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O Kronborg

Publications and source records attributed to O Kronborg.

At least 127 records · Page 7Linked to original sources

Population screening for colorectal cancer, the goals and means.

The causes of colorectal cancer are complex and in most cases obscure, making primary prevention impossible at present. Secondary prevention by finding and treating early asymptomatic cancers may possibly reduce mortality from this very common cancer. Results from conventional treatment have changed little during recent decades and are unsatisfactory, with more than half of the patients dying from the disease. The incidence has increased during recent years in many countries, making it vital to evaluate possible benefits from screening. This review considers different methods of screening for colorectal cancer and includes an overview of continuing European controlled randomised trials with the faecal occult blood test, Haemoccult-II. No final evaluation is possible, but advantages and drawbacks of different strategies are discussed. Assuming that the goal of reducing mortality is achieved, several other problems remain unsolved: the organisation of screening, the training of doctors in endoscopy, cost benefit and cost effectiveness all of which will have to be solved before a population screening can be recommended. Present screening tools are not ideal and we have to continue the search for better markers of early colorectal cancers and even possible precursors like adenomas.

Barium Sulfate↗

[Rectoscopy and Hemoccult II in irritable colon. A prospective study].

It was investigated whether Hemoccult-II test (H-II) could reduce the number of colonic examinations in patients with the irritable bowel syndrome, with normal rigid proctoscopic findings. A negative H-II was obtained in 299 patients from general practice and a positive test in nine. Colonoscopy was done in 157 and double contrast barium enema in 142 after random allocation. The nine patients with positive H-II all had colonoscopy. Among the 299 with negative H-II, colonic adenomas were detected in ten and an early cancer in an adenoma in the sigmoid colon; overlooked rectal adenomas were found in three, rectal cancer in one, rectal carcinoid in another and a coecal cancer, which could be palpated, in a third patient. Two patients with colonic cancer and one with adenoma were detected among those with positive H-II. All patients were followed by clinical examination after one year. In conclusion, colonic examination should carry a low priority in patients with symptoms of irritable bowel, negative Hemoccult-II and normal rigid proctoscopic findings performed by an experienced examiner. The investigation confirmed the recommendation of total colonoscopy in patients with a positive H-II and added support for increasing number of endoscopy services in contrast to those of diagnostic radiology, which should be reduced.

Adenoma↗

[The pH and acidity of feces in colorectal neoplasms].

The pH and faecal titratable acidity in fresh faeces were measured in patients with colo-rectal carcinoma or adenoma and in normal individuals. Significantly higher pH values and lower acidity were found in patients with cancer than in normal individuals. Patients with cancer had pH greater than 6.90 more frequently than normal. Patients with adenomata did not differ significantly from normal individuals. These results support performance of intervention trials with lowering of the pH in the colon with the object of cancer prophylaxis even although the causal connection is obscure.

Adenoma↗

Observer reproducibility in grading dysplasia in colorectal adenomas: comparison between two different grading systems.

The two most well known and well defined grading systems for dysplasia in colorectal adenomas were compared with regard to reproducibility. The Konishi-Morson system (KMS) operates with several histological and cytological variables and grades of mild, moderate, and severe dysplasia. The Kozuka system is based on the extent of nuclear pseudostratification and also has three grades of dysplasia (III-V). As the group of severe dysplasia is very large in this system, it was extended with two higher grades, similarly based on individual histological criteria, known hereafter as the extended Kozuka system (EKS). Fifty six adenomas were graded by two observers, each observer grading twice according to the KMS criteria and twice according to EKS criteria. Intraobserver reproducibility was excellent for the KMS and moderate for the EKS, but this was not significant. The overall interobserver reproducibility was similar (moderate) for the KMS and for the EKS. Kappa values for interobserver reproducibility on individual categories were excellent for severe dysplasia according to the KMS, but low for all other categories in both systems. By simplifying both systems into two groups a high reproducibility can be obtained, but this implies that all the original grades (III-V) for the EKS must be grouped together. It is therefore recommended that a simplified KMS is used for further studies on the biological importance of dysplasia and for comparison between histological changes and other markers for colorectal neoplasia.

Adenoma↗

Risk and surveillance of individuals with colorectal polyps. Who Collaborating Centre for the Prevention of Colorectal Cancer.

