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Biomedical subjects

T Powles

Publications and source records attributed to T Powles.

At least 37 records · Page 2Linked to original sources
PubMed2000

Changes in acquired immunodeficiency syndrome-related lymphoma since the introduction of highly active antiretroviral therapy.

Clinical data on 7840 HIV-positive patients, representing 43 745 patient-years of follow-up, has been collected. All patients with ARL since 1986 (n = 150) were assessed at presentation for prognostic factors and outcomes recorded. Comparisons are made between cases in the pre-HAART era (1988-1995), and the HAART era (1996-1999). Statistical models are used to calculate the incidence of ARL and factors predicting its development. The incidence of ARL has not changed over time (3 to 7 of 1000 patients per year, P = .933), but contributes to a greater percentage of first AIDS-defining illnesses (ADI) in the HAART era (P < or = .0001). Older age, nadir CD4 count, and no prior HAART use, predict the development of ARL. There has been no change in stage at presentation, presence of B symptoms, performance status, or marrow involvement between the 2 time cohorts or between patients with or without prior HAART exposure. Similarly, there is no difference in survival duration between the pre-HAART and HAART era (log rank P = .15) or specifically in patients treated with HAART before ARL diagnosis (log rank P = .12). The use of HAART has not yet been shown to influence the incidence or survival of ARL. However, because nadir CD4 count and use of HAART are independent predictors of ARL development, this may translate into a future fall in new cases. (Blood. 2000;96:2730-2734)

Adult↗
PubMed2000

Secondary myelodysplastic syndrome/acute myeloid leukaemia following mitoxantrone-based therapy for breast carcinoma.

Of 1774 patients with breast cancer given mitoxantrone (MTZ) with methotrexate (n = 492) or with methotrexate and mitomycin C (n = 1282), nine developed MDS/AML after a median of 2.5 years. Median duration of survival from diagnosis of MDS/AML was 10 months and six patients died. The crude incidence of developing MDS/AML after MMM or MM chemotherapy was 15 per 100,000 patient years follow-up, while the actuarial risk was 1.1% and 1.6% at 5 and 10 years respectively. MTZ-based regimens carry a 10 x higher risk of subsequent MDS/AML compared to that seen in the general population.

Acute Disease↗
PubMed2000

AIDS related systemic non-Hodgkin's lymphoma.

OBJECTIVE: To review the current literature on HIV associated non-Hodgkin's lymphoma. METHODS: A comprehensive Medline/Pubmed search of articles pertaining to HIV associated non-Hodgkin's lymphoma as well as personal experience from the treatment of over 200 patients at the Chelsea and Westminster Hospital, one of the largest centres for the management of HIV disease in Europe. CONCLUSION: High grade B cell non-Hogdkin's lymphoma is the second commonest tumour affecting people with HIV. The incidence of this tumour is not declining following the introduction of highly active antiretroviral therapy. Chemotherapy has been employed with modest success in this group of patients; however, the prognosis remains worse than for immunocompetent patients. Advances in molecular genetics and virology have led to a greater understanding of the biology of these tumours. However, these advances have yet to be translated into improvements in the clinical management of patients with AIDS associated non-Hodgkin's lymphoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

HIV-associated Hodgkin's disease.

Hodgkin's disease (HD) appears to occur more frequently in people with HIV and within this population HD demonstrates a number of differences. In people with HIV, Epstein-Barr virus (EBV) is found more frequently in Reed-Sternberg cells and mixed cellularity and lymphocyte depleted histological subtypes predominate. Patients with HIV present with more advanced stage HD often with extranodal disease. The prognostic variables for HD in patients with HIV relate to the HIV rather than the HD. In people with HIV the response rates are lower, the relapse rates higher, the infectious complications more frequent and the overall survival worse than for HD in the general population.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

The molecular genetics of human herpesvirus 8.

Epidemiological evidence from the early 1990s suggested that a sexually transmitted infectious agent other than the HIV virus was associated with the development of Kaposi's sarcoma in patients with HIV. A novel gamma herpesvirus was identified in Kaposi's sarcoma lesions. The molecular genetics of this virus are reviewed in this article.

AIDS-Related Opportunistic Infections↗
PubMed1999

A high incidence of vertebral fracture in women with breast cancer.

