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Biomedical subjects

O Kronborg

Publications and source records attributed to O Kronborg.

At least 73 records · Page 4Linked to original sources
PubMed1996

Randomised study of screening for colorectal cancer with faecal-occult-blood test.

BACKGROUND: Case-control studies and a voluntary-based follow-up study have suggested that repeated screening with faecal-occult-blood (FOB) tests can lead to a reduction in mortality from colorectal cancer (CRC). The aim of this randomised study was to compare mortality rates after FOB tests every 2 years during a 10-year period with those of unscreened similar controls. METHODS: 140,000 people aged 45-75 years lived in Funen, Denmark, in August, 1985, and were considered for inclusion in our study. Before randomisation we excluded individuals who had CRC or precursor adenomas and those who had taken part in a previous pilot study. Randomisation of 137,485 people in blocks of 14 allocated three per 14 to the screening group (30,967), three per 14 to the control group (30,966), and eight not to be enrolled in the study (75,552). Controls were not told about the study and continued to use health-care facilities as normal. Hemoccult-II blood tests (with dietary restrictions but without rehydration) were sent to screening-group participants. Only those participants who completed the first screening round were invited for further screening--five rounds of screening during a 10-year period. Participants with positive tests were asked to attend to full examination and were offered colonoscopy whenever possible. The primary endpoint was death from CRC. FINDINGS: Of the 30,967 screening-group participants, 20,672 (67%) completed the first screening round and were invited for further screening; more than 90% accepted repeated screenings. During the 10-year study, 481 people in the screening group had a diagnosis of CRC, compared with 483 unscreened controls. There were 205 deaths attributable to CRC in the screening group, compared with 249 deaths in controls. CRC mortality, including deaths attributable to complications from CRC treatment, was significantly lower in the screening group than in controls (mortality ratio 0.82 [95% CI 0.68-0.99]) p = 0.03). INTERPRETATION: Our findings indicate that biennial screening by FOB tests can reduce CRC mortality. This study is being continued to improve its statistical power and to assess the effect of the removal of more precursor adenomas in the screening-group participants than in controls on CRC incidence.

Adenoma↗
PubMed1996

[Intraoperative ultrasonography in colorectal cancer. A prospective, blind study].

This study was designed to compare diagnostic accuracies of measuring liver enzymes, preoperative ultrasonography, surgical examination, and intraoperative ultrasonography for detection of liver metastases from colorectal cancer. A blind prospective comparison between the diagnostic examinations mentioned above were performed in 295 consecutive patients with colorectal cancer. An experienced ultrasonologist performed the preoperative examinations and the results were not known to the other experienced ultrasonologist, who did the intraoperative examinations. The latter was also unaware of the findings by the surgeon. The presence of metastases was further assessed by ultrasonography three months postoperatively, as well as surgery and liver biopsy in some of the patients. The sensitivity of intraoperative ultrasonography (62/64) was significantly superior to that of surgical exploration (54/64), and that of preoperative ultrasonography (45/64). The lowest sensitivity was presented by liver enzymes. "Bilobar" metastases were detected in 42 of 46 patients by intraoperative ultrasonography, but in no more than 33 by the surgeon. Intraoperative ultrasonography demonstrated the highest specificity of all examinations. Intraoperative ultrasonography reduces the number of patients with liver metastases being subjected to superfluous or even harmful liver surgery and it may increase the number in whom liver surgery will prolong life.

Adult↗
PubMed1996

Comparison of two techniques of transrectal ultrasonography for the assessment of local extent of polypoid tumours of the rectum.

The capability of transrectal ultrasonography (TRUS) to differentiate between benign and malignant rectal polyps was evaluated. Digital palpation and sigmoidoscopy were followed by TRUS with a 7.5-MHz linear-array transducer, in a blinded design. In the second part of the study the procedure was extended with an acoustic window system (AWS), preventing compression of the polyp. Pathological examination after surgical resection was used for definitive diagnosis in 110 polyps. Digital examination detected 10 of 22 carcinomas with adenomas, compared with 19 by TRUS (P < 0.01). However, TRUS falsely indicated 20 of 49 adenomas to be carcinomas, compared with 4 out of 49 by digital examination (P < 0.001). TRUS combined with AWS detected 23 of 24 carcinomas, and gave a false positive result in only 3 of 26 benign polyps. The results suggest that the best way to discriminate between benign and malignant rectal polyps is to combine TRUS with AWS.

