Impact of Perioperative Immunonutrition on Postoperative Outcomes for Patients Undergoing Head and Neck or Gastrointestinal Cancer Surgeries: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To clarify whether perioperative immunonutrition is effective in adult patients with or without malnutrition undergoing elective surgery for head and neck (HAN) or gastrointestinal (GI) cancers. BACKGROUND: It is important to avoid postoperative complications in patients with cancer as they can compromise clinical outcomes. There is no consensus on the efficacy of perioperative immunonutrition in patients with or without malnutrition undergoing HAN or GI cancer surgery. MATERIALS AND METHODS: We searched MEDLINE (PubMed), MEDLINE (OVID), EMBASE, Cochrane Central Register of Controlled Trials, Web of Science Core Selection, and Emcare from 1981 to 2022 using search terms related to immunonutrition and HAN or GI cancer. We included randomized controlled trials. Intervention was defined as immunonutritional therapy including arginine, n-3 omega fatty acids, or glutamine during the perioperative period. The control was defined as standard nutritional therapy. The primary outcomes were total postoperative and infectious complications, defined as events with a Clavien-Dindo classification grade ≥ II that occurred within 30 days after surgery. RESULTS: Of the 4825 patients from 48 included studies, 19 had upper GI cancer, 9 had lower, and 8 had mixed cancer, whereas 12 had HAN cancers. Immunonutrition reduced the total postoperative complications (relative risk ratio: 0.78; 95% CI, 0.66-0.93; certainty of evidence: high) and infectious complications (relative risk ratio: 0.71; 95% CI, 0.61-0.82; certainty of evidence: high) compared with standard nutritional therapy. CONCLUSIONS: Nutritional intervention with perioperative immunonutrition in patients with HAN and GI cancers significantly reduced total postoperative complications and infectious complications.

Acute necrotic disorder of the small intestine post-coronavirus disease-2019 vaccination.

The Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine is extensively used worldwide, and its safety has been proven. Herein, we report a case of an acute necrotic disorder in the small intestine post-COVID-19 vaccination. The patient developed severe abdominal pain the day after the first vaccination. Contrast-enhanced computed tomography showed extensive ileum wall thickening and ascites. Colonoscopy revealed a ring-shaped ulcer and stricture in the terminal ileum. Ileocecal resection was performed, and the patient did not have further episodes of a necrotic disorder in the small intestine. Although it is unknown if this event is associated with vaccination, and this occurrence also does not outweigh the efficacy and safety of the Pfizer-BioNTech COVID-19 vaccine, gastroenterologists need to be aware of this rare case, given its noteworthy timing.

Factors for conversion risk of colorectal endoscopic submucosal dissection: a multicenter study.

BACKGROUND: Endoscopic submucosal dissection (ESD) has become a widely accepted treatment method for colorectal tumors; however, there are some persistent problems. This multi-center study aimed to characterize the risk factors for incomplete resection and perforation in standardized colorectal ESD procedures. METHODS: This study included 2423 consecutive patients who underwent ESD for 2592 colorectal tumors between August 2013 and December 2018 at 11 institutions (1 academic hospital and 10 affiliated hospitals) from the Hiroshima GI Endoscopy Research Group. We evaluated the risk factors for interruption, piecemeal resection, and perforation of standardized colorectal ESD in relation to clinicopathologic and endoscopic characteristics. RESULTS: The incidences of interruption, piecemeal resection, and perforation were 0.7%, 2.9%, and 3.0%, respectively. Multivariate analysis identified the following risk factors for interruption: perforation during the procedure, deep submucosal invasion (> 1000 µm), poor scope operability, and severe submucosal fibrosis. The risk factors for piecemeal resection included poor scope operability, severe submucosal fibrosis, and procedure time (≥ 85 min). The risk factors for perforation during the procedure were severe submucosal fibrosis, poor scope operability, procedure time (≥ 85 min), and tumor size (≥ 40 mm). Independent risk factors for severe submucosal fibrosis included a history of biopsy and lesions located on the fold or flexure. CONCLUSIONS: Severe submucosal fibrosis and poor scope operability are the common risk factors for interruption, piecemeal resection, and perforation in standardized colorectal ESD.

Efficacy and safety comparison of scissor-type knives with needle-type knives for colorectal endoscopic submucosal dissection: a post-hoc propensity score-matched analysis (with videos).

