Challenges posed by non-random missing quality of life data in an advanced-stage colorectal cancer clinical trial

Factors predicting missing instruments in three cancer randomized clinical trials

PURPOSE

Missing patient-reported outcome (PRO) data can seriously threaten the validity of randomized clinical trials (RCTs). Identifying which factors predict missing instruments may help researchers develop strategies to prevent it from happening. This study examined the association of factors with time to the first missing instrument after randomization in three cooperative group RCTs.

METHODS

We performed descriptive analyses and Cox proportional hazards regressions for three RCTs selected from the Canadian Cancer Trials Group: MA17 (breast cancer), PR7 (prostate cancer), and LY12 (non-Hodgkin's lymphoma). The outcome was the time from randomization to the first missing instrument. Variables for 15 factors were used as covariates based on availability and previously-reported putative associations with missing PRO data.

RESULTS

Nine percent of 1352 subjects on MA17, 37% of 923 subjects on PR7, and 59% of 477 subjects on LY12 had a missing instrument. Twenty-five percent of subjects on MA17 had first missing instrument within 4.6 years. The median time to first missing instrument was: not observed for MA17, 7.3 years for PR7, 0.12 years for LY12. Cox regression revealed statistically significant independent associations with outcome for only five factors: baseline age (PR7) and level of well-being (LY12), and centre level of activity (LY12), presence of post-graduate residency training program (MA17, PR7), and centre geographic location (PR7, LY12).

CONCLUSION

Many factors reported to have association with missing instruments do not seem to predict time to the first missing instrument after randomization in RCTs. Context is important in understanding the few that may.

Association of Disease Progression With Health-Related Quality of Life Among Adults With Breast, Lung, Pancreatic, and Colorectal Cancer

IMPORTANCE

Mortality, morbidity, and health-related quality of life (HRQoL) are patient-relevant end points generally considered in the early benefit assessments of new cancer treatments. Progression-related end points, such as time to progression or progression-free survival, are not included, although patients and physicians testify to the detrimental association of disease progression with HRQoL.

OBJECTIVE

To examine the association of disease progression and HRQoL in 4 prevalent solid-cancer entities in routine clinical practice.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study evaluated data from 4 prospective, nonintervention, multicenter registries collected between 2011 and 2018 in 203 centers in Germany. Patients' HRQoL was assessed regularly for up to 5 years. The change in HRQoL scores after disease progression was examined with linear mixed models, adjusting for demographic and clinical covariates. Patients with metastatic breast, pancreatic, lung, and colorectal cancer were recruited at the start of systemic first-line treatment. Data analysis was performed from February 2019 to April 2019.

EXPOSURES

All patients received systemic, palliative first-line treatment according to their physician's choice.

MAIN OUTCOMES AND MEASURES

The primary outcome was deterioration of HRQoL associated with disease progression, as measured by 4 validated questionnaires: Functional Assessment of Cancer Therapy-General version 4, European Organization for Research and Treatment of Cancer QLQ-C30 version 3.0, European Organization for Research and Treatment of Cancer QLQ-C15-PAL version 1, and Hospital Anxiety and Depression Scale.

RESULTS

More than 8000 questionnaires from 2314 patients with 2562 documented disease progressions were analyzed. In total, 464 patients had breast cancer (464 [100.0%] female; median [range] age, 61.6 [26.4-90.1] years), 807 patients had pancreatic cancer (352 [43.6%] female; median [range] age, 70.0 [39.0-93.0] years), 341 patients had lung cancer (118 [34.6%] female; median [range] age, 65.9 [28.4-88.2] years), and 702 patients had colorectal cancer (248 [35.3%] female; median [range] age, 66.9 [26.9-92.1] years). The first disease progression was associated with a statistically significant worsening of 37 of 45 HRQoL scales; for 17 of these scales, the worsening was clinically meaningful. Scale scores for appetite loss (pancreatic cancer, 10.2 points [95% CI, 6.8-13.5 points]; lung cancer, 10.8 points [95% CI, 5.4-16.2 points]; colorectal cancer, 8.8 points [95% CI, 5.5-12.2]; all P < .001), physical functioning (pancreatic cancer, 6.2 points [95% CI, 3.8-8.5 points]; lung cancer, 8.4 points [95% CI, 5.4-11.5 points]; colorectal cancer, 5.0 points [95% CI, 3.0-7.0 points]; all P < .001), and fatigue (pancreatic cancer, 5.5 points [95% CI, 3.0-7.9 points]; lung cancer, 7.7 points [95% CI, 4.3-11.1]; colorectal cancer, 4.5 points [95% CI, 2.1-6.9 points]; all P < .001) were most affected, irrespective of the type of cancer. The association with global HRQoL was most pronounced in lung cancer (6.7 points [95% CI, 3.5-9.9 points]; P < .001) and pancreatic cancer (5.4 points [95% CI, 3.3-7.5 points]; P < .001) and less in colorectal cancer (3.5 points [95% CI, 1.3-5.7 points]; P = .002) and breast cancer (2.4 points [95% CI, 1.0-3.9 points]; P = .001). The second progression was associated with an even larger decrease in HRQoL.

