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Biomedical subjects

R C Bennett

Publications and source records attributed to R C Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1990

Oral contraceptive oestrogen and progestin potencies and the incidence of deep venous thromboembolism.

To assess possible differences in the incidence of venous thrombosis and pulmonary embolism associated with oral contraceptives of varying hormonal potencies, the authors conducted a retrospective cohort study in the 15-44 year old Michigan Medicaid population. Cohorts were defined by the progestin- and oestrogen-potencies of oral contraceptives in use at the time of follow-up as classified by an oral contraceptive potency scheme. Using the low-oestrogen-/low-progestin-potency formulations for reference (rate ratio = 1), adjusted rate ratios of 0.8 (95% CI: 0.5 to 1.3, P = 0.41) and 0.6 (95% CI 0.4 to 1.2, P = 0.13) were observed for intermediate-progestin-potency and high-progestin-potency formulations, respectively. Adjusted rate ratios of 1.4 (95% CI: 0.8 to 2.3, P = 0.21) and 2.6 (95% CI: 1.2 to 5.5, P = 0.01) were observed for intermediate- and high-oestrogen-potency formulations. These data suggest a dose-response relationship between oral contraceptive oestrogen potency and venous thromboembolism, whereas no such evidence for a dose-response relationship between oral contraceptive progestin potency and venous thrombo-embolism was found.

Adolescent↗
PubMed1990

Incidence and toxicological aspects of cannabis and ethanol detected in 1394 fatally injured drivers and pedestrians in Ontario (1982-1984).

A comprehensive epidemiological study of the involvement of cannabis and ethanol in motor vehicle fatalities in the Province of Ontario, Canada, is described. The study is based on toxicological analyses of blood and, when available, urine specimens. Ethanol was determined by headspace gas chromatography (GC). For cannabis, the methods employed were radioimmunoassays (RIAs) for screening and gas chromatography/mass spectrometry (GC/MS) for the determination of delta-9-tetrahydrocannabinol (THC) in blood. The study sample consisted of 1169 drivers and 225 pedestrians. THC was detected in the blood of 127 driver victims (10.9%) in concentrations ranging from 0.2 to 37 ng/mL, with a mean of 3.1 +/- 5.0 ng/mL. Ethanol was found in 667 driver victims (57.1%), in concentrations ranging from 9 to 441 mg/100 mL, with a mean of 165.8 +/- 79.5 mg/100 mL. For pedestrians, the incidence of THC and ethanol in the blood was 7.6 and 53.3%, respectively. The incidence of THC in the driver victims in this study constitutes an approximately threefold increase over the results of an Ontario study completed in 1979. At least a part of the increase may be attributed to interstudy differences in analytical methodology for cannabinoids.

Accidents, Traffic↗
PubMed1989

Controlled clinical trial of adjuvant immunotherapy with BCG and neuraminidase-treated autologous tumour cells in large bowel cancer.

A controlled, randomised clinical trial of immunotherapy was performed in 301 patients with stage B or C colorectal cancer. The immunotherapy treatment consisted of 18 vaccinations over a 2 year period following surgery with a combination of BCG given by scarification plus subcutaneous injection of Vibrio cholera neuraminidase (VCN)-modified autologous tumour cells. Five year follow-up has now been completed in all patients. The immunotherapy did not alter either the disease-free interval or the overall survival of patients in comparison with a control group of patients not receiving immunotherapy.

Adenocarcinoma↗
PubMed1988

Estrogen receptors in bilateral breast cancer.