Because treatment for breast cancer may adversely affect skeletal metabolism, we investigated vertebral fracture risk in women with non-metastatic breast cancer. The prevalence of vertebral fracture was similar in women at the time of first diagnosis to that in an age-matched sample of the general population. The incidence of vertebral fracture, however, was nearly five times greater than normal in women from the time of first diagnosis [odds ratio (OR), 4.7; 95% confidence interval (95% CI), 2.3-9.9], and 20-fold higher in women with soft-tissue metastases without evidence of skeletal metastases (OR, 22.7; 95% CI, 9.1-57.1). We conclude that vertebral fracture risk is markedly increased in women with breast cancer.

Administration, Oral↗
PubMed1998

Interim analysis of the incidence of breast cancer in the Royal Marsden Hospital tamoxifen randomised chemoprevention trial.

BACKGROUND: Tamoxifen, a drug with antioestrogenic effects, is predicted to prevent the occurrence of breast cancer. We have undertaken a trial of tamoxifen in healthy women who are at increased risk of breast cancer because of family history. We report a planned interim analysis. METHODS: Between October, 1986, and April, 1996, we accrued 2494 healthy women aged between 30 and 70 with a family history of breast cancer. They have been randomised (double blind) to receive tamoxifen 20 mg per day orally or placebo for up to 8 years. Follow-up included clinical assessment, annual mammography, and assessment of toxicity and compliance. The primary endpoint was the occurrence of breast cancer, which was analysed on an intention-to-treat basis with a survival curve. FINDINGS: With a median follow-up of 70 months, 2471 women (tamoxifen 1238, placebo 1233) were suitable for analysis. The groups were evenly matched at baseline, and compliance was good. The overall frequency of breast cancer is the same for women on tamoxifen or placebo (tamoxifen 34, placebo 36, relative risk 1.06 [95% CI 0.7-1.7], p=0.8). Participants who were already on hormone-replacement therapy when they entered the study had an increased risk of breast cancer compared with non-users. Those participants who started such therapy while on trial had a significantly reduced risk. The safety profile of tamoxifen was as expected. INTERPRETATION: We have been unable to show any effect of tamoxifen on breast-cancer incidence in healthy women, contrary to the report from the NSABP-P1 study showing a 45% reduction in healthy women given tamoxifen versus placebo. Differences in the study populations for the two trials may underlie these conflicting findings: eligibility in our trial was based predominantly on a strong family history of breast cancer whereas in the NSABP trial was mostly based on non-genetic risk factors. The importance of oestrogen promotion may vary between such populations.

Adult↗
PubMed1996

Clodronate decreases the frequency of skeletal metastases in women with breast cancer.

The aims of this study were to determine the effects of the bisphosphonate, clodronate, on the incidence of skeletal metastases and associated morbidity in women with advanced breast cancer. 133 women with recurrent breast cancer, but no evidence of skeletal metastases, were randomly allocated to receive clodronate 1600 mg daily by mouth or an identical placebo for 3 years under double-blind conditions at two clinical oncology centers in the UK and Canada. Main outcome measures included the occurrence of skeletal metastases, as judged by sequential bone scans and radiographs, and the morbidity associated with skeletal metastases comprising the incidence of hypercalcemia, vertebral, and nonvertebral fractures, and bone pain assessed by the requirements for skeletal radiotherapy. The number of patients developing skeletal metastases was lower in clodronate-treated patients than with placebo (15 vs. 19), but was not significantly different. The number of skeletal metastases was significantly lower with clodronate treatment than with placebo (32 vs. 63; p < 0.005). The complications of skeletal disease were fewer by 26% in clodronate-treated patients compared to controls (p < 0.01). Compared to placebo, significant effects in favor of clodronate were observed for vertebral deformities (29%) and nonvertebral fractures (75%), but the event frequency of each was low. There was a small (22%) but nonsignificant treatment effect on the requirements for radiotherapy and hypercalcemia (39%). There was no effect of clodronate on survival. We conclude that clodronate by mouth significantly decreases the number and complications of skeletal metastases in women with advanced breast cancer.

Administration, Oral↗
PubMed1996

Anxiety in women "at risk' of developing breast cancer.

Do family history clinics offering counselling, surveillance and preventative programmes alleviate or exacerbate anxiety in women at a high risk of developing breast cancer? In this study risk perceptions and anxiety of 99 'at risk' women participating in the Tamoxifen Prevention Trial were compared with those of 87 'at risk' women not attending any specialist clinic who were recruited from the National Breast Screening Programme (NBSP). Most anxiety was found in NBSP women with a family history. Women attending the family history clinic and participating in the trial had anxiety scores comparable with 86 women recruited from the NBSP who did not have a family history. We conclude that such specialist clinics do not see a selected group of the most anxious 'at risk' women nor does participation in tamoxifen prevention programmes appear to increase anxiety.

