PubMed Health⌕ Search

Biomedical subjects

D G R Evans

Publications and source records attributed to D G R Evans.

At least 19 recordsLinked to original sources
PubMed2007

Familial colorectal cancer referral to regional genetics department--a single centre experience.

Evaluation of familial colorectal cancer referral can assist in the planning of future cancer surveillance. The aim of the study is to assess colorectal cancer referral pattern to our regional genetics service. Hospital computer records and/or department referral books were used to identify cases referred to the regional genetic service during a 10-year period (1992-2001 inclusive). All files were reviewed along with associated demographic data, risk assessments, referral details, results from mutation testing and screening recommendations. In terms of result, a total of 1100 family files were reviewed (Familial Adenomatous Polyposis families were in a separate register). The number of referrals showed a 10-fold increase over the 10 years. 171 (15.6%) of families met the Amsterdam criteria II were classified as high-risk, 589 (53.5%) families were classified as moderate-risk and 337 (31.0%) as average or low risk. 22.9% families were referred with inaccurate cancer history. Sixty-one families have been identified with mismatch repair mutations. 56.8% of referred individuals were recommended to have regular colonoscopy ranging from 18 monthly to 5 yearly depending on their risks. In conclusion, there has been a 10-fold increase in individuals with suspected hereditary bowel cancer referred to the North West Regional Genetics Service in the last ten years. Genetic assessment may reduce the number of low-risk individuals and those who were found not to be mutation carriers from having unnecessary colonoscopic screening. Thus genetic risk assessment should precede the initiation of regular endoscopic screening.

Adult↗
PubMed2006

Phenocopies in BRCA1 and BRCA2 families: evidence for modifier genes and implications for screening.

BACKGROUND: The identification of BRCA1 and BRCA2 mutations in familial breast cancer kindreds allows genetic testing of at-risk relatives. Those who test negative are usually reassured and additional breast cancer surveillance is discontinued. However, we postulated that in high-risk families, such as those seen in clinical genetics centres, the risk of breast cancer might be influenced not only by the BRCA1/BRCA2 mutation but also by modifier genes. One manifestation of this would be the presence of phenocopies in BRCA1/BRCA2 kindreds. METHODS: 277 families with pathogenic BRCA1/BRCA2 mutations were reviewed and 28 breast cancer phenocopies identified. The relative risk of breast cancer in those testing negative was assessed using incidence rates from our cancer registry based on local population. RESULTS: Phenocopies constituted up to 24% of tests on women with breast cancer after the identification of the mutation in the proband. The standardised incidence ratio for women who tested negative for the BRCA1/BRCA2 family mutation was 5.3 for all relatives, 5.0 for all first-degree relatives (FDRs) and 3.2 (95% confidence interval 2.0 to 4.9) for FDRs in whose family all other cases of breast and ovarian cancer could be explained by the identified mutation. 13 of 107 (12.1%) FDRs with breast cancer and no unexplained family history tested negative. CONCLUSION: In high-risk families, women who test negative for the familial BRCA1/BRCA2 mutation have an increased risk of breast cancer consistent with genetic modifiers. In light of this, such women should still be considered for continued surveillance.

Adult↗
PubMed2006

Screening younger women with a family history of breast cancer--does early detection improve outcome?

Women with a family history are often offered mammographic surveillance at an earlier age and with greater frequency than those in the National Breast Screening Programme. In this study, we compared the survival of 62 breast cancer patients diagnosed in the context of a family history clinic offering 12-18 monthly mammographic screening with that of 1108 patients of the same age range but having no exposure to screening. We subtracted the expected additional observation time due to lead time from the survival of the screen-detected cases. Survival was significantly better in the family history group with relative hazards of 0.19 (95% CI 0.07-0.52, P<0.001) for breast cancer death and 0.19 (95% CI 0.08-0.43, P<0.001) for disease-free survival. After correcting for lead-time, the relative hazards were 0.24 (95% CI 0.09-0.66, P=0.005) for breast cancer death and 0.25 (95% CI 0.11-0.57, P<0.001) for disease-free survival. These results strongly suggest that screening younger women with a family history of breast cancer leads to improved survival. More precise estimates of the benefit will accrue from further follow-up and other such studies.

Adult↗
PubMed2006

Effects of oestrogens and anti-oestrogens on normal breast tissue from women bearing BRCA1 and BRCA2 mutations.