Estrogen receptor status, tumor histology, and the interval between the development of tumors were assessed in 99 patients with bilateral breast cancer. Tumors were first grouped into those simultaneously detected in both breasts or within 12 months of each other (synchronous bilateral breast cancer, of which there were 64) and second, those detected within more than 12 months of each other (asynchronous bilateral breast cancer, of which there were 35). Nineteen percent of all tumors were lobular carcinomas. Overall, the rate of receptor discordance between the two tumors was not significantly different from that previously reported between biopsies of primary tumor and metastases in patients with unilateral breast cancer. Synchronous receptor-positive tumors occurred significantly more frequently than expected, suggesting that the development of the two tumors was influenced by a common mechanism. In patients with asynchronous bilateral breast cancer there was a significantly longer interval between tumors if both were receptor-positive compared with concordant receptor-negative tumors and tumors with discordant receptor status. There was a significant discordance in the receptor status of asynchronous tumors when the histology also differed, indicating that the tumors in this group were likely to be separate primary tumors.

Breast Neoplasms↗
PubMed1988

Melbourne trial of adjuvant immunotherapy in operable large bowel cancer.

A controlled randomized clinical trial was undertaken to assess the ability of combined non-specific and specific immunotherapy to alter the disease-free interval and overall survival of patients with Stage B or C large bowel cancer. The immunotherapy consisted of a 2 year programme of vaccinations with BCG and neuraminidase-treated autologous tumour cells. Three hundred and one patients entered the trial. At 5 years of follow-up there is no evidence that this form of immunotherapy can alter either the disease-free interval or survival in this group of patients.

Antigens, Neoplasm↗
PubMed1988

The role of surgery in advanced carcinoma of the breast.

The role of surgery in the management of advanced carcinoma of the breast is controversial. Locally advanced carcinoma may present as a primary tumour or as recurrent disease. Treatment should be the result of a multi-disciplinary approach and may involve one or more different modalities. Minor surgery is usually meddlesome and often followed by local recurrence which is hard to control. Major resection does have a place, often in association with other modalities of treatment, and its use in carefully selected patients is described in this paper.

Breast Neoplasms↗
PubMed1988

The prognostic importance of steroid receptors in endometrial carcinoma.

Three hundred forty-nine cases of primary endometrial carcinoma (endometrioid, adenosquamous, and clear-cell) were studied to investigate the relative prognostic importance of age, menopausal status, stage, histology, myometrial invasion, and estrogen and progesterone receptor content. Excluding menopausal status, all of these variables had a significant relationship to overall survival in a univariate analysis. Using a Cox multivariate regression analysis, stage, age, and an estrogen receptor value of more than 70 fmol/mg protein, combined with a progesterone receptor value of more than 30 fmol/mg protein, were independently associated with survival. The results demonstrate that for maximum prognostic information, both estrogen and progesterone content of tumors should be measured. Maximum prognostic information is obtained by using cutoff levels that are much higher than those traditionally accepted. This has particular relevance for patient stratification in clinical trials investigating receptor information and response to adjuvant or therapeutic treatment.

Adenocarcinoma↗
PubMed1987

Validation of a prognostic index in breast cancer.

The validation of a prognostic index for patients with primary breast cancer is described. The actual survival data in a group of 383 patients was compared with expected survival predicted by an index based on axillary lymph node status, oestrogen receptor, progesterone receptor and age. There was no significant difference between actual and predicted deaths for five ranges of index value at 2 years and for the three highest ranges of index value at 5 years. However, in the two lowest ranges, the index significantly underpredicted deaths at 5 years. The Cox proportional hazards model was used to determine if there was any significantly better combination of coefficients and covariates to predict survival in the test group. The original index--1 = N + E + P + A, where N = 0 if no nodes are involved, 13 if one to three nodes are involved, and 31 if more than three nodes are involved; E = 15 if oestrogen receptor value is less than 10 fmol/mg cytosol protein and 0 otherwise; P = 12.5 if progesterone receptor value is less than 10 fmol/mg cytosol protein and 0 otherwise; and A = number of years over age 65--was as good as any competing model in ranking survival prospects in the test group. However, it was a less sensitive predictor in this group than in the original set of patients. A second index based on tumour size, hormone receptor status and age, for use when lymph node status was unavailable, was tested by the same method and validated.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1986

Prognostic factors in breast cancer and the development of a prognostic index.