CONCLUSIONS AND RELEVANCE

These findings suggest that disease progression is associated with a deterioration in HRQoL among patients with metastatic breast, pancreatic, lung, and colorectal cancer. This evidence highlights the importance of progression-related end points, such as time to progression and progression-free survival, as additional patient-relevant end points when evaluating the benefit of new treatments for patients with metastatic cancer.

First Descents, an adventure program for young adults with cancer: who benefits?

BACKGROUND

Participation in camps, adventure programs, retreats, and other social events offers experiences that can promote self-efficacy and quality of life.

PURPOSE

The purpose of the study was to examine whether participation in a 1-week outdoor adventure program resulted in improvements in psychological distress, self-efficacy, and/or social support for young adult cancer patients (AYAs) aged 18-40 years. The study examined the differential effect of participation for AYAs who indicated moderate to severe symptoms of psychological distress prior to their trip.

METHODS

Standardized measures of distress, self-efficacy, and social support were administered pre-trip, post-trip, and 1 month after program completion (follow-up). Univariate and multivariate models examined baseline scores for non-distressed participants compared to distressed participants, changes in outcomes from pre-trip to post-trip and follow-up for the entire sample, and the extent to which change rates for each outcome differed for distressed versus non-distressed participants.

RESULTS

All participants demonstrated significant improvement in self-efficacy over time. Distressed participants reported a significantly greater decrease in distress symptoms and greater increase in self-efficacy and social support at post-trip and 1 month later when compared to non-distressed participants.

CONCLUSIONS

Findings suggest that participation in an outdoor recreational activity designed specifically for AYAs with cancer contributes to significant reductions in distress and improvements in self-efficacy and social support, and particularly for AYAs reporting clinically significant distress symptoms prior to the initiation of their activity.

Quality of life after surgery for rectal cancer: a systematic review of comparisons with the general population

Rectal cancer treatments may impact negatively on patients' bowel and sexual functions and, in turn, on health-related quality of life. Information on the likely effects of treatment is essential in order to facilitate the care process and the adaptation of patients to their condition. Studies that report on the comparison between rectal cancer patients and the general population are a useful source of this evidence, providing elements to aid in answering questions such as 'is my life going to be the same as before?' In this article, the authors have systematically reviewed articles published in the last 6 years that report on the comparison between rectal patients' and the general population's health-related quality of life. Sixteen out of 645 articles were included. The results are summarized and critically discussed.

Enhancing nurse contributions to SWOG clinical trials

OBJECTIVES

To review nursing research contributions and future opportunities for nurses in cooperative oncology group research in SWOG (formerly Southwest Oncology Group).

DATA SOURCES

Peer-reviewed journal articles, grant submissions, professional manuals, research policy reports, and meeting minutes.

CONCLUSION

Nurses and nurse researchers have had active roles in SWOG research involving quality of life, symptom management, recruitment and adherence, and data quality. There are opportunities for nurses to make greater contributions to cooperative group research, particularly in cancer survivorship, health outcomes, and quality of life.

IMPLICATIONS FOR NURSING PRACTICE

Nursing science and evidence-based practice will be enhanced by conducting nursing research in the multi-site cooperative group setting.

Intermittent versus continuous androgen deprivation in prostate cancer

BACKGROUND

Castration resistance occurs in most patients with metastatic hormone-sensitive prostate cancer who are receiving androgen-deprivation therapy. Replacing androgens before progression of the disease is hypothesized to prolong androgen dependence.

METHODS

Men with newly diagnosed, metastatic, hormone-sensitive prostate cancer, a performance status of 0 to 2, and a prostate-specific antigen (PSA) level of 5 ng per milliliter or higher received a luteinizing hormone-releasing hormone analogue and an antiandrogen agent for 7 months. We then randomly assigned patients in whom the PSA level fell to 4 ng per milliliter or lower to continuous or intermittent androgen deprivation, with patients stratified according to prior or no prior hormonal therapy, performance status, and extent of disease (minimal or extensive). The coprimary objectives were to assess whether intermittent therapy was noninferior to continuous therapy with respect to survival, with a one-sided test with an upper boundary of the hazard ratio of 1.20, and whether quality of life differed between the groups 3 months after randomization.

