|
|||||
|
|
||||||
Journal of Clinical Oncology, Vol 26, No 22 (August 1), 2008: pp. 3763-3769 © 2008 American Society of Clinical Oncology. DOI: 10.1200/JCO.2007.13.5145 Quality of Life in Patients With Metastatic Renal Cell Carcinoma Treated With Sunitinib or Interferon Alfa: Results From a Phase III Randomized Trial
From the Evanston Northwestern Healthcare and Northwestern University Feinberg School of Medicine, Evanston, IL; Pfizer Global Research and Development, San Diego, CA; Pfizer Global Research and Development, New London, CT; Pfizer Global Research and Development; and Memorial Sloan-Kettering Cancer Center, New York, NY Corresponding author: David Cella, PhD, Center on Outcomes, Research and Education (CORE), Evanston Northwestern Healthcare and Northwestern University Feinberg School of Medicine, 1001 University Place, Evanston, IL 60201; e-mail: d-cella{at}northwestern.edu
Purpose In an international, randomized phase III trial, sunitinib demonstrated statistically significant efficacy over interferon alfa (IFN- ) as first-line therapy in patients with metastatic renal cell carcinoma (mRCC) (progression-free survival time, 11 v 5 months, respectively; P < .001; objective response rate, 31% v 6%, respectively; P < .001). We report health-related quality-of-life (QOL) results from this trial.
Patients and Methods Seven hundred fifty mRCC patients were randomly assigned to sunitinib (6-week cycles: 50 mg orally once daily for 4 weeks, followed by 2 weeks off) or IFN-
Results Patients receiving sunitinib reported higher FKSI-15 and FKSI-DRS scores at each cycle than those receiving IFN-
Conclusion Sunitinib provides superior QOL compared with IFN-
Renal cell carcinoma (RCC) is the most common form of kidney cancer.1,2 At initial presentation, 25% to 30% of RCC patients have overt metastases.1 Five-year survival rates range from 0% to 20%.1-4
Metastatic RCC (mRCC) is difficult to treat and generally unresponsive to conventional chemotherapy. In the absence of effective treatment, many patients die within 6 to 10 months of diagnosis.5,6 Until recently, cytokines were widely used as first-line mRCC therapy.2,7 Treatment with cytokines, such as interferon alfa (IFN-
The introduction of targeted therapies, such as sunitinib malate (Sutent; Pfizer Inc, New York, NY), represents a significant shift in mRCC treatment. In a prospectively planned interim analysis of an international, phase III, randomized trial, treatment with sunitinib was well tolerated and resulted in significantly longer progression-free survival and higher objective response rate than IFN-
Eligibility and Treatments The study population included patients aged 18 years with mRCC with a component of clear cell histology. Key eligibility criteria included the following: no previous treatment with systemic RCC therapy; measurable disease; Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1; and adequate hepatic, renal, and cardiac function. Patients were excluded if they had brain metastases, uncontrolled hypertension, or clinically significant cardiovascular events or disease during the preceding 12 months.
Eligible patients were randomly assigned to sunitinib or IFN-
QOL Assessments
FKSI-15
FACT-G
EuroQoL Instrument
Statistical Analysis
Frequency distributions, means, and standard deviation were used to describe patient demographics and baseline characteristics. Frequencies and percentages of missing data for each instrument were compared between treatment groups. Between-group differences in the proportion of missing data (withdrawal from treatment for reasons other than documented disease progression or death) were tested using the Repeated-measures mixed-effects models with random intercepts and slopes were used to assess treatment differences in QOL measures over time. The outcomes were QOL postbaseline scores, and the predictors were baseline QOL score, treatment, time (which was treated as a continuous variable and measured at the planned time [cycle] of assessment), and treatment x time interaction.19-21 The changes in QOL scores over time were considered to be linear over the entire range of assessments (an assumption that was retrospectively tested and satisfied). All available data for each patient were used in the analysis; thus, patient end-of-treatment assessments were included, and missing responses as a result of withdrawal were not (although patients previous completed responses were included). All parameter estimates were obtained using restricted maximum likelihood estimation. Estimated mean scores were calculated for all QOL measures and compared between treatments