BACKGROUND AND AIMS: Many knives have been developed to improve the efficacy and safety of endoscopic submucosal dissection (ESD). We aimed to evaluate the efficacy and safety of scissor-type knives for colorectal ESD compared with needle-type knives. METHODS: We performed a post-hoc propensity score-matched analysis in an 11-facility study between August 2013 and December 2018. A total of 2330 patients (2498 lesions) who underwent colorectal ESD were divided into needle-type (1923 patients, 2067 lesions) and scissor-type (407 patients, 431 lesions) knife groups. Short-term outcomes were compared between the 2 groups. RESULTS: Two-to-one propensity score-matched analysis identified 814 (709 patients) and 407 (386 patients) lesions in the needle- and scissor-type knife groups, respectively. The median resection speed was significantly faster in the needle-type group (18.3 mm2/min) than in the scissor-type group (13.2 mm2/min, P < .0001), whereas en-bloc and histologic complete resection rates were not significantly different between the needle- and scissor-type groups (96.8% [788/814] vs 98.3% [400/407], P = .1888 and 95.1% [774/814] vs 95.6% [389/407], P = .7763, respectively). The rate of lesions resected using a single knife was significantly higher in the scissor-type group (98.5% [401/407]) than in the needle-type group (43.9% [357/814], P < .0001). Rates of intraoperative perforation and delayed bleeding were significantly lower in the scissor-type group than in the needle-type group (.7% [3/407] vs 2.5% [20/814], P = .0431 for each). CONCLUSIONS: Scissor-type knives are safer for colorectal ESD. However, they are associated with slower resection speeds compared with needle-type knives. (Clinical trial registration number: UMIN000016197.).

Indications and outcomes of colorectal hybrid endoscopic submucosal dissection: a large multicenter 10-year study.

BACKGROUND AND AIMS: Hybrid endoscopic submucosal dissection (ESD) is a colorectal lesion resection procedure that includes both planned and salvage procedures. Previous colorectal hybrid ESD studies have involved single institutions or few operators over a short timeframe, and the size for indication has not been established. In this multicentre study, we investigated the clinical outcomes of hybrid ESD for colorectal tumors that met the 30 mm lesion size criterion. METHODS: From January 2008 to December 2018, colorectal hybrid ESD was performed for 172 lesions (diameter range, ≥ 20- < 30 mm) at Hiroshima GI Endoscopy Research Group. We compared clinicopathological characteristics and outcomes between 56 and 116 lesions in planned and salvage groups, respectively. We also compared data between 2008 and 2013 (the first period) and 2014 and 2018 (the second period) to assess operator experience. RESULTS: No significant difference was found in the complete en bloc resection rate between the planned and salvage groups (92.9% vs. 83.6%, respectively). Procedure time was shorter in the planned group (44.5 min) than in the salvage group (72.0 min, p < 0.01). The perforation rate was higher in the salvage group (21.6%) than in the planned group (0%, p < 0.01); however, the perforation rate during snaring in the salvage group was 1.8%. During the second period relative to the first period, we recorded a significantly higher complete en bloc resection rate (95.7% vs. 75.6%, respectively, p < 0.01) and experienced operator rate (75.5% vs. 53.9%, respectively, p < 0.01). Furthermore, no significant difference was found in the complete en bloc resection rate between the planned and salvage groups during the second period (100% vs. 94.4%, respectively). CONCLUSION: Colorectal hybrid ESD, especially salvage hybrid ESD performed by experienced operators, is adoptable and safe for lesions with diameters ranging from ≥ 20 to < 30 mm.

A case of collagenous colitis associated with novel oral anticoagulants use.

An 84-year-old man was referred to our hospital because of watery diarrhea. Due to cerebral infarction, he had started treatment with a novel oral anticoagulants (NOAC) 1 month prior to admission. The patient underwent blood tests, enhanced computed tomography, and colonoscopy, which indicated infectious or medicinal colitis. The diarrhea persisted and he developed hypokalemia, so a second colonoscopy was performed, which showed edematous mucosa. Colonic mucosal biopsies showed a thick collagen band in the subepithelial region, and collagenous colitis was diagnosed. The watery diarrhea subsequently resolved 1 week after changing the NOAC to warfarin. Reports on collagenous colitis caused by NOAC are very rare, and we consider this case valuable.

Randomized study of lafutidine vs lansoprazole in patients with mild gastroesophageal reflux disease.