RESULTS

A total of 3040 patients were enrolled, of whom 1535 were included in the analysis: 765 randomly assigned to continuous androgen deprivation and 770 assigned to intermittent androgen deprivation. The median follow-up period was 9.8 years. Median survival was 5.8 years in the continuous-therapy group and 5.1 years in the intermittent-therapy group (hazard ratio for death with intermittent therapy, 1.10; 90% confidence interval, 0.99 to 1.23). Intermittent therapy was associated with better erectile function and mental health (P<0.001 and P=0.003, respectively) at month 3 but not thereafter. There were no significant differences between the groups in the number of treatment-related high-grade adverse events.

CONCLUSIONS

Our findings were statistically inconclusive. In patients with metastatic hormone-sensitive prostate cancer, the confidence interval for survival exceeded the upper boundary for noninferiority, suggesting that we cannot rule out a 20% greater risk of death with intermittent therapy than with continuous therapy, but too few events occurred to rule out significant inferiority of intermittent therapy. Intermittent therapy resulted in small improvements in quality of life. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00002651.).

Quality of life after rectal resection for cancer, with or without permanent colostomy

BACKGROUND

For almost one hundred years abdominoperineal excision has been the standard treatment of choice for rectal cancer. With advances in the techniques for rectal resection and anastomosis, anterior resection with preservation of the sphincter function has become the preferred treatment for rectal cancers, except for those cancers very close to the anal sphincter. The main reason for this has been the conviction that the quality of life for patients with a colostomy after abdominoperineal excision was poorer than for patients undergoing an operation with a sphincter-preserving technique. However, patients having sphincter-preserving operations may experience symptoms affecting their quality of life that are different from stoma-patients.

OBJECTIVES

To compare the quality of life in rectal cancer patients with or without permanent colostomy.

SEARCH METHODS

We searched PUBMED, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Colorectal Cancer Group's specialised register. Abstract books from major gastroenterological and colorectal congresses were searched. Reference lists of the selected articles were scrutinized.

SELECTION CRITERIA

All controlled clinical trials and observational studies in which quality of life was measured in patients with rectal cancer having either abdominoperineal excision/Hartmann's operation or low anterior resection, using a validated quality of life instrument, were considered.

DATA COLLECTION AND ANALYSIS

One reviewer (JP) checked the titles and abstracts identified from the databases and hand search. Full text copies of all studies of possible relevance were obtained. The reviewer decided which studies met the inclusion criteria. Both reviewers independently extracted data. If information was insufficient the original author was contacted to obtain missing data. Extracted data were cross-checked and discrepancies resolved by consensus.

MAIN RESULTS

Sixty-nine potential studies were identified. Thirty-five of these, all non-randomised and representing 5127 participants met the inclusion criteria. Fourteen trials found that people undergoing abdominoperineal excision/Hartmann's operation did not have poorer quality of life measures than patients undergoing anterior resection. The rest of the studies found some difference, but not always in favour of non-stoma patients. Due to clinical heterogeneity and the fact that all studies were observational trials, meta-analysis of the included studies was not possible.

AUTHORS' CONCLUSIONS

The studies included in this review do not allow firm conclusions as to the question of whether the quality of life of people after anterior resection is superior to that of people after abdominoperineal excision/Hartmann's operation. The included studies challenges the assumption that anterior resection patients fare better. Larger, better designed and executed prospective studies are needed to answer this question.

Most colorectal cancer survivors live a large proportion of their remaining life in good health

PURPOSE

Colorectal cancer (CRC) diagnosis reduces life expectancy and decreases patients' well-being. We sought to assess the determinants of health and functional status and estimate the proportion of remaining life that CRC survivors would spend in good health.

METHODS

Using Sullivan method, healthy life expectancy was calculated based on survival data of 14,849 CRC survivors within a population-based cancer registry in southern Netherlands and quality of life information among a random sample of these survivors (n = 1,291).

RESULTS

Overall, albeit short life expectancy (LE at age 50 = 12 years for males and 13 years for females), most CRC survivors spent a large proportion of their remaining life in good health (74 and 77 %, for males and females, respectively). Long-term survivors may expect to live a normal life span (LE at age 50 = 30 years) and spent a large proportion of the remaining life in good health (78 %). In distinction, those with stage IV CRC had less than 2 years to live and spent more than half of their remaining life in poor health.

CONCLUSIONS

Most CRC patients may expect no compromise on living a healthy life, underlining the importance of early detection. On the other hand, the high proportion of non-healthy years among stage IV CRC survivors confirms the importance of early detection and palliative care.

Evaluating health-related quality-of-life therapeutic effectiveness in a clinical trial with extensive nonignorable missing data and heterogeneous response: results from a phase III randomized trial of gemcitabine plus paclitaxel versus paclitaxel monotherapy in patients with metastatic breast cancer

PURPOSE

This manuscript presents health-related quality of life (HRQL) results from a phase III trial of gemcitabine-paclitaxel (GT) versus paclitaxel (T) in metastatic breast cancer patients.