Analysis of Variance↗
PubMed1994

The effect of endocrine therapy on the levels of oestrogen and progesterone receptor and transforming growth factor-beta 1 in metastatic human breast cancer: an immunocytochemical study.

The levels of oestrogen receptor (ER), progesterone receptor (PR) and transforming growth factor-beta 1 (TGF-beta 1) were measured by immunocytochemistry in 19 patients prior to and 1 month after the start of endocrine therapy (tamoxifen 10 patients; aromatase inhibition 9 patients). A complete or partial response was observed in 10 patients. The proportion of cells showing ER staining was higher in responding patients, but there was no change observed with endocrine therapy in either responding or non-responding patients. In contrast, cells staining for PR in responding patients were significantly reduced following therapy (59 +/- 9% to 24 +/- 9%: P < 0.05). There was no reduction in immunocytochemical PR in non-responding patients, although the numbers of these patients with initially positive PR levels was small. Stromal tissue adjacent to tumour cells stained with the antibody to TGF-beta 1, with particularly intense staining at the periphery of tumour cell aggregates. There was no correlation between the degree of TGF-beta 1 staining and ER or PR status, and no evidence of a change with endocrine therapy. It is concluded that neither tamoxifen nor aromatase inhibitors produce a change in the ER content or TGF-beta 1 content of breast tumours as detected immunocytochemically, but PR levels are significantly reduced after therapy in responding patients.

Adult↗
PubMed1993

The prognostic significance of transforming growth factors in human breast cancer.

Transforming growth factor alpha (TGF alpha) and Transforming growth factor beta-1 (TGF-beta 1) are growth regulatory for breast cancer cell lines in vitro and several studies have suggested that levels of the receptor for TGF alpha, the epidermal growth factor (EGFR) in tumour biopsies predict relapse and survival. We have examined the prognostic significance of TGF alpha, TGF-beta 1 and EGFR mRNA expression in a series of patients with primary breast cancer with a median follow up period of 60 months. In 167 patients the expression of TGF-beta 1 was inversely correlated with node status (P = 0.065) but not ER status, tumour size or menopausal status. Patients with high levels of TGF-beta 1 had a longer disease free interval with a significantly longer probability of survival at 80 months although the overall relapse free survival was not increased. EGFR mRNA expression was measured in 106 patients and was inversely correlated with ER status (P = 0.018). EGFR levels did not predict for early relapse or survival. TGF alpha mRNA levels were measured in 104 patients, no correlation was seen tumour size, node status, Er status, or clinical outcome.

Adenocarcinoma, Mucinous↗
PubMed1992

Aromatase activity, serum oestradiol and their correlation with demographic indices.

Peripheral aromatase activity was measured in 24 postmenopausal women suffering from advanced breast cancer. The % conversion of androstenedione to oestrone was then assessed for a significant correlation with age, weight, height, Quetelets index (weight/height2, Q.I.) and length of menopause. Serum oestradiol (E2) levels were measured in 22 of the subjects and compared with the same indices. There was no correlation between E2 or aromatase activity with the length of menopause (P = 0.3 and P = 0.5, respectively). In our data aromatase activity did not correlate with age (P greater than 0.5, n = 22). Serum E2 levels (P = 0.07, n = 20) expressed a negative correlation (i.e. decreased) with age. There was also a poor correlation between aromatase activity and weight of Quetelets index (P = 0.3, n = 20 for both). Serum E2 levels showed a statistically significant correlation with weight (P = 0.01, n = 21), but the relationship with Quetelets index just failed to attain statistical significance (P = 0.07, n = 20). In both cases the regression line was positive. When aromatase activity was correlated with serum E2 levels the regression line was positive but not statistically significant (P = 0.4, n = 22). The data indicate that aromatase activity is only one factor determining the differences in serum E2 levels between postmenopausal women.

Adult↗
PubMed1991

Pharmacokinetics and pharmacodynamics of the aromatase inhibitor 3-ethyl-3-(4-pyridyl)piperidine-2,6-dione in patients with postmenopausal breast cancer.

