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Biomedical subjects

O Kronborg

Publications and source records attributed to O Kronborg.

At least 91 records · Page 5Linked to original sources
PubMed1995

A randomized surveillance study of patients with pedunculated and small sessile tubular and tubulovillous adenomas. The Funen Adenoma Follow-up Study.

BACKGROUND: We wanted to assess the influence of various surveillance intervals on the risk of new neoplasia after removal of pedunculated and small sessile tubular and tubulovillous adenomas. METHODS: After initial colonoscopic polypectomy patients were randomized to surveillance with either 2 years (group A) or 4 years (group B) between colorectal examinations. RESULTS: The cumulated risk of a patient having new adenomas was 35.0% (28.7-41.4%) in group A and 35.5% (28.4-42.7%) in group B after 48 months. The risk increased to 44.9% (36.0-53.9%) and 60.1% (48.5-71.7%), respectively, after 96 months. The risk of significant neoplasia (carcinoma or adenoma with villous structure, severe dysplasia, or diameter > 10 mm) was 5.2% (2.3-8.1%) and 8.6% (3.8-13.3%) after 48 months and 8.6% (4.2-13.0%) and 17.4% (7.6-27.2%) after 96 months. More than one adenoma at first examination was associated with higher risk of new adenomas. Furthermore, we found a tendency for age above 60 years and male gender to be associated with higher risk of new adenomas. More than two adenomas at first examination was the only factor found to be associated with a higher risk of new significant neoplasia. One patient in group A and two patients in group B developed cancer, which is not significantly different from the number expected (3.43) in the average Danish population (RR = 0.9, 0.2-2.6). CONCLUSION: After colonoscopy with removal of all polyps, colorectal examination at 4 years resulted in a similar risk of new adenomas compared with examinations at 2 and 4 years. However, new significant neoplasia tended to be more frequent when first surveillance was at 4 years. Extending the surveillance to 8 years also tended to increase the risk more in the group being examined every 4 years, but reduction of the number of surveillance examinations by more than 50% and a probable reduction of complications from surveillance examinations themselves may justify a recommendation for the longest interval.

Adenoma↗
PubMed1995

Prevention of colorectal cancer: guidelines based on new data. WHO Collaborating Center for the Prevention of Colorectal Cancer.

Recently published good quality data are the basis for this update. The newly reported studies include randomized trials, non-randomized cohort studies, and case-control studies; some of the data had mortality reduction as the endpoint. These guidelines, which were developed by the WHO Collaborating Center for the Prevention of Colorectal Cancer at Memorial Sloan-Kettering Cancer Center in conjunction with an International Advisory Committee, include primary prevention, screening of average-risk individuals, screening of individuals with heritable factors for colorectal cancer, surveillance of patients with colorectal polyps, and surveillance of patients with chronic ulcerative colitis. A list of papers reviewed for this update are cited, including recently published trials evaluating faecal occult-blood testing, case-control studies of sigmoidoscopy, the National Polyp study, and familial colon cancer studies. These guidelines will help inform patients and guide physicians in their approach to the prevention of colorectal cancer.

Colorectal Neoplasms↗
PubMed1994

[Rectoscopy and Hemoccult-II as initial diagnosis. A procedure in patients with symptoms of irritable colon].

The diagnostic accuracy for colorectal cancer (CRC) of rigid sigmoidoscopy and faecal occult blood test (Hemoccult-II) (H-II) was investigated in patients with irritable bowel syndrome in general practice in a three year period and the results were compared with those of the previous three years, where rigid sigmoidoscopy and double contrast barium enema (DCBE) were the initial preferred examinations. Colonoscopy was recommended in patients with positive H-II, but also in patients with repeated negative H-II within three months, provided that the symptoms persisted. CRC was detected in 141 of 630 patients with positive H-II and in 52 of 8697 with negative H-II. The number of CRC's in the two study periods was similar, in spite of a pronounced reduction in DCBE's from 12,196 to 5656 and a small increase in colonoscopies from 3053 to 4127. It was concluded that the new strategy was no worse than the previous one and the major savings in DCBE's could be used to exchange the rigid sigmoidoscopy with a 60 cm flexible sigmoidoscopy, increasing diagnostic accuracy, shortening delay of diagnosis and removing more adenomas, which eventually may reduce the future incidence of CRC and thereby the mortality from CRC.