METHODS

Patients completed the Rotterdam Symptom Checklist (RSCL) and Brief Pain Inventory (BPI) at baseline and at the end of each cycle. Sensitivity analyses for six longitudinal pattern mixture models (PMMs) assessed potential bias due to informative dropout. Cumulative probability plots with 50% confidence intervals indicated the proportion of patients whose HRQL was likely to improve, decline, or stay the same.

RESULTS

Sensitivity analyses addressing nonignorable missing RSCL data included 351 patients. The mean RSCL global HRQL score for GT was significantly and consistently better than that for T (all PMMs P < 0.040). The slope estimate of 1.5 points (100-point scale) per cycle from one PMM translated to a clinically significant 9-point improvement over six cycles with GT versus T. For GT, ~25% of patients were more likely than not to have improved HRQL, whereas that proportion for T was ~5%. PMMs showed no consistent treatment arm differences for BPI or other RSCL outcomes.

CONCLUSIONS

Adding gemcitabine to paclitaxel for the treatment of metastatic breast cancer is more likely to improve global HRQL over time compared to monotherapy treatment.

Quality-of-life concerns in lung cancer patients

Lung cancer is a leading cause of cancer deaths for both men and women across the world. In the past, studies on lung cancer have focused on traditional end points such as survival, disease-free survival or local control. More recently, investigators have begun to appreciate the importance of health-related quality-of-life outcomes, particularly in the setting of lung cancer. This article provides an overview of the importance, methodology, analysis and presentation of health-related quality of life in lung cancer trials, and also discusses some of the limitations and challenges of such studies.

Pain and emotional well-being outcomes in Southwest Oncology Group-directed intergroup trial S0205: a phase III study comparing gemcitabine plus cetuximab versus gemcitabine as first-line therapy in patients with advanced pancreas cancer

PURPOSE

S0205 was a randomized clinical trial that compared the therapeutic impact of gemcitabine versus gemcitabine plus cetuximab. Study results for patient-reported health-related quality of life (HRQL) outcomes are reported.

PATIENTS AND METHODS

Patients completed the Brief Pain Inventory and a measure of emotional well-being (each measured on a 0 to 10 scale) at baseline and at weeks 5, 9, 13, and 17 postrandom assignment. Worst pain status was classified as palliated (worst pain scores < 5 maintained for 2 consecutive cycles) or not palliated (remaining patients) and tested with a chi(2) test. Change in emotional well-being and worst pain (exploratory analysis) were assessed over 17 weeks using generalized estimating equations with inverse probability of censoring weights.

RESULTS

Seven hundred twenty of 766 enrolled patients contributed baseline HRQL data. The two treatment arms did not differ statistically in the percentage of patients with successful worst pain palliation. Longitudinal analyses showed significantly improved emotional well-being for patients on both arms by weeks 13 and 17 (P < .01 and P < .001). An exploratory longitudinal analysis of worst pain showed significant decreases at all time points for both arms (P < .01 and P < .001). Significant treatment arm differences for either worst pain or emotional well-being were not observed at any of the assessment times.

CONCLUSION

We observed palliated pain and improved well-being for patients on this trial. However, these improvements were similar in both treatment arms, suggesting that the addition of cetuximab did not contribute to improvement in these HRQL outcomes.

Patients' perceptions of having a central venous catheter or a totally implantable subcutaneous port system-results from a randomised study in acute leukaemia

GOALS OF WORK

The selection process of type of central venous access device (CVAD) in patients with acute leukaemia (AL) is generally based on appropriate catheter capacity/function and risk of complications in relation to the planned length of therapy. Advantages and disadvantages of the CVAD from the patient's perspective should also be important parts in the selection of type of device. Perceptions on having a CVAD were thus analysed in a series of adult patients with AL included in a prospective randomised study evaluating the use of a double lumen totally implantable subcutaneous port system (PORT) or a double lumen central venous catheter (CVC) regarding survival time and complication rate.

MATERIALS AND METHODS

Perceptions were registered in 32 patients (median age 68 years, range 24-83 years) on three occasions (T1; the day after placement, T2; 3 weeks after placement and T3 after 12 weeks and/or when the CVAD was removed) with the use of two study specific questionnaires.

MAIN RESULTS

Overall, many patients reported minor catheter related discomfort, feelings of anxiety and restrictions. Half of the patients (6/11) who experienced a local bleeding after CVAD insertion described the placement procedure as unpleasant. More patients in the CVC group compared with the PORT group stated that they thought of having a CVAD (T3; p = 0.02) and that the CVAD interfered when dressing themselves (T2; p = 0.02 and T3; 0.04) or taking a shower (T3; p = 0.009).

CONCLUSION

Our findings support the view that the PORT is less restrictive in daily life than the CVC.

