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A Goldhirsch

Publications and source records attributed to A Goldhirsch.

At least 181 records · Page 10Linked to original sources
PubMed1993

Cox regression models for quality adjusted survival analysis.

We develop a method for incorporating covariates as regressors in a quality adjusted survival analysis (Q-TWiST) using Cox's proportional hazards model. The standard Q-TWiST method assumes that patients progress through a series of health states which differ in quality of life. The Kaplan-Meier product limit method is used to estimate the mean duration of each state by estimating the survival curves for the health state transition times. These estimates provide the basis for quality adjusted survival analysis. In this paper, the survival curves are modelled using Cox's proportional hazards regression. Quality adjusted survival is estimated given sets of covariate values, allowing one to profile patients. The results are useful for investigating how prognostic factors affect treatment benefits in terms of quality of life. We give a brief review of the standard Q-TWiST method and illustrate the extended methodology with an example from the International Breast Cancer Study Group Trial V comparing short duration versus long duration chemotherapy in the treatment of node-positive breast cancer.

Antineoplastic Agents↗
PubMed1993

The Perceived Adjustment to Chronic Illness Scale (PACIS): a global indicator of coping for operable breast cancer patients in clinical trials. Swiss Group for Clinical Cancer Research (SAKK) and the International Breast Cancer Study Group (IBCSG).

Subjective well-being is a major aspect of quality of life and is therefore increasingly used as an endpoint in clinical trials. It is influenced to a great extent by the complex process of coping with the disease and its treatment. Assessment of coping is methodologically demanding, especially in large clinical trials. We therefore developed a single-item measure, the Perceived Adjustment to Chronic Illness Scale (PACIS), as an indicator of coping, complementary to other scales related to quality of life. We sought to validate this instrument in a subgroup of 121 Swiss patients participating in the International Breast Cancer Study Group (IBCSG) adjuvant trials. At months 3 and 6 of adjuvant treatment PACIS showed a distinct pattern of highly significant rank correlations with several disease- and treatment-related problem areas from the Herschbach coping inventory (FBBK); 42% of the variance of PACIS at month 3 was explained by the FBBK (P = .0001). The portion of explained variance was considerably higher for the Italian- (70%) than for the German-speaking (30%) subgroups. Patients who rated more effort to cope with their disease on PACIS indicated more frequent use of 3 of 15 coping strategies in relation to psychological distress. These were "crying and becoming desperate", "taking tranquillizers and alcohol" and "other people are far worse off". These three coping strategies may define a high-risk group for poor psychosocial outcome. Patients whose PACIS scores showed that it required less effort to cope tended to use the strategy "seeing a positive side of the problem". We conclude that PACIS can be used as a global indicator of the coping process in large multicultural clinical trials of adjuvant therapy for breast cancer.

Activities of Daily Living↗
PubMed1993

Parametric extrapolation of survival estimates with applications to quality of life evaluation of treatments. International Breast Cancer Study Group.

Using parametric models, a procedure for projecting survival estimates beyond the follow-up limits of a clinical trial is developed. The methodology consists of fitting an appropriate parametric model to the tail of a survival curve and using the estimated model in conjunction with the Kaplan-Meier product-limit estimate to produce a composite survival-function estimator. This estimator is especially useful whenever a parametric model is more easily fit to the tail rather than to the entire survival curve. Probability plots are used to evaluate different parametric models as well as to determine appropriate values for the cut points that define the survival-function tail. The bootstrap method provides estimates of variation in the projected survival curve. The resulting projected survival estimates allow one to make inferences on long-term treatment effects in clinical trials. As a motivating application, we project survival curves to estimate long-term treatment effects on quality-of-life-adjusted survival. This represents an extension of a statistical procedure called Q-TWiST (Quality-adjusted Time Without Symptoms of disease and Toxicity of treatment), which evaluates treatments in terms of both quantity and quality of life. In a standard Q-TWiST analysis, the average time spent in each of a number of health states, which differ in quality of life, is estimated from clinical trial data. The health states are weighted according to the quality of life experienced, and the results are combined to produce an estimate of quality-adjusted survival. Such estimates, however, are restricted to the follow-up limit of the data. The way in which the extrapolation methodology provides longer range estimates of Q-TWiST is described. To illustrate the techniques, we apply the methodology to data from the International Breast Cancer Study Group Trial V, which compares long-duration adjuvant chemotherapy versus short-duration chemotherapy in the treatment of node-positive breast cancer. Five-year median follow-up data are used to predict 10-year results in terms of mean survival and mean Q-TWiST. The results indicate that patients continue to benefit greatly from the long-duration chemotherapy between 5 and 10 years following treatment.

