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Biomedical subjects

O Kronborg

Publications and source records attributed to O Kronborg.

At least 109 records · Page 6Linked to original sources
PubMed1993

Staging and surgery for colorectal cancer.

Staging of colorectal cancer has become increasingly important to select groups of patients for limited or more extensive surgery, and for adjuvant radiotherapy and chemotherapy. The main treatment is still surgery, but subgroups may benefit from adjuvant therapy, even accepting additional side effects. Accurate staging is necessary to define different treatment groups. A critical review is given of the present methods of clinicopathological staging.

Colorectal Neoplasms↗
PubMed1993

Coffee, tobacco and alcohol as risk factors for cancer and adenoma of the large intestine.

Our aim was to estimate the association between smoking history, alcohol and tobacco smoking and tumours of the large intestine. Associations were studied at an early stage of colorectal cancer in order to avoid bias in the information. In order to estimate the link between adenoma and cancer the exposures were analysed separately for cancer and adenoma patients. The study was conducted as a case-control study within a randomized trial for colorectal cancer among males and females aged 45-74 years. Cases initially included all individuals with a positive Haemoccult-II test in three screens and an age- and sex-matched reference group was selected from the test negatives. Subsequent colonoscopy defined the final case group, which consisted of 49 colorectal cancer patients, 171 with adenoma and 177 test positives with no diagnosis or with non-adenomatous polyps or haemorrhoids. Controls were 362 age- and sex-matched test negatives. Data were collected by blind telephone interviewing before the first clinical examinations of test positives. Smoking history, coffee or alcohol intake were not statistically significantly associated with colorectal cancer. For adenomas, the odds ratios (OR) were between 2.0 and 2.7 in all smoking categories. For smokers with > 40 years duration OR = 2.7 (95% confidence interval (Cl): 1.6-4.7). Coffee consumption showed a clear protective effect. Consumers of 4-7 cups per day had an OR of 0.5 (95% Cl: 0.3-0.8) and heavy consumers of > or = 8 cups had an OR of 0.3 (95% Cl: 0.1-0.6). Neither tea nor alcohol consumption was related to adenoma risks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1993

Modelling of serial carcinoembryonic antigen changes in colorectal cancer.

Carcinoembryonic antigen (CEA) is a tumour marker mainly used for detection of recurrent colorectal cancer. CEA series in 295 patients, who had a macroscopic radical resection of a primary colorectal cancer were studied. A kinetic model was fitted to CEA series of individual patients. Applying the kinetic model recurrences were identified with a sensitivity of 70-80% and specificity of 80-90%. Simulations were performed in order to find the optimal sampling strategy for CEA during follow-up. Simulations showed that CEA determinations at a few weeks interval between would be optimal for early detection of recurrences.

Carcinoembryonic Antigen↗
PubMed1993

The Funen Adenoma Follow-Up Study. Characteristics of patients and initial adenomas in relation to severe dysplasia.

Between 1978 and 1992 a total of 1689 colorectal adenomas were removed in 1042 patients with no history of previous colorectal neoplasms. One hundred and eighteen patients had at least one adenoma with severe dysplasia. A 'clean colon' was ensured by total colonoscopy in 97% of the patients. A multiple logistic model was used to assess the independent risk factors associated with severe dysplasia. The size of largest adenoma and the extent of villous component were identified as independent patient risk factors associated with high risk of severe dysplasia. The results indicated that the risk of severe dysplasia is high in patients with large and/or villous adenomas and the risk is even higher when the adenomas are found in the sigmoid colon or rectum.

Adenoma↗
PubMed1993

The Funen Adenoma Follow-up Study. Incidence and death from colorectal carcinoma in an adenoma surveillance program.

The results of a prospective randomized study of 1056 patients with colorectal adenomas are presented. After initial polypectomy from 1978 to 1992, patients were allocated at random to different follow-up intervals varying from 6 to 48 months, except 53 patients who were allocated to intervals of 6 months. The examinations were mainly done by colonoscopy. Ten patients developed colorectal carcinoma, a number similar to that expected (7.96), when compared with a sex- and age-matched normal Danish population. The expected number of carcinomas was also calculated from adenoma to carcinoma conversion rates estimated in other studies and compared with that observed. If all carcinomas develop in large (> or = 10 mm) adenomas or adenomas with severe dysplasia, the expected number of carcinomas would have been 62 and 110, respectively, indicating a significant reduction of carcinomas in the present study. One patient died of colorectal carcinoma, which is significantly lower than the number expected (7.58). Two patients died of complications from therapeutic and diagnostic colonoscopy--that is, 2 deaths in 3959 colonoscopies. In conclusion, the follow-up strategy has resulted in a mortality from colorectal carcinoma which is reduced when compared with the normal population, in spite of an apparently similar incidence of carcinoma. However, previous suggested adenoma-carcinoma conversion rates indicate that a major reduction of incidence actually has taken place.