There is considerable interest in whether anti-oestrogens can be used to prevent breast cancer in women bearing mutations in the BRCA1 and BRCA2 genes. The effects of oestradiol (E2), tamoxifen (TAM) and fulvestrant (FUL) on proliferation and steroid receptor expression were assessed in normal breast epithelium taken from women at varying risks of breast cancer and implanted into athymic nude mice, which were treated with E2 in the presence and absence of TAM or FUL. Tissue samples were taken at various time points thereafter for assessment of proliferative activity and expression of oestrogen and progesterone receptors (ERalpha and PgR) by immunohistochemistry. Oestradiol increased proliferation in the breast epithelium from women carrying mutations in the BRCA1/2 genes, those otherwise at increased risk and those at population risk of breast cancer. This increase was reduced by both TAM and FUL in all risk groups. In the absence of E2, PgR expression was reduced in all risk groups but significantly more so in the BRCA-mutated groups. Subsequent E2 treatment caused a rapid, complete induction of PgR expression in the population-risk group but not in the high-risk or BRCA-mutated groups in which PgR induction was significantly delayed. These data suggest that the mechanisms by which E2 induces breast epithelial PgR expression are impaired in BRCA1/2 mutation carriers, whereas those regulating proliferation remain intact. We conclude that early anti-oestrogen treatment should prevent breast cancer in very high-risk women.

Adolescent↗
PubMed2006

Inherited association of breast and colorectal cancer: limited role of CHEK2 compared with high-penetrance genes.

We assessed the association between breast cancer (BC) and colorectal cancer (CRC) from referral pattern to the Regional Genetics Service including molecular analysis. Hospital computer records and/or department referral books were used to identify cases referred to the Regional Genetic Service during a 16-year period (1990-2005 inclusive). All files were reviewed along with associated demographic data, risk assessments, referral details and results from mutation testing. Families were assessed for hereditary breast and colorectal cancer (HBCC) criteria, and all families with eligible individuals were tested for the 1100delC mutation in CHEK2. A total of 8,612 families were identified. One hundred and sixteen of 1,631 (7.5%) families with a primary referral for CRC fulfilled the criteria for HBCC, whereas only 68/6981 (1%) BC referrals fulfilled these criteria. Blood samples were obtained from 113 individuals from 83/184 families. Only 1/113 (1%) has screened positive for the CHEK2 mutation, whereas 14 (17%) families segregate BRCA1/2 mutations and at least 7 (8.5%) carry MLH1/MSH2 mutations. HBCC syndrome, if it exists as a separate entity, is not likely to be due to CHEK2 mutations. Many families are explicable by existing high-penetrance genes, and further work is necessary to elucidate whether the remainder is due to chance or as yet undiscovered genes.

Base Sequence↗
PubMed2006

A case of multiple cutaneous schwannomas; schwannomatosis or neurofibromatosis type 2?

A 54 year old man presented with numerous cutaneous schwannomas, cranial nerve lesions, and spinal cord lesions, but no evidence of vestibular nerve involvement. There was no family history of neurocutaneous lesions. To help discriminate between the various possible diagnoses in this patient, molecular analysis of two cutaneous schwannomas was undertaken. An identical point mutation in the NF2 gene in the two anatomically distinct tumours was found, confirming this as a case of NF2 mosaicism.

Diagnosis, Differential↗
PubMed2005

Malignant transformation and new primary tumours after therapeutic radiation for benign disease: substantial risks in certain tumour prone syndromes.

In recent years the use of radiation treatment for benign tumours has increased with the advent of stereotactic delivery and, in particular, single high dose gamma knife therapy. This has been particularly true for benign CNS (central nervous system) tumours such as vestibular schwannoma, meningioma, pituitary adenoma, and haemangioblastoma. While short term follow up in patients with isolated tumours suggests this treatment is safe, there are particular concerns regarding its use in childhood and in tumour predisposing syndromes. We have reviewed the use of radiation treatment in these contexts with particular regard to malignant transformation and new tumour induction. This review indicates that much more caution is warranted regarding the use of radiation treatment for benign tumours in childhood and in tumour prone conditions such as the neurofibromatoses.

Basal Cell Nevus Syndrome↗
PubMed2005

Surgical decisions made by 158 women with hereditary breast cancer aged <50 years.

AIM: To establish the uptake of contralateral risk reducing mastectomy in women informed of their risks and options at time of diagnosis of their primary unilateral breast cancer. METHODS: We have assessed the surgical choices of 70 women diagnosed with breast cancer <50 years as part of a family history surveillance program and fully informed about their contralateral risks and surgical options. We have compared this to women from other surgical clinics who were subsequently found to harbour a pathogenic BRCA1/2 mutation. RESULTS: Sixty-five percent (13/20) of BRCA1/2 mutation carriers and 59% (n=20/34) of those at the highest level of risk pre-diagnosis (33+% lifetime risk) opted for contra-lateral mastectomy in the study sample. In contrast only 10% (n=9/88) women identified as mutation carriers from other clinics opted for such surgery. CONCLUSIONS: We would suggest that women with a significant family history and therefore a high contra-lateral breast cancer risk, should have these risks and management options discussed at the time of diagnosis of breast cancer.

