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Biomedical subjects

R C Bennett

Publications and source records attributed to R C Bennett.

At least 55 records · Page 3Linked to original sources
PubMed1985

Phaeochromocytoma: a review of the St Vincent's Hospital, Melbourne experience (1969-84) and of recent advances in management.

Phaeochromocytoma is an unusual tumour which is eminently curable by surgical means. It is difficult to diagnose clinically because it mimics other illnesses. The clinical features of 13 cases of phaeochromocytoma diagnosed at St Vincent's Hospital, Melbourne, between 1969 and 1984 are briefly described. This review emphasizes the several major improvements in both diagnostic and localizing tests which have occurred over the 16 year period of the series. These include the clonidine suppression test and plasma and urine catecholamine estimations in diagnosis and techniques such as CT scanning and the I131-meta-iodobenzyl-guanidine scan used for localization of the tumour. Careful pre-operative preparation, based on adequate alpha blockade and intra-operative monitoring, is essential for the safe and successful removal of the tumour, which was eventually accomplished for all 12 cases in which removal was attempted. However, the most important step in the diagnosis and treatment of phaeochromocytoma is the initial consideration of the diagnosis. This step depends on the level of awareness of the disorder amongst clinicians.

Adrenal Gland Neoplasms↗
PubMed1985

Donor transportation.

Explore the source record for details and available documents.

Health Services Accessibility↗
PubMed1984

Androgen receptors in breast cancer.

Androgen receptor assays have been performed on 1371 specimens of histologically confirmed primary and recurrent breast cancer. Forty-two patients who had received tamoxifen as treatment for advanced disease were assessed for objective response. Another 42 patients who had received chemotherapy were similarly studied. Patients with androgen receptor-negative tumors had a significantly poorer response rate to hormone therapy than those with receptor-positive tumors (P less than 0.05). This clinical correlation is supported by survival data of 1181 patients with primary breast cancer which showed that patients with androgen receptor-negative tumors had a highly significant trend toward shorter overall survival than those with receptor-positive tumors (P less than 0.001). Androgen receptor data added significantly to the information provided by estrogen receptor data both in terms of response to hormone treatment and survival.

Breast Neoplasms↗
PubMed1984

Progesterone receptors in breast cancer.

Sixty-six women who had received hormonal therapy for advanced disease were assessed for objective response to treatment. Another 51 patients who had received chemotherapy were similarly studied. Progesterone receptor was of no value as a predictor of patients unlikely to respond to hormone therapy, though it may have a role in predicting patients likely to respond favourably. The addition of progesterone receptor data to oestrogen receptor data may increase prediction of response in the ER+ range but clinicians should be cautious in their interpretation of progesterone receptor results in the ER- range. Progesterone receptor was of no value in predicting response to chemotherapy in this series. Analysis of survival data of 1731 women with primary breast cancer showed a highly significant trend toward longer survival in patients with progesterone receptor positive tumours than in those with receptor negative tumours (P less than 0.001). This trend was evident in both pre- and post-menopausal women. Even though the prognostic discrimination provided by progesterone receptor was correlated with that of oestrogen receptor, the addition of progesterone receptor data to oestrogen receptor data significantly improved prediction of survival (P less than 0.05).

Adult↗
PubMed1984

Hormone receptors in male breast cancer.

Hormone receptor assays were performed on specimens of breast cancer from 19 male patients over a six year period. Ninety-four per cent were positive for oestrogen receptor, 93% for progesterone receptor and 57% for androgen receptor. Eight patients had hormonal treatment for advanced disease and five (62.5%) responded. Duration of response ranged from six months to 23 months. There appeared to be no clear relationship between hormone receptor status or quantitative receptor level and response to treatment in this small series. It is unlikely that oestrogen and progesterone receptors will be of value as discriminators because of their high incidence and it is suggested that further study of androgen receptor is indicated.

Aged↗
PubMed1984

Haematemesis and melaena at St. Vincent's Hospital, Melbourne.

One hundred and fifty-three patients with haematemesis and melaena were studied retrospectively. The majority were managed in general medical units. Fifty-one per cent had a past history of peptic ulcer and/or bleeding, and only 9% had no identifiable predisposing factors. Endoscopy was the major diagnostic tool, with a diagnostic rate of 85%. Nineteen per cent of patients had no diagnostic investigations performed for varied reasons. The operative rate was 15% overall, with an operative mortality of 17%. The presence of other serious disease states concomitant with the haematemesis and melaena, and the presence of oesophageal varices as the aetiology, were both shown to be associated with statistically worse prognoses. Age of greater than 50 years and transfusion of four or more units of blood were also associated with a worse prognosis. Overall mortality was 14%, comparable to or less than that at several institutions, but more than double that of a Haematemesis and Melaena Unit in another Melbourne hospital [Br. Med. J. 1, 1238-40 (1979)] Patient population should be considered closely when comparing mortalities from different series. It is felt that results could be improved using a combined medical and surgical approach, and a set protocol of management, and that such changes should be monitored via a prospective study.