Health-Related Quality of Life Results in Pathologic Stage C Prostate Cancer From a Southwest Oncology Group Trial Comparing Radical Prostatectomy Alone With Radical Prostatectomy Plus Radiation Therapy

Purpose

To compare short- and long-term effects of adjuvant treatment versus observation after surgery on health-related quality of life (HRQL) of prostate cancer patients.

Patients and Methods

The Southwest Oncology Group (SWOG) intergroup trial compared radical prostatectomy (RP) plus observation versus RP plus adjuvant radiation therapy (RT). Two-hundred seventeen of 425 therapeutic trial patients were eligible and registered to the HRQL study. Patients completed the SWOG Quality of Life Questionnaire (emotional, physical, social, and role function; general symptom status; treatment/disease-specific symptoms; and global HRQL [GHRQL]) at baseline, 6 weeks, 6 months, and annually for 5 years. Prespecified outcomes were three genitourinary symptoms (bowel function tenderness, frequent urination, and erectile dysfunction [ED]) and measures of physical and emotional function. Adjustments were made for the baseline score.

Results

Patients receiving adjuvant RT reported worse bowel function (through approximately 2 years) and worse urinary function. There were no statistically significant differences for ED. GHRQL was initially worse for the RP+RT arm but improved over time and was better at the end of the period than the GHRQL reported for RP alone (treatment arm × time interaction, P = .0004). Symptom distress was significantly worse for the RP+RT arm compared with the RP alone arm, but the treatment arms did not differ with respect to other general measures of HRQL.

Conclusion

The addition of RT to surgery resulted in more frequent urination, as well as early report of more bowel dysfunction, although bowel function differences disappeared over the 5-year period. The addition of RT did not negatively impact ED.

Assessment and data analysis of health-related quality of life in clinical trials for gastric cancer treatments

This review contains a practical guide as well as a number of design and analytical methods for conducting health-related quality of life assessments in clinical trials for gastric cancer treatment. Although we address issues specific to the assessment of gastric cancer, many are applicable to clinical trials for different cancer types.

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.

Dimensions of quality of life and psychosocial variables most salient to colorectal cancer patients

Colorectal cancer is one of the most common invasive cancers, and is responsible for considerable physical and psychosocial morbidity. Understanding the quality of life experienced by colorectal cancer patients is essential for evaluating the full impact of the disease on individuals, their families and their communities. Patient perspective is essential in establishing a proper understanding of the quality of life of colorectal cancer patients. Despite this, few studies have employed a qualitative methodology to explore quality of life issues for colorectal cancer patients. A review of the literature identified only seven qualitative studies pertaining to quality of life issues for colorectal cancer patients, a surprising finding given the prevalence of this cancer. Accordingly, this study sought to build on the findings of previous qualitative research by providing descriptive data on the quality of life and psychosocial variables most salient to colorectal cancer patients. Six core themes emerged from interview and focus group data: Satisfaction with diagnosis and treatment; support (including information provision); quality of life; benefits of diagnosis; making sense of the cancer experience; and coping strategies. The information derived from this study will help inform the development of supportive care services to address the needs of the increasing number of people diagnosed with colorectal cancer.

The impact of a second breast cancer diagnosis on health related quality of life

A growing of research documents the negative impact of recurrent breast cancer on quality of life (QOL), however few prospective investigations are available that compare QOL outcomes across different types of second cancer events (e.g., local/regional recurrence (LR) versus distant/metastatic recurrence (DR) versus a new primary breast cancer (NP)). In addition, although participant attrition is a major issue in this group of cancer patients, the potential impact of attrition or response bias on QOL outcomes is not typically examined. To address these issues, we prospectively examined QOL data obtained from a sample of women (n=140) participating in the Women's Healthy Eating and Living (WHEL) Study who experienced a second cancer event (LR, DR or NP). Women in our study reported significant worsening in most areas of QOL, except for emotional wellbeing, from pre- to post-second cancer event. Although the patterns of change to QOL differed slightly within each category (LR versus DR versus NP), participants were more similar than different in their QOL ratings. However, the perceived health status of women with DR was significantly lower than women with LR or NP. We also identify important sources of response bias that should be considered when interpreting findings. Specifically, women diagnosed with DR (a) were more likely to decline to complete the post-recurrence QOL questionnaire (27% refusal rate versus 14% LR and 13% NP), and (b) had higher death rates (28% death rate versus 4% LR and 6% NP) after agreeing to but before completing the post-second diagnosis QOL questionnaire.

Quality of life as an endpoint in Phase I oncology clinical trials of novel chemotherapy drugs

This paper examines the rationale, utility and feasibility of including quality of life as an outcome measure in Phase I trials of new applications of chemotherapy drugs. Typically, Phase I trials in oncology are designed to assess safety and maximal tolerated dose; however, it is argued that when subjectively assessed, self perceived quality of life is as important as physical toxicity. The outcomes of studies that have applied quality-of-life assessment in Phase I trials are reviewed, and recommendations are made for future research based on both methodologic and practical considerations.