Adenoma↗
PubMed1993

[Screening for colorectal cancer--does it help?].

During the last decade, evidence from retrospective as well as prospective case-control studies suggest that screening for colorectal cancer in average-risk persons above 50 years of age may be worthwhile. Screening with proctoscopy may reduce the mortality from rectal cancer and screening with fecal occult blood tests (Hemoccult-II) may reduce the mortality from colorectal cancer. Final results from ongoing population studies will appear within a few years and there are reasons to believe that mortality for colorectal cancer may be reduced with at least 30 per cent by a combination of Hemoccult-II and flexible 60 cm sigmoidoscopy.

Aged↗
PubMed1992

[Requirement of hospital beds in connection with screening for colorectal cancer. The first 5-years of a randomized population survey].

Colorectal cancer puts a major burden on the hospital resources because of its frequency and demands for extensive surgery. Screening with Hemoccult-II detects the disease at an earlier stage in a number of persons. The possible influence upon length of hospital stay is investigated in a randomised trial of 61,938 persons between 45 and 74 years, 30,970 being invited to screening with Hemoccult-II bianually. The first screening was accomplished in 20,672 persons and 17,284 have completed three screenings from 1985 to 1990. The test was positive in 1%, and further examination (colonoscopy) among these revealed cancer in 74 and adenomas in 248 persons. The whole screening group contained 239 persons with cancer and 380 with adenomas, the figures among controls being 216 and 181, respectively. The excess hospital stay in the screening group was 487 days (7%), the major part being one-day admissions for colonoscopy. The average stay was shorter in the screening group and shortest among those with colorectal neoplasia being detected because of positive Hemoccult-II. Measurements of hospital stay included admissions for diagnosis, treatment and complications as well as recurrence within the first year of diagnosis. In conclusion, the excess use of hospital days introduced by screening was limited in the first five years. This will probably later disappear and become negative because of decreasing numbers of cancers in the screening group. Advanced cancers and admissions for possible colorectal cancer will also be less frequent in the screening group.

Adenoma↗
PubMed1992

Can Hemoccult-II replace colonoscopy in surveillance after radical surgery for colorectal cancer and after polypectomy?

Surveillance after colorectal carcinoma and adenoma includes colonoscopy, which is a demanding procedure for the patient, doctor, and society. Therefore, it was investigated whether a simple fecal occult blood test could replace colonoscopy. Hemoccult-II (H-II) was performed before 1,244 colonoscopies in patients with previous cancer and before 328 colonoscopies in an adenoma surveillance program. The H-II test was positive in 3 of 9 patients with local recurrence, in 2 of 13 with metachronous cancer, and in 31 of 186 with adenomas. The test was positive more often in patients with large and multiple adenomas, sigmoid adenomas, and adenomas with villous elements and moderate-to-severe dysplasia, but the sensitivity did not reach more than 25 to 40 percent. It was concluded that markers more sensitive than H-II are needed to detect metachronous cancers and new adenomas. In the meantime, colonoscopy has to be used with intervals of several years, but not for detection of local recurrent cancer, which in most cases may be found by simpler means.

Chi-Square Distribution↗
PubMed1992

Echo pattern of lymph nodes in colorectal cancer: an in vitro study.

Surgical specimens from 75 patients with colorectal cancer were examined within 15 min of removal with a 7.5 MHz linear-array transducer. The echo pattern of 139 lymph nodes was analysed to evaluate previous criteria of malignancy and to establish other possible criteria, which could be tested in vivo. The pathologist examined each node without knowledge of the sonographic finding. Malignant nodes were larger than benign nodes. Of 21 nodes less than 5 mm in diameter, 20 were benign. Round nodes were malignant more often (45/78) than ovoid nodes (6/61). A homogeneous echo pattern was associated with malignancy in 39 of 82 nodes in contrast to 12 of 57 with a heterogeneous pattern. Thirty-one nodes were ovoid as well as heterogeneous and all of these were benign. A hyperechoic centre was found in 14 nodes of which two were malignant. The highest predictive value for malignancy (59%) was obtained by combining the discriminative properties of shape, homogeneity and echogenicity.

Colorectal Neoplasms↗
PubMed1992

Causes of death during the first 5 years of a randomized trial of mass screening for colorectal cancer with fecal occult blood test.

