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Biomedical subjects

I C Bennett

Publications and source records attributed to I C Bennett.

At least 19 recordsLinked to original sources
PubMed1999

The genetic basis of breast cancer and its clinical implications.

While it has long been recognized that a proportion of breast cancer cases are the result of an inherited familial predisposition, precise knowledge of the underlying genetic processes has been lacking. Recent advances in molecular biology, however, have shown that hereditary breast cancer may eventuate as a result of mutations on several specific gene loci including BRCA1, BRCA2, ATM gene, PTEN and p53. Several other less frequently occurring predisposition genes such as the androgen receptor gene (AR), the HNPCC genes and the oestrogen receptor gene may also be involved, but to a lesser extent. Overall, approximately 5-10% of all breast cancers are thought to involve one of these inherited predisposition genes, with BRCA1 and BRCA2 being responsible for as much as 90% of this group. Because of the complex nature of genetic testing, mutation analysis is not presently routinely available outside genetic counselling clinics. In this review the current knowledge and role of each predisposition gene is outlined and the management implications of genetic testing for members of breast cancer families for both affected and non-affected members are discussed. The need to provide comprehensive counselling for women with an inherited predisposition to breast cancer has seen the evolution of the familial cancer clinic, involving a multidisciplinary specialist team approach. Familial cancer clinics will provide individuals with information about their risk of developing breast cancer and offer advice regarding further management strategies. It is important that surgeons, who have traditionally played a key role in breast cancer treatment, remain cognizant of these advances in genetic molecular biology, and in so doing continue to remain key participants in the conduct of breast cancer management.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Occult axillary node metastases in breast cancer: their detection and prognostic significance.

Although the presence of axillary node metastases in breast cancer is a key prognostic indicator and may influence treatment decisions, a significant proportion of patients diagnosed as axillary node negative (ANN) using standard histopathological techniques may have occult nodal metastases (OMs). A combination of limited step-sectioning (4 x 100 microns intervals) and immunohistochemical staining (with cytokeratin (MNF.116) and MUC1 (BC2) antibodies) was used to detect OM in a retrospective series of 208 ANN patients. OMs were found in 53 patients (25%), and both step-sectioning and immunohistochemical detection significantly improved detection (P < 0.05). Detection using BC2 (25%) was superior to MNF.116 (18%) and haematoxylin and eosin (H&E) (8%). OMs were found in 51 patients using only the first and deepest sectioning levels and BC2 staining. OMs were more frequently found in lobular (38%) than ductal carcinoma (25%), and more frequently in women less than 50 years (41%) than in older women (19%). Univariate overall and disease-free survival analyses showed that the presence, size and number of OM had prognostic significance as did tumour size (disease-free only) and histological and nuclear grade (P > 0.05). Cox multivariate proportional hazard regression analyses showed that the presence and increasing size of OMs were significantly associated with poorer disease-free survival, independently of other prognostic factors (P < 0.05). However there was not a significant independent association of the presence of occult metastases with overall survival (P = 0.11). These findings have important implications with regard to selection of ANN patients for adjuvant therapy.

Adult↗
PubMed1996

Trends in dental education: a literature review.

The dental literature for the past 30 years, with emphasis on recent publications, was reviewed for articles on trends in dental education. A keyword search of the MEDLINE database identified 6,055 papers, from which those most likely to predict future trends are considered in this article. Particular emphasis is placed on the Institute of Medicine of the National Academy of Sciences 1995 study, "Dental Education at the Crossroads: Challenges and Change." Reactions to this U.S.-based study are also detailed. Trends in curriculum analysis, curriculum change and reform, curriculum length, dental school financing, dental student costs, dental school and university relationships, dental school patient care, dental research, accreditation, oral health and trends from outside North America are documented. In addition, a series of predictions are made, and a brief bibliography of the 51 most relevant references is included.

Accreditation↗
PubMed1992

Phyllodes tumours: a clinicopathological review of 30 cases.