Antineoplastic Agents↗
PubMed1993

Evaluation of effectiveness: Q-TWiST. The International Breast Cancer Study Group.

The effectiveness of cancer treatments is often expressed in terms of disease-free survival or overall survival relative risk reduction or odds ratios, and the quality of life effects are often assessed separately from survival. Such end points and summary measures may be inadequate, however, for comparing two treatments in terms of their palliative effects because there is a trade-off between treatment toxicity and increased disease-free interval. Furthermore, this trade-off may depend on individual patient preferences and prognostic situations. The goal of this paper is to describe a method for evaluating the effectiveness of cancer treatments in terms of palliation by simultaneously considering both quality and quantity of time following treatment so that therapeutic choice may be determined according to patient preferences on quality of life and prognostic situation. The method we present is an extension of the Quality-adjusted Time Without Symptoms and Toxicity (Q-TWiST) method for comparing treatment effectiveness in clinical trials of adjuvant therapies. We illustrate an application using data from the International Breast Cancer Study Group Trial V which compares two chemotherapy schedules with different toxicities.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Primary endocrine therapy for advanced breast cancer: to start with tamoxifen or with medroxyprogesterone acetate?

BACKGROUND: The availability of compounds effective against metastatic disease and at the same time excellently tolerated even in long-term administration has determined the choice of tamoxifen as primary treatment for palliation in metastatic breast cancer. Other drugs or other hormonal approaches were hardly tested against tamoxifen, especially as first-line treatment. PATIENTS AND METHODS: 119 patients with metastatic breast cancer and no prior endocrine therapy were randomized to receive either tamoxifen (TAM) 20 mg/day orally (64 patients), or medroxyprogesterone acetate (MAP) 1g/day i.m. 5 days/week for 4 weeks and then 500 mg twice a week (55 patients). The subsequent endocrine therapy was also prospectively defined at study entry. RESULTS: A total of 111 events, contributing to the endpoint 'time to progression' have so far been observed: a study of similar size would have a 90% power to detect a hazard ratio of 1.85. Initial MAP was associated with a significantly higher remission rate (50% versus 30% for tamoxifen; p = 0.023) and a marginally significantly longer median time to progression (8.8 versus 5.4 months; p = 0.051). Overall survival was also longer for the MAP group (28 versus 20 months; p = 0.384). The use of MAP was associated with a significantly higher toxicity, mainly hypertension, weight gain and tremor. CONCLUSIONS: The implications of these results are that initial endocrine therapy in postmenopausal patients with metastatic disease should be MAP if the patient is willing to accept the side effects of high-dose progestins. Progestins should be tested in the adjuvant setting for postmenopausal women, especially those with no tendency to hypertension or obesity.

Adult↗
PubMed1992

Quality-of-life evaluation in a clinical trial of zidovudine therapy in patients with mildly symptomatic HIV infection. The AIDS Clinical Trials Group.

OBJECTIVE: To evaluate the effects of zidovudine therapy in patients with mildly symptomatic HIV infection using Q-TWiST (quality-adjusted: Time Without Symptoms and Toxicity). DESIGN: Analysis of a previously reported multicenter, randomized, placebo-controlled clinical trial. SETTING: Thirty-two AIDS Clinical Trial units. PATIENTS: A total of 351 patients with mildly symptomatic HIV infection were assigned to placebo, and 360 patients were assigned to zidovudine, 1200 mg/d. MEASUREMENTS: A modified Q-TWiST method for comparing treatments based on time spent without severe symptomatic adverse events and without disease progression. Zidovudine and placebo were compared in a threshold utility analysis considering reduction in quality of life associated with adverse events and disease progression. Adverse events defined by laboratory findings were distinguished from findings representing symptomatic events. RESULTS: The incidence of severe symptomatic adverse events was 22.8% for the zidovudine group and 15.1% for the placebo group (P = 0.01), but, as previously reported, zidovudine improved progression-free survival relative to placebo (at 18 months, 91% compared with 81%; P = 0.001). In an 18-month period, patients receiving zidovudine went an average of 14.5 months without disease progression or a severe symptomatic adverse event compared with 14.7 months for placebo. The zidovudine group gained 0.9 months without disease progression but lost 1.1 months due to adverse events. Within the 18-month observation period, treatment provided more Q-TWiST than placebo if the quality of life after HIV disease progression was assumed to be 10% to 20% worse than the quality of life after a severe symptomatic adverse event. CONCLUSIONS: The Q-TWiST analysis projects that quality-of-life reductions due to severe symptomatic adverse events might be balanced by the quality-of-life benefits of delayed HIV disease progression for patients who received zidovudine for mildly symptomatic HIV infection. At currently recommended doses (500 to 600 mg/d, half the dose used in this study) zidovudine therapy is likely to yield a more favorable result.

