology and aggressive clinical behavior despite their small size. To identify distinct genetic alterations, loss of heterozygosity (LOH) analysis was performed on microdissected tissues. MATERIALS AND METHODS: DNA was extracted from multiple microdissected foci in 43 cases of early-stage flat-type colorectal tumors and LOH analysis was performed on 2q, 4q, 5q, 12q, 14q, 15q, 17p, 18q, 18p and 22q. RESULTS: LOH patterns were detected in one of two forms: (i) homogeneous LOH throughout the microdissected foci, which indicated the early acquisition of LOH; and (ii) heterogeneous LOH, which were detected in a part of analyzed foci. Homogeneous and heterogeneous LOH were most frequently detected on 17p (92%) followed by 18q (81%), 18p (81%), 5q (61%), 22q (51%), 14q (44%), 15q (41%), 2q (39%), 12q (36%) and 4q (32%). Homogeneous LOH was detected most frequently on 17p (68%) followed by 18p (53%), 18q (53%), 22q (34%) and 12q (27%). The average fractional allelic loss (FAL) for heterogeneous and homogeneous LOH was 0.57 and the average FAL for homogeneous LOH was 0.37. CONCLUSIONS: Early flat-type colorectal tumors frequently shows the early occurrence of multiple LOH including 17p, 18p, 18q and 22q, which is coupled with additional LOH of other loci either simultaneously or in the early clonal progression phase. The extent and sequences of LOH may be the mechanisms responsible for the aggressive clinical behaviors of these tumors.

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The efficacy of 5-fluorouracil (5-FU) treatment and the incidence of adverse events differ among patients and depend to some extent on individual variations in drug catabolism. This feasibility study aimed to determine the optimum conditions for a 5-FU oral load test, which would allow the simple evaluation of individual differences in 5-FU catabolism. Patients with colon cancer were given oral 5-FU (200 mg/day) for 3 days (n = 36) or a single 100 mg dose (n = 14). Serum concentrations of uracil, dihydrouracil, 5-FU and 5-fluoro-5,6-dihydrouracil were measured before and after 5-FU administration. The results suggested that a decline in 5-FU metabolism was associated with continuous administration and increasing age. We conclude that a continuous load of 5-FU is necessary in order to predict the efficacy and side-effects of the drug. The 3-day regimen, with its ease of administration, merits further study to assess its possible clinical application.

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Submucosal tumor-like colorectal carcinoma, most of whose surface is covered with normal mucosa, is very rare. We report a case of colonic carcinoma resembling submucosal tumor. A 54-yr-old man visited our institution for an evaluation of a positive fecal occult blood test. Colonoscopic examination revealed a small, mainly red polypoid lesion with a central deep ulceration and many white spots in the sigmoid colon. Indigocarmine staining demonstrated that the white spots were faint shallow depressions. Magnifying colonoscopic examination showed that the lesion surface, except for the ulceration and the depressions, was covered with normal mucosa. Although the tumor was small, we strongly suspected its malignancy due to a deep ulceration. As we could not excise it endoscopically, we performed sigmoidectomy. The lesion was 12 mm in size. Histologic examination revealed that the lesion was a moderately differentiated adenocarcinoma that was mainly covered with normal mucosa, that carcinoma was exposed only at the ulceration and the depressions on the surface, and that it had expanded to the muscularis propria. Together with considerations from the literature, this type of colorectal carcinoma is supposed to be invasive and surgical resection should be considered, no matter how small it may be.