Since colorectal adenomas are very probably the precursors of colorectal cancer, their detection and removal should result in a decrease in the incidence and mortality from colorectal cancer. Individuals who harbour an adenoma have a 30-50% probability of having additional adenomas at that time, and a 30% probability of having additional adenomas later. Adenomas are prevalent in countries where colorectal cancer is prevalent, about two-thirds of them being tubular and the rest tubulovillous or villous. The initial management of patients with an adenoma consists in searching by colonoscopy the entire colon and removing all additional polyps. Surgical resection is required wherever there is invasive cancer with adverse histological factors. Follow-up in most patients can be after 2-4 years, earlier follow-up being reserved for patients with numerous polyps or with a polyp that had been removed piecemeal. The results of ongoing trials should provide firm guidelines for follow-up and could also be used in mathematical modelling to examine alternative strategies and to help understand the evolving patterns of appearance of new polyps. Finally, a deeper understanding of the biology and inherited and acquired genetics will help identify individuals at risk for adenomas initially and at follow-up. Nutritional factors may also provide a basis for prevention of adenomas in high-risk countries. Many of these issues are being addressed in current research.

Adenoma↗

Screening of average-risk individuals for colorectal cancer. WHO Collaborating Centre for the Prevention of Colorectal Cancer.

Recent developments in screening, diagnosis and treatment of colon cancer could lead to a reduction in mortality from this disease. Removal of adenomas, identification of risk factors, appropriate application of accurate diagnostic tests, and aggressive anatomic-surgical resection of colon cancers may already be having a favourable impact. Screening of average-risk populations over the age of 50 also offers promise in the control of this important cancer. The disease is of sufficient magnitude to deserve detection at an early stage with better prospects of patient survival, since screening tests with moderate sensitivity and high specificity are available. Flexible sigmoidoscopy and faecal occult blood tests are sufficiently acceptable to be included in case-finding among patients who are in the health care system. The results of current controlled trials involving more than 300,000 individuals for evaluating the impact of screening on mortality from colon cancer are needed before this approach can be recommended for general public health screening of the population. Further research is required to develop better screening tests, improve patient and physician compliance, and answer more definitively critical questions on cost-effectiveness. Mathematical modelling using current and new data can be used to determine the effectiveness of screening in conjunction with recommendations for primary prevention.

Colorectal Neoplasms↗

Pancreaticogastrostomy for chronic pancreatitis.

Forty-five patients with painful chronic pancreatitis underwent side-to-side pancreaticogastrostomy. Correct diagnosis was ensured by endoscopic retrograde cholangiopancreatography, decreased exocrine pancreatic secretion, abdominal calcifications, and histologic verification. A main etiologic factor was alcohol abuse (84 percent of patients). At a median follow-up period of 3.8 years, good, fair, and poor results were achieved in 56, 23, and 21 percent of patients, respectively. The operative mortality rate was 4.4 percent. At follow-up, 16 of the patients were employed, weight was increased by a mean of 2.5 kg, and the use of opiates was significantly reduced. Poor results were significantly related to preoperative use of tranquilizers and postoperative alcohol consumption. Neither patency of the anastomosis nor the time of observation were related to the operative result. The 8-year cumulative survival rate was 83 percent.

Adolescent↗

Repeated screening for colorectal cancer with fecal occult blood test. A prospective randomized study at Funen, Denmark.

Two screenings with Hemoccult-II were performed in a randomized study, allocating 30,970 persons to screening and 30,968 as controls in a population of 140,000 between 45 and 74 years old on the island of Funen, Denmark. The test was completed in 20,672 initially and in 18,779 of these during rescreening 2 years later. Positive H-II tests were found in 215 and 159 persons during the two screenings, respectively. A total colonoscopy was performed in 187 and 144, and cancer was detected in 37 and 13 and adenomata in 86 and 76, respectively. Interval cancers had developed in 40 persons at the end of the second screening, and 39 non-responders had developed cancer. Cancer was diagnosed in 115 controls and an adenoma in 100 during the same period. Interval cancers presented as rectal cancers more frequently than those detected by screening. Early cancers were more frequent in the screening group, and, accordingly, more patients had curative and also less extensive surgery, with a low postoperative mortality. The total number of deaths from colorectal cancer was 37 in the screening group, including interval cancers and cancers in non-responders and persons who developed cancer before they could be invited, which suggests a reduction in mortality of 27% (51 deaths among controls, compared with 37). The reduction is as yet not statistically significant, and final evaluation must await at least one more screening, ending in 1990, and a follow-up of some years. Removal of more large adenomas during screening makes it possible that the incidence of cancer will decrease.

