Multiplicity in polyp count and extracolonic manifestations in 40 Dutch patients with MYH associated polyposis coli (MAP)

Objective: To investigate the contribution of MYH associated polyposis coli (MAP) among polyposis families in the Netherlands, and the prevalence of colonic and extracolonic manifestations in MAP patients. Methods: 170 patients with polyposis coli, who previously tested negative for APC mutations, were screened by denaturing gradient gel electrophoresis and direct sequencing to identify MYH germline mutations. Results: Homozygous and compound heterozygous MYH mutations were identified in 40 patients (24%). No difference was found in the percentage of biallelic mutation carriers between patients with 10–99 polyps or 100–1000 polyps (29% in both groups). Colorectal cancer was found in 26 of the 40 patients with MAP (65%) within the age range 21 to 67 years (median 45). Complete endoscopic reports were available for 16 MAP patients and revealed five cases with gastro-duodenal polyps (31%), one of whom also presented with a duodenal carcinoma. Breast cancer occurred in 18% of female MAP patients, significantly more than expected from national statistics (standardised morbidity ratio = 3.75). Conclusions: Polyp numbers in MAP patients were equally associated with the attenuated and classical polyposis coli phenotypes. Two thirds of the MAP patients had colorectal cancer, 95% of whom were older than 35 years, and one third of a subset of patients had upper gastrointestinal lesions. Endoscopic screening of the whole intestine should be carried out every two years for all MAP patients, starting from age 25–30 years. The frequent occurrence of additional extraintestinal manifestations, such as breast cancer among female MAP patients, should be thoroughly investigated.     

Can we test for hereditary cancer at 18 years when we start surveillance at 25? Patient reported outcomes

DNA-testing for BRCA1/2 or Lynch syndrome is possible from the age of 18 years, although surveillance usually starts at 25. Some patients regret their decision of testing before age 25. This retrospective study evaluates whether the testing age should be above 25 years to prevent adverse effects such as regret or decisional conflict, by determining the percentage and characteristics of patients reporting these problems. 111 of 219 patients (51 %) tested for BRCA1/2 mutations or Lynch syndrome between 18 and 25 years from July 1996 to February 2011, returned self-report surveys. Primary measures were regret, decisional conflict and family influence. Secondary measures included quality of life (QoL), coping style, impact of genetic testing, and risk perception. Median age was 27 [21–40] years, with 86 % female. 73 % was tested for BRCA1/2, 27 % for Lynch syndrome. Only 3 % reported regret, however 39 % had moderate (32 %) to severe (7 %) decisional conflict. Regression analysis revealed that decisional conflict was associated with more monitoring/neutral coping style (p < 0.03) or paternal/no family mutation (p < 0.02); there were no differences in QoL, impact or risk perception. 42 % were mutation carriers, showing equal decisional conflict to non-carriers. 68 % would recommend testing <25 years; 77 % desired surveillance <25 years if a mutation carrier. Almost no patient tested for hereditary cancer between 18 and 25 years regretted this decision. A third reported retrospective decisional conflict, especially those actively seeking information when faced with a threat and/or those with a paternal or unknown inheritance. These patients may benefit from decisional support and personalized information.     

No signs of subclinical atherosclerosis after risk-reducing salpingo-oophorectomy in BRCA1/2 mutation carriers

BackgroundBRCA1/2 mutation carriers are generally exposed to early menopause due to risk-reducing salpingo-oophorectomy (RRSO) around the age of 40 years. This risk-reducing intervention is based on a 10–40% life-time risk of ovarian cancer in this population. Although effective, premature and acute menopause induces non-cancer related morbidity in both the short and long term. Little is known about the impact of RRSO on the cardiovascular system.MethodsThis cross-sectional study explored the relationship between time since RRSO and signs of subclinical atherosclerosis, as measured by carotid intima-media thickness (CIMT) and pulse wave velocity (PWV), in 165 BRCA1/2 mutation carriers. All participants, aged 40 to 63 years, underwent RRSO before the age of 45 years, and at least 5 years ago. Cardiovascular risk factors were assessed by questionnaires and a single screening visit. Data were analyzed using linear regression models.ResultsMean CIMT was 692.7 μm (SD 87.0), and mean central PWV 6.40 m/s (SD 1.42). After adjustment for age and several relevant cardiovascular risk factors, time since RRSO was not associated with CIMT (β=0.68 μm; 95% CI –4.02, 5.38) and PWV (β=44 mm/s; 95% CI –32, 120). Compared to women of a reference group from the general population, lower systolic blood pressure [mean difference 12 mmHg; 95% confidence interval (CI) 10, 14] was found in BRCA1/2 mutation carriers.ConclusionsWe found that, in BRCA1/2 mutation carriers, at 5 to 24 years follow-up, time since RRSO is not related to development of subclinical atherosclerosis. However, the follow-up period in these relatively young women might have been too short.     

