PubMed Health⌕ Search

Biomedical subjects

A Howell

Publications and source records attributed to A Howell.

At least 127 records · Page 7Linked to original sources
PubMed1996

Indices of differential endometrial: myometrial growth may be used to improve the reliability of detecting endometrial neoplasia in women on tamoxifen.

The aim of this study was to test the hypothesis that the use of indices of differential endometrial: myometrial growth may be a non-invasive method of improving the reliability of detecting endometrial neoplasia in women on tamoxifen. Thirty postmenopausal women were involved in this prospective study. Nineteen had been treated with tamoxifen for 2 years or more, and eleven were age- and ponderal index-matched controls who had never been exposed to tamoxifen and who were non-smokers. Transvaginal ultrasonography and color Doppler imaging were performed, to measure the length, anteroposterior diameter, uterine sagittal area, endometrial thickness and uterine blood flow (using the pulsatility index and the resistance index as measures of uterine blood flow impedance). The anteroposterior diameter: endometrial thickness ratio and product, and the saggital area: endometrial thickness ratio and product were used as indices of differential endometrial: myometrial growth. The predictive values (sensitivity, specificity, positive and negative predictive values) of each index were calculated using established criteria. For the purpose of analysis the women were allocated to three groups: controls (group 1); women on tamoxifen without endometrial neoplasia (group 2) and women on tamoxifen who developed endometrial neoplasia (group 3). The mean age was similar in the three groups as was the duration of tamoxifen treatment in groups 2 and 3. Analysis of the decision matrix based on increased endometrial thickness (> 5 mm) alone revealed good sensitivity (100%) and negative predictive value (100%) but poor specificity (46.15%) and positive predictive value (26.32%). However, when the indices of differential endometrial: myometrial growth were taken into consideration, the sensitivities and negative predictive values were similar but the specificities and positive predictive values were significantly improved, indicating an improvement in the reliability of predicting the development of endometrial neoplasia.

Aged↗
PubMed1996

Mobilisation kinetics of primitive haemopoietic cells following G-CSF with or without chemotherapy for advanced breast cancer.

BACKGROUND: The objective of this study was to determine the optimal conditions for blood progenitor cell harvest for transplantation, with main emphasis on the mobilisation kinetics of primitive, marrow repopulating cells. PATIENTS AND METHODS: Sixteen patients with advanced breast cancer were treated with 4 cycles of dose escalating FAC chemotherapy (5-fluorouracil, adriamycin, cyclophosphamide) each followed by 10 micrograms/kg/d G-CSF for 13 days. We assessed the number of colony-forming cells (CFC), and estimated the long-term culture initiating cells (LTC-IC) and CD34+ cells during the recovery phase of cycle 1 and 4 of chemotherapy, and during additional periods of G-CSF administration either preceding or following the full course of chemotherapy. RESULTS: The highest peak numbers of CFC per ml of blood (median 10489, range 860-39282) were mobilised after the first cycle of chemotherapy. The lowest peak numbers of CFC were obtained during the recovery phase from cycle 4 (median 4739, range 40-26789). In contrast, the numbers of CD34+ cells per ml of blood were significantly higher in cycle 4 (median 650, range 30-2600 x 10(2)) compared to those of cycle 1 (median 240, range 20-770 x 10(2)). The peak numbers of CFC mobilised by G-CSF before commencement and after the cessation of chemotherapy were equivalent, with a median of 5470 (range 1056-25669) and 5948 (range 2710-38975) per ml of blood, respectively. However, while mononuclear cells (MNC) collected at the days of maximal CFC mobilization following G-CSF administration before or after cycle 1 were similar to normal bone marrow MNCs in their ability to generate haemopoiesis when seeded onto performed irradiated stroma, those collected after cycle 4 or during G-CSF administration after the cessation of chemotherapy were markedly compromised in this respect. CONCLUSIONS: Our results indicate that repeated cycles of FAC chemotherapy followed by G-CSF result in a far lower number of LTC-IC than of CFC mobilised into the circulation. Furthermore although the combination of chemotherapy and G-CSF mobilised the highest numbers if CFC, G-CSF alone pre-chemotherapy was more effective at mobilising LTC-IC. These data indicate that neither the numbers of CFC mobilised nor the numbers of CD34+ cells are necessarily a reliable indicator for the putative marrow repopulating capability of the blood cells mobilised with chemotherapy plus G-CSF.