over time. Sensitivity analyses using pattern-mixture models22,23 were performed to test the robustness of results from the mixed-effects models; for these data, all parameters were identifiable and estimable. In this model, each pattern/stratum is defined by the time of last assessment. The first two cycles are combined as the first stratum, and each subsequent stratum is based on a cycle whose patients had data up until that cycle. Subsequently, in this analysis, there is a separate stratum for each potential dropout time by cycle. Pattern-mixture models allow assumptions that missing data are missing at random to be relaxed by permitting group comparisons on available data, within subgroups of patients who drop out early. Similar results between mixed-effects and pattern-mixture models would suggest that the results are not overly dependent on the nature of the missing data. All the data were analyzed using SAS 8.2 (SAS Institute, Cary, NC), and P < .05 was considered nominally statistically significant without multiplicity adjustment. No adjustments were made for multiple comparison testing. Average QOL scores during the study for all instruments were calculated and compared between the treatment groups. To estimate the magnitude of the difference between treatment groups, the standardized effect size (SES) and minimally important difference (MID) were used. SES is calculated as the mean difference divided by the baseline standard deviation and provides a standardized value for the size of the treatment differences. Cohen's definitions were used to characterize SES (0.20 for a small but tangible effect, 0.50 for a moderate effect, and 0.80 for a large effect).24 The MIDs in the FKSI-15, FACT-G, and their subscale scores have been established with the following lower boundaries: 2 points for FKSI-DRS, 3 points for FKSI-15, 5 points for FACT-G, and 2 points for each of the four FACT-G subscales.25,26
Baseline Characteristics Seven hundred fifty patients were randomly assigned and included in the intent-to-treat analysis (Fig 1). Median age was 62 years for the sunitinib arm and 59 years for the IFN- arm; 71% of patients were male, and more than 90% were white. There were no significant between-treatment differences in baseline characteristics (Table 1).
Questionnaire Completion Rates The questionnaire completion rates were based on the number of patients who entered the cycles; there were fewer patients in later cycles because many had not reached them yet. The completion rates (the proportion of expected evaluations received) for the FKSI-15 and FACT-G questionnaires, through up to 10 cycles for which QOL data were available, were 95.4% and 95.2% for the sunitinib and IFN- groups, respectively. Patient refusal was the most common reason for noncompletion.
FKSI Assessments
Within-group changes over time for the postbaseline scores, as shown in Figure 2, indicate that there were sharp decreases in both FKSI-15 and FKSI-DRS scores after the first cycle of treatment; the initial decreases were more pronounced for the IFN- group, exceeding the pre-established MIDs for both scores, perhaps reflecting the more toxic nature of IFN- . After the initial decreases, the FKSI-15 and FKSI-DRS scores remained lower than baseline, except for the FKSI-DRS scores in the sunitinib group, which increased slowly but significantly over time (slope = 0.138, P = .003), suggesting that sunitinib-treated patients disease-related symptoms lessened over time; however, this change was only a slight or moderate improvement over baseline.
When examining the nine items in the FKSI-DRS, patients treated with sunitinib experienced significantly less severe symptoms of lack of energy, weight loss, bone pain, fatigue, breathlessness, coughing, and fever symptoms than those receiving IFN-
FACT-G Assessments The mean treatment difference over all cycles was estimated to be 5.58 points significantly higher for the sunitinib group (95% CI, 3.91 to 7.24 points; P < .0001), with a small to moderate overall treatment effect (SES = 0.36, ranging from 0.35 at cycle 1, day 28 to 0.40 at cycle 11, day 28); mean treatment differences also favored sunitinib for each of the four FACT-G subscales (P .0009; Table 2). Between-treatment differences in FACT-G scores exceeded the pre-established MID at all assessment points. However, of the FACT-G subscales, only the difference in FWB subscale scores exceeded the MID after cycle 4, day 1. Small treatment effects were observed for PWB (SES = 0.27), social/family well-being (SES = 0.26), emotional well-being (SES = 0.17), and FWB (SES = 0.32) subscales.