Adult↗
PubMed1996

Chromosome abnormalities in colorectal adenomas: two cytogenetic subgroups characterized by deletion of 1p and numerical aberrations.

Cytogenetic analysis of short-term cultures from 34 benign colorectal polyps, all histologically verified as adenomas, revealed clonal chromosome aberrations in 21 of them. Eight polyps had structural rearrangements, whereas only numerical changes were found in 13. A combination of structural and numerical chromosomal aberrations was found in three polyps. The most common numerical change was gain of chromosome 7, found either as the sole anomaly (five polyps), together with other numerical changes (six polyps), or together with structural rearrangements (two polyps). Other recurrent numerical changes were +20, +13, and monosomy 18, found in six, five, and two adenomas, respectively. Rearrangement of chromosome 1 was the most common structural change. Abnormalities involving 1p were seen in six adenomas, leading to visible loss of material in three. One adenoma had one clone with a large and another with a small 1p deletion. In three adenomas, del(1)(p36) was the only cytogenetic aberration, supporting the authors' previous conclusion that loss of one or more gene loci in band 1p36 is a common early change in colorectal tumorigenesis. Chromosome 8 was involved in structural changes in two adenomas; in one this led to loss of 8p and in the other to gain of 8q. The cytogenetic findings did not correlate in a statistically significant manner with clinicopathologic parameters, such as grade of dysplasia, macroscopic or microscopic adenoma structure, tumor size and location, or the patients' sex and age.

Adenoma↗
PubMed1996

Possible causes of a positive Haemoccult-II test in a population screening study for colorectal neoplasia.

In a population study for colorectal neoplasia possible relationships were sought between faecal occult bleeding and clinical findings. Samples were taken from three different stools, collected during biennial screening from 1985 to 1994 in the age group 45-75 years at the beginning of the study. A total of 943 persons had positive Haemoccult-II (H-II) tests in at least one of the five screening rounds, and 87% had a complete colonoscopy. Of the 20,672 persons accepting initial screening, 1% had a positive test, the figure increasing to 1.8% during the fifth screen. The degree of positivity (1-3 slides) decreased with time. Positive tests were most frequent in men. Predictive values (PVpos) for colorectal cancer (CRC) increased with increasing number of positive slides from 6 to 31%. The average PVpos decreased from 17% during the initial screen to 8% during the fifth. Average PVpos for possible precursors (adenomas) varied from 40% at the beginning to 33% at the end. PVpos for CRC and inflammatory bowel disease increased when visible blood in the stools was present. Marcoumar increased PVpos for adenomas. Colorectal examination in the 943 persons revealed 114 persons with CRC and further 377 with adenomas. Early CRC (Dukes' stage A) was detected in 46 of the 114 with CRC, a more favourable distribution than that found in symptomatic patients. The study defined a group of people with a high risk of colorectal neoplasia, with a good prognosis, out of a group who had been selected at random from a normal population.

Aged↗
PubMed1996

Prophylaxis against colorectal cancer.

Colorectal cancer is diagnosed in more than 3000 people every year in Denmark, with a population of 5 million, and 2000 die from this disease every year. The aetiology of the disease is complex, but an increasing number of cancers have been related to genetics and Denmark is contributing with a well-established register of familial adenomatous polyposis and a recently founded register for hereditary nonpolyposis colorectal cancer, both with major international relationships. The Danish tradition of epidemiology and clinical trials has also been demonstrated in population screening trials for colorectal cancer in average-risk persons as well as high-risk groups with precursors of the disease. The present review places Danish contributions within the prophylaxis of colorectal cancer during the last decade in an international context.

Adenomatous Polyposis Coli↗
PubMed1995

[Acute colonic ileus caused by left-sided colorectal cancer. A randomized trial of emergency ostomy versus resection].