The pyridylglutarimide 3-ethyl-3-(4-pyridyl)-piperidine-2,6-dione (PyG) is a novel inhibitor of aromatase that was shown to cause effective suppression of plasma oestradiol levels in postmenopausal patients. In four patients receiving oral doses of PyG (500 mg) twice daily for 3-4 days, oestradiol levels fell to 31.1% +/- 6.3% of baseline values within 48 h and remained suppressed during treatment. Of a further six patients who received oral PyG (1 g) as a single dose, five had quantifiable oestradiol levels. Oestradiol suppression was sustained for 36 h and recovery correlated with a fall of PyG concentrations below a threshold value of ca. 2 micrograms/ml. The pharmacokinetics of PyG were non-linear and, when fitted to the integrated Michaelis-Menten equation, yielded good parameter estimates for Co (21.7 +/- 1.82 micrograms/ml), Km (2.66 +/- 0.68 micrograms/ml) and Vmax (0.86 +/- 0.06 micrograms ml-1 h-1). On subsequent repeated dosing with PyG, both the Km (4.31 +/- 0.48 micrograms/ml) and the Vmax (1.83 +/- 0.13 micrograms ml-1 h-1) values increased and recovery from oestradiol suppression was more rapid, indicating that PyG induces its own metabolism.

Aminoglutethimide↗
PubMed1991

Clodronate: the potential for the future.

Osteolytic bone metastases secondary to breast cancer are extremely common, occurring in more than 50% of breast cancer patients. The resulting increased bone resorption leads to significant symptomatic morbidity caused by bone pain, hypercalcaemia and pathological fracture. Clodronate, an anti-osteolytic agent, inhibits osteoclastic bone resorption and has considerable therapeutic value. Recent studies have shown that clodronate is effective in the treatment of malignancy hypercalcaemia, relief of bone pain and decreases the risk of pathological fracture. The use of clodronate in the future, other than as a palliative therapy, may focus upon the prevention of osteolytic bone metastases at the time of primary diagnosis or later in the disease progression in those patients at risk, for example, those with non-osseous relapse. Since patients with bone metastases secondary to breast cancer often have an increased duration of survival, any agent that would decrease the symptomatic morbidity would have a significant impact upon quality of life, even more so if the actual development of osteolytic bone metastases was delayed or prevented.

Adrenal Cortex Hormones↗
PubMed1991

The influence of CGS 16949A on peripheral aromatisation in breast cancer patients.

The influence of a new aromatase inhibitor, CGS 16949A on peripheral aromatisation of androstenedione into oestrone was investigated in postmenopausal women with breast cancer. A mixture of 3H androstenedione and 14C oestrone was injected, and all urine was collected for the following 96 h. The isotope ratio was determined in the urinary oestrogen metabolites after isolation by HPLC. Eight patients were investigated before and during treatment with CGS 16949A. At a dose of 1 mg b.d. (eight patients) CGS 16949A inhibited aromatisation by a mean value of 82.4% (range 71.3 to 93.7%). When the drug dose was escalated to 2 mg b.d. (three patients) aromatisation was inhibited by a mean of 92.6% (range 90.6 to 95.8%), these results suggest that CGS 16949A at a dose of 1 mg b.d. causes submaximal aromatase inhibition in many patients, while a dose of 2 mg b.d. seems to result in greater than 90% aromatase inhibition. These data are consistent with previous observations that the higher dose is more effective in suppression of plasma oestradiol levels.

Aged↗
PubMed1987

Comparison of different trials of adjuvant chemotherapy in stage II breast cancer using a natural history data base.

Prognostic factors and treatment were analyzed for 2,578 patients to assess the impact of various forms of adjuvant chemotherapy on the natural history of operable stage II (node-positive) breast cancer. The outcome after surgery alone (or with radiotherapy) was determined in 1,014 patients in the natural history data base (NHDB). Adjuvant chemotherapy consisted of L-phenylalanine mustard (L-PAM; 130 patients); cyclophosphamide, methotrexate, and 5-fluorouracil (CMF; 645 patients); doxorubicin and cyclophosphamide (AC; 241 patients); CMF plus vincristine and prednisone (CMFVP; 263 patients); and 5-fluorouracil plus AC (FAC; 285 patients). L-PAM had minimal effect on relapse-free survival (RFS) compared to the NHDB, but all combination chemotherapy programs significantly improved RFS and survival compared to the NHDB. In women with 1-3 positive nodes, all combination chemotherapy programs produced similar results. In women with 4-9 positive nodes, the FAC regimen appeared to be associated with superior RFS compared to other programs, but all were superior to the NHDB. In women with 10 or more positive nodes, FAC was the only regimen associated with improved RFS. The use of a NHDB and known pretreatment characteristics, such as nodal status and tumor size, permits comparison of patients at similar risk of recurrence of breast cancer who have received adjuvant chemotherapy and provides leads for evaluation in future prospective clinical trials.

Adult↗