Adenoma↗
PubMed1994

[99mTc anti-carcinoembryonic antigen in colorectal cancer].

This investigation is a part of a phase three multicentre immunoscintigraphy study of a technetium-99m labelled monoclonal antibody (Mab), BW 431/26, directed against carcino-embryonic antigen (CEA). Ten patients with recently colonoscopically verified primary colorectal cancer were evaluated. In nine of ten patients colorectal cancers were detected by wholebody immunoscintigraphy and by single photon emission computerized tomography (SPECT). The ten patients were operated upon, and in nine cases immunohistochemical investigations were performed. Immunohistochemical investigation of nine tumour specimens show that CEA was present in much higher concentrations in the tumour than in normal intestinal epithelium. Active accumulation of the labelled Mab in tumours was demonstrated by scintimetry. There is a demand for new diagnostic techniques for early diagnosis of colo-rectal cancer. Immunoscintigraphy must however compete with other diagnostic possibilities. The development of immunoscintigraphic technique is proceeding very rapidly, and there is probably a future for the use of immunological methods in diagnosis and therapy of cancer.

Antibodies, Monoclonal↗
PubMed1994

[Surgical treatment of diffuse peritonitis caused by perforated perisigmoiditis. A prospective, randomized study].

A prospective randomized trial was carried out on 62 patients with diffuse peritonitis from perforated diverticulitis of the left colon, which compared acute transverse colostomy, suture and omental covering of a visible perforation to acute resection without primary anastomosis. For purulent peritonitis the postoperative mortality rate was significantly higher after acute resection (six of 25) than after colostomy (none of 21). In those treated by acute resection, the mortality rate was not significantly higher after Hartmann's procedure (five of 15) than after exteriorization of both lumens (one of ten). The postoperative mortality rate in patients with faecal peritonitis did not differ significantly between colostomy (six of ten) and acute resection (two of six). Stomas became permanent in four of 25 patients with diverticulitis surviving acute colostomy and in seven of 22 surviving acute resection. Suture and transverse colostomy is superior to resection for purulent peritonitis because of the lower postoperative mortality rate.

Adult↗
PubMed1994

Clonal karyotypic abnormalities in colorectal adenomas: clues to the early genetic events in the adenoma-carcinoma sequence.

Cytogenetic analysis of short-term cultures from colorectal adenomas revealed acquired clonal chromosome aberrations in 14 of 17 tumors. In 4 adenomas, only numerical changes were found, whereas 10 had structural rearrangements. Trisomy 7 was found as the sole change in one of the tumors and together with other numerical changes in another. A +7 was also present in one case with structural aberrations. Other recurrent numerical aberrations were -14 and -18, both found in 2 adenomas with structural karyotypic changes; in addition, one chromosome 14 was lost in one of the tumors with only numerical changes. The chromosome most often involved in structural aberrations was chromosome 1. In 6 cases, the rearrangements led to changes in 1p, always with loss of material. The breakpoints were at 1p32-36. One adenoma had deletion of 1p as the only change. Other chromosomes that were involved in changes in more than 2 cases were chromosomes 8, 13, and 17. These rearrangements typically led to gain of 8q and 13q and loss of 17p. The adenomas with structural abnormalities were generally larger and had a higher degree of dysplasia than did the adenomas with numerical changes only or those with a normal karyotype. All adenomas with a tubulovillous or villous architecture had structural rearrangements. Our findings confirm that a subset of colorectal adenomas exists that have only numerical chromosome aberrations. They also support our previous conclusion that loss of material from distal 1p is an early event in colorectal tumorigenesis, but that other cytogenetic aberrations follow and typically are present already at the adenomatous stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1994

Dietary risk factors for cancer and adenomas of the large intestine. A case-control study within a screening trial in Denmark.