AIM: To compare the clinical efficacy of the second-generation H2RA lafutidine with that of lansoprazole in Japanese patients with mild gastroesophageal reflux disease (GERD). METHODS: Patients with symptoms of GERD and a diagnosis of grade A reflux esophagitis (according to the Los Angeles classification) were randomized to receive lafutidine (10 mg, twice daily) or lansoprazole (30 mg, once daily) for an initial 8 wk, followed by maintenance treatment comprising half-doses of the assigned drug for 24 wk. The primary endpoint was the frequency and severity of heartburn during initial and maintenance treatment. The secondary endpoints were the sum score of questions 2 and 3 in the Gastrointestinal Symptom Rating Scale (GSRS), and the satisfaction score. RESULTS: Between April 2012 and March 2013, a total of 53 patients were enrolled, of whom 24 and 29 received lafutidine and lansoprazole, respectively. After 8 wk, the frequency and severity of heartburn was significantly reduced in both groups. However, lafutidine was significantly inferior to lansoprazole with regard to the severity of heartburn during initial and maintenance treatment (P = 0.016). The sum score of questions 2 and 3 in the GSRS, and satisfaction scores were also significantly worse in the lafutidine group than the lansoprazole group (P = 0.0068 and P = 0.0048, respectively). CONCLUSION: The clinical efficacy of lafutidine was inferior to that of lansoprazole, even in Japanese patients with mild GERD.

Long-term outcomes after treatment for pedunculated-type T1 colorectal carcinoma: a multicenter retrospective cohort study.

BACKGROUND: The risk for lymph node metastasis and the prognostic significance of pedunculated-type T1 colorectal carcinomas (CRCs) require further study. We aimed to assess the validity of the 2014 Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines based on long-term outcomes of pedunculated-type T1 CRCs. METHODS: In this multicenter retrospective cohort study, we examined 176 patients who underwent resection endoscopically or surgically at 14 institutions between January 1990 and December 2010. Patients meeting the JSCCR curative criteria were defined as "endoscopically curable (e-curable)" and those who did not were "non-e-curable". We evaluated the prognosis of 116 patients (58 e-curable, 58 non-e-curable) who were observed for >5 years after treatment. RESULTS: Overall incidence of lymph node metastasis was 5 % (4/81; 95 % confidence interval 1.4-12 %: three cases of submucosal invasion depth ≥1000 µm [stalk invasion] and lymphatic invasion, one case of head invasion and budding grade 2/3). There was no local or metastatic recurrence in the e-curable patients, but six of them died of another cause (observation period, 80 months). There was no local recurrence in the non-e-curable patients; however, distant metastasis was observed in one patient. Death due to the primary disease was not observed in non-e-curable patients, but six of them died of another cause (observation period, 72 months). CONCLUSIONS: Our data support the validity of the JSCCR curative criteria for pedunculated-type T1 CRCs. Endoscopic resection cannot be considered curative for pedunculated-type T1 CRC with head invasion alone.

Clinical usefulness of transabdominal ultrasonography prior to patency capsule for suspected small-bowel strictures.

OBJECTIVE: Patency capsule (PC) examination has made it possible to perform capsule endoscopy (CE) in patients with a suspected small-bowel stricture. However, PC has some drawbacks, so we assessed the usefulness of transabdominal ultrasonography (TUS) prior to PC in patients with suspected small-bowel strictures to avoid unnecessary PC examination. PATIENTS AND METHODS: Fifty-two patients who underwent TUS prior to PC were enrolled in this study. TUS findings were classified as follows: intestinal narrowing and distension at the oral side (Type A); extensive bowel wall thickening (Type B); focal bowel wall thickening (Type C) or no abnormality detected (Type D). We evaluated the TUS and PC findings for the detection of small-bowel strictures. RESULTS: Double-balloon endoscopy (DBE) revealed small-bowel strictures in 13 of 50 patients (26%). TUS yielded Type B or C findings in 12 of 13 patients (92%), while PC revealed strictures in all 13 patients. In Crohn's disease (CD) patients with Type B TUS findings, 8 of 9 (89%) had small-bowel strictures on DBE. However, only two of six non-CD patients (33%) with Type B TUS findings had small-bowel strictures. The incidence of Type B strictures was significantly higher in CD patients. CONCLUSIONS: CD patients with Type B TUS findings should not undergo PC or CE because of the high rate of small-bowel strictures. Non-CD patients diagnosed with Type B TUS strictures, as well as patients diagnosed with Type C or D strictures should undergo CE after confirming small-bowel patency using PC.