Adenoma↗

Follow-up after radical surgery for colorectal cancer. Design of a randomized study.

The value of different follow-up examinations after radical surgery for colorectal cancer has not been proven. The risk of such programmes, including invasive examinations, may invalidate the possible benefit from early diagnosis of recurrent and metachronous cancer. The present trial is a randomized study, evaluating possible benefit from a very detailed programme compared to that of virtually no follow-up. The design is presented, but so far no more than 207 of the 600 patients wanted for trial, have been included. Differences in mortality rates, survival and morbidity will be evaluated and the influence of repeated polypectomy upon risk of metachronous colorectal cancer will also be estimated.

Clinical Trials as Topic↗

Fistula-in-ano.

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Colorectal Surgery↗

Prognostic evaluation of planned follow-up in patients with colorectal adenomas. An interim report.

Between 1978 and 1986 colorectal adenomas without invasion were removed in 552 patients under 76 years of age. Patients were randomly allocated to different follow-up groups with intervals of colorectal examination varying from 6 to 48 months after the initial polypectomy. A large bowel carcinoma developed in three patients and new adenomas in 87 patients. Based on the morphology of the initial adenomas possible relationships between prognostic factors and the risk of new adenoma formation were assessed using life-table analysis. The advantage of a possible decrease in the risk of developing carcinoma was offset by the disadvantage of eight severe complications occurring in 1818 colonoscopies, one of which proved fatal. The occurrence of one of the three carcinomas was considered a failure of the follow-up programme.

Actuarial Analysis↗

Posterior transsphincteric rectotomy. Indications and safety.

This study intends to make the transsphincteric approach to the rectum more well known, mainly because of the increasing number of small carcinomas and adenomas being detected by endoscopy following screening for occult blood. Thirty patients had rectotomy from 1983 to 1987. Curative surgery was performed on 15, whereas adenomas were excised in 11. Other indications were palliative excision, rectovaginal fistula, and postsurgical bleeding. Two patients had had previous transversostomies and a covering colostomy was done in one. Complications included wound infection in four and rectal fistula in four. Transversostomy became necessary in three. All colostomies were closed later and the mortality was zero. All preserved anal continence for solid and fluid feces, whereas three suffered from flatulence during a follow-up period from one to 46 months. The approach allows surgery in the upper part of the lower third of the rectum and the midrectum with a low mortality and complication rate, and should be preferred over major surgery in selected patients.

Adenoma↗

Single or multiple doses of metronidazole and ampicillin in elective colorectal surgery. A randomized trial.

A randomized trial including 294 patients was performed to evaluate the prophylactic effect of single vs. multiple doses of antibiotics in elective colorectal surgery. All patients received 1.5 g metronidazole and 3.0 g ampicillin peroperatively and were randomized to: no further prophylactic antibiotic treatment, or ampicillin 1 g X 3 and metronidazole 0.5 g X 3 given intravenously during the second and third postoperative days. Deep wound infection was seen in 9/149 (6 percent) receiving a single dose and in 8/145 (6 percent) receiving multiple doses. No differences were found in the two groups between frequencies of anastomotic dehiscences, intra-abdominal abscesses, sepsis, and pulmonary infections. The two groups were similar according to distribution of sex, age, diagnosis, and type of surgery. A single peroperative dose of metronidazole and ampicillin is a simple and satisfactory antibiotic prophylaxis in elective colorectal surgery.

Adolescent↗

Early complications after low anterior resection for rectal cancer using the EEA stapling device. A prospective trial.

Complications following 178 low anterior resections for rectal carcinoma with the EEA autosuture device are reported prospectively. The operative mortality was 2.8 percent. Clinical anastomotic leakage developed in 27 patients, but in none of the 30 patients over 76 years of age. Two of the five hospital deaths were related to leakage. Long-term steroid treatment and previous pelvic radiotherapy were associated with increased risk of leakage. Severe stenosis following anastomotic leakage was seen in one patient. Intraoperative diverting colostomy was done in 16 patients, but no benefit could be demonstrated. It was concluded that use of the upper sigmoid colon for anastomosis probably is not associated with a higher mortality and morbidity than that after more extensive resections reported in the literature. Future randomized trials should exclude very old patients, in whom no leak was seen, when the upper sigmoid colon was used for stapling after low anterior resection.

Adult↗