Differential regulation of IGF-binding proteins in rabbit costal chondrocytes by IGF-I and dexamethasone

Cartilage is a primary target tissue for the IGFs. The mitogenic activity of these peptides is regulated by a family of high-affinity IGF-binding proteins (IGFBP-1 to -6). We characterized the IGFBPs produced by cultured chondrocytes derived from rib cartilage of prepubertal rabbits. Culture medium, which had been conditioned by these cells for 48 h showed bands of 22 kDa, 24 kDa and a 31/32 kDa doublet by Western ligand blotting with [(125)I]IGF-II. When the cells were grown in the presence of increasing amounts of IGF-I or IGF-II, the 31/32 kDa doublet increased in intensity (reaching a plateau of about 11-fold stimulation between 2 and 10 nM IGF-I). The 22 kDa and 24 kDa bands increased only slightly while a 26 kDa band became faintly visible. By Western immunoblotting the 31/32 kDa doublet was identified as IGFBP-5. An IGF-I analog with reduced affinity for IGFBPs, Long-R3 IGF-I, also induced IGFBP-5, while insulin was less effective (2.2-fold stimulation at 10 nM). IGF-I protected IGFBP-5 against proteolytic degradation by conditioned medium. IGF-I also enhanced the level of IGFBP-5 mRNA. LY294002, a specific inhibitor of the intracellular signaling molecule phosphatidylinositol 3-kinase, inhibited stimulation of IGFBP-5 by IGF-I. Dexamethasone suppressed IGFBP-5 (by 70% at 20 nM) but, at the same time, a 39/41 kDa doublet (presumably IGFBP-3) was induced. IGFBP-5 has been shown in several cell types to enhance the mitogenic activity of IGF-I. IGFBP-3 generally acts as a growth inhibitor. Therefore, the differential effects of dexamethasone on these regulatory proteins could account, at least in part, for the growth-arresting effect of this glucocorticoid.     

Human insulin-like growth factor (IGF) binding protein-1 inhibits IGF-I-stimulated body growth but stimulates growth of the kidney in snell dwarf mice

The actions of insulin-like growth factor-I (IGF-I) are modulated by IGF binding proteins (IGFBPs). The effects of IGFBP-1 in vivo are insufficiently known, with respect to inhibitory or stimulatory actions on IGF-induced growth of specific organs. Therefore, we studied the effects of IGFBP-1 on IGF-I-induced somatic and organ growth in pituitary-deficient Snell dwarf mice. Human GH, IGF-I, IGFBP-1, and a preequilibrated combination of equimolar amounts of IGF-I and IGFBP-1 were administered sc during 4 weeks. Treatment with IGF-I alone induced a significant increase in body length (108% of control) and weight (112%) as well as an increase in weight of the submandibular salivary glands (135%), kidneys (124%), femoral muscles (111%), testes (129%), and spleen (126%) compared with saline-treated controls. IGFBP-1 alone induced a significant increase in weight of the kidneys (152% of control). Coadministration of IGF-I with IGFBP-1 neutralized the stimulating effects of IGF-I on body length and weight as well as on the femoral muscles and testes. In contrast, the weights of the submandibular salivary glands (143%) were not significantly different from those of IGF-I-treated animals, whereas the weights of the kidneys (171%) and spleen (156%) were significantly increased compared with IGF-I-treated mice. The effect of IGFBP-1 plus IGF-I on kidney weight was not significantly greater than the effect of IGFBP-1 alone. Western ligand blotting showed induction of the IGFBP-3 doublet as well as IGFBPs with molecular masses of 24 kDa, most probably IGFBP-4, by human GH, IGF-I alone, and IGF-I in combination with IGFBP-1. Our data show that coadministration of IGFBP-1 inhibits IGF-I-induced body growth of GH-deficient mice but significantly stimulates the growth promoting effects of IGF-I on the kidneys and the spleen. These data warrant further investigation because differences in concentrations of IGFBP-1 occurring in vivo may influence IGF-I-induced anabolic processes.     

