The incidence rate of familial adenomatous polyposis. Results from the Danish Polyposis Register

Based on the Danish Polyposis Register epidemiological calculations on familial adenomatous polyposis (FAP) were carried out. The mean annual incidence was 1.85 x 10(-6) during the years 1971-1992, and the prevalence increasing to about 32 x 10(-6) at the end of 1992. FAP patients constituted a decreased percentage of all Danish patients with colorectal cancer (0.07% in 1980-1992). The completeness of registration was 97% in 1983-1992. The results are similar to Finnish estimates based on the same direct method of calculation, and as both series are based on almost complete national polyposis registration in well-registered populations we regard our results to be close to the true incidence rate.

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.

Centralized registration, prophylactic examination, and treatment results in improved prognosis in familial adenomatous polyposis. Results from the Danish Polyposis Register

BACKGROUND

Over the last few decades numerous regional and national registers have been established all over the world with the aim of improving survival in familial adenomatous polyposis (FAP). The Danish Polyposis Register was founded in 1971 and coordinates the screening and subsequent prophylactic colectomy of FAP patients.

METHODS

The crude cumulative survival in 321 patients (205 probands and 116 call-up cases) with verified FAP was calculated in accordance with the life-table method.

RESULTS

At the time of diagnosis of FAP only 2 of 116 (2%) had colorectal cancer versus 142 of 205 probands (69%). The 10-year cumulative survival was 94% (95% confidence limits, 89-99) in call-up cases compared with only 41% (34-49) in probands (p < 0.00001), and survival improved significantly (p < 0.00001) after the establishment of the Danish Polyposis Register.

CONCLUSION

The establishment of a centralized polyposis register has resulted in a substantial improvement of the prognosis in FAP.

Convalescence and hospital stay after colonic surgery with balanced analgesia, early oral feeding, and enforced mobilisation

OBJECTIVE

To evaluate the combined effects of pain relief by continuous epidural analgesia, early oral feeding and enforced mobilisation on convalescence and hospital stay after colonic resection.

DESIGN

Uncontrolled pilot investigation.

SETTING

University hospital, Denmark.

SUBJECTS

17 unselected patients (median age 69 years) undergoing colonic resection.

INTERVENTIONS

Patients received combined epidural and general anaesthesia during operations and after operation were given continuous epidural bupivacaine 0.25%, 4 ml hour and morphine 0.2 mg hour, for 96 hours and oral paracetamol 4 g/daily. No patient had a nasogastric tube, and oral feeding with normal food and protein enriched solutions (1000 Kcal (4180 KJ/day) was instituted 24 hours postoperatively together with intensive mobilisation.

RESULTS

Median visual analogue pain scores were zero at rest and minimal during coughing and mobilisation, which allowed early mobilisation for up to 11 hours on the third postoperative day. Gastrointestinal function with defaecation had returned to normal in 12 patients within the first two postoperative days. Median hospital stay was five days with minimal increase in fatigue and without postoperative weight loss.

CONCLUSION

These results suggest that a combined approach of optimal pain relief with balanced analgesia, enforced early mobilisation, and oral feeding, may reduce the length of convalescence and hospital stay after colonic operations.

Duodenal adenomatosis in familial adenomatous polyposis. DAF Project Group

In order to evaluate the prevalence of duodenal adenomas in familial adenomatous polyposis (FAP) and the risk of carcinoma development, a multicenter study was initiated in Denmark, Finland, Holland, Norway and Sweden, which have national polyposis registers with an almost complete registration. Patients aged 20 years or more are being examined with biennial gastroduodenoscopy during 1990-2000. Multiple duodenal biopsies are examined by one pathologist from each country, and the endoscopic and histological criteria of Spigelman have been adopted. At the end of August 1992, 312 patients with a median age of 37 years (range 20-86) had completed their first endoscopy. The duodenum was examined in 310 patients, of whom 199 (64%) had duodenal adenomas. Twenty-two patients (11% of all patients with duodenal adenomas) had no endoscopically visible polyps. One patient had an asymptomatic adenocarcinoma. The Spigelman stage worsened significantly (P < 0.05) with time from the diagnosis of FAP, which may suggest an increasing risk of carcinoma by time.

