Search PubMed⌕ Search

Biomedical subjects

H Sobol

Publications and source records attributed to H Sobol.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Inserm ad hoc committee: Recommendations for the management of women with a genetic risk for developing cancer of the breast and/or the ovary].

BACKGROUND: Almost 10% of breast and ovarian cancer are inherited, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite the uncertainty, consensus guidelines were defined to assist practitioners', and patients' decisions about the health care decisions to be made. METHODOLOGY: The ad hoc committee consisted of 14 experts designated by the French National Institute for Health and Medical Research. They all attended eleven workshops at which a systematic analytical review of more than 3,500 articles was carried out. Five additional experts critically analyzed the first version of the report. PROCESS: Two thresholds were defined on a probability scale giving the risk of developing breast or ovarian cancer, to serve as a means of deciding as whether an intervention is worthwhile. The first threshold is that above which an intervention can be envisaged or recommended; the second is that under which an intervention can be ruled out; between the two, the decision has to be made on a each by case basis. SCREENING AND PREVENTIVE STRATEGIES ANALYZED: About breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. About ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: With each strategy the following points were dealt with: the information to be delivered to the consult and, the procedure and the indications. The committee's opinion about BRCA mutation screening is that population-based or even large scale implementation are not justified. The committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and involvement in clinical trials.

Age Factors↗
PubMed1999

[INSERM-FNCLCC collective expertise. Recommendations for medical management of women with genetic risk of developing breast and/or ovarian cancer].

BACKGROUND: Almost 10% of breast and ovarian cancer are inherited, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite the uncertainty in the management of women gene carriers, consensus guidelines were defined to assist practitioners', and patients' decisions about the health care decisions to be made. METHODOLOGY: The Ad Hoc Committee consisted of 14 experts designated by the French National Institute for Health and Medical Research. They all attended eleven workshops at which a systematic analytical review of more than 3500 articles was carried out. Five additional experts critically analysed the first version of the report. CRITERIA AND DECISION PROCESS: Two thresholds were defined on a probability scale giving the risk of developing breast or ovarian cancer, to serve as a means of deciding as whether an intervention is worthwhile. The first threshold is that above which an intervention can be envisaged or recommended; the second is that under which an intervention can be ruled out; between the two, the decision has to be made on a each by case basis. STRATEGIES ANALYZED: About breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. About ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: With each strategy the following points were dealt with; the information to be delivered to the Consultant, the procedure and the indications. In addition, the Committee's opinion about BRCA1 and BRCA2 mutation screening is that population-based or even large scale implementation are not justified. Although no scientific evidence is available, the Committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and involvement in clinical trials.

BRCA1 Protein↗
PubMed1998

Marker segregation information in breast/ovarian cancer genetic counseling: is it still useful? Groupe Génétique et Cancer de la Fédération Nationale des Centres de Lutte Contre le Cancer.

The use of mutation screening of BRCA1 and BRCA2 genes as a genetic test is still to a certain extent limited and the oncogeneticist may want to use complementary approaches to identify at-risk individuals. In a series of 23 families with at least three breast or ovarian cancer cases, screened for mutations at BRCA1 and BRCA2 and typed for markers at both loci, we investigated the usefulness of marker segregation information at two levels: 1) to what extent can the indirect approach identify the mutation carrier status of screened cases and their first-degree relatives, and 2) in what way does it help to identify the gene implicated in a family in which neither BRCA1 nor BRCA2 mutation has been detected? Using the indirect approach, the carrier status of the screened case could be determined with quasi certainty in three families and with a high probability in eight families. This status could be inferred in unaffected first-degree relatives as almost certain in one family and as highly probable in six families. Fourteen mutations were found concurrently in our series. Among the nine mutation-negative families, we were able to conclude that a BRCA1 mutation most probably segregated in one and that a mutation other than BRCA1 and BRCA2 was probably involved in two families. Our results show that, in small families, little help is to be expected from linkage data and mutation screening is the only way of identifying the origin of a genetic predisposition in a family. Marker segregation information may be useful in some large breast/ovarian cancer families in which no BRCA1 or BRCA2 mutation has been detected.