Australia↗
PubMed1984

Oestradiol receptor values in breast cancer and response of metastases to therapy.

Eighty-one women who had received hormonal therapy for advanced disease were assessed for objective response to treatment. Another 73 patients who had received chemotherapy were similarly studied. Patients with ER - tumours had a significantly poorer response rate to hormonal therapy than those with ER + tumours (P less than 0.05) and a significant trend toward an increasing rate of response occurred with increasing quantitative levels of receptor (P less than 0.01). This trend was even more significant when the assay had been performed on recurrent tumour (P less than 0.001), suggesting that this provides a more accurate index of response to hormonal treatment than assays performed on the primary lesion. These results suggest that whilst the quantitative receptor level used to discriminate between 'negative' or 'positive' assays is appropriate, this division is an over-simplification. Oestrogen receptor was not helpful in predicting response to chemotherapy.

Breast Neoplasms↗
PubMed1984

The prognostic value of oestrogen receptors in breast cancer.

Survival data for 2006 women who had oestrogen receptor assay carried out on primary breast cancer tissue between 1976 and 1982 are presented. There was a significant trend to shorter survival in patients with low ER levels than in those with high ER levels (P less than 0.01). This trend was evident in both pre- and post-menopausal women. The point of maximum discrimination between prognostic groups occurred at 8 fm in premenopausal women and the four year survival rates of patients above and below this level were 84% and 48%, respectively. In post-menopausal women, maximum discrimination occurred at 90 fm, and the four year survival rates above and below this level were 82% and 64%, respectively.

Adult↗
PubMed1983

Hormone-receptor assays in breast cancer. A five-year experience.

Over a five-year period, from 1976 to 1981, hormone-receptor assays were performed in breast cancer specimens from 1868 women and 10 men. Oestrogen, progesterone, and androgen receptor results were distributed from zero to high levels without any clear separation into identifiable groups, which suggests that the division of results into negative and positive is an arbitrary one. The number of positive results increased significantly during the course of the study, probably due to improved tissue handling and increasing experience with assays. Over-all results showed that 61% of primary breast cancers in women compared with only 49% of secondary cancers gave positive results for oestrogen receptor. The incidence of progesterone and androgen receptors was also higher in primary cancers than in secondary cancers. In women with primary cancers, 72% of cancers were women with primary cancers, 72% of cancers were oestrogen-receptor positive in women after menopause, whereas in those before menopause only 48% were positive. Oestrogen receptor was detected in nine out of 10 male breast cancers.

Adult↗
PubMed1983

Hepatic metastases--a physiological approach to treatment.

Hepatic metastases derived from primary malignancy of the gastrointestinal tract have a grave prognosis, with median survival rates varying from 3 to 11 months. Surgery for isolated metastases and intrahepatic artery chemotherapy are the most effective treatment options currently available. We have explored the potential use of radioactive microspheres delivered into the liver by the hepatic artery as a form of internally irradiating metastatic liver cancer. Microspheres containing radioactive Yttrium injected into the hepatic artery concentrate in the metastases rather than normal liver parenchyma, due to the fact that the blood supply of metastases is derived preferentially from the hepatic artery. Using a rabbit tumour model, radioactive microspheres delivered into the hepatic artery have been shown to lodge preferentially in tumour tissue. The therapeutic application of this phenomenon is that metastases may receive many times the radiation dose delivered to normal liver parenchyma when radioactive microspheres are delivered into the hepatic artery. This would mean that a mean dose of 30 Gy delivered to normal liver tissue would result in greater than 150 Gy being delivered to tumour tissue. Current results in experiments suggest that this form of treatment may have considerable potential for prolonging survival of patients with hepatic metastases.

Animals↗
PubMed1983

Peripheral blood lymphocyte levels in large-bowel cancer.

The relationship between peripheral blood lymphocyte levels and monitoring and assessment of prognosis of patients with large-bowel cancer has been assessed. There does not appear to be a correlation between the absolute lymphocyte count and the state of disease. Furthermore, the preresection and postresection lymphocyte levels do not accurately predict the likelihood of recurrent cancer subsequently developing, and the serial monitoring of patients with peripheral blood lymphocyte levels adds no important new information to clinical follow-up.