Ophthalmoscopy for congenital hypertrophy of the retinal pigment epithelium (CHRPE) in patients with sporadic colorectal carcinoma

In order to investigate the frequency of congenital hypertrophy of the retinal pigment epithelium (CHRPE) in sporadic colorectal cancer, ophthalmoscopy was carried out in 34 patients with colorectal carcinoma without known familial disposition. CHRPE is one of the most frequent extracolonic manifestations in familial adenomatous polyposis. None of the patients showed any sign of CHRPE. It is concluded that although genetic factors are presumably of importance in the development of sporadic colorectal cancer, CHRPE cannot be used as a marker for future risk of colorectal carcinoma except in polyposis families.

Closure of rectal stump after colectomy for acute colitis

In a retrospective study complications, mortality and morbidity following acute colectomy for severe colitis with intra-abdominal closure of the rectal stump were reviewed in 147 consecutive patients (71 women and 76 men, median age of 40 years, range 18-95 years). Five patients (3%) died within 30 days postoperatively; none of the deaths were related to the rectal stump. Three patients (2%) had a pelvic abscess due to leakage of the rectal closure, all were treated successfully with percutaneous drainage, guided by ultrasonography. No difficulties in locating the rectal stump or performing intended subsequent surgery were reported. The overall complications and mortality rate in this study are low and comparable to the best results reported from centers using the mucous fistula. Closure of the rectal stump is a safe procedure, and has the advantage of not leaving the patient with a second stoma.

The establishment of an HNPCC register

Guidelines for the establishment of an HNPCC-register are presented. The aims of a register are discussed. Steps in identification of families and persons at risk are suggested, and possible sources of family and pedigree data are mentioned. The role of a register in surveillance, information of family members and medical colleagues, research and international collaboration are discussed.

Multiple lymphomatous polyposis of the colon and rectum. Report of a case and review of the literature

BACKGROUND

Multiple lymphomatous polyposis is a non-Hodgkin's centrocytic lymphoma that presents with polyposis of the mucosa and can be found anywhere in the gastrointestinal tract.

METHODS

On the basis of a new case and 31 cases in the literature since 1971, the treatment is discussed.

CONCLUSIONS

Surgery is not indicated and chemotherapy is the appropriate treatment.

Familial adenomatous polyposis (FAP): frequency, penetrance, and mutation rate

The nationwide Danish polyposis register includes all known Danish cases of familial adenomatous polyposis (FAP) and their relatives. By identifying all FAP patients born between 1920 and 1949, we found the frequency of the disease to be 1 in 13,528. By comparing the number of affected and nonaffected offspring born to affected parents during the same period we found the penetrance of the disease for inherited cases to be close to 100% at the age of 40 years. The mutation rate found by the direct method was 9 mutations per million gametes per generation and the proportion of new mutants was estimated to 25%. Fitness for patients between 15 and 29 years was found close to one, while for patients older than 30 the fitness was reduced, but increasing during the three decades (from 0.44 to 0.71) probably because treatment became more widespread and efficient. As we have used the overall fitness in the period, 0.87, to estimate the mutation rate by the indirect method, we found a lower value than by the direct method, namely 5 mutations per million gametes per generation.

Serum gastrin values in patients with familial adenomatous polyposis

PURPOSE

An evaluation of the importance of gastrin in the colorectal carcinogenesis in patients with familial adenomatous polyposis was conducted.

METHODS

Blood samples from 168 family members of 26 families were investigated for circulating gastrin. Blood was drawn from 65 affected patients, 66 clinically unaffected first-degree relatives, and 37 spouses.

RESULTS

We did not find any difference in distribution of serum gastrin among these groups.

CONCLUSION

Our results seem to exclude gastrin from being relevant in early carcinogenesis in patients with familial adenomatous polyposis.

[A colostomy plug (the Conseal system). Assessment of early postoperative use]

The Conseal plug was evaluated in a four week period among 30 consecutive colostomy patients. The clinical trial, a multicenter study covering 11 Danish Hospitals, was started five to 12 days postoperatively among motivated patients in good physical condition. Twenty patients (67%) completed the trial. Ten patients (33%) gave up because of wound infection, leakage, extrusion of the foam part or fault in the test procedure. At the end of the trial all 20 patients wanted to continue using the plug and 84% were still using the Conseal system six months later. We conclude that the plug is well tolerated among motivated patients less than a week postoperatively and that the Conseal plug is a good alternative to the colostomy bag early in the postoperative course.