Analysis of incomplete quality of life data in advanced stage cancer: A practical application of multiple imputation

This paper presents a practical approach to analyzing incomplete quality of life (QOL) data that contains non-ignorable dropouts in patients with advanced non-small-cell lung cancer (NSCLC). QOL scores for the physical domain at baseline and at the end of the first and second courses of chemotherapy were compared between two treatment groups in a phase III trial. One hundred and 103 eligible patients were randomized to receive cisplatin and irinotecan (CPT-P) or cisplatin and vindesine, respectively; of those two groups, 83 and 85, respectively, completed a QOL questionnaire at least at baseline. A multiple imputation incorporating auxiliary QOL variables was implemented as one of alternatives of sensitivity analyses; these were complete case, available case, and pattern mixture analyses. Although larger sensitivity to missing data was found for CPT-P treatment, none of the alternative analyses demonstrated a significant difference in estimated slopes over time between the groups. This study presents an analytical approach for dealing with the complex problem of missing QOL data. It must be noted, however, that the validity of the multiple imputation method we present is not certain unless we can specify sufficiently informative auxiliary variables to ensure the conversion of non-ignorable missingness to ignorable.

Quality of life after rectal resection for cancer, with or without permanent colostomy

BACKGROUND

For almost one hundred years abdominoperineal excision has been the standard treatment of choice for rectal cancer. With advances in the techniques for rectal resection and anastomosis, anterior resection with preservation of the sphincter function has become the preferred treatment for rectal cancers, except for those cancers very close to the anal sphincter. The main reason for this has been the conviction that the quality of life for patients with a colostomy after abdominoperineal excision was poorer than for patients undergoing a sphincter-preserving technique. However, patients having sphincter-preserving operations may experience symptoms affecting their quality of life that are different from those with stoma-patients.

OBJECTIVES

To compare the quality of life in rectal cancer patients with or without permanent colostomy.

SEARCH STRATEGY

We searched PUBMED, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Colorectal Cancer Group's specialised register. Abstract books from major gastroenterological and colorectal congresses were searched. Reference lists of the selected articles were scrutinized.

SELECTION CRITERIA

All controlled clinical trials and observational studies in which quality of life was measured in patients with rectal cancer having either abdominoperineal excision or low anterior resection, using a validated quality of life instrument, were considered.

DATA COLLECTION AND ANALYSIS

One reviewer (JP) checked the titles and abstracts identified from the databases and hand search. Full text copies of all studies of possible relevance were obtained. The reviewer decided which studies met the inclusion criteria. Both reviewers independently extracted data. If information was insufficient the original author was contacted to obtain missing data. Extracted data were crosschecked and discrepancies resolved by consensus.

MAIN RESULTS

Thirty potential studies were identified. Eleven of these, all non-randomised and representing 1412 participants met the inclusion criteria. Six trials found that people undergoing abdominoperineal excision did not have poorer quality of life measures than patients undergoing anterior resection. One study found that a stoma only slightly affected the person's quality of life. Four studies found that patients receiving abdominoperineal excision had significantly poorer quality of life than after anterior resection. Due to heterogeneity, meta-analysis of the included studies was not possible.

AUTHORS' CONCLUSIONS

The studies included in this review do not allow firm conclusions as to the question of whether the quality of life of people after anterior resection is superior to that of people after abdominoperineal excision. The included studies challenged the assumption that anterior resection patients fare better.Larger, better designed and executed prospective studies are needed to answer this question.

Colorectal Cancer Screening and Treatment: Review of Outcomes Research

BACKGROUND

Colorectal cancer is the second leading cause of cancer deaths in the United States each year. Screening is effective in reducing colorectal cancer mortality; however, compliance with screening is poor, and factors associated with its compliance are poorly understood. The outcomes of treatment of colorectal cancer (surgery, radiation therapy, and chemotherapy) may have profound effects on quality of life (QOL). Furthermore, colorectal cancer screening and treatment may be expensive, and the costs are important from a policy perspective. This review examines patient-centered outcomes research related to colorectal cancer screening and treatment and outlines the work that has been done in several areas, including patient preferences, QOL, and economic analysis.

METHODS

The literature on the health outcomes associated with colorectal cancer screening and treatment was reviewed. A MEDLINE search of English language articles published from January 1, 1990 through February 2001, was conducted and was supplemented by a review of references of obtained articles. Criteria for study inclusion were identified a priori. A standardized data abstraction form was developed. Summary statistical analyses were performed on the results.

RESULTS

Six hundred eighty-six articles were selected for review. In total, 530 articles were excluded because they either did not include patient-centered outcomes, were duplicate articles, or could not be obtained. There were 156 articles included in the analysis; 67 addressed screening, 18 examined surveillance of high-risk groups, 22 concerned treatment of local disease, 10 examined treatment of local and metastatic disease, and 19 considered treatment of metastatic disease only. One study examined end-of-life care. In 19 studies, the phase of care was unspecified.