Adult↗
PubMed1996

Carcinomatous meningitis in solid tumours.

Carcinomatous meningitis (CM) is an uncommon but devastating complication of malignancy. The management is controversial and clear recommendations cannot be made because: 1) Most series include patients with CM that has arisen from different primary malignancies which are associated with different median survival intervals. 2) There have been no prospective randomised investigations of treatment modalities in patients with CM from a particular tumour type. 3) The definition of response varies from one report to another so that some response rates refer to cytological changes in the CSF while others take clinical, cytological and biochemical parameters into account. 4) Reports include patients with and without parenchymal metastases and the natural history of carcinomatous meningitis in the two situations may differ. The median survival of solid tumour carcinomatous meningitis (excluding leukaemia and lymphoma) is approximately 2-3 months and patients with breast cancer have the longest survival (median 3 months). Currently patients are treated with radiotherapy to part or all of the neuraxis with either intrathecal or intravenous chemotherapy but the relative contribution of these modalities to survival or quality of life remains unknown. Approximately 50% of patients with carcinomatous meningitis die from other causes, including systemic disease. The two most important endpoints for the patient, neurological improvement and overall survival, are seldom used in isolation in the literature. Many reports have focused on surrogate markers of response, namely biochemical and cytological data points but the correlation between clinical status and these parameters is poor because of differences between lumbar and ventricular CSF and disturbances of CSF flow in CM. The current literature does not provide clear guidelines for the treatment of this condition. Multicentre, prospective, randomised trials should be conducted that address questions of most relevance to the patient, namely neurological status and overall survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Anastrozole, a potent and selective aromatase inhibitor, versus megestrol acetate in postmenopausal women with advanced breast cancer: results of overview analysis of two phase III trials. Arimidex Study Group.

PURPOSE: To compare the efficacy and tolerability of anastrozole (1 and 10 mg once daily), a selective, oral, nonsteroidal aromatase inhibitor, and megestrol acetate (40 mg four times daily), in postmenopausal women who progressed following tamoxifen treatment. PATIENTS AND METHODS: Two randomized, double-blind for anastrozole, open-label for megestrol acetate, parallel-group, multicenter trials were conducted in 764 patients. Because both trials were identical in design, an analysis of the combined results was performed to strengthen interpretation of results from each trial. RESULTS: The median follow-up duration was approximately 6 months. The estimated progression hazards ratios were 0.97 (97.5% confidence interval [CI], 0.75 to 1.24) for anastrozole 1 mg versus megestrol acetate and 0.92 (97.5% CI, 0.71 to 1.19) for anastrozole 10 mg versus megestrol acetate. The overall median time to progression was approximately 21 weeks. Approximately one third of patients in each group benefited from treatment. Twenty-seven patients (10.3%) in the anastrozole 1-mg group, 22 (8.9%) in the anastrozole 10-mg group, and 20 (7.9%) in the megestrol acetate group had a complete or partial response, and 66 (25.1%), 56 (22.6%), and 66 (26.1%) patients, respectively, had stable disease for > or = 24 weeks. For all end points, individual trial results were similar to the results of the combined analysis. Anastrozole and megestrol acetate were well tolerated. Gastrointestinal disturbance was more common among patients in the anastrozole groups than the megestrol acetate group; the difference between the anastrozole 10 mg and megestrol acetate groups was significant (P = .005). Significantly fewer patients in the anastrozole 1-mg (P < .0001) and 10-mg (P < .002) groups had weight gain than in the megestrol acetate group. More than 30% of megestrol acetate-treated patients had weight gain > or = 5%, and 10% of patients had weight gain > or = 10%. Patients who received megestrol acetate continued to gain weight over time. CONCLUSION: Anastrozole, 1 and 10 mg once daily, is well tolerated and as effective as megestrol acetate in the treatment of postmenopausal women with advanced breast cancer who progressed following tamoxifen treatment. Moreover, anastrozole therapy avoids the weight gain associated with megestrol acetate treatment.

Adult↗
PubMed1995

Response to a specific antioestrogen (ICI 182780) in tamoxifen-resistant breast cancer.