Adult↗
PubMed2005

Methodological issues in longitudinal studies: vestibular schwannoma growth rates in neurofibromatosis 2.

Four longitudinal studies of vestibular schwannoma (VS) growth rates in neurofibromatosis 2 (NF2) have yielded very different results on the relationship of VS growth rates to age. The studies had different patient eligibility criteria, indices of VS growth rates, VS volumetric methods, and sample sizes. We reanalysed data from two of the longitudinal studies and used data from the population based United Kingdom NF2 Registry to determine the most likely reason for the different results and the actual relationship of VS growth rates to age. We found that the eligibility criterion in one study caused selection bias for slower growing VS. The proper interpretation of the results from the four studies is that VS growth rates in NF2 are highly variable but tend to decrease with increasing age. Clinical trials for VS in NF2 should focus on younger patients because VS growth rates tend to decrease with increasing age, and because faster growing VS are more likely to be excised with increasing age than slower growing VS.

Age Factors↗
PubMed2005

Neurofibromatosis 2 (NF2) and malignant mesothelioma in a man with a constitutional NF2 missense mutation.

Neurofibromatosis 2 (NF2) is caused by inactivating mutations of the NF2 tumor suppressor gene. Somatic NF2 mutations also occur in a high proportion of human primary malignant mesotheliomas. We report an elderly man with NF2, malignant mesothelioma, and a constitutional NF2 missense mutation. The long latent period for mesothelioma in this patient (61 years) raises the possibility that the type of mutant NF2 allele could affect mesothelioma tumorigenesis or progression.

Aged↗
PubMed2005

Management of the patient and family with neurofibromatosis 2: a consensus conference statement.

A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.

Adult↗
PubMed2005

Multiple meningiomas: differential involvement of the NF2 gene in children and adults.

OBJECTIVE: To screen for NF2 mutations in people with meningiomas. METHODS: Lymphocyte or tumour DNA was analysed from 46 individuals from 36 families who presented with a meningioma at age < or =15 years without vestibular schwannoma (VS), or who had multiple meningiomas in adulthood before the diagnosis of VS. RESULTS: Eight of 13 people with meningioma and other features of neurofibromatosis 2 (NF2) had an identified constitutional NF2 mutation in blood DNA, but none of the other subjects had identified constitutional NF2 mutations. CONCLUSIONS: Constitutional NF2 mutations are the most likely cause of meningioma in children and in people with a meningioma plus other non-VS features of NF2. Mosaic NF2 may be the cause of about 8% of multiple meningiomas in sporadic adult cases, but there are other causes in the majority of other such patients and in multiple meningioma in families.

Adolescent↗
PubMed2005

Age related shift in the mutation spectra of germline and somatic NF2 mutations: hypothetical role of DNA repair mechanisms.

It has been suggested that somatic mutations that accumulate due to an age related decline in the efficiency of DNA repair mechanisms might contribute to the increased incidence of cancer in older people. However, there is little direct evidence for this phenomenon. The spectra of germline and somatic mutations can be compared in cancer genes that cause inherited tumour syndromes and sporadic tumours, respectively. In addition, mosaic patients reflect the nature of mutations that occur in early development. Hence, we hypothesised that the "temporal mutation record" of a human cancer gene might provide insight into mechanisms of mutagenesis in the germline, in early development, and in adulthood. We compared the ratio of frameshift to nonsense mutations in three diseases that are related to the NF2 tumour suppressor gene: classic neurofibromatosis 2 (NF2), caused by germline NF2 mutations; mosaic NF2; and unilateral sporadic vestibular schwannoma (USVS), caused by somatic NF2 inactivation. Nonsense mutations predominated in both classic and mosaic NF2, but the ratio of nonsense to frameshift mutations was reversed in USVS. Moreover, in USVS patients, the ratio of somatic frameshift to nonsense mutations increased significantly with increasing age at diagnosis. This pattern is consistent with an age related decline in the efficiency of DNA repair mechanisms. Similar studies for other familial cancer genes may provide further evidence for this hypothesis.

Age Factors↗
PubMed2005

The location of constitutional neurofibromatosis 2 (NF2) splice site mutations is associated with the severity of NF2.