Adenocarcinoma↗
PubMed1983

Internal radiotherapy for hepatic metastases I: The homogeneity of hepatic arterial blood flow.

Internal radiotherapy, in the form of arterially infused yttrium-90-labeled microspheres, theoretically appears encouraging as a method of treatment for hepatic metastases. Previous investigators have assumed a homogeneous distribution of these microspheres and given dosages of isotope based solely on an estimated liver mass. The purpose of this study has been to establish the homogeneity of isotope distribution in liver substance when 15 micrometers microspheres are arterially injected. This has been done in three mammalian species, with the results expressed as a mean percentage coefficient of variation of 28 +/- 5%. Also demonstrated is the fact that 15 micrometers particles, while not penetrating to the venous circulation, achieve a more homogeneous spread throughout the liver than larger particles. It has been demonstrated that to achieve this maximum homogeneity distribution, 4000 beads/g of liver tissue are required. This equates in the therapeutic situation to a maximum activity of 4 Ci/g of infused microspheres. These results are considered significant in that they indicate criteria necessary to achieve the maximum homogeneity of therapeutic agent within liver substance when it is administered by this method, and will allow confidence limits to be attached to direct in vivo measurement of hepatic irradiation.

Animals↗
PubMed1983

Internal radiotherapy for hepatic metastases II: The blood supply to hepatic metastases.

Given that metastatic hepatic malignancy remains as a significant cause of death, with a median survival after diagnosis of only 7 months despite treatment, there exists a need for some effective treatment modality. Internal radiotherapy in the form of yttrium-90 microspheres infused into the hepatic artery appears to be a promising method of therapy. One criterion required for the success of this treatment is that of a differentially greater arterial supply to tumor as opposed to liver tissue. This arterial hypervascularity of tumor has been demonstrated before. However, some conflict has been reported as to the maintenance of this state as tumor size increases. Using 15 micrometers Cobalt-57 microspheres for studying salivary adenocarcinoma implants in DA rat livers, these experiments have demonstrated a constant blood flow in the tumor periphery of 3.9 times that within the normal hepatic parenchyma, regardless of tumor size. Also demonstrated is a progressive decrease in central tumor arterial blood flow after a tumor diameter of 6 mm has been exceeded. Arterial hypervascularity of liver tissue adjacent to the tumor has been demonstrated while an intermediate zone of liver tissue appeared hypovascular, suggesting the presence of shunting. In three humans with metastatic liver disease, hepatic artery infusion of particulate radiotracer has demonstrated the peripheral tumor hypervascularity and relative central tumor hypovascularity with good correlation obtained with the images of the metastases on conventional colloidal hepatic scintigraphy. This method allows assessment of the patient's suitability for internal radiotherapy by enabling assessment of the tumor vascularity and the degree of potentially dangerous extrahepatic irradiation.

Animals↗
PubMed1983

Reliability of steroid hormone receptor assays: an international study.

The reproducibility of oestrogen and progestin receptor assays performed by laboratories participating in an international breast cancer treatment trial has been assessed. Three tissue reference powders containing low, medium and high oestrogen receptor levels (22 +/- 4, 88 +/- 7, 227 +/- 13 fmol/mg cytosol protein respectively) were prepared in Louisville, KY, U.S.A., assayed repeatedly and multiple samples of each shipped on solid CO2 to the coordination-distribution centre in Berne, Switzerland. Samples were dispatched from Berne to Cantons within Switzerland, to Yugoslavia, South Africa, Australia, New Zealand and also back to the United States for oestrogen and progestin receptor assays. Results were returned to Berne, Switzerland. There was a decrease in the levels of oestrogen and progestin receptors during the time of storage and transit. However, the ability to assign a powder to either the low, medium or high level of oestrogen receptor was not affected. Laboratories also determined progestin receptor. All laboratories clearly identified the powder containing the low level of progestin receptor, but there was poor quantitation with the other two assay standards. It is recommended that clinical hormone receptor laboratories, especially those participating in clinical trials, establish regular quality control procedures for both daily evaluation internally and periodic outside monitoring of interlaboratory variation.

Animals↗
PubMed1983

Long term follow-up of surgical adrenalectomy for breast cancer.

A long term follow-up of 300 patients treated by bilateral adrenalectomy for advanced breast cancer is presented. The notable features are the lengthy remissions and survival times which occurred in some patients. This is further evidence of at least two important biological subsets within the general population of breast cancers. Of the responders, 11% were still in remission at four years and 10% were alive at 10 years. Responders also enjoyed a good quality of life. These results are of considerable importance in assessing the relative merits of newer methods of treatment.

Adrenalectomy↗