The aims of the study were to estimate the importance of dietary habits for colorectal cancers and adenomas. By comparing risk factors among cancer and adenoma patients the adenoma cancer theory was indirectly evaluated. The study was performed as a case-control study within a large screening trial in Denmark. All cancer and adenoma patients diagnosed at the screening were recruited as cases; controls were selected among test negatives after matching for age, sex and time of screening. All those selected except 85, participated in a 7-day dietary recall. Altogether 49 colorectal cancer patients and 172 with adenomas were examined; 362 individuals who were test negatives in the Hemoccult-II screen served as controls. The intake of crude dietary fibres was shown to be associated with reduced risk of cancer as well as adenomas. Neither cancer nor adenoma occurrences were related to total energy intake or body mass. Vitamins E and A were negatively associated with adenoma occurrence.

Adenoma↗
PubMed1994

Nitrous oxide does not influence operating conditions or postoperative course in colonic surgery.

We studied 150 patients undergoing elective colonic surgery; they were allocated randomly to undergo artificial ventilation with either air-oxygen or nitrous oxide-oxygen during surgery. Eleven patients were excluded. Preoperative management, surgery and postoperative analgesia were similar in both groups. Anaesthesia included propofol by infusion, pancuronium and fentanyl 3 micrograms kg-1 h-1. The air-oxygen group required a continuous infusion of propofol of 4-6 mg kg-1 h-1 whereas the nitrous oxide-oxygen group required only 1-2 mg kg-1 h-1. There were no differences between the groups in duration of anaesthesia, distension of the bowel and postoperative bowel function. The postoperative hospital stay was similar for both groups.

Adult↗
PubMed1994

Digital rectal examination and transrectal ultrasonography in staging of rectal cancer. A prospective, blind study.

Staging of rectal carcinoma before surgical treatment was performed in a prospective blind study, comparing digital rectal exploration and transrectal linear ultrasonography (TRUS) with the resulting pathological examination. TRUS underestimated depth of penetration in 3 of 33 patients and overestimation resulted in 9 of 74. The figures for digital examination were 5 of 18 and 20 of 76, respectively. Penetration of the rectal wall was correctly identified in 56 of 61 patients by digital examination and in 59 of 61 by TRUS. Specimens without penetration of the rectal wall were identified in 26 of 33 patients by TRUS, but in not more than 13 of 33 by digital examination. Regional lymph node metastases were present in 19 patients; none were diagnosed by digital examination, but TRUS identified 11 of the 19. It is concluded that TRUS will result in more patients having the possibility of local surgery for cure.

Female↗
PubMed1993

Tumor detection with 131I-labeled human monoclonal antibody COU-1 in patients with suspected colorectal carcinoma.

A major factor limiting the use of rodent monoclonal antibodies for diagnosis and therapy of cancer is the development of human anti-mouse immunoglobulin antibodies. Here we report a phase I/II immunodetection study of a human monoclonal antibody, COU-1, labeled with 131I. COU-1 is produced by a human-human hybridoma and recognizes a M(r) 43,000 cytokeratin-like protein strongly expressed by adenocarcinomas of the colon, breast, and ovary. Ten patients were given an i.v. infusion of 2 mg of antibody COU-1 labeled with 185 MBq of 131I. No adverse effects or toxicity were detected by conventional clinical tests nor by a complement activation assay for C3d. None of the patients developed antibodies against antibody COU-1 as determined by enzyme-linked immunosorbent assay and agglutination analysis. Tumor detection was successful in 7 of 9 cancer patients. The tenth patient proved to be a true negative. In several instances immunoscintigraphy gave additional or more correct information than conventional detection techniques. Tumors were most clearly outlined at days 5 and 7 after infusion. Primary colorectal carcinomas were detected by planar imaging in the cecum, ascending colon, and rectum with the smallest lesion measuring 3.0 cm in diameter. Immunoscintigraphy revealed multiple liver metastases in 1 of 3 patients. However, the livers of all 3 patients contained significantly more radioactivity (P < 0.005) than tumor-free livers of the other patients. Pharmacokinetics was evaluated in all patients. The clearance of 131I-labeled COU-1 from the circulation followed a triphasic pattern; an initial phase [t1/2 = 0.4 +/- 0.4 (SD) h] cleared 23% of the radioactivity followed by a rapid phase with a half-life of 13 +/- 3.8 h. The third phase (beta-phase) exhibited a half-life of 119 +/- 36 h, which is similar to the half-life reported for normal IgM. The human monoclonal antibody COU-1 directed against a predominantly intracellular cancer-associated antigen does not produce toxicity or induce antibody formation and seems to be a promising agent for detecting tumors with immunoscintigraphy.