The main purpose of population screening for colorectal cancer is to reduce mortality from the disease. The criteria of death from colorectal cancer are defined in the present randomized trial of 61,938 persons between 45 and 74 years old, and the need for an impartial death review committee was demonstrated. Causes of death within the first 5 years are described within subgroups of the test group and compared with those in the control group. Death rates were higher among non-responders to screening than among controls and among those in whom Hemoccult-II had been performed at least once. Persons with negative Hemoccult-II had a lower death rate than controls. The overall autopsy rate was 32%. Lethal complications from treatment of colorectal neoplasia were evaluated per se. Death from colorectal cancer occurred in 74 persons in the total screening group and in 91 among controls. Sources of bias are discussed. A method of evaluating possible benefit to those being screened is suggested. Final results cannot be expected before 1996.

Aged↗
PubMed1992

Interval cancers in screening with fecal occult blood test for colorectal cancer.

Interval cancers, which are cancers diagnosed in spite of one or more negative screening tests, were studied in a randomized population with Hemoccult-II for colorectal cancer in 61,938 persons between 45 and 74 years old. Three biannual screenings were performed from 1985 to 1991, and 52% of all the cancers detected after doing at least one Hemoccult-II test were interval cancers (81 persons). These were more advanced than cancers diagnosed after a positive Hemoccult-II test, of larger size, less frequently of Dukes stage A, more often invading neighboring organs, and less often resectable for cure. They were located in the rectum more often than cancers diagnosed by screening and cancers in controls. Otherwise, interval cancers did not differ from cancers in controls or cancers in non-responders, and all characteristics suggested that no delay in diagnosis resulted from one or more negative Hemoccult-II tests, compared with controls. However, even if screening with Hemoccult-II demonstrates a reduction in mortality from colorectal cancer, the present high number of interval cancers makes it necessary to look for other methods of screening populations for colorectal cancer.

Aged↗
PubMed1992

Screening guidelines for colorectal cancer.

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.

Colonoscopy↗
PubMed1991

[Curative local excision of colorectal cancer. A prospective study].

The importance of local treatment for early colorectal cancer is apparent because of increasing endoscopical activity for diagnostic purposes and screening. Curative local treatment was attempted in 63 patients with polypoid, mobile tumours thought to be within the bowel wall and without palpable lymph nodes in the perirectal tissue. Tumours more than 3 cm in diameter were excluded, unless they were pedunculated or were believed to be adenomas with carcinoma. Removal was effected by polypectomy, piecemeal removal, peranal excision, posterior rectotomy or colotomy. Complications were few, and hospitalization was shorter than after conventional surgery, but one patient died from treatment. More extensive surgery followed in 12 patients, in whom cancer remained in the resection margin or where this could not be excluded. However, seven of the 12 patients had no residual cancer tissue. Survival without recurrence was longer in patients with tumours below 3 cm in diameter. Recurrence was seen in nine patients, but not in those with cancer limited to head and the stalk of pedunculated tumours and not with cancer limited to the luminal part of submucosa, regardless of shape of tumour. Adenoma in continuity with cancer did not influence survival significantly, but synchronous adenomas in other parts tended to increase recurrence-free survival. Local treatment is satisfactory in most patient with cancer within pedunculated polyps and in some with cancer in sessile polypopid tumours. Criteria of selection are not optimal and the use of endoluminal ultrasound examinations must be evaluated in prospective trials. At present, conventional surgery should be used when cancer in the resection margin cannot be excluded, when cancer is present in the deeper layers of muscularis propria and in patients with poorly differentiated cancers.

Adult↗
PubMed1991

[Colonoscopy after radical surgery for colorectal cancer. A 10-year prospective study of 309 patients].

Experience from ten year colonoscopic follow-up in patients after radical surgery for colorectal cancer is presented. In all, 309 patients below 76 years were included from 1978 to 1983. All had preoperative proctoscopy and barium enema. Colonoscopy was performed perioperatively, every six months the first three years, four and five years, seven to eight years and ten years after surgery. A minority had double-contrast barium enemas. Synchronous adenomas were removed during surgery and at perioperative colonoscopy and these patients had the same risk of metachronous cancer as those without synchronous adenomas. Five patients with six metachronous cancers, all had new curative surgery. Patients with synchronous adenomas had a higher risk of metachronous adenomas, but had a better prognosis than those without synchronous adenomas. Colonoscopically demonstrated intraluminal local recurrence in the colon could not be treated with new radical surgery in contrast to four out of eight intraluminal recurrences in the rectum. Most local recurrences were extraluminal and were diagnosed by other means.

Adenoma↗