CONCLUSIONS

Standardized, disease-specific QOL instruments should be applied in clinical trials so that the results may be compared across different types of interventions. Valid and reliable methods that accurately capture patient preferences regarding screening and treatment should be developed.

Outcomes research in cancer clinical trial cooperative groups: the RTOG model

BACKGROUND

The Radiation Therapy Oncology Group (RTOG), a National Cancer Institute sponsored cancer clinical trials research cooperative, has recently formed an Outcomes Committee to assess a comprehensive array of clinical trial endpoints and factors impacting the net effect of therapy.

METHODS

To study outcomes in a consistent, comprehensive and coordinated manner, the RTOG Outcomes Committee developed a model to assess clinical, humanistic, and economic outcomes important in clinical trials.

RESULTS

This paper reviews how the RTOG incorporates outcomes research into cancer clinical trials, and demonstrates utilization of the RTOG Outcomes Model to test hypotheses related to non-small-cell lung cancer (NSCLC). In this example, the clinical component of the model indicates that the addition of chemotherapy to radiotherapy (RT) improves survival but increases the risk of toxicity. The humanistic component indicates that esophagitis is the symptom impacting quality of life the greatest and may outweigh the benefits in elderly (> or =70 years) patients. The economic component of the model indicates that accounting for quality-adjusted survival, concurrent chemoRT for the treatment of NSCLC is within the range of economically acceptable recommendations.

CONCLUSION

The RTOG Outcomes Model guides a comprehensive program of research that systematically measures a triad of endpoints considered important to clinical trials research.

Quality of life and colorectal cancer: a review

OBJECTIVES

To describe what is known of quality of life for colorectal cancer patients, to review what has been done in the Australian setting and to identify emerging directions for future research to address current gaps in knowledge.

METHOD

A literature search (using Medline, Psychinfo, CINAHL and Sociological Abstracts) was conducted and 41 articles identified for review.

RESULTS

Three key areas relating to quality of life in colorectal cancer patients emerged from the literature review: the definition and measurement of quality of life; predictors of quality of life; and the relationship of quality of life to survival. Results of existing studies are inconsistent in relation to quality of life over time and its relationship to survival. Small sample sizes and methodological limitations make interpretation difficult.

CONCLUSIONS

There is a need for large-scale, longitudinal, population-based studies describing the quality of life experienced by colorectal cancer patients and its determinants. Measurement and simultaneous adjustment for potential confounding factors would productively advance knowledge in this area, as would an analysis of the economic cost of morbidity to the community and an assessment of the cost effectiveness of proposed interventions.

IMPLICATIONS

As the Australian population ages, the prevalence of colorectal cancer within the community will increase. This burden of disease presents as a priority area for public health research. An improved understanding of quality of life and its predictors will inform the development and design of supportive interventions for those affected by the disease.

Statistics in clinical trials

Statistical developments over the past several years are described in this review. Efforts in phase I studies have focused on efficient estimation of maximum tolerated dose. Issues investigated for phase II trials include incorporation of multiple endpoints and randomization. For phase III trials, methods to reduce time or use the sample size more efficiently have been investigated. However, design innovations come with costs, including possible increased risk of incorrect conclusions. Other recent challenging statistical developments in clinical trials relate to use of complementary outcomes such as quality of life and to associated biologic questions, including the emergence of the field of genomics.

Quality of life after rectal resection for cancer, with or without permanent colostomy

BACKGROUND

For almost one hundred years abdominoperineal excision has been the standard treatment of choice for rectal cancer. With advances in the techniques for rectal resection and anastomosis, anterior resection with preservation of the sphincter function has become the preferred treatment for rectal cancers, except for those cancers very close to the anal sphincter. The main reason for this has been the conviction that the quality of life for patients with a colostomy after abdominoperineal excision was poorer than for patients undergoing a sphincter-preserving technique. However, patients having sphincter-preserving operations may experience symptoms affecting their quality of life that are different from those withstoma-patients.

OBJECTIVES

To compare the quality of life in rectal cancer patients with or without permanent colostomy.

SEARCH STRATEGY

We searched PubMed, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Colorectal Cancer Group's specialised register. Abstracts books from major gastroenterological and colorectal congresses were searched. Reference lists of the selected articles were scrutinized.

SELECTION CRITERIA

All controlled clinical trials and observational studies in which quality of life was measured in patients with rectal cancer having either abdominoperineal excision or low anterior resection, using a validated quality of life instrument, were considered.

DATA COLLECTION AND ANALYSIS

One reviewer (JP) checked the titles and abstracts identified from the databases and hand search. Full text copies of all studies of possible relevance were obtained. The reviewer decided which studies met the inclusion criteria. Both reviewers independently extracted data. If information was insufficient the original author was contacted to obtain missing data. Extracted data were crosschecked and discrepancies resolved by consensus.