A trial of the use of patency capsules in combination with overnight capsule endoscopy.

BACKGROUND: The PillCam® patency capsule (PPC) was developed to minimize the risk of capsule retention during capsule endoscopy (CE). Typically, the use of patency capsules prior to CE requires patients to be monitored over a period of time. To reduce the need for frequent outpatient visits during PPC examination and CE, we developed the overnight CE (ON-CE) procedure. METHODS: Between October 2012 and January 2014, a total of 19 patients (15 males and 4 females, mean age 48.4 years) were administered PPC to assess the patency of the small intestine prior to ON-CE at JA Onomichi General Hospital in Hiroshima, Japan. RESULTS: PPC confirmed patency of the small intestine in 15 of the 19 patients. Of these 15 patients, 14 proceeded to ON-CE. The CE was cancelled in 1 patient and the cecal intubation time exceeded 8 h in another patient. For the remaining 12 patients, the mean small intestine observation coverage was 92.3% and the mean cecal intubation time was 325 min. There were no adverse events and the discharge of the capsule was confirmed in all cases. CONCLUSION: When patency of the gastrointestinal tract was confirmed with the PPC, ON-CE was performed safely and effectively.

Percutaneous transhepatic sclerotherapy for recurrent bleeding ileal varices diagnosed by capsule endoscopy and computed tomography during percutaneous transhepatic venography.

We report a case of acute uncontrolled gastrointestinal bleeding in a patient with liver cirrhosis. A 64-year-old man was admitted to our hospital for further investigation of blood in stools. Preliminary examination by computed tomography (CT) as well as upper and lower endoscopy could not detect the bleeding source. Exploratory laparotomy was considered difficult due to potential easy bleeding and adhesions caused by past abdominal surgery. The hemoglobin level was normalized by blood transfusion. Capsule endoscopy (CE) identified ileal varices. The top of these ileal varices was red, prompting their identification as the source of bleeding. Percutaneous transhepatic venography (PTV) confirmed the presence of many varices in the branch of the superior mesenteric vein, although the bleeding source could not be identified. CT during PTV identified varices protruding into the ileal lumen, which were managed subsequently by percutaneous transhepatic sclerotherapy (PTS). The procedure stopped the bleeding completely. CE proved less invasive and effective in detecting obscure gastrointestinal bleeding. CT during PTV followed by PTS is suitable for diagnosis and treatment of bleeding varices in patients with portal hypertension.

[A case of mucosal Schwann cell hamartoma].

A 40-year-old man was referred to our hospital because of a positive fecal occult blood test. Colonoscopy revealed many small whitish nodules in the mucosa of the sigmoid colon. Specimens endoscopically resected from the lesions revealed spindle cell proliferation in the lamina propria. Immunohistochemical study revealed strong and diffuse positivity for S-100 protein. Results of staining for neurofilament protein and epithelial membrane antigen were negative. The neurogenic tumors were diagnosed as mucosal Schwann cell hamartoma. No clinical features of multiple endocrine neoplasia type 2B or neurofibromatosis type 1 were found in the present case.

Evaluation of individual risk in nonvariceal gastrointestinal bleeding patients with NSAID administration: a multicenter study in Japan.

BACKGROUNDS: Gastrointestinal (GI) toxicity is an undesirable effect of nonsteroidal anti-inflammatory drugs (NSAIDs). We conducted a multicenter study in Japan to clarify the GI risk grade in patients with NSAID-induced GI bleeding. METHODS: Patients with emergent endoscopic hemostasis by nonvariceal bleeding were registered from 36 hospitals in Hiroshima. In cases with NSAID use, the GI risk grade (low, moderate, or high) was evaluated, and concomitant drugs were investigated. We asked 79 gastroenterologists and 234 orthopedists what concomitant drugs they would prescribe to 3 simulated patients. RESULTS: A total of 1,350 patients were registered. NSAIDs were used in 278 cases (21%). Concerning the risk grade in each patient, the largest group was the moderate-risk group (203 patients; 73%), while the high-risk group comprised 10% of all NSAID users with bleeding. A proton pump inhibitor (PPI) or misoprostol was administrated to only 20 patients (7%). A small number of the gastroenterologists and orthopedists who responded to the questionnaire would prescribe PPI or misoprostol to simulated patients with short-term loxoprofen use. CONCLUSIONS: In NSAID users with GI bleeding, the moderate-risk group was the largest group for GI toxicity in Japan. In these cases, PPI or misoprostol was not commonly medicated in clinical practice.