We treated 19 patients with advanced breast cancer resistant to tamoxifen with a new specific antioestrogen (ICI 182780) which, in animal studies, has no agonist activity. 13 (69%) patients responded (7 had partial responses and 6 showed no change) to monthly intramuscular injections of ICI 182780 after progression on tamoxifen, for a median duration of 18 months with minimum side effects. Preliminary evidence suggests that the agent is without effects on the liver or the hypothalamic-pituitary axis. ICI 182780 appears to be a promising new agent for treatment of advanced and early breast cancer.

Aged↗
PubMed1995

Lobular carcinoma of the breast can be managed by breast-conserving therapy.

There has been a reluctance to treat patients with invasive lobular carcinoma by breast-conserving therapy because of the possibility of increased rates of local recurrence. This study is a retrospective review of 226 patients with pure invasive lobular carcinoma 4 cm or less treated by breast conservation therapy or mastectomy. Local relapse occurred in four of 52 patients (8 per cent) after breast conservation compared with 21 of 174 (12 per cent) after mastectomy. Breast conservation for invasive lobular carcinoma did not result in a higher incidence of local relapse and patients with invasive lobular and ductal carcinomas may be managed in a similar fashion.

Adult↗
PubMed1995

Allelic imbalance on chromosome 1 in human breast cancer. II. Microsatellite repeat analysis.

We have determined regions of allelic imbalance in human breast cancer cells using highly polymorphic microsatellite markers, which can be rapidly typed by the polymerase chain reaction (PCR) using very small amounts of DNA. It appears that there are several regions of chromosome I which may be the targets of allelic imbalance, including some regions which have been identified previously by different groups. The detail with which we have mapped these regions of imbalance is, however, much greater than has been previously reported, and we have been able to localise these regions to small intervals of the genome. In addition we have identified previously uncharacterised regions of allelic imbalance on chromosome arm 1p, one of which (at 1p22-31) is lost in a high proportion of malignant lesions. We are currently attempting to analyse this latter region in detail in order to identify and characterise the sequence(s) involved. Study of such regions should help us understand some of the mechanisms underlying the development and progression of breast cancer.

Alleles↗
PubMed1995

A randomised study to compare the effect of the luteinising hormone releasing hormone (LHRH) analogue goserelin with or without tamoxifen in pre- and perimenopausal patients with advanced breast cancer.

The use of goserelin with or without tamoxifen was investigated in a randomised multicentre study involving 318 pre- and perimenopausal advanced breast cancer patients. With a median follow-up of 93 weeks, 31% of goserelin-treated patients had objective responses (UICC criteria) compared with 38% of goserelin plus tamoxifen-treated patients (P = 0.24). There was a modest benefit in favour of combination therapy in time to progression (P = 0.03) but not in survival (P = 0.25). Median follow-up for survival was 117.5 weeks. Median times for disease progression and survival were 23 and 127 weeks in the goserelin alone group and 28 and 140 weeks in the combination group, respectively. In 115 patients with skeletal metastases only, significant differences in favour of combination therapy were seen in response rate, time to progression and survival. Both treatments were well tolerated and no additional safety issues were associated with combination therapy.

Adult↗
PubMed1995

A single-blind, randomised, vehicle-controlled dose-finding study of recombinant human granulocyte colony-stimulating factor (lenograstim) in patients undergoing chemotherapy for solid cancers and lymphoma.

This study evaluated the effect of glycosylated recombinant human granulocyte colony-stimulating factor (rHuG-CSF; lenograstim) on neutrophil granulocyte counts and on cells of other haematopoietic lineages in 66 patients with solid cancer or lymphoma who received myelosuppressive chemotherapy. Beginning 1 day after completion of chemotherapy, patients received lenograstim (at dosages of 0.5, 2, 5 or 10 micrograms/kg) or vehicle subcutaneously once daily for 14 consecutive days. Compared with vehicle, lenograstim significantly accelerated neutrophil recovery after chemotherapy in a dose-dependent manner. Mean neutrophil counts recovered to > 1.0 x 10(9) cells/l by day 13 in the vehicle group compared with days 11, 10, 8 and 7 in the 0.5, 2, 5 and 10 micrograms/kg lenograstim groups, respectively. Doses of 0.5 and 2 micrograms/kg of lenograstim had a significant effect on the duration of neutropenia (< 1.0 x 10(9) cells/l), the area under the absolute neutrophil count (ANC) curve and the time to ANC nadir. The dose of 5 micrograms/kg additionally decreased the total area of neutropenia and gave the narrowest range of values for all neutrophil parameters, while the 10 micrograms/kg dose brought no added benefit. A dose-response effect of lenograstim on time to neutrophil recovery was observed both for patients who received chemotherapy on a single day (n = 35) and for those who received chemotherapy over several days (n = 29). Based on these findings, a dose of 5 micrograms/kg/day was chosen for further trials.