BRCA1 Protein↗
PubMed1998

Multifactorial analysis of differences between sporadic breast cancers and cancers involving BRCA1 and BRCA2 mutations.

BACKGROUND: We have previously demonstrated that breast cancers associated with inherited BRCA1 and BRCA2 gene mutations differ from each other in their histopathologic appearances and that each of these types differs from breast cancers in patients unselected for family history (i.e., sporadic cancers). We have now conducted a more detailed examination of cytologic and architectural features of these tumors. METHODS: Specimens of tumor tissue (5-microm-thick sections) were examined independently by two pathologists, who were unaware of the case or control subject status, for the presence of cell mitosis, lymphocytic infiltration, continuous pushing margins, and solid sheets of cancer cells; cell nuclei, cell nucleoli, cell necrosis, and cell borders were also evaluated. The resulting data were combined with previously available information on tumor type and tumor grade and further evaluated by multifactorial analysis. All statistical tests are two-sided. RESULTS: Cancers associated with BRCA1 mutations exhibited higher mitotic counts (P = .001), a greater proportion of the tumor with a continuous pushing margin (P<.0001), and more lymphocytic infiltration (P = .002) than sporadic (i.e., control) cancers. Cancers associated with BRCA2 mutations exhibited a higher score for tubule formation (fewer tubules) (P = .0002), a higher proportion of the tumor perimeter with a continuous pushing margin (P<.0001), and a lower mitotic count (P = .003) than control cancers. CONCLUSIONS: Our study has identified key features of the histologic phenotypes of breast cancers in carriers of mutant BRCA1 and BRCA2 genes. This information may improve the classification of breast cancers in individuals with a family history of the disease and may ultimately aid in the clinical management of patients.

Adult↗
PubMed1998

Mutations at BRCA1: the medullary breast carcinoma revisited.

BRCA1-associated breast cancers (BRCA1-BCs) frequently harbor a high histoprognostic grade, p53 alterations, and estrogen receptor negativity. Although these parameters predict a poor outlook, the overall survival in BRCA1-BCs is equivalent to or even better than that in sporadic cases. These features are reminiscent of what is observed for breast carcinoma of the medullary type, a high-grade tumor with a particular favorable course. To explore a possible relationship between this phenotype and BRCA1 mutations, we first compared 32 BRCA1-BCs and 200 consecutive cases of breast cancer without familial history for the prevalence of typical medullary breast carcinoma (TMC) using the criteria given by Ridolfi et al. [R. Ridolfi et al, Cancer (Phila.), 40: 1365-1385, 1977]. Second, we searched for BRCA1 mutations in a set of 18 cases of TMC, using denaturing gradient gel electrophoresis and Cleavase fragment length polymorphism scanning. Six of 32 (19%) BRCA1-BCs were of the TMC type, compared to 0 of 200 controls (P < 0.0001). Among the 18 TMCs, 2 BRCA1 nonsense mutations were found. This corresponds to almost 7 times the contribution of BRCA1 mutations in the general population. Two additional missense mutations were identified. Together, these results suggest that, although TMC and BRCA1-BCs are not strictly coincidental, an important connection between the two populations does exist.

BRCA1 Protein↗
PubMed1998

Loss of heterozygosity at loci from chromosome arm 22Q in human sporadic breast carcinomas.

Forty-four breast carcinomas were studied for loss of heterozygosity (LOH) at 25 microsatellite markers distributed almost evenly along chromosome arm 22q. LOH at at least one marker were observed in 66% tumors, while 6 regions of consistent LOH were identified. The size of each region ranged between 3 and 6 cM, and the distance between each region was estimated to be 8 to 12 cM. Even if not all these regions contain a bona fide tumor-suppressor gene, it is possible that several loci from chromosome arm 22q may be involved in breast carcinogenesis.

