Screening for hereditary non-polyposis colorectal cancer: a study of 22 kindreds in The Netherlands

PURPOSE

Identification of the hereditary non-polyposis colorectal carcinoma syndrome (HNPCC) is a basis for secondary prevention. The objectives of this study are to investigate the natural history of HNPCC and to assess the effect of screening.

PATIENTS AND METHODS

Screening for colorectal carcinoma was performed in 22 HNPCC families (colonoscopy or double-contrast barium enema and sigmoidoscopy). The patients were subdivided into two groups. Group A comprised patients with colorectal cancer who were referred because they were symptomatic. Group B included family members of these patients who were found to have a colorectal lesion by screening. We compared these groups with respect to the stage of tumor growth.

RESULTS

Histologic examination of the tumors in Group A (87 patients) revealed Dukes A carcinomas in six patients, Dukes B carcinomas in 37, Dukes C carcinomas in 21, and Dukes D carcinomas in 10 patients (classification unknown in 13 patients). In Group B (20 patients), adenoma was found in 14 and carcinoma in six patients (Dukes A in two and Dukes B in four patients). A total of 93 patients, including those whose tumors were detected by screening, had a colorectal carcinoma. The age at diagnosis ranged from 24 to 81 years (mean age: 46 years). The location of the colonic tumors was proximal in 60 percent. Multiple primary tumors were found in 26 percent.

CONCLUSION

These results suggest that screening leads to the early detection of colorectal carcinomas and adenomas in asymptomatic members of HNPCC families. Screening should be initiated at the age of 20 and continued during the life of the individual. Careful examination of the right colon is indicated because of the frequent occurrence of tumors in the proximal colon. A subtotal colectomy is indicated at the time of diagnosis of the initial colon cancer because of the risk of multiple primary tumors.

The familial dysplastic nevus syndrome. Natural history and the impact of screening on prognosis. A study of nine families in the Netherlands

Since 1982, nine families with the dysplastic nevus syndrome have been identified in the Leiden area (The Netherlands). A total of 50 primary melanomas were diagnosed in 38 persons. Nineteen of these melanomas had been diagnosed before the start of the screening programme (category I), 11 were detected at the initial examination of the families (category II), and 20 were found during the course of follow-up (category III). To assess the effect of screening, we compared these categories with respect to the developmental stage of the melanomas. One of the 19 melanomas in category I, two of the 11 in category II and seven of the 20 in category III were melanoma in situ. The average thickness of the invasive melanomas in categories I, II and III was 1.75, 0.80 and 0.54 mm respectively. Sixteen of the 19 melanomas in category I (84%) were Clark III or IV, whereas 15 of the 20 melanomas in category III (75%) were Clark I or II. From these findings it may be concluded that screening can lead to the detection of melanomas at an earlier stage, which in turn can permit curative treatment and improvement of both prognosis and life expectancy. The need for supervision based on central registration of affected families to guarantee the continuity of screening is discussed.

Close linkage of a highly polymorphic marker (D5S37) to familial adenomatous polyposis (FAP) and confirmation of FAP localization on chromosome 5q21-q22

Fifteen apparently unrelated Dutch families with familial adenomatous polyposis (FAP) also known as familial polyposis coli (FPC; McKusick No. 17510) were screened for linkage with the DNA probe C11p11 localized on chromosome 5q21-22 and previously reported to be closely linked to FAP (Bodmer et al. 1987; Leppert et al. 1987). In our study C11p11 was minimally informative, which is ascribable to its low heterozygosity in the North European populations. Of the above families, 12 were investigated also for linkage with D5S37 (DNA probe Pi227). Data from 11 of them were found to be informative and showed that FAP is closely linked to D5S37 previously localized on chromosome 5q21 (peak lod score 7.85 at a recombination fraction of 0.048 with 95% probability limits 0.005-0.145). Results discussed below indicate for the first time that the most likely location of the FAP gene is in the band 5q22 very close to 5q21, if not in the transitional zone between these two bands. The probe Pi227 recognizes 4 restriction fragment length polymorphism (RFLP) sites, exhibiting a total of 9 alleles with 24 theoretically possible haplotypes in the Dutch population. Therefore, this probe appears to have potential as a generally useful predictive marker for FAP until much closer and similarly useful markers become available.