Adjuvants, Immunologic↗
PubMed1995

The proliferation of normal human breast tissue implanted into athymic nude mice is stimulated by estrogen but not progesterone.

In order to resolve the question of which ovarian steroid stimulates normal human mammary epithelial cell proliferation, we have implanted pieces of normal human breast tissue subcutaneously into athymic nude mice. These mice were then treated with slow-release pellets containing estradiol (E2) or progesterone (P) such that serum levels of E2 and P were increased to those seen in normal women. The proliferative activity of the tissue implants was assessed by uptake of tritiated thymidine and steroid receptor expression was measured immunocytochemically. Insertion of a 2 mg E2 pellet 14 days after tissue implantation increased the thymidine labeling index (TLI) from a median of 0.4% (n = 34) to a median of 2.1% after 7 days (n = 43; P < 0.001 by Mann Whitney U test). In contrast, treatment with a P pellet (4 mg) had no effect upon the TLI whereas P (4 mg) in combination with E2 (2 mg) had no effect over and above that of E2 alone. There was a significant correlation between the increase in TLI and either the E2 content of the pellets (P < 0.001 by linear regression) or the serum E2 levels achieved (P < 0.001). Expression of the P receptor was increased 15- to 20-fold by E2 treatment. We conclude that E2 is sufficient to stimulate human breast epithelial cell proliferation at physiologically relevant concentrations and that P does not affect proliferation either alone or after E2 priming.

Adult↗
PubMed1995

Hypercalcemia and bone resorption in malignancy.

Hypercalcemia is the most common paraneoplastic syndrome associated with cancer. This paper addresses the etiology and pathogenesis of hypercalcemia of malignancy and discusses the relative contributions of local and humoral effects on bone and renal calcium homeostasis. The roles of parathyroid hormone-related protein and other osteolytic cytokines are outlined. New biochemical markers that enable more specific monitoring of the response of bone metastases to treatment are introduced, including urinary excretion of the collagen crosslinks pyridinoline and deoxypyridinoline. The clinical management and prevention of hypercalcemia is systemically outlined, including indications for bisphosphonate, glucocorticoid, and calcitonin therapy. The results of recent trials of bisphosphonate therapy for the prevention of tumor progression and its subsequent problems such as bone pain, fracture, and hypercalcemia also are discussed.

Animals↗
PubMed1994

Carcinomatous meningitis in patients with breast cancer. An aggressive disease variant.

BACKGROUND: Carcinomatous meningitis is a rare and often devastating complication in patients with breast cancer, and the treatment is controversial. METHODS: A retrospective analysis of 35 patients with carcinomatous meningitis from breast cancer was performed to define the biology of the disease and to guide treatment. RESULTS: An aggressive variant of breast cancer was revealed: meningeal metastasis complicates less than 3.5% of cases of metastatic breast carcinoma. Sixty-seven percent of these patients had tumors that were lobular or combined lobular/ductal histology; the median intervals from primary treatment to disease recurrence and from recurrence to death were 10.9 and 15 months, respectively. The median survival after diagnosis of carcinomatous meningitis was 77 days. The most significant prognostic factor was the Karnofsky performance status (KP) at presentation of meningeal disease. Patients with a KP greater or equal to 70 survived a median of 313 days, whereas those with a KP of 60 or less survived for a median of 36 days (P = 0.0002). In addition, there was a trend suggesting that the response 2 weeks after treatment was initiated, correlated with survival. CONCLUSIONS: Carcinomatous meningitis from breast carcinoma is an aggressive metastatic complication with a poor prognosis. The authors suggest that patients with a poor KP (< 70) should be treated symptomatically and those with a good KP (> or = 70) should receive more aggressive treatment. The patients' survival in this study compared well with other reports, and yet, only one patient was treated with intraventricular chemotherapy. Therefore, these data question the superiority of intraventricular treatment versus other modalities.

Adult↗
PubMed1994

Phenotypic heterogeneity in breast fibroblasts: functional anomaly in fibroblasts from histologically normal tissue adjacent to carcinoma.