A case of Helicobacter pylori-negative depressed type gastric adenoma.

A 75-year-old woman was referred to our hospital for further examination of gastric antral abnormal endoscopic findings. Endoscopic study of the stomach revealed a depressed lesion in the gastric antrum. Atrophic findings were not recognized in the background gastric mucosa, and Helicobacter pylori infection was not detected by histology, an urea breath test, a rapid urease test and serological test. A diagnosis of adenoma was given histopathologically from the resected specimens. As a result of immunohistological study, the phenotype of the tumor was not classified as either gastric type or intestinal type. CDX2 was positive in part of the tumor.

Expression of vascular endothelial growth factor (VEGF)-C and VEGF-D in early gastric carcinoma: correlation with clinicopathological parameters.

In this study, we investigated whether expression of vascular endothelial growth factor (VEGF)-C and/or VEGF-D correlates with clinicopathological features of human gastric carcinoma. We immunohistochemically examined the expression of VEGF-C and VEGF-D in 140 archival surgical specimens of submucosally invasive gastric carcinoma. Of these specimens, 32 (22.9%) and 12 (8.6%) showed intense VEGF-C and VEGF-D immunoreactivity in cancer cells, respectively. VEGF-C immunoreactivity was associated with histological type, lymphatic invasion, lymph node metastasis, and microvessel density. No association was identified between VEGF-D immunoreactivity and clinicopathological variables. These results suggest that VEGF-C is a dominant regulator of lymphangiogenesis in early-stage human gastric carcinoma.

Regulation of vascular endothelial growth factor (VEGF)-C and VEGF-D expression by the organ microenvironment in human colon carcinoma.

Vascular endothelial growth factor (VEGF)-C and VEGF-D are potent lymphangiogenic factors produced by tumour and stromal cells. The purpose of this study was to investigate the expression of VEGF-C and VEGF-D in the organ microenvironment. We implanted human KM12 colon carcinoma cell lines into the subcutis and caecal wall of nude mice. The expression of VEGF-C and VEGF-D mRNAs and proteins were examined by reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. Under culture conditions, VEGF-C mRNA was not detected in KM12 cells; however, VEGF-C expression was detected after implantation of KM12 cells into nude mice. VEGF-C and VEGF-D protein contents were higher in orthotopic (caecal wall) tumours than in ectopic (subcutis) tumours. Small vessels expressing VEGF receptor-3 were observed in the peripheral portions of caecal tumours. In metastatic liver tumours, VEGF-C and VEGF-D proteins were produced in lower amounts than those in caecal tumours. These data suggest that the expression of lymphangiogenic factors is influenced by the organ microenvironment. Therefore, experimental studies of colon cancer lymphangiogenesis should be performed with orthotopic implantation models.

Angiogenic switch occurs during the precancerous stage of human esophageal squamous cell carcinoma.

We previously reported that vascular endothelial growth factor (VEGF) expression correlates with vessel density in human esophageal squamous cell carcinomas. However, tumor angiogenesis is not controlled simply by the presence of VEGF, and is likely regulated by several angiogenic factors produced by tumor and host cells. The goal of the present study was to determine the angiogenic profile of precancerous and cancerous lesions of the esophagus. Expression of mRNAs for VEGF, platelet derived endothelial cell growth factor (PD-ECGF), basic fibroblast growth factor (bFGF), and interleukin (IL)-8 was examined in six esophageal carcinoma cell lines and fresh biopsy specimens from 16 patients with invasive esophageal carcinoma by RT-PCR. Immunohistochemical analyses with antibodies against VEGF, PD-ECGF, bFGF, and IL-8 were performed on archival specimens of 60 normal esophageal mucosa, 11 dysplasias and 49 carcinomas of the esophagus. Microvessels were stained with anti-CD34 antibody and quantified by counting the number of vessels in a x200 field in the most vascularized areas of the tumor. Esophageal carcinoma cell lines and tumor tissues expressed mRNAs for one or more these angiogenic factors at various levels. An initial increase in vessel density and enhanced expression of PD-ECGF and VEGF were observed in dysplastic epithelium. Vessel density was significantly higher in more advanced lesions. bFGF and IL-8 were not expressed in dysplasias and mucosal carcinomas, but expression was increased in late stage squamous cell carcinoma. These findings suggest that the angiogenic switch is a very early event in the development of invasive carcinoma. Several different angiogenic factors produced by tumor cells and host cells may regulate angiogenesis during different steps of esophageal carcinogenesis.