Thirty cases of phyllodes tumour (cystosarcoma phyllodes) of the breast that presented to the Clinical Oncology Unit at Guy's Hospital were reviewed. Tumours were classified as benign, malignant or borderline according to the following histological criteria: mitotic rate, nuclear pleomorphism, stromal overgrowth and tumour margins. In 14 (46.5%) cases the tumours were considered histologically benign, in 11 (36.5%) malignant, and in five (17%) borderline. Recurrence was seen in a similar proportion of patients with tumours classified as benign (21%) and malignant (18%) according to histological criteria. Malignant lesions tended to recur earlier. Infiltrating tumour margins were noted in all patients and stromal overgrowth in all but one in whom recurrence was observed. Risk of recurrence also appeared to be related to tumour size. Only one patient developed distant metastases and died of her disease. Because of treatment variation no conclusion can be made regarding optimal therapy but the importance of adequate clearance, either through wide excision or mastectomy, is emphasized for all phyllodes tumours irrespective of histological features.

Adult↗
PubMed1991

Diagnosis of breast cancer in young women.

While the prognosis of younger women with breast cancer is controversial, there have been several significant reports indicating a more unfavourable outcome of the disease in this age group. A review has been conducted of the problems encountered in the diagnosis of breast cancer in younger women. The records of 227 consecutive patients aged 30-40 years who underwent breast biopsy were retrospectively analysed, and data studied in relation to the proportion of malignant to benign biopsies, the clinical and pathological features of the malignant cases, and the method of diagnosis. A total of 235 biopsies was performed in 227 patients, of which 199 were benign (85%) and 36 were malignant (15%), giving a malignant to benign biopsy ratio of 1:5.5. Thirty-six cancers were diagnosed in 35 patients. Among these young women with breast cancer, the average duration of symptoms was 26 weeks, the mean clinical cancer diameter was 3.3 cm and only a small proportion (28%) of women had early (Stage I) disease. There were 4 women with breast cancer (11%), in whom the diagnosis of malignancy was unsuspected preoperatively. Mammography in these younger women appears to have a more limited role, with a sensitivity of only 76%. These findings indicate that the diagnosis of breast cancer in younger women is often more difficult than in older age groups and that the presentation and detection of such cancers is often delayed. Younger women need to be educated in relation to seeking early medical review of breast lumps and clinicians need to be aware of the limitations of mammography in such cases.

Adult↗
PubMed1991

Accreditation of predoctoral dental education: clinical outcomes assessment.

The Curriculum Outcomes Review and Evaluation (CORE) system of outcomes assessment used in the accreditation of Canadian Dental Faculties by the Commission on Dental Accreditation of the Canadian Dental Association is described. The CORE system, which has become an integral part of the regular accreditation site visit of Canadian dental predoctoral programs consists of (a) two methods of chart review, (b) assessment of the performance of a random sample of final year students in both diagnosis and treatment planning and in case presentation, (c) a structured observation in the clinical setting, (d) the application of a detailed and focused survey instrument prior to the site visit, and (e) the solicitation of feedback from involved students, faculty members, school administrators and accreditation site visitors. The overall response to the CORE program was favorable and plans to expand the program to dental hygiene accreditation are described.

Accreditation↗
PubMed1991

The abnormal mammogram--what to do.

When an abnormality is detected in a mammogram the following questions should be answered: 1. Does a significant abnormality exist, that is, is the abnormality present in at least two views? 2. Should special imaging techniques, such as ultrasound, be used? 3. What is the conclusion of the radiologist? 4. Is the radiological abnormality clinically palpable? 5. Is the opinion of a breast specialist required? 6. Can fine needle aspirations cytology of the area be performed accurately and without trauma? 7. Should biopsy be undertaken? By posing these questions in sequence and obtaining firm answers, small cancers should not be missed and the biopsy rate will be kept to an acceptably low level.

Biopsy↗
PubMed1990

Serum oestradiol in women with and without breast disease.