Histologically normal breast tissue was obtained from women undergoing surgery for benign breast lesions (n = 12) and mammary carcinomas (n = 15). Four fibroblast subpopulations (FI, FII, FIII and FIV) were isolated from these specimens by differential digestion and centrifugation. FI cells were the first to be released from the tissue digest and consequently assumed to be derived from the interlobular stroma; FIV fibroblasts were tightly associated with the epithelial organoids and are therefore believed to be of intralobular origin. These cells were characterised in terms of their migratory phenotype (classified as either foetal- or adult-like) and the production of motility factors according to previously described techniques. FI fibroblasts obtained from patients with benign breast lesions displayed a foetal migratory phenotype (10/11) and secreted detectable quantities of motility factors (11/11). In contrast, none of the FIV fibroblasts (0/10) obtained from these same patients displayed a foetal-like migratory phenotype or secreted motility factors. In the case of fibroblasts obtained from cancer patients, both FI (13/13) and FIV (13/13) fibroblasts displayed a foetal-like migratory phenotype and secreted motility factors. Fibroblasts were also derived from skin (n = 12) and breast fat tissue (n = 4) of certain patients. In agreement with our previously published observations, skin fibroblasts obtained from non-cancer and cancer patients also differed in terms of their migratory behaviour: none of the skin fibroblast lines (0/5) obtained from non-cancer patients were foetal-like, compared to 3/7 lines from cancer patients. All fat-derived fibroblasts (1 non-cancer and 3 cancer patients) were also foetal-like. Our results indicate (i) functional heterogeneity between FI and FIV fibroblasts of normal breast, and (ii) the presence of functionally aberrant (i.e., foetal-like) FIV fibroblasts in histologically normal breast tissue adjacent to a carcinoma.

Adipose Tissue↗
PubMed1994

Investigation of a new pure antiestrogen (ICI 182780) in women with primary breast cancer.

We have conducted a clinical trial of a novel pure antiestrogen, 7 alpha-[9-(4,4,5,5,5-pentafluoropentylsulfinyl)nonyl]estra-1,3,5,(1 0)-triene-3,17 beta-diol (ICI 182780), to assess its tolerance, pharmacokinetics, and short term biological effects in women with primary breast cancer. Fifty-six patients were randomized to either a control group (n = 19), in which they received no preoperative treatment, or a treatment group (n = 37), in which they received daily i.m. injections of ICI 182780 at doses of 6 mg (n = 21) or 18 mg (n = 16) for 7 days prior to primary breast surgery. Serum drug concentrations, gonadotropin levels, and sex hormone-binding globulin levels were measured during the study period by radioimmunoassay. Expression of estrogen receptors (ER), progesterone receptors, the estrogen-induced protein pS2, and the cell proliferation-related antigen Ki67 was determined immunocytochemically in pre- and poststudy tumor samples. Treatment with ICI 182780 caused no serious drug-related adverse events and had no effect on serum gonadotropin or sex hormone-binding globulin levels. Minor adverse events occurred in 5 patients receiving the 6-mg dose and 3 patients receiving the 18-mg dose. The serum concentration of ICI 182780 was dose dependent but showed variation between individuals. There was evidence of an approximately 3-fold drug accumulation over the short treatment period but steady state levels were not reached by the end of the 7 days. In patients with ER-positive tumors, treatment with ICI 182780 was associated with significant reductions in the tumor expression of ER (median ER index, 0.72 before versus 0.02 after treatment; P < 0.001), progesterone receptor (median progesterone receptor index, 0.50 before versus 0.01 after treatment; P < 0.05), and Ki67 (median Ki67 labeling index, 3.2 before versus 1.1 after treatment; P < 0.05). Treatment with ICI 182780 also resulted in a significant reduction in pS2 expression (P < 0.05) but this appeared unrelated to tumor ER status. In conclusion, ICI 182780 was well tolerated after short term administration and produced demonstrable antiestrogenic effects in human breast tumors in vivo, without showing evidence of agonist activity. These properties identify ICI 182780 as a candidate agent with which to evaluate whether a pure estrogen antagonist offers any additional benefit in the treatment of human breast cancer over conventional nonsteroidal antiestrogens, typified by tamoxifen, which exhibit variable degrees of agonist activity.

Aged↗