Staged resection (group T) versus acute resection (group R) for curative purpose was compared in a randomized study of 121 patients presenting with signs of left-sided obstructive colorectal tumours during emergency surgery from 1978 to 1993. Patients with distant spread were excluded. Transversostomy was done in 58 and resection without immediate anastomosis in 56. Duration of emergency surgery was shorter, blood transfusions fever and wound infections less frequent in T compared to R, but postoperative mortality was similar (eight patients in each group). The diagnosis of tumour was wrong in 11 patients in T and six in R. The proportion of patients surviving the second stage curative resection in T without a permanent colostomy (32/35) was higher than after acute resection (36/50) in spite of six patients having anastomotic surgery (Coloshield) at the time of acute resection in R. Days spent in hospital were less in R. Overall recurrence rates and survival rates were similar in T and R. In conclusion, no major advantage besides shorter hospital stay could be demonstrated by acute resection without simultaneous anastomosis compared to the traditional 3-stage procedure, which on the other hand carried a much smaller risk of a permanent colostomy. The latter should therefore serve as a control in a prospective evaluation of emergency resection with simultaneous anastomosis.

Adult↗
PubMed1995

[Rectal exploration and transrectal ultrasound scanning 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 the depth of penetration in three of 33 patients and overestimated it in nine of 74. The figures for digital examination were five of 18 and 20 of 76, respectively. Penetration of the rectal wall was correctly identified in 56 of 61 patients by digital rectal 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 no 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 being given the possibility of curative local surgery.

Double-Blind Method↗
PubMed1995

Faecal occult blood testing and colonoscopy in the surveillance of subjects at high risk of colorectal neoplasia.

Colonoscopy is the established method of surveillance of subjects at high risk of developing colorectal neoplasia but the procedure is expensive, time consuming and occasionally hazardous. Faecal occult blood tests can be prepared at home and are cheap, simple and safe. Hemeselect is an immunological faecal occult blood test that is more sensitive for colorectal cancer than Haemoccult. The aim of this study was to determine the sensitivity of the Hemeselect test for asymptomatic colorectal neoplasia in subjects at high risk of the disease who were undergoing colonoscopy, thus assessing its suitability as an alternative means of screening high-risk groups. A total of 919 asymptomatic subjects were asked to complete Hemeselect tests. These were completed satisfactorily by 808 individuals (compliance rate 88 per cent) and were positive in 164 patients (20 per cent). At colonoscopy 11 cancers were detected in ten patients (seven Hemeselect positive) and 36 (16 Hemeselect positive) had at least one adenoma 1 cm or more in diameter. The test sensitivites of Hemeselect for carcinoma and large (1 cm or more) adenomas were 70 and 44 per cent respectively. In a subset of 417 subjects who also completed Haemoccult tests, the sensitivities were 33 and 18 per cent. Hemeselect specificity is 88 per cent compared with 98 per cent for Haemoccult. While the sensitivity of Hemeselect is higher than that of Haemoccult, it is still insufficient to replace colonoscopy in high-risk groups.

Colonoscopy↗
PubMed1995

Karyotypic characterization of colorectal adenocarcinomas.

Cytogenetic analysis of short-term cultures from 52 primary colorectal adenocarcinomas revealed clonal chromosome aberrations in 45 tumors, whereas the remaining 7 had a normal karyotype. More than 1 abnormal clone was detected in 26 tumors; in 18 of them, the clones were cytogenetically unrelated. The modal chromosome number was near-diploid in 32 tumors and near-triploid to near-tetraploid in 13. Only numerical aberrations were identified in 13 carcinomas, only structural aberrations in 3, and 29 had both numerical and structural changes. The most common numerical abnormalities were, in order of decreasing frequency, gains of chromosomes 7, 13, 20, and Y and losses of chromosomes 18, Y, 14, and 15. The structural changes most often affected chromosomes 1, 17, 8, 7, and 13. The most frequently rearranged chromosome bands were, in order of decreasing frequency, 13q10, 17p10, 1p22, 8q10, 17p11, 7q11, 1p33, 7p22, 7q32, 12q24, 16p13, and 19p13. Frequently recurring aberrations affecting these bands were del(1)(p22), i(8)(q10), i(13)(q10), and add(17)(p11-13). The most common partial gains were from chromosome arms 8q, 13q, and 17q and the most common partial losses from chromosome arms 1p, 8p, 13p, and 17p. A correlation analysis between the karyotype and the clinicopathologic features in our total material, which consists of altogether 153 colorectal carcinomas, including 116 with an abnormal karyotype, showed a statistically significant association (P < 0.05) between the karyotype and tumor grade and site. Carcinomas with structural chromosome rearrangements were often poorly differentiated; well and moderately differentiated tumors often had only numerical aberrations or normal karyotypes. Abnormal karyotypes were more common in rectal carcinomas than in carcinomas situated higher up. Near-triploid to near-tetraploid karyotypes were more than twice as frequent in tumors of the distal colon as in those of the proximal colon and rectum. The cytogenetic data indicate that carcinomas located in the proximal colon and rectum, which often are near-diploid with simple numerical changes and cytogenetically unrelated clones, probably arise through different mechanisms than do tumors located in the distal colon, which more often have complex near-triploid to near-tetraploid karyotypes.