Transsphenoidal microsurgery as primary treatment in 25 acromegalic patients: results and follow-up

Twenty-five patients with acromegaly were treated by transsphenoidal microsurgery. Fourteen patients (56%) were considered cured according to the following criteria: a. basal plasma GH less than 10 mU/l; b. glucose suppressed plasma GH less than or equal to 4 mU/l, and c. disappearance of TRH responsiveness if present preoperatively. Thirteen of the cured patients were re-evaluated after a mean follow-up period of 3.5 years (range 1.5 to 5.5 years). At that time, basal plasma GH was still less than 10 mU/l and glucose suppressed plasma GH was still less than or equal to 4 mU/l in all patients, indicating the practical value of our criteria. The remaining 11 patients (44%) received additional treatment by external pituitary irradiation and bromocriptine. Owing to surgery, 5 patients (20%) developed partial or panhypopituitarism.

Multiple endocrine neoplasia syndrome type 2: the value of screening and central registration. A study of 15 kindreds in The Netherlands

Since 1975, 10 families with the multiple endocrine neoplasia (MEN)-2A syndrome and five with the MEN-2B syndrome, making a total of 101 patients, have been identified in The Netherlands. Twenty-three of the MEN-2A patients died before the start of the screening program. The average age of the patients whose death was due to pheochromocytoma (n = 11) or medullary thyroid carcinoma (n = 12) was 34.9 and 49.2 years, respectively. Eighty-seven patients with the MEN-2A syndrome and eight with the MEN-2B syndrome underwent thyroidectomy for C-cell hyperplasia and/or medullary thyroid carcinoma. Eighteen patients had signs or symptoms caused by MEN-2A (group A), 60 were relatives of these patients who had been found to be affected at the first screening of the family (group B), and nine relatives had had negative screening results that later became positive (group C). Five patients had signs or symptoms due to MEN-2B (group A) and three were relatives of these patients who had been found to be affected at the initial screening (group B). To assess the effect of screening, we compared these groups with respect to the occurrence of metastatic medullary thyroid carcinoma at thyroidectomy and the results of the postoperative calcitonin tests. Among the MEN-2A families, 72 percent of group A, 33 percent of group B, and none of group C were found to have metastatic medullary thyroid carcinoma at surgery. In the MEN-2B families, all five patients in group A and one of the three patients in group B had metastatic disease. The "cure rates" in these three groups with MEN-2A, as determined by stimulated calcitonin assessment, were 11, 57, and 100 percent, respectively. One of the five patients with MEN-2B in group A and two of the three patients in group B showed normalization of the stimulated calcitonin value after surgery. From these results, it may be concluded that screening can lead to the detection of medullary thyroid carcinoma in an earlier stage, which in turn may permit curative treatment and improvement of both prognosis and life expectancy. The need for supervision of affected families by central registration to promote periodic examination and to guarantee the continuity of such screening is discussed.

Multiple endocrine neoplasia syndromes

The multiple endocrine neoplasia (MEN) syndromes are characterized by autosomal dominant inheritance with a high degree of penetrance but varying expression. This review gives a classification of these syndromes and a short summary of the historical background. The pathogenesis of the disease and its possible origin in the APUD cell system are discussed together with the mechanisms underlying normal and ectopic hormone production by MEN tumors on the basis of recent findings in molecular endocrinology. The natural history and the clinical manifestations of the different syndromes are described. The sensitivity and discriminative capacity of the tests used to detect the syndromes in an early stage are compared. The choice of therapy and criteria for the timing and extensiveness of treatment are also considered. Lastly, problems associated with the ethical and legal aspects of screening, central registration, and monitoring of relatives at risk are described.