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Several epidemiological studies suggested an inverse relation between serum cholesterol level and cancer mortality. We analyzed the relation between gastrointestinal cancers and serum cholesterol levels. A total of 631 patients were recruited as cancer-bearing cases, comprising 181 esophageal cancers, 251 gastric cancers and 199 colorectal cancers. A case-control analysis was conducted on the serum TC, HDL-C, LDL-C and TG levels. TC and LDL-C were significantly lower in cancer-bearers by approximately 15 mg/dl. Furthermore, analyses by cancer site also showed significantly lower TC and LDL-C levels in cancer-bearers than in controls for all three sites. In this analysis, early stage cancer-bearers showed a significant decrease in TC levels by approximately 11 mg/dl compared with controls, and also a similar decrease in LDL-C levels. These results suggest that low TC levels are not related to cancer stage. Furthermore, findings of no significant differences in HDL-C and TG between cancer-bearing cases and controls in addition to a specific decrease in LDL-C in cancer-bearers suggest that hypocholesterolemia observed in these cases stems from low LDL-C. However, cancer-bearers and controls showed a similar distribution of TC and LDL-C levels. We should be aware that latent cancer bearers may be present among subjects with hypocholesterolemia.

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AIMS: To elucidate the mechanism of marked stromal fibrosis in strictured colorectal carcinomas (SC) that cause complete ileus. METHODS AND RESULTS: Sixteen cases of SC and 29 cases of non-strictured colorectal carcinoma (NSC) were studied. These carcinomas showed similar clinicopathological features except for bowel stricture. The stricture index (SI) showing the degree of bowel stricture was 59.8 +/- 12.1% in SC versus 20.8 +/- 24.6% in NSC (P < 0.001). The fibrosis index (FI), defined to reflect the extent of stromal fibrosis, was 56.3 +/- 8.8% in SC versus 21.9 +/- 10.6% in NSC (P < 0.001). COX-2+ myofibroblasts were detected in 13 cases (81.3%) in SC versus eight cases (27.6%) in NSC (P < 0.01). The COX-2+ myofibroblast density was 276.7 +/- 181.1 cells/mm(2) in SC versus 26.6 +/- 52.7 cells/mm(2) in NSC (P < 0.001). When all cases were divided into two groups with and without COX-2+ myofibroblasts, the SI was 48.8 +/- 19.1% in those with COX-2+ myofibroblasts versus 24.8 +/- 29.3% in those with COX-2- myofibroblasts (P < 0.001). CONCLUSION: COX-2+ myofibroblasts may play an important role in extensive bowel stricture in colorectal carcinomas.

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BACKGROUND: Stent placement is a useful palliative treatment for inoperable acute malignant colorectal obstruction. However, data comparing stent placement with colostomy are scarce. METHODS: We compared the clinical outcome of 18 patients who had stent placement and 17 patients who underwent only colostomy. RESULTS: The postoperative hospital stay was 22.3 days for stent placement compared with 47.4 days for colostomy (p = 0.016). The duration to readmission was 129.2 days for stent placement and 188.4 days for colostomy. The estimated duration of primary stent patency was 106 days. Mean survival period was 134 days in patients with stent placement and 191 days in patients with colostomy. CONCLUSION: Postoperative hospital stay was shorter in patients with stent placement but duration to readmission and survival were longer in patients with colostomy. However, stent placement increases the option of palliative treatment and is an effective treatment contributing to improving quality of life.

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Autoamputation of a gastric polyp is a relatively rare phenomenon and its precise mechanism is unclear. To learn more about the mechanism(s) involved, it is important to observe a polyp just before and just after its disappearance. We report a case of a gastric polyp that was observed endoscopically just before and then just after autoamputation. A 61-year-old woman with a thumb-sized, pedunculated hyperplastic polyp in the gastric antrum visited our institution for investigation of hematemesis. She was being treated with oral hypoglycaemic drugs for diabetes mellitus but was not taking any other medicine around that time. Emergency gastroscopy revealed a bleeding point near the polyp; gastroscopy the next day revealed that the polyp had disappeared. It was concluded that autoamputation of a gastric polyp may follow gastric injury induced by diabetes mellitus or oral antidiabetic drugs.