The establishment of a polyposis register

Guidelines are presented for the establishment of a regional or national register of patients with familial adenomatous polyposis. The detailed recommendations are based on the work in committees of the "Leeds Castle Polyposis Group" and the "EuroFAP". The aims of national and regional polyposis registers are discussed, and the stages of development of a register are reviewed: Ascertainment of probands, construction of pedigrees, identification of family members at risk, and screening of members at risk. The problem of data confidentiality is discussed.

Mandibular osteomas in sporadic colorectal carcinoma. A genetic marker

Pantomography of the mandible was performed in 98 patients with sporadic colorectal adenocarcinoma. Twenty-eight patients (29%) had osteomas versus 5% in a control group (P < 0.001). Mandibular osteomas are found in most patients with the premalignant dominant syndrome familial adenomatous polyposis. Sporadic colorectal cancer examinations of married couples have shown that diet has only a moderate influence on the development of colorectal cancer, whereas pedigree studies indicate a genetic component. On this basis we conclude that mandibular osteomas are probably genetic markers of the development of sporadic colorectal carcinoma.

Rectal cancer risk in patients treated for familial adenomatous polyposis. The Leeds Castle Polyposis Group

Total colectomy with ileorectal anastomosis (IRA) in familial adenomatous polyposis (FAP) leaves patients at risk for rectal cancer. To assess this risk, the rectal cancer incidence in 297 patients with FAP undergoing IRA since 1951 was determined in the population-based registers of Denmark, Finland and Sweden. At the same time, detailed data on 50 patients with FAP and invasive rectal cancer were obtained from 11 international polyposis registries. The cumulative incidence of rectal cancer was 13.1 per cent at 25 years. The 5-year survival rate of patients with FAP developing rectal cancer was 71 per cent. Combining both studies, the risk of dying from rectal cancer after IRA was 2.0 per cent at 15 years of follow-up. These results justify IRA as primary treatment for most patients; restorative proctocolectomy is preferred for some subgroups. The high all-cause mortality rate observed in this relatively young population necessitates lifelong surveillance of patients with FAP.

Hepatoblastoma in two cousins in a family with adenomatous polyposis. Report of two cases

Two cases of hepatoblastoma in cousins in a family with familial adenomatous polyposis (FAP) are reported. Twenty-five cases of hepatoblastoma with family history of FAP have been documented in the literature, but there has never been a report of two cases of hepatoblastoma in the same polyposis family.

[Hereditary non-polyposis colorectal cancer]

Hereditary non-polyposis colorectal cancer (HNPCC) probably constitutes 5% of all the cases of sporadic colorectal cancer. At present, the diagnosis can only be established on the basis of a family history which should fulfill the "Amsterdam criteria": 1) Colorectal cancer in at least three family members, 2) One family member must be a close relative of the other two, and 3) The diagnosis must have been established prior to the age of 50 years in at least one relative. Other forms of cancer also occur in the HNPCC syndrome, particularly endometrial cancer. The syndrome has a dominant inheritance and, therefore, all close relatives should be submitted to control examinations for the most important forms of cancer associated with the syndrome.

[Preclinical and prenatal diagnosis of familial adenomatous polyposis]

In order to investigate the possibility of preclinical and prenatal genetic diagnosis of familial adenomatous polyposis (FAP) by means of DNA-systems and other markers, blood samples were collected from 246 persons in 29 families, including 90 with the clinical diagnosis FAP and 73 clinically unaffected first degree relatives (persons at risk). The material was studied with up to 4 DNA-marker systems located in the region around the disease gene. Among the first degree relatives eight (11%) had probably inherited the disease gene, while 31 persons (42%) in this risk group had probably not inherited the gene. It was not possible to evaluate the risk in the remaining 34 persons (47%). In 45 (85%) out of 53 persons under 40 years the DNA-systems were informative, so that it would be possible to offer the option of prenatal diagnosis. It is concluded that preclinical and possibly prenatal genetic diagnosis may be offered; but the current practice of prophylactic proctosigmoidoscopic surveillance should be maintained.