It has been suggested that the percentage of non-protein-bound or free oestradiol (E2) is abnormally high in patients with breast cancer. In this study, the serum oestradiol profiles of a large group of women were analysed to determine whether a significant correlation could be found between serum oestradiol and various breast diseases. In addition oestradiol levels were measured in relation to sex hormone binding globulin (SHBG), albumin levels, oestrogen receptor status and family history of breast cancer. Serum samples were taken from a total of 300 women who had either no breast disease, benign breast disease or breast cancer. The percentage of free oestradiol was found to be highest in women with breast cancer, lowest in the control group and intermediate for the women with benign breast disease. These differences were most marked in post-menopausal women. The absolute values for total and free oestradiol were not statistically different in the three groups studied. There did not appear to be a correlation between oestrogen receptor (ER) concentration in breast cancer tissue and free E2 percentage levels. Women who had a family history of breast cancer did not appear to have higher percentage levels of free E2 than those with no such history. The presence of elevated proportions of free oestradiol in the serum of women with breast cancer may be significant in regard to understanding the aetiology of breast neoplasia. There also may be important implications for the use of this measurement in the earlier diagnosis and detection of breast cancer.

Aged↗
PubMed1990

Changing patterns in the presentation of breast cancer over 25 years.

The clinical stage at presentation of 280 women with histologically proven breast cancer is reviewed over a 25 year time span from 1962 to 1987. The data from 240 unscreened patients, including 87 women from the period 1962 to 1963, 103 women from 1981 to 1982, and 50 women from 1986 to 1987 demonstrate a chronologically based improvement in the stage of disease at presentation over the 25 years. Specifically, over that period, there was a fall in the mean tumour diameter, a reduction in the proportion of patients with involved axillary nodes, and a greater percentage of patients with Stages I and II disease. A reduction in the symptomatic period was also noted over this time, and a direct relationship was found between the duration of symptoms and tumour size, nodal status and overall stage of disease. A subsequent comparison with the staging data from 40 women with breast cancer detected at a breast screening clinic (1985-87) shows that significant further advances in the earlier diagnosis of breast cancer can be achieved. Mammographic breast screening centres represent the best-known means of early breast cancer detection, and thus may hold the key to reducing breast cancer mortality.

Adult↗
PubMed1990

Provincial origin of first-time writers of the Canadian Dental Aptitude Test.

A brief summary of the current status of the Canadian Dental Aptitude Test (CDAT) is presented. The number of first-time writers of the CDAT is reported by the province of their preference as designated by the candidate on the test application form. Anomalies in the numbers taking the test are discussed and relationships with other provincial and regional parameters developed. It is clear that the effect of the policy change at the University of Toronto, where the CDAT is no longer required for admissions purposes, has had a major effect on the numbers taking the test and the information available about the demographics, quality and size of the Canadian dental school applicant pool. The regional and provincial differences highlighted include a relatively smaller applicant pool in British Columbia, Manitoba and the Atlantic Provinces in addition to a relatively limited educational opportunity for potential dental professionals in British Columbia, Ontario and the Atlantic Provinces.

Aptitude Tests↗
PubMed1989

Dirofilariasis in Australia: unusual cause of a breast lump.

A breast lump due to infestation with Dirofilaria repens is reported in a Sri Lankan student residing in Brisbane. Although human infestation with this parasite is not uncommon in certain Asian countries, this is the first report of such a lesion occurring in Australia.

Adult↗
PubMed1989

First year enrollment of Canadians in North American dental schools.

Data is presented relating to the number of students admitted to the first year classes of Canadian dental schools for the period 1974 through 1988 and projections for 1989. Additional data showing the number of non-Canadians in Canadian dental schools and the number of Canadians enrolled in the first year of United States dental schools is included. The study concludes that the number of Canadians in North American dental schools has not decreased but has actually increased over the last five years. Also, since there is a significant number of Canadians studying dentistry in the United States, there will probably be increased pressure to change the policies of the National Dental Examining Board of Canada presuming that these Canadians will return home. Further data is presented which leads to the conclusion that the proportion of admitted students who graduate as dentists has remained fairly constant over the study period.

Canada↗
PubMed1988

The impact of the differences in the decline of dental school applicants in the United States and Canada.

The number of individuals writing the Canadian Dental Association Dental Aptitude Test and the American Dental Association Dental Admissions Test for the first time is used as a measure of the number of new additions to the dental school applicant pool in each of the past 15 years. Dramatic changes have occurred during that period. Comparisons are made and similarities noted between the situations in the United States and Canada. A discussion of the probable causes of the differences highlights the changing government programs in the two countries, the perceptions of potential applicants, and the attitudes of members of the dental profession. Some suggestions for future action are proposed.

Canada↗