Breast Neoplasms↗
PubMed1998

Cancer genetic clinics: why do women who already have cancer attend?

Cancer patients attend oncogenetic clinics so that the existence of a genetic risk can be checked and the relatives informed. The aim of this study was to describe the expectations of cancer patients about genetic counselling and their beliefs about the aetiology of their disease. A survey based on self-administered questionnaires before and after the consultation was carried out on 115 women with breast/ovarian cancer who attended one of the six French participating clinics. In 59 cases (51%), the consultees' expectations focused on the preventive options available and in 86 cases (75%) on their offspring; 87 (76%) found the consultation informative. On average, the women rated heredity and diet as lower risk factors (P < 0.05) after the consultation than before. Heredity, stress and the environment were thought to be more decisive than diet, smoking and alcohol. 34 patients who seemed unlikely to have a genetic risk in the consultant's opinion thought heredity to be less relevant (P < 0.05) after the consultation than before. At the time of the survey, cancer patients accounted for at least half of the consultees attending oncogenetic clinics in France. They need to have the clinical specificities of their disease and its medical management explained. They attend mainly for their offspring's sake, whereas healthy clients attend for their own sake.

Attitude to Health↗
PubMed1998

Recommendations for medical management of hereditary breast and ovarian cancer: the French National Ad Hoc Committee.

BACKGROUND AND PURPOSE: Almost 10% of breast and ovarian cancers are familial, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite uncertainty about the management of female gene carriers, consensus guidelines have been established to assist practitioners and consultees in making health care decisions. METHODOLOGY: The Ad Hoc Committee was composed of 14 experts appointed by the French National Institute for Health and Medical Research, all of whom attended eleven workshops at which more than 3500 articles were systematically analyzed. Five additional experts critically analysed the first version of the report. CRITERIA AND DECISION PROCESS: On a probability scale of the risk of developing breast or ovarian cancers, two thresholds were defined for use in determining whether an intervention would be worthwhile. The first is the threshold above which an intervention can be envisaged or recommended, and the second is the one below which an intervention can be ruled out; between the two, the decision has to be made on a case-by-case basis. SCREENING AND PREVENTIVE STRATEGIES ANALYZED: With respect to breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. With respect to ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: For each strategy the following points were addressed: the information to be given to the consultee, the procedure and the indications. In addition, the committee's opinion about BRCA1 and BRCA2 mutation screening is that population-based, or even large-scale, implementation are not justified. Although no scientific evidence is available, the committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and participation in clinical trials.

Breast Neoplasms↗
PubMed1998

Genetic heterogeneity and penetrance analysis of the BRCA1 and BRCA2 genes in breast cancer families. The Breast Cancer Linkage Consortium.

The contribution of BRCA1 and BRCA2 to inherited breast cancer was assessed by linkage and mutation analysis in 237 families, each with at least four cases of breast cancer, collected by the Breast Cancer Linkage Consortium. Families were included without regard to the occurrence of ovarian or other cancers. Overall, disease was linked to BRCA1 in an estimated 52% of families, to BRCA2 in 32% of families, and to neither gene in 16% (95% confidence interval [CI] 6%-28%), suggesting other predisposition genes. The majority (81%) of the breast-ovarian cancer families were due to BRCA1, with most others (14%) due to BRCA2. Conversely, the majority of families with male and female breast cancer were due to BRCA2 (76%). The largest proportion (67%) of families due to other genes was found in families with four or five cases of female breast cancer only. These estimates were not substantially affected either by changing the assumed penetrance model for BRCA1 or by including or excluding BRCA1 mutation data. Among those families with disease due to BRCA1 that were tested by one of the standard screening methods, mutations were detected in the coding sequence or splice sites in an estimated 63% (95% CI 51%-77%). The estimated sensitivity was identical for direct sequencing and other techniques. The penetrance of BRCA2 was estimated by maximizing the LOD score in BRCA2-mutation families, over all possible penetrance functions. The estimated cumulative risk of breast cancer reached 28% (95% CI 9%-44%) by age 50 years and 84% (95% CI 43%-95%) by age 70 years. The corresponding ovarian cancer risks were 0.4% (95% CI 0%-1%) by age 50 years and 27% (95% CI 0%-47%) by age 70 years. The lifetime risk of breast cancer appears similar to the risk in BRCA1 carriers, but there was some suggestion of a lower risk in BRCA2 carriers <50 years of age.