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To identify factors that influence the clinical response to 5-fluorouracil (5-FU), we studied the correlation between in vitro sensitivity to 5-FU and the expression of seven biological markers. The markers, thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), pyrimidine nucleoside phosphorylase, p53 (wild/mutant), p21, cyclo-oxygenase-2, and inducible nitric oxide synthase were measured in tumour tissues from 32 colorectal cancer patients. The activities of TS and DPD were significantly lower in the tumours sensitive to 5-FU compared with those that were not sensitive to 5-FU. In tumours with TS < 3.7 pmol/min per mg protein and DPD < 98 pmol/min per mg protein, the percentage of cases sensitive to 5-FU (67%) and the mean percentage inhibition of tumour cells by 5-FU (42.8%) were significantly higher than in the other tumours (0% and 13.1%, respectively). The other biological markers did not correlate with in vitro sensitivity to 5-FU. Tumour sensitivity to 5-FU can be more precisely predicted by taking the activities of both TS and DPD into consideration than by using either alone.

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Perforations of the esophagus are uncommon complications of flexible gastrointestinal endoscopy. Perforations after endoscopy are likely to occur in the cervical esophagus, where fiber insertion is difficult anatomically. The diagnosis should be made as soon as possible, because mediastinitis and sepsis frequently develop following esophageal perforations. The surgical strategies are dependent on the location of the perforations and the condition of the patients. For a successful outcome, surgery is a preferred treatment for most perforation cases, and non-operative treatment, such as antibiotics, parental nutrition, and no food intake by mouth, should be applied carefully.

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We report a case of sigmoid colon cancer that was left untreated for a period of 4 years, because the patient declined treatment. A 59-year-old man was found to have an early carcinoma of the sigmoid colon measuring approximately 12 mm in diameter. The lesion, initially a flat cancer, increased in height and became sessile 4 months later. Subsequently, the central portion of the lesion became ulcerated, leaving an elevated ring along its periphery. The lesion eventually evolved into an ulcerated, invasive cancer. This sequence has not been observed with colonoscopy before.

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OBJECTIVE: To study the effect of peritoneal macrophages on tumor cell proliferation, we cultured ascites hepatoma AH-130 cells with unstimulated, or lipopolysaccharide (LPS)- or interleukin (IL)-2-stimulated rat peritoneal macrophages, and examined the proliferation of AH-130 cells. MATERIALS AND METHODS: Rat peritoneal macrophages isolated from male Wistar rats were co-cultured with AH-130 cells in the absence or presence of LPS or IL-2. After incubation, proliferation of AH-130 cells was analyzed using flow cytometry. In addition, the levels of tumor necrosis factor (TNF)-alpha and nitric oxide (NOx, nitrate + nitrite) in the culture supernatants were measured. Furthermore, anti-TNF-alpha antibody (10 microg/ml) and nitric oxide synthase inhibitor, N(G)-monomethyl-L-arginine (L-NMMA, 100 microM) were added to the coculture, and their effect on AH-130 cell proliferation was examined. RESULTS: When AH-130 cells were co-cultured with unstimulated peritoneal macrophages, proliferation of AH-130 cells was not affected. In contrast, when AH-130 cells were cocultured with peritoneal macrophages in the presence of LPS (0.1-20 microg/ml) or IL-2 (1-200 U/ml), proliferation of AH130 cells was dose-dependently suppressed by LPS or IL-2. Moreover, LPS- or IL-2-stimulation increased the levels of TNF-alpha and NOx in the supernatants of AH-130 cell and macrophage co-culture, although LPS and IL-2 did not induce TNF-alpha and NOx production by AH-130 cells incubated without macrophages. Interestingly, anti-TNF-alpha antibody and L-NMMA significantly inhibited the suppression of AH-130 cell proliferation by LPS- or IL-2-stimulated macrophages (p < 0.05). Furthermore, exogenously added recombinant rat TNF-alpha (0.26-1300 ng/ml) or NO donor (GSNO, S-nitroso-L-glutathione) (0.1 - 10 mM) dose-dependently suppressed the proliferation of AH-130 cells in the absence of macrophages. CONCLUSION: Together these observations suggest that when peritoneal macrophages are activated by LPS and IL-2, they suppress the proliferation of ascites hepatoma AH-130 cells via the production of TNF-alpha and nitric oxide.

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