MAIN RESULTS

Twenty five potential studies were identified. Eight of these, all non-randomised and representing 620 participants, met the inclusion criteria. Four trials found that people undergoing abdominoperineal excision did not have poorer quality of life measures than patients undergoing anterior resection. One study found that a stoma only slightly affected the persons quality of life. Three studies found that patients receiving abdominoperineal excision had significantly poorer quality of life than after anterior resection. Due to heterogeneity, meta-analysis of the included studies was not possible.

REVIEWERS' CONCLUSIONS

The studies included in this review do not allow firm conclusions as to the question of whether the quality of life of people after anterior resection is superior to that of people after abdominoperineal excision. The included studies challenged the assumption that anterior resection patients fare better.Larger, better designed and executed prospective studies are needed to answer this question.

Pattern mixture models for longitudinal quality of life studies in advanced stage disease

Analyses of longitudinal quality of life (QOL) for patients with advanced stage disease are frequently plagued by problems of non-random drop-out attributable to deteriorating health and/or death. As an example, Moinpour et al. cite specific challenges which limited their report and assessment of QOL for patients treated for advanced stage colorectal cancer in a clinical trial of several chemotherapeutic regimes performed by the Southwest Oncology Group. A particular source of confusion that arises in studies of advanced stage disease is whether or not to differentiate loss of follow-up due to death from drop-out where the patient is still alive but has dropped from the study. In this paper we examine exploratory data techniques for longitudinal QOL data with non-random missingness due to drop-out and censorship by death. We propose a pattern mixture model for longitudinal QOL, time of drop-out and survival, which allows for straightforward implementation of sensitivity analyses and explicit comparisons to the raw data. Our method is illustrated in the context of analysing the data and addressing the challenges posed by Moinpour et al.

Quality of life in advanced non-small-cell lung cancer: results of a Southwest Oncology Group randomized trial

PURPOSE

The main purpose of this paper is to present the results of a randomized trial comparing the effects of two chemotherapy regimens on the Quality of life (QOL) of patients with advanced non-small-cell lung cancer (NSCLC). Trials in advanced stage disease represent an important treatment context for QOL assessment. A second purpose of this paper is to examine methods for handling the level of missing data commonly observed in the advanced stage disease context.

METHODS

Patients were randomized to receive cisplatin plus vinorelbine or carboplatin plus paclitaxel. The QOL of 222 patients was assessed with the Functional Assessment of Cancer Therapy-Lung (FACT-L) prior to randomization; follow-up assessments occurred at 13 and 25 weeks. Three methods were used to analyze the QOL data: (1) cross-sectional analysis of four patient categories (improved, stable, missing, and declined) based on changes in the FACT-L score, (2) a mixed linear model, and (3) a pattern mixture model. The longitudinal analyses addressed two potential data biases.

RESULTS

Questionnaire submission rates were 91% at baseline, 68% at 13 weeks, and 47% at 25 weeks. The cross-sectional and mixed linear model analyses did not show significant differences by treatment arm in patient-reported QOL. The pattern mixture model analysis, more appropriate given non-ignorable missing data, also found no statistically significant effect of treatment on patient QOL.

CONCLUSION

We present a sensitivity analysis approach with multiple methods for analyzing treatment effects on patient QOL in the presence of substantial, non-ignorable missing data in an advanced stage disease clinical trial. We conclude that the two treatment arms did not differ statistically in their effects on patient QOL over a 25-week treatment period.

Alternative methods of interpreting quality of life data in advanced gastrointestinal cancer patients

Understanding of how to analyse and interpret quality of life (QoL) data from clinical trials in patients with advanced cancer is limited. In order to increase the knowledge about the possibilities of drawing conclusions from QoL data of these patients, data from 2 trials were reanalysed. A total of 113 patients with pancreatic, biliary or gastric cancer were included in 2 randomised trials comparing chemotherapy and best supportive care (BSC) with BSC alone. Patient benefit was evaluated by the treating physician (subjective response) and by using selected scales and different summary measures of the EORTC QLQ-C30 questionnaire. An increasing number of drop-outs (mainly due to death) with time did not occur in a random fashion. Therefore, the mean scores in the different subscales of the QLQ-C30 obtained during the follow-up of interviewed patients did not reflect the outcome of the randomised population. The scores of the patient-provided summary measure, 'Global health status/QoL', were stable in a rather high proportion of the patients and could not discriminate between the 2 groups. 3 other summary measures revealed greater variability, and they all discriminated between the 2 groups. A high agreement was also seen between the changes in the summary measures and the subjective response. A categorisation of whether an individual patient had benefited or not from the intervention could overcome the problem with the selective attrition.