A total of 26,975 asymptomatic individuals were identified from family doctors' age/sex registers and randomly allocated to test or control group. The first test group (10,253) were offered 3-day fecal occult blood (FOB) testing; 3,613 (37%) completed the tests and 77 (2.1%) were found to be positive. In this group, 13 cancers were detected (3.5/1000 persons screened), of which 9 (70%) were Stage A. Of these subjects, 3349 have been rescreened at 2 years; 2799 (85%) completed the tests and 80 (2.8%) were found to be positive. Four cancers have been detected (three Stage A). In the whole test group followed for 2 years (10,462), 34 cancers have presented (17 screening detected, 3 interval cases in test responders, 14 symptomatic cancers in nonresponders), of which 14 (43%) were Stage A. In the control group (10,272 individuals), 17 patients have presented with symptomatic colorectal cancer during the 2-year follow-up, with rates of 0.9/1000 and 0.8/1000 persons/year in the first and second years of follow-up, respectively. No Stage A tumors were present. In the second test group (3,225) offered both guaiac (Hemoccult; Smith Kline Diagnostics) and immunologic (Feca EIA; Nordic) FOB tests, 1304 (44%) completed the tests, of which 126 (9.7%) were positive. Five cancers were detected (four Stage A), of which only three were positive by Hemoccult testing. In this group of test responders, one cancer has presented symptomatically at 1 year follow-up. Thus, at 2-year follow-up of the responding individuals of both cohorts of the initial screen of the test group, 5 of 21 cancers (24%) were negative by Hemoccult testing. Fecal occult blood testing has doubled the detection of colorectal cancer in the test group compared with the number presenting with symptoms in 2 years in the control group, and increased the proportion of early stage cancers (chi 2 = 8.0, P = less than 0.001).
von Willebrand disease (VWD) is the most common bleeding disorder known in humans, with type 1 VWD representing the majority of cases. Unlike the other variant forms of VWD, type 1 disease represents a complex genetic trait, influenced by both genetic and environmental factors.
To evaluate the contribution of the von Willebrand factor (VWF) and ABO blood group loci to the type 1 VWD phenotype, and to assess the potential for locus heterogeneity in this condition, we have performed genetic linkage and association studies on a large, unselected type 1 VWD population.
We initially collected samples from 194 Canadian type 1 VWD families for analysis. After the exclusion of families found to have either type 2 or type 3 VWD, and pedigrees with samples from single generations, linkage and association analysis was performed on 155 type 1 VWD families.
The linkage study has shown a low heterogeneity LOD score of 2.13 with the proportion of families linked to the VWF gene estimated to be 0.41. Linkage was not detected to the ABO locus in this type 1 VWD population. In the family-based association test, significant association was found between the type 1 VWD phenotype, the quantitative traits, VWF:Ag, VWF:RCo, and FVIII:C and the ABO 'O' and 'A' alleles and the VWF codon 1584 variant. There was also weak association with the -1185 promoter polymorphism and VWF:Ag, VWF:RCo, and FVIII:C plasma levels. These studies provide further evidence to support the role for genetic loci other than VWF and ABO in the pathogenesis of type 1 VWD.
Malignant epithelial tumours associated with autoimmune sialadenitis are rare in white races but occur more often in those of Eskimo or oriental descent. Ultrastructurally these tumours are squamous in origin, and they may arise from the epithelial component of autoimmune sialadenitis. The two cases reported are the first described in natives of this country, and in one, a case of parotid tumour, autoimmune sialadenitis preceded the development of undifferentiated carcinoma by 12 years; the other, a submandibular lesion, indicates some diagnostic difficulties that were found. This condition deserves wider recognition, as adequate primary treatment may result in long term survival.