Expression of VEGF-C and VEGF-D at the invasive edge correlates with lymph node metastasis and prognosis of patients with colorectal carcinoma.

Vascular endothelial growth factor (VEGF)-C and VEGF-D are potent lymphangiogenic factors produced by tumor and stromal cells. The purpose of this study was to determine whether expression of VEGF-C and/or VEGF-D correlates with clinicopathological features of human colorectal carcinoma. Expression of mRNAs for VEGF-C, VEGF-D, and their receptor VEGFR-3 was examined by reverse transcription-polymerase chain reaction (RT-PCR) in six colon carcinoma cell lines and in fresh endoscopic biopsy specimens from 20 patients with colorectal carcinoma. Expression of VEGF-C and VEGF-D protein was also examined immunohistochemically in 139 archival surgical specimens of human colorectal carcinoma. Of the six cell lines, one (Colo320D) constitutively expressed VEGF-C and four (Colo320D, DLD-1, km12sm, km12c) constitutively expressed VEGF-D mRNA. Expression of VEGF-D mRNA was increased under low oxygen conditions, and all six cell lines constitutively expressed VEGF-D mRNA under hypoxic conditions. Of the 139 specimens of human colorectal carcinoma, 65 (46.8%) showed intense VEGF-C immunoreactivity and 41 (29.5%) showed intense VEGF-D immunoreactivity. In 49 (75.3%) of the 65 and 20 (48.8%) of the 41 cases, heterogeneous intratumoral staining was observed for VEGF-C and VEGF-D, respectively, with the highest levels of expression at the invasive edges. VEGF-C expression correlated with the depth of tumor invasion, lymphatic involvement, venous involvement, lymph node metastasis, and liver metastasis, and VEGF-D expression correlated with the depth of tumor invasion, lymph node metastasis, and liver metastasis. No correlation was observed between VEGF-C and VEGF-D expression in tumors. The survival time of patients with VEGF-C-positive tumors was significantly shorter than that of patients with VEGF-C-negative tumors, and the survival time of patients with VEGF-D-positive tumors was significantly shorter than that of patients with VEGF-D-negative tumors. The survival time of patients with both VEGF-C- and VEGF-D-positive tumors was significantly shorter than that of patients with both VEGF-C- and VEGF-D-negative tumors. These results suggest that VEGF-C and VEGF-D may be independent and important prognostic factors in patients with human colorectal carcinoma.

Expression of hypoxia-inducible factor-1alpha is associated with tumor vascularization in human colorectal carcinoma.

HIF-1 is reported to transactivate expression of VEGF, which is an important angiogenic factor. To determine whether HIF-1alpha plays a role in angiogenesis through its regulation of VEGF, we examined expression of HIF-1alpha and its relation to clinicopathologic features, VEGF expression and prognosis of patients with colorectal carcinoma. Expression of HIF-1alpha and VEGF was examined in 4 colorectal carcinoma cell lines (COLO320DM, COLO201, DLD-1, WiDr) and 149 colorectal carcinoma tissues (10 fresh specimens, 139 archival, paraffin-embedded specimens). HIF-1alpha protein levels were increased by hypoxia in 3 of 4 colorectal carcinoma cell lines (COLO201, DLD-1, WiDr), and VEGF mRNA levels were also increased by hypoxia in the same cell lines. In 8 of 10 patients with colorectal cancer, expression of HIF-1alpha and VEGF was increased in tumor tissues compared to corresponding normal mucosa. Of 139 archival specimens of colorectal carcinoma, 81 (58.3%) expressed HIF-1alpha protein at a high level. HIF-1alpha expression was correlated with tumor invasion, tumor stage, lymphatic invasion, venous invasion and liver metastasis. Moreover, HIF-1alpha expression was correlated significantly with VEGF expression and microvessel density. Although there was a tendency for poorer prognosis in patients with high HIF-1alpha-expressing tumors, this correlation was not statistically significant. These findings suggest that HIF-1alpha may play a role in angiogenesis and tumor progression via regulation of VEGF in human colorectal carcinoma.