Purification and Characterization of Chorismate Synthase from Euglena gracilis: Comparison with Chorismate Synthases of Plant and Microbial Origin

Chorismate synthase was purified 1200-fold from Euglena gracilis. The molecular mass of the native enzyme is in the range of 110 to 138 kilodaltons as judged by gel filtration. The molecular mass of the subunit was determined to be 41.7 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified chorismate synthase is associated with an NADPH-dependent flavin mononucleotide reductase that provides in vivo the reduced flavin necessary for catalytic activity. In vitro, flavin reduction can be mediated by either dithionite or light. The enzyme obtained from E. gracilis was compared with chorismate synthases purified from a higher plant (Corydalis sempervirens), a bacterium (Escherichia coli), and a fungus (Neurospora crassa). These four chorismate synthases were found to be very similar in terms of cofactor specificity, kinetic properties, isoelectric points, and pH optima. All four enzymes react with polyclonal antisera directed against chorismate synthases from C. sempervirens and E. coli. The closely associated flavin mononucleotide reductase that is present in chorismate synthase preparations from E. gracilis and N. crassa is the main difference between those synthases and the monofunctional enzymes from C. sempervirens and E. coli.

[Occurrence of colorectal cancer among parents of patients with this disease]

In order to investigate the influence of a possible genetic factor on the development of colorectal cancer (KRC), a cohort investigation was carried out among parents of patients with KRC. A total of 1,542 patients participated in the investigation. These patients were under the age of 60 years and registered in The Danish Cancer Register as cases of KRC during the period 1982-1984. 96% of the parents of these patients were identified by means of the administrative registers. The parents were then sought in The Danish Cancer Register for cancer during the period 1943-1986. The incidence rates for the Danish population were employed to calculate anticipated number of cases of KRC among these parents. significantly increased frequencies of KRC were found among both the mothers and the fathers, as the standardised incidence ratio was 1.62 in mothers and 1.87 among fathers. As a Danish investigation of spouses of patients with KRC has not demonstrated any increased frequency of KRC among spouses, it is concluded that this finding indicates a possible genetic factor in the etiology of KRC.

Metachronous colorectal cancer in young patients: expression of the hereditary nonpolyposis colorectal cancer syndrome?

The cumulative incidence rate of metachronous colorectal cancer in patients younger than 40 years of age at diagnosis of the primary cancer has been shown to be 30 percent. Metachronous colorectal cancer is predominantly located in the right colon with a decreasing frequency toward the rectum. The risk of developing a metachronous colorectal cancer was found to be 16-29 times increased when compared with the risk of having a primary colorectal cancer. Because of the resemblance between characteristics of metachronous colorectal cancer and the features of hereditary nonpolyposis colorectal cancer (HNPCC), it is proposed that young colorectal cancer patients developing metachronous colorectal cancer could in fact be HNPCC patients.

Contaminated fistula following J-pouch ileoanal reservoir. Treatment with a collagen sponge containing gentamicin and metronidazole. Case report

In a 55-year-old woman, a 1 x 5 cm fistula developed in the ileoanal anastomosis after restorative proctocolectomy with J-pouch ileoanal reservoir and temporary ileostomy for intractable ulcerative colitis. The fistula extended between the pouch and the sacral bone. Lasting closure was achieved by intrafistular placement of a collagen sponge containing gentamicin and soaked in metronidazole solution and pouch drainage through a transanal Foley catheter.

[Metachronous colorectal cancer]

The occurrence of metachronous colo-rectal cancer was investigated in 903 patients under the age of 40 years at the time of diagnosis of the primary cancer. A constant frequency of metachronous colo-rectal cancers was found and a cumulated incidence of 30% after an observation period of 41 years. Metachronous cancer of the colon was encountered most frequently in the right half of the colon regardless of the site of the primary cancer. On the basis of the above mentioned results, a life-long follow-up programme is recommended, consisting of regular examination for blood in the faeces and colonoscopy.