Double-Blind Method↗
PubMed1992

Quality of life measures for patients receiving adjuvant therapy for breast cancer: an international trial. The International Breast Cancer Study Group.

Serial quality of life (QL) assessments are being obtained every 3 months for 2 years from patients with operable breast cancer in two ongoing International Breast Cancer Study Group (IBCSG) randomised clinical trials of adjuvant treatment. The QL-assessments include patient-derived perceived coping (PACIS, personal adjustment to chronic illness scale), well-being (Bf-S, Befindlichkeitsskala von Zerssen), mood, physical well-being and appetite (LASA, linear analogue self assessments). The first assessment within 6 weeks of surgery was performed by 70% of the patients. The analysis of serial assessments for 265 patients with each of the first four assessments completed showed that all measures improved with increasing time from study entry; that the degrees of improvement for the four major language groups were similar; and that measures were sensitive to treatment difference. In conclusion, measurement of QL related aspects in a multicultural clinical trial is feasible and possibly relevant for the evaluation of treatment results.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Phase II study of continuous subcutaneous interferon-alfa combined with cisplatin in advanced malignant melanoma.

Interferon-alfa (IFN-alpha) and cisplatin have shown synergism in vitro against tumour cell lines and optimal effects were observed with continuous and high IFN concentration. 20 patients with advanced malignant melanoma were treated with 10 MU IFN subcutaneously continuously, daily, plus cisplatin 50 mg/m2 intravenously on days 8 and 9. Cisplatin was repeated every 4 weeks. The main toxic effects were myelosuppression, fatigue and weight loss. Toxicities always resolved completely after reduction/interruption of IFN and no life-threatening infection was observed. There were 1 complete and 6 partial responses. 6 patients had stable disease. Median time to progression was 7 months with a range of 16 to 2 months. The combined regimen of IFN-alpha and cisplatin is active in patients with multiple visceral and skeletal sites.

Adult↗
PubMed1992

Meta-analysis: the fashion of summing-up evidence. Part II: Interpretations and uses.

In this commentary, we use evidence produced by the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) ten-year update of a meta-analysis of trials of adjuvant therapies for early breast cancer which started prior to 1985 to illustrate aspects of interpretations and uses of meta-analysis results. The following issues are discussed: i) The meta-analysis provides an average summary for the effect of a treatment. Greater statistical power is obtained by increasing the number of events contributing to the analysis. However, summing up the results of various trials necessitates the loss of individual information concerning the magnitude of treatment effects which depend on tumor- and patient-related factors. Subgroup analyses within the meta-analysis process allow some recovery of such features; ii) The absolute benefit obtained from an effective treatment depends not only on the relative benefit of the treatment but also on the prognosis of the individual patients; iii) The results are more immediately applicable if less reliance is placed on the arithmetic construct inherent in the overview, using instead unconfounded information about the value of treatments actually administered. This avoids the need to extrapolate the effect for one component of the therapy by assuming a lack of interaction with its other components; iv) Although indirect comparisons between different meta-analyses are regularly made to pick the "winner" from among tested treatment modalities, it is unlikely that the optimal therapeutic regimen can be defined via such indirect comparisons, though such comparisons may raise interesting, testable hypotheses.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Sequential estrogen receptor determinations from primary breast cancer and at relapse: prognostic and therapeutic relevance. The International Breast Cancer Study Group (formerly Ludwig Group).

We retrospectively evaluated 401 selected patients who had estrogen receptor (ER) assays both at primary surgery and at relapse in an accessible site to determine the clinical relevance of the subsequent ER determination. The median time between ER assessments was 27 months (range: 2-122 months). The median follow-up time from diagnosis was 6 years (range: 2-12 years). For patients with ER+ tumors at primary diagnosis, 29% (76/261) had ER- tumors at relapse, while for ER- primaries, the conversion rate was 33% (46/140). Conversions from ER+ to ER- occurred more often when the time interval between assays was less than one year (p = 0.004), while conversions from ER- to ER+ tended to occur late (beyond three years; p = 0.0003). Treatments received between assays (usually adjuvant therapy) had only a slight influence on ER status conversion. Post-relapse survival was poor for patients who had the biopsy accessible recurrence within one year; an expression of the aggressive nature of the disease. Among patients whose accessible relapse was beyond one year, those with ER- primaries who converted to ER+ had a longer survival than those whose recurrence was classified again as ER- (p = 0.006). This group of patients with ER- primaries who recurred beyond one year with an ER+ tumor in an accessible site represented 29% (40/140) of all patients with ER- primaries and had an estimated overall survival rate of more than 60% at 6 years from the accessible relapse. ER determination upon relapse within one year has very little clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