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Biomedical subjects

A Howell

Publications and source records attributed to A Howell.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1994

Tropisetron compared with a metoclopramide-based regimen in the prevention of chemotherapy-induced nausea and vomiting.

This randomised, open, parallel group study compared the antiemetic efficacy and tolerability of tropisetron with metoclopramide plus lorazepam in 102 patients receiving a first course of non-cisplatin-containing chemotherapy. Control of acute vomiting by tropisetron was significantly superior to that of the metoclopramide regimen, with total control (no vomiting) in 45% of 51 patients in the tropisetron group compared with 22% of 51 patients in the metoclopramide group (P = 0.013); total and partial control (< 5 vomits) occurred in 67 and 47% of patients, respectively (P = 0.044). The incidences of acute nausea and of delayed nausea and emesis were similar in the two treatment groups. Both tropisetron and metoclopramide were well tolerated; no adverse effects were attributed to tropisetron administration with the exception of headache. One patient in the metoclopramide group reported confusion and tremor thought to be related to the antiemetic therapy. Tropisetron is an effective and well-tolerated agent in the prevention of chemotherapy-induced vomiting. The control of acute nausea was similar in the two treatment groups, but tropisetron was superior to a metoclopramide-based regimen in the control of acute vomiting.

Acute Disease↗
PubMed1994

Cancer experience in the relatives of an unselected series of breast cancer patients.

First- and second-degree relatives of an unselected series of 402 breast cancer patients have been studied for their cancer experience. In the first-degree relatives an excess of all cancers is seen [overall relative risk (RR) = 1.28, P = 0.002; males RR = 1.26, P = 0.047; females RR = 1.30, P = 0.022). There is a marked excess of sarcoma (RR = 4.26, P = 0.0064); females are at high risk of breast cancer (RR = 2.68, P < 0.0001) and males have an excess of carcinoma of the lip, oral cavity and pharynx (RR = 4.22, P = 0.0032). Second-degree relatives have a non-significant excess of all cancers (RR = 1.14, P = 0.14); females have a borderline excess of breast cancer (RR = 1.53, P = 0.08) and an excess of carcinoma of the kidney (RR = 7.46, P = 0.0012) and males have an excess of carcinoma of the trachea and lung (RR = 1.50, P = 0.032). No excess of prostate or ovarian carcinoma was seen. Relatives are at slightly higher risk if the index patient is diagnosed between the ages of 40 and 49 (first-degree RR = 1.64, P = 0.007; second-degree RR = 1.43, P = 0.02). The excess of cancers, including breast cancers, is not limited to a few high-risk families, but appears to be spread across many. These observations may be accounted for by shared environmental factors within families or a common predisposing gene with low penetrance.

Adolescent↗
PubMed1994

Response to intravenous bisphosphonate therapy in hypercalcaemic patients with and without bone metastases: the role of parathyroid hormone-related protein.

Plasma parathyroid hormone related-protein (PTHrP) may inhibit the calcium-lowering effect of bisphosphonate therapy. In this prospective study we examined the relationship between plasma PTHrP levels, renal tubular markers of calcium reabsorption, and the effectiveness of intravenous bisphosphonate therapy (IVBPT) in lowering serum calcium in patients with hypercalcaemia of malignancy (HM), with and without bone metastases. Thirty-five symptomatic hypercalcaemic patients (17 without and 18 with bone metastases) were treated with IVBPT (pamidronate 30-60 mg or BM21.0955 2-6 mg). Normocalcaemia was achieved in 24/35 (71%) patients with a mean fall in serum calcium of 0.85 mmol l-1 (range 0.11-1.93, P < 0.001). In the 35 patients studied, serum calcium levels reached a nadir between days 3 and 7, and this was accompanied by a small but significant reduction in plasma PTHrP levels (median reduction 0.77 pmol l-1, P = 0.007). Patients who responded to bisphosphonate therapy by becoming normocalcaemic had significantly lower basal plasma PTHrP levels, mean 4.06 vs 8.2 pmol l-1 (P < 0.04). A significant reduction in urinary calcium excretion was seen (mean 106 mumol l-1, P < 0.02) in patients with bone metastases, and urinary cAMP (mean 170 mmol l-1, P < 0.01) fell in all patients. Patients without demonstrable bone metastases had significantly higher plasma PTHrP levels (P < 0.002), required more doses of IVBPT, and had a poorer reduction in serum calcium compared with patients with bone metastases, only one of whom required more than one dose. We conclude that circulating PTHrP has an important role in increasing renal tubular reabsorption of calcium in HM, thus reducing the effectiveness of bisphosphonate therapy, particularly in patients with humoral HM and no bone metastases.

Bone Neoplasms↗