Quality of Life endpoints in prostate chemoprevention trials

Smoldering multiple myeloma: Reviewing the rationale for intervention

Smoldering multiple myeloma has been recognized for over 40 years and represents a pre-symptomatic phase of the 2nd most common hematologic malignancy. 1/3 of patients will remain asymptomatic at 10 years. There is an identifiable subset of patients that will develop CRAB within 2 years of recognition and these patients are considered for therapeutic intervention before the development of potentially irreversible complications. Obstacles to widespread implementation of therapeutic guidelines are limited by the variable definitions associated with this high-risk group as well as the poor concordance between classification schemes. Analysis of clinical trial outcomes as well as uniform eligibility helps determine whether a given patient should be considered for therapeutic intervention outside of a clinical trial.

North Central Cancer Treatment Group--achievements and perspectives

The North Central Cancer Treatment Group (NCCTG) was founded in 1977 as a regional cooperative group to allow cancer patients in the upper Midwest of the United States to gain access to clinical trials in oncology by establishing a network of community oncology practices with one academic research base, the Mayo Clinic. Since then, the NCCTG has grown into an international cooperative group with 43 members in 33 US states and Canada. This article details 30 years of achievements of the NCCTG, including important scientific contributions from disease-specific and treatment modality committees, the cancer control program, patient-reported outcomes and quality-of-life research, and biostatisticians that support the NCCTG's specific aims: to improve the duration and quality of life of cancer patients, to enhance our understanding of the biological consequences of cancer and its treatment, and to improve methods for clinical trial conduct.

Measurement Issues in Quality-of-Life Assessments

PURPOSE/OBJECTIVES

To describe issues to be considered when measuring the quality of life (QOL) of patients with cancer.

DATA SOURCES

Published articles and books, conference proceedings, and abstracts.

DATA SYNTHESIS

A review of the existing literature reveals an emerging field of research and considerable discussion of measurement issues. Consensus is growing about measurement approaches to this subjective concept; however, agreement differs regarding specific aspects of measurement approaches and interpretation of data.

CONCLUSIONS

The purpose of the QOL assessment and how the data will be analyzed are the main determinants of the choice of assessment and measurement approaches. Differences regarding how QOL is measured may be encountered based on a clinical or research purpose.

IMPLICATIONS FOR NURSING

QOL assessments may be used as part of data collection to address a specific research question or may be used to guide clinical practice. Research findings used to guide clinical practice should be evaluated for validity, reliability, and fit of the sample before being incorporated into clinical practice. QOL assessment in clinical practice may be used as an exploratory tool to identify potential problems or may be used to evaluate the effectiveness of a targeted intervention.

Statistical design issues and other practical considerations for conducting phase III prostate cancer prevention trials

PURPOSE

We briefly describe the purpose of phase II studies as a source of preliminary data for phase III prevention trials, and address statistical and other practical considerations for phase III prostate cancer prevention trials.

MATERIALS AND METHODS

Objectives of 2 types of phase II studies and general criteria for validating surrogate end points are described, and statistical considerations needed for planning a phase III prevention trial are explained, including selection of an appropriate study population and end point, the corresponding expected event rate, estimates of loss to followup, and death and compliance rates. If a preventive agent has an impact on the ability to detect prostate cancer, additional study design considerations are then made. Other practical issues are addressed, including collection of biological materials for correlative studies, assessment of quality of life measures and the addition of ancillary studies that may include the collection of additional end points unrelated to prostate cancer.

RESULTS

The Southwest Oncology Group is coordinating 2 recently reported phase III prostate cancer prevention trials. The Prostate Cancer Prevention Trial final results of 18,882 men randomized to either finasteride or placebo, and the Selenium and Vitamin E Cancer Prevention Trial has accrued more than half of its goal of 32,400 men. These studies are used to illustrate some statistical design features.

CONCLUSIONS

The aforementioned trials provide valuable lessons in the successful design and conduct of phase III prostate cancer prevention trials.

Efficacy and quality-of-life data are related in a phase II trial of oral chemotherapy in previously untreated patients with metastatic colorectal carcinoma

PURPOSE

To evaluate quality of life (QOL) and tumor response after administration of an oral chemotherapy regimen in patients with previously untreated metastatic colorectal cancer.

PATIENTS AND METHODS

Seventy-eight patients received a mean number of 5.8 cycles of therapy. QOL data were analyzed at baseline, after every two cycles of therapy, and at the time of treatment discontinuation. The Uniscale and the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 were both utilized.

RESULTS

The confirmed response rate was 26% (95% confidence interval [CI], 17% to 37%). Median survival was 11.3 months (95% CI, 9.6 to 15.1 months). Global QOL scores were unchanged over the course of therapy by either tool. Only the physical function subscale score had worsened at the end of therapy. In an analysis of responding patients, significant and durable improvements in both global QOL measures as well as select subscale scores were observed. Diarrhea and physical function QOL scores had declined at the time of treatment discontinuation. Patients who did not respond to therapy had preserved QOL scores when they were evaluated after two cycles of therapy.

CONCLUSION

This oral treatment strategy preserved QOL in treated patients. Global QOL measures as well as several QOL subscale scores significantly improved in patients with a documented response to therapy. The profile of improved QOL components indicated that patient well-being was related to tumor response in specific and perceivable ways. Nonresponding patients reported preserved QOL during the first two cycles of therapy. QOL analysis was feasible and informative in this moderately sized multicenter phase II trial.

Design considerations for efficient prostate cancer chemoprevention trials

Prostate cancer, even with its substantial public health impact of 180,400 new cases and 31,900 deaths estimated for 2000, still has a very low annual incidence (0.27% for men 34.4 years and older), which makes designing and conducting efficient prostate cancer prevention trials a challenge. Definitive prevention trials with cancer endpoints, such as the Breast Cancer Prevention Trial (BCPT), Prostate Cancer Prevention Trial (PCPT), and Selenium and Vitamin E Cancer Prevention Trial (SELECT), require long trial duration (up to 12 years) and large sample size (up to 32,400 subjects) to accomplish their objectives. This article discusses design concepts for potential prostate cancer prevention trials that require fewer years, subjects, and resources to complete. Design elements, such as high-risk populations, randomization, surrogate endpoints, including quality-of-life endpoints, masking/blinding, and various clinical/statistical designs (including 1-way layout, all-versus-none, factorial, and adaptive designs), are discussed, along with the ultimate goal of gaining US Food and Drug Administration approval for prostate-cancer preventive agents that can improve public health by reducing prostate cancer incidence and mortality.