A number of different factors are known to be correlated with survival of patients with breast cancer. Among these are lymph node status, tumour size, oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) status. The purpose of this study was to investigate the relative significance of these factors and use this information to construct a prognostic index capable of predicting survival. These factors together with age and menopausal status were studied and correlated with prognosis in 796 women with primary breast cancer. The data were analysed in a stepwise manner by the Cox proportional hazards regression technique. Statistically, greater than 3 nodes involved gave the worst prognosis (P less than 0.001). This was followed by ER if less than 10 fmol/mg cytosol protein (P less than 0.001), PR if less than 10 fmol (P less than 0.01), greater than 0 lymph nodes involved (P less than 0.01) and the number of years over age 65 (P less than 0.01). When these factors were accounted for, tumour size, menopausal status and AR did not significantly improve prediction of survival. The significant factors were incorporated into a prognostic index: I = N + E + P + A, where N = 0 if no nodes involved, 13 (if 1-3 nodes involved and 31 if greater than 3 nodes involved, E = 15 if ER less than 10 fmol, P = 12.5 if PR less than 10 fmol and A = number of years over 65. Using this index five year survival curves were constructed corresponding to groups of patients with widely differing prognoses. Predicted five year survival ranged from 96 to 12 per cent.

Adult↗
PubMed1986

Evaluation of a new oestrogen receptor assay.

Replicate assays of oestrogen receptor (ER) concentration on 81 specimens of human breast carcinoma were performed to compare the ligand binding Sephadex separation method with a polystyrene bead linked anti-oestrogen receptor monoclonal antibody technique (enzyme immunoassay [EIA], Abbott Laboratories). Each specimen was homogenized and the cytosol divided into four fractions. Replicate assays by each method gave an estimate of reproducibility. The mean CV (coefficient of variation = standard deviation/mean) for the ligand binding method was 9.73% compared with a mean CV of 17.9% for the EIA method. In the clinically significant range of ER values, around the cut-off point between negative and positive assays, there was no difference in the precision of the two assays (Mann Whitney U-test). The correlation between methods gave a Pearson's Product Moment Correlation Coefficient (r value) of 0.822, significant at the P less than 0.001 level, indicating a close correlation between the two methods. The highest CVs for both methods were in the range of oestrogen receptor concentrations, below 10 fmol/mg cytosol protein. Using 10 fmol/mg cytosol protein as a cut-off between negative and positive assays, 9.87% of the specimens would be reclassified as either positive or negative by the new assay method. The new assay method is, therefore, acceptable for clinical use.

Antibodies, Monoclonal↗
PubMed1986

Abdomino-anal pull-through resection of the rectum.

Abdomino-anal pull-through resection of the rectum is one method of achieving resection of carcinomas involving the middle third of the rectum while allowing sphincter conservation. A number of different techniques have been described and are now reviewed along with the reported results with special reference to operative mortality, cancer curing potential, post-operative morbidity, and the quality of post operative function. Considerable variability in the published results and in the experience of different authors has prevented this procedure becoming widely adopted in the past. Its current place in the management of rectal carcinoma is discussed with reference to other sphincter saving techniques, and in particular the use of stapling devices which are now frequently used to achieve anastomosis following resection of low-lying tumours. It is considered that, at the present time, there is little place for abdomino-anal pull-through techniques in the management of rectal carcinoma.

Abdominal Muscles↗
PubMed1985

A case of pancreatitis associated with gastrinoma.

A case is presented of a 56 year old man with a history of idiopathic pancreatitis and multiple admissions for Klebsiella sepsis from an intra-abdominal focus, who in February 1980, developed spontaneous jejunal perforations on two occasions due to multiple ulcers in the small intestine associated with multiple hepatic metastases from a gastrin-secreting islet-cell tumor (gastrinoma) of the pancreas. On searching the literature, no other record could be found of an association between pancreatitis and a gastrinoma, although in this patient the two disease processes appear to be inextricably related.

Acute Disease↗