Neurofibromatosis 2 (NF2) patients with constitutional splice site NF2 mutations have greater variability in disease severity than NF2 patients with other types of mutations; the cause of this variability is unknown. We evaluated genotype-phenotype correlations, with particular focus on the location of splice site mutations, using mutation and clinical information on 831 patients from 528 NF2 families with identified constitutional NF2 mutations. The clinical characteristics examined were age at onset of symptoms of NF2 and number of intracranial meningiomas, which are the primary indices of the severity of NF2. Two regression models were used to analyse genotype-phenotype correlations. People with splice site mutations in exons 1-5 had more severe disease than those with splice site mutations in exons 11-15. This result is compatible with studies showing that exons 2 and 3 are required for self-association of the amino terminal of the NF2 protein in vitro, and that deletions of exons 2 and 3 in transgenic and knockout mouse models of NF2 cause a high prevalence of Schwann cell derived tumours.

Alternative Splicing↗
PubMed2004

Psychosocial impact of breast/ovarian (BRCA1/2) cancer-predictive genetic testing in a UK multi-centre clinical cohort.

This multi-centre UK study assesses the impact of predictive testing for breast and ovarian cancer predisposition genes (BRCA1/2) in the clinical context. In the year following predictive testing, 261 adults (59 male) from nine UK genetics centres participated; 91 gene mutation carriers and 170 noncarriers. Self-report questionnaires were completed at baseline (pre-genetic testing) and 1, 4 and 12 months following the genetic test result. Men were assessed for general mental health (by general health questionnaire (GHQ)) and women for general mental health, cancer-related worry, intrusive and avoidant thoughts, perception of risk and risk management behaviour. Main comparisons were between female carriers and noncarriers on all measures and men and women for general mental health. Female noncarriers benefited psychologically, with significant reductions in cancer-related worry following testing (P<0.001). However, younger female carriers (<50 years) showed a rise in cancer-related worry 1 month post-testing (P<0.05). This returned to pre-testing baseline levels 12 months later, but worry remained significantly higher than noncarriers throughout (P<0.01). There were no significant differences in GHQ scores between males and females (both carriers and noncarriers) at any time point. Female carriers engaged in significantly more risk management strategies than noncarriers in the year following testing (e.g. mammograms; 92% carriers vs 30% noncarriers). In the 12 months post-testing, 28% carriers had bilateral risk-reducing mastectomy and 31% oophorectomy. Oophorectomy was confined to older (mean 41 yrs) women who already had children. However, worry about cancer was not assuaged by surgery following genetic testing, and this requires further investigation. In all, 20% of female carriers reported insurance problems. The data show persistent worry in younger female gene carriers and confirm changes in risk management consistent with carrier status. Men were not adversely affected by genetic testing in terms of their general mental health.

Adult↗
PubMed2004

Molecular stool screening for colorectal cancer.

BACKGROUND: Mass screening for colorectal cancer reduces mortality and, with recent advances in molecular genetics, molecular stool-based tests have produced promising results. This article reviews this innovation and discusses its clinical significance. METHODS: Medline searches were used to identify recent key articles relating to stool-based testing. Further articles were obtained by manual scanning of the reference lists of identified papers. RESULTS: Current screening methods are based on endoscopic, radiological and stool-based testing. Recent recognition of the adenoma-carcinoma sequence and pathophysiological studies of colonic epithelium have enabled tumour markers to be used in the screening setting. Non-invasive molecular stool testing has now been shown to have a high sensitivity and specificity. CONCLUSION: Recent studies on molecular stool-based testing have shown higher sensitivity and specificity than earlier studies, but larger clinical trials are required. Laboratory methods are still undergoing research, with the aim of improving sensitivity to allow large-scale testing.

Biomarkers, Tumor↗
PubMed2004

Non-uptake of predictive genetic testing for BRCA1/2 among relatives of known carriers: attributes, cancer worry, and barriers to testing in a multicenter clinical cohort.

BRCA1/2 test decliners/deferrers have received almost no attention in the literature and this is the first study of this population in the United Kingdom. The aim of this multicenter study is to examine the attributes of a group of individuals offered predictive genetic testing for breast/ovarian cancer predisposition who did not wish to proceed with testing at the time of entry into this study. This forms part of a larger study involving 9 U.K. centers investigating the psychosocial impact of predictive genetic testing for BRCA1/2. Cancer worry and reasons for declining or deferring BRCA1/2 predictive genetic testing were evaluated by questionnaire following genetic counseling. A total of 34 individuals declined the offer of predictive genetic testing. Compared to the national cohort of test acceptors, test decliners are significantly younger. Female test decliners have lower levels of cancer worry than female test acceptors. Barriers to testing include apprehension about the result, traveling to the genetics clinic, and taking time away from work/family. Women are more likely than men to worry about receiving less screening if found not to be a carrier. The findings do not indicate that healthy BRCA1/2 test decliners are a more vulnerable group in terms of cancer worry. However, barriers to testing need to be discussed in genetic counseling.

Adult↗