Adenocarcinoma↗
PubMed1995

Acute obstruction from tumour in the left colon without spread. A randomized trial of emergency colostomy versus resection.

Staged resection (group T) versus acute resection (group R) for cure was compared in a randomized study of 121 patients presenting with signs of leftsided obstructive colorectal tumours during emergency surgery from 1978 to 1993. Patients with distant spread were excluded. Transverse colostomy was done in 58 and resection without immediate anastomosis in 56. Duration of emergency surgery was shorter, blood-transfusions less and wound infections less frequent in T compared to R, but postoperative mortality was similar (8 patients in each group). The diagnosis of tumour was wrong in 11 patients in T and 6 in R. The proportion of patients surviving the second stage curative resection in T without a permanent colostomy (32/35) was higher than after acute resection (36/50) in spite of 6 patients having anastomotic surgery (Coloshield) at the time of acute resection in R. Days spent in hospital were less in R. Overall recurrence rates and survival rates were similar in T and R. No major advantage besides shorter hospital stay could be demonstrated by acute resection without simultaneous anastomosis compared with the traditional three stage procedure, which on the other hand carried a much smaller risk of a permanent colostomy. The latter should therefore serve as a control in a prospective evaluation of emergency resection with simultaneous anastomosis.

Acute Disease↗
PubMed1995

Intraoperative ultrasonography in detection of hepatic metastases from colorectal cancer.

PURPOSE: This study was designed to compare diagnostic accuracies of measuring liver enzymes, preoperative ultrasonography, surgical examination, and intraoperative ultrasonography for detection of liver metastases from colorectal cancer. METHODS: Blind, prospective comparisons of diagnostic examinations mentioned above were performed in 295 consecutive patients with colorectal cancer. An experienced ultrasonologist performed the preoperative examinations, and results were unknown to the other experienced ultrasonologist who performed the intraoperative examinations. The latter, also was unaware of the findings by the surgeon. The presence of metastases was further assessed by ultrasonography three months postoperatively, as well as additional surgery and liver biopsy in some of the patients. RESULTS: The sensitivity of intraoperative ultrasonography (62/64) was significantly superior to that of surgical exploration (54/64) and that of preoperative ultrasonography (45/64). The lowest sensitivity was presented by liver enzymes. Bilobar metastases were detected in 42 of 46 patients by intraoperative ultrasonography but in only 33 patients by the surgeon. Intraoperative ultrasonography demonstrated the highest specificity of all examinations. CONCLUSIONS: Intraoperative ultrasonography reduces the number of patients with liver metastases from being subjected to superfluous or even harmful liver surgery, and it may increase the number in whom liver surgery will prolong life.

Adult↗
PubMed1995

Plasma tetranectin and colorectal cancer.

The prognostic significance of plasma tetranectin (PL-TN) in colorectal cancer was retrospectively examined in 504 patients (80 Dukes' A, 174 Dukes' B, 98 Dukes' C and 152 Dukes' D). Follow-up time was 7-12 years. No significant prognostic variable was found for Dukes' A patients by Cox multivariate analysis. In stage B, PL-TN was the second strongest prognostic variable [relative hazard (RH) = 3.3 for patients with PL-TN < or = 7.5 mg/l]. The other prognostic variables were perineural invasion (RH = 3.7), tumour distance < or = 10 cm from the anal verge (RH = 3.0), postoperative radiotherapy (RH = 2.9) and a high carcinoembryonic antigen (CEA) score (RH = 1.8). In Dukes' C, only CEA score and gender were of prognostic significance. For Dukes' D, PL-TN was the only prognostic variable (RH = 1.7). Testing all patients in one multivariate analysis, Dukes' staging was the strongest and PL-TN the second strongest prognostic variable. The shortened survival for patients with low PL-TN levels is illustrated with lifetables.

Aged↗