Adult↗
PubMed1998

[Impact of recent oncogenetic progress on the management of high risk breast cancer patients: the example of BRCA1 and BRCA2 genes].

Evidence is mounting that hereditary breast cancers and sporadic cases harbor distinct clinical and morphological patterns that are thought to be linked to different natural histories. BRCA1-associated breast cancers appear as high grade, poorly differentiated, highly proliferating, and frequently estrogen receptor negative tumors. Surprisingly, despite these features usually associated with a poor outlook, no decrease in the overall survival is observed in hereditary cases. These elements may be of valuable help in the design of strategies in the medical management of cancer prone individuals.

Animals↗
PubMed1998

[INSERM-FNCLCC collective expert's report. Recommendations for management of women having a genetic risk of developing breast and/or ovarian cancer. National Federation of Centers of the Fight Against Cancer].

BACKGROUND: Almost 10% of breast and ovarian cancer are inherited, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite the uncertainty, consensus guidelines were defined to assist practitioners', and patients' decisions about the health care decisions to be made. METHODOLOGY: The Ad Hoc Committee consisted of 14 experts designated by the French National Institute for Health and Medical Research. They all attended eleven workshops at which a systematic analytical review of more than 3500 articles was carried out. Five additional experts critically analyzed the first version of the report. PROCESS: Two thresholds were defined on a probability scale giving the risk of developing breast or ovarian cancer, to serve as a means of deciding as whether an intervention is worthwhile. The first threshold is that above which an intervention can be envisaged or recommended; the second is that under which an intervention can be ruled out; between the two, the decision has to be made on a each by case basis. SCREENING AND PREVENTIVE STRATEGIES ANALYZED: About breast cancer: 1) hormonal interventions; 2) primary prevention (diet, family planning and chemoprevention); 3) screening (breast self-examination, clinician breast examination, tumor markers, imaging); 4) prophylactic mastectomy. About ovarian cancer: 1) hormonal stimulation; 2) screening (clinical screening, ultrasound and tumor markers); 3) prophylactic oophorectomy. MAIN CONCLUSIONS: With each strategy the following points were dealt with: the information to be delivered to the consultant, the procedure and the indications. The Committee's opinion about BRCA mutation screening is that population-based or even large scale implementation are not justified. The Committee feels that specific management is indispensable and advocates the use of defined and evaluated procedures, and involvement in clinical trials.

Anticarcinogenic Agents↗
PubMed1997

Genome-wide search for loss of heterozygosity shows extensive genetic diversity of human breast carcinomas.

Deletions of genomic regions involving tumor suppressor genes are thought to be important in the initiation and progression of breast cancer. We conducted a genome-wide search for deleted regions in a series of 75 human breast carcinomas by studying the allelic patterns of 184 microsatellite markers distributed over all chromosomes and looking for loss of heterozygosity (LOH). We identified 56 regions of consistent LOH. Strikingly, every tumor had a different set of deletions. To study this complexity, we applied a phylogenetic-like type of analysis. Each region was involved in a certain proportion of tumors, ranging from 20 to 62%; the most frequently involved regions were on chromosome arms 8p, 11q, 16q, and 17p. There was a correlation (P = 0.005) between the level of LOH and the size of the tumors. Tumors with a high level of LOH were also highly proliferative and had a high mitotic index.

Alleles↗