Animals↗
PubMed1993

[Screening for colorectal neoplasms. A review and recommendations].

A review is given of methods and results of screening for colorectal cancer in average-risk and high-risk groups. Possible methods are digital rectal exploration, endoscopic examination, barium enemas, faecal occult blood tests, tumour markers like carcinoembryonic antigen, Ca-19-9, and others, and gene markers. Final results of large randomized population studies with faecal occult blood tests are expected within the next few years, but it will probably be necessary to add flexible sigmoidoscopy to achieve a major reduction in mortality from colorectal cancer in average-risk persons. Recommendations for screening in high-risk groups are proposed, but strong support for these guidelines are still missing, an exception being first-degree relatives of individuals with familial adenomatous polyposis; the other high-risk groups include members of hereditary non-polyposis colorectal cancer families, relatives of patients with sporadic colorectal cancer, patients with colorectal adenomas, patients with previous colorectal cancer, and patients with inflammatory bowel disease.

Colonic Neoplasms↗
PubMed1993

[Staging of colorectal cancer with the aim of optimal treatment].

Staging of colorectal cancer has become important with respect to selection of patients for minor surgery, major surgery and adjuvant radio- and chemotherapy. The most important treatment is still surgical, but the prognosis can be improved in some patients with adjuvant treatment, even though it involves more side-effects. Exact staging is necessary in order to avoid overtreatment of some and undertreatment of others. This article critically reviews the staging systems used at present.

Colonic Neoplasms↗
PubMed1993

Deletion of 1p36 as a primary chromosomal aberration in intestinal tumorigenesis.

Cytogenetic analysis of short-term cultures from benign intestinal tumors revealed clonal chromosome aberrations in five colorectal adenomas, one adenoma of the papilla Vateri, and one hyperplastic polyp of the rectum. One adenoma had numerical aberrations only, but in all other tumors structural rearrangements were found that led to loss of genetic material from 1p. In three of the cases, the deletion was restricted to the 1p36 band; the rest had lost larger 1p segments. The rearrangement of chromosome 1 was the sole karyotypic anomaly in three adenomas, all with mild or moderate dysplasia, and in the hyperplastic polyp. Both adenomas that had additional aberrations beyond the 1p loss showed severe dysplasia. We conclude that cytogenetically detectable loss of genetic information from 1p36 is an early, seemingly primary, premalignant event in intestinal tumorigenesis. The fact that the adenomas with 1p- as the sole change showed only mild or moderate dysplasia and that the del(1p) was found also in the hyperplastic polyp suggests that this aberration is more related to the induction of hyperproliferation than to differentiation disturbances in the intestinal mucosa.

Adenoma↗
PubMed1993

Treatment of perforated sigmoid diverticulitis: a prospective randomized trial.

A prospective randomized trial was carried out on 62 patients with diffuse peritonitis from perforated diverticulitis of the left colon, comparing acute transverse colostomy, suture and omental covering of a visible perforation with acute resection without primary anastomosis. For purulent peritonitis the postoperative mortality rate was significantly higher after acute resection (six of 25) than after colostomy (none of 21). In those treated by acute resection, the mortality rate was not significantly higher after Hartmann's procedure (five of 15) than after exteriorization of both lumens (one of ten). The postoperative mortality rate in patients with faecal peritonitis did not differ significantly between colostomy (six of ten) and acute resection (two of six). Stomas became permanent in four of 25 patients with diverticulitis surviving acute colostomy and in seven of 22 surviving acute resection. Suture and transverse colostomy is superior to resection for purulent peritonitis because of the lower postoperative mortality rate and in spite of the shorter hospital stay in those surviving acute resection.

Adult↗