Mutations in the NSD1 gene in patients with Sotos syndrome associate with endocrine and paracrine alterations in the IGF system

OBJECTIVE: To investigate the effect of nuclear receptor Su-var, 3-9, enhancer of zeste, trithorax (SET) domain-containing protein 1 (NSD1) gene alteration in patients with Sotos syndrome on plasma IGFs and IGF-binding proteins (IGFBPs), as well as on the IGF/IGFBP system activity at the tissue level. DESIGN: Twenty-nine patients suspected of Sotos syndrome were divided into two groups: patients with heterozygous deletions or mutations in the NSD1 gene (NSD1(+/-)) (n=11) and subjects without (NSD1(+/+)) (n=18). Plasma samples (n=29) and skin fibroblasts (n=23) were obtained. The results of both groups were compared and related to reference values. METHODS: IGF-I, IGF-II, IGFBP-2, IGFBP-3, IGFBP-4 and IGFBP-6 levels were determined by RIAs. The mitogenic response of fibroblasts to IGFs was investigated by [methyl-(3)H]thymidine incorporation. IGFBP-3 levels in the culture media were measured by RIA. IGFBP-3 mRNA expression was determined by real time RT-PCR. RESULTS: NSD1(+/-) patients showed significantly altered levels of IGF-I (mean-1.2 SDS), IGF-II (-1.2), IGFBP-3 (-1.7), IGFBP-4 (-0.4), IGFBP-2 (+0.8) and IGFBP-6 (+1.5). The NSD1(+/+) patients did not differ from the reference, with the exception of the mean IGFBP-3 level (-1.3). Basal proliferation and mitogenic response to IGFs was diminished in NSD1(+/-) fibroblasts compared with NSD1(+/+) (basal, P=0.02; IGF-I, P<0.001; IGF-II, P=0.02). Compared with control fibroblasts, only the mitogenic response was diminished (basal, P=0.07; IGF-I, P=0.04; IGF-II, P=0.04). A trend of higher IGFBP-3 secretion after IGF-I stimulation (P=0.09) and 3.5-5 times higher mRNA expression of IGFBP-3 in basal conditions was found in NSD1(+/-) fibroblasts in comparison to controls. CONCLUSIONS: NSD1(+/-) patients show endocrine and paracrine changes in the IGF system. These changes may contribute to the abnormal growth pattern.     

Familial colorectal cancer risk assessment needs improvement for more effective cancer prevention in relatives

Aim

Twelve to thirty % of colorectal cancer (CRC) patients and relatives with an increased familial risk of CRC are referred for preventive measures. New guidelines recommend genetic counselling for high‐risk families and surveillance colonoscopy for moderate‐risk families. Assessment of familial risk of CRC and referral rates for these preventive measures were determined 1 year after the introduction of new guidelines.

Method

Assessment of familial risk of CRC and referral for preventive measures were measured in clinical practice among 358 patients with CRC in 18 hospitals using medical records and questionnaires. Additionally, a knowledge survey was performed among 312 clinicians.

Results

Sixty‐seven % of patients with an increased familial risk (n = 65/97) were referred for preventive measures, as were 23% (61/261) of low‐risk patients. The uptake of genetic counselling in high‐risk families was 33% (12/36). The uptake of surveillance colonoscopy in moderate‐risk families was 34% (21/61). In the knowledge survey clinicians correctly determined familial risk in 55% and preventive measures in 65% of cases.

Conclusion

Currently 67% of individuals with an increased familial risk of CRC were referred for preventive measures. Only one‐third were referred in accordance with guidelines.

     

Failure to demonstrate pluripotential hemopoietic stem cells in mouse brains.

Hemopoietic stem cells as defined by the capacity to produce spleen colonies in lethally irradiated recipients were reported by P. F. Bartlett [(1982) Proc. Natl. Acad. Sci. USA 79, 2722-2725] to be present in high frequencies in mouse brain. He also reported similar numbers of colony-forming units, spleen (CFU-s), in the brains of Wf/Wf mice, the bone marrow of which lacks detectable spleen colony-forming cells. To verify these observations, single cell suspensions were produced from murine brains by incubation with trypsin and DNase, followed by removal of myelin by Percoll gradient centrifugation. Two to 13 CFU-s were detected per brain. This low number suggested contamination of the brains by either blood or bone marrow leaking from the skull bones during dissection. When the isolated, intact brains were washed carefully in balanced salt solution, the recovered number of CFU-s decreased to 0.1-0.4 per brain. No CFU-s could be detected in the brains of W/Wv mice. It is concluded that the CFU-s observed by Bartlett in preparations of mouse brain did not originate from the brain tissue.