Comparisons of the postbaseline scores with their respective baseline values indicate that there were sharp decreases in the FACT-G total score (Fig 3A) and the PWB and FWB subscale scores for the IFN-
EuroQol Assessments The overall postbaseline mean treatment difference for the EQ-5D Index was estimated to be 0.0364 points in favor of sunitinib (95% CI, 0.0109 to 0.0620 points; P = .0052; Table 2), although the mean difference was not statistically significant after cycle 5, day 1 (Fig 3). The overall mean treatment difference for EQ-VAS was estimated to be 4.74 points in favor of sunitinib (95% CI, 2.60 to 6.87 points; P < .0001), and mean treatment differences were found to be statistically significant at all time points (P < .01; Fig 3). The overall SES values were close to zero (0.05 for the EQ-5D and 0.07 for the EQ-VAS). Comparisons of postbaseline EQ-5D Index and EQ-VAS scores with their respective baseline values (Figs 3B and 3C, respectively) yielded similar patterns as were shown for the FACT-G total scores.
Sensitivity Analyses
To our knowledge, this is the first head-to-head comparison of patients QOL between an oral tyrosine kinase inhibitor and a systemic cytokine in the first-line treatment of mRCC. Previous studies of QOL among mRCC patients were case series,27 evaluations of other therapeutic options such as surgery,28 or comparisons of immunotherapy.8,29,30 Complementing previously published interim results from this trial in which sunitinib demonstrated statistically superior efficacy over IFN- ,9 these results indicate that patients on the sunitinib arm also had significantly better QOL compared with patients on the IFN- arm. These results predominantly reflected between-group differences rather than within-group improvement from baseline with sunitinib. Validated generic and disease-specific QOL instruments were used to measure kidney cancer–related symptoms (FKSI-15 and FKSI-DRS), cancer-specific health-related QOL (FACT-G and its subscales), and overall health status (EQ-5D Index and EQ-VAS). Longitudinal data allowed assessment of the impact of treatments over the course of the trial.
Use of FKSI-DRS (the primary QOL end point) was intended to examine the impact of sunitinib on disease-related symptom experience rather than on treatment-related adverse effects. In the context of a drug trial, symptoms are often the most proximal result of treatment and an important component of QOL for people with advanced kidney cancer; therefore, it is important to isolate the symptom domain from other domains within the QOL concept.11 Patients receiving sunitinib reported better scores on FKSI-DRS, indicating that they experienced fewer severe disease-specific symptoms than patients treated with IFN- However, despite use of the FKSI-DRS, it remains difficult to clearly distinguish treatment effects related to a drug's adverse effect profile from those effects related to its capacity to relieve disease-related symptoms; thus, further analysis via use of a mediation model is warranted. The development of such a model to better clarify these findings is currently being explored by the authors.
The advantage of sunitinib was also reflected in the results for the secondary QOL end points (FKSI-15, FACT-G, EQ-5D Index, and EQ-VAS). FKSI-15 and the FACT-G both exhibited clinically meaningful differences at all assessments. Consistent with the other findings, EQ-5D and EQ-VAS scores were superior for patients on sunitinib compared with patients on IFN-
Patients were aware of their assigned therapy, opening the possibility that the QOL benefit of sunitinib (the active treatment) may have been overestimated. However, this potential concern is mitigated by having patients assess their current status noncomparatively, and doing so on many questions, rather than retrospectively, compared with baseline. Therefore, the instruments used here are harder to answer in a biased way. Moreover, the consistency of the postbaseline responses across time within treatment group provides evidence for the validity of the QOL benefit of sunitinib over IFN- This study enrolled patients from different countries, and we have not adjusted for potential cultural differences.31 Other factors, such as social support, may affect QOL in cancer patients as well.32 Although these factors merit exploration, they are unlikely to have had a significant impact because of the randomized study design.
As a result of the efficacy difference,9 there was an increasing between-treatment difference in the proportions of patients remaining in the study over time. Use of the repeated-measures mixed-effects models reduced the potential for bias resulting from the uneven dropouts by using all available assessments. Results from the pattern-mixture models supported and enhanced the validity of these findings. However, this model has a limitation because its assumption, that trajectories for patient outcome within each stratum can be extrapolated past the point of dropout, cannot be tested because of missing data; also, if a stratum is comprised of censored patients and dropouts, the latter's true impact will be unclear. In summary, this large, international, randomized trial showed that, in addition to providing significantly superior efficacy compared with IFN-
Although all authors completed the disclosure declaration, the following author(s) indicated a financial or other interest that is relevant to the subject matter under consideration in this article. Certain relationships marked with a "U" are those for which no compensation was received; those relationships marked with a "C" were compensated. For a detailed description of the disclosure categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors. Employment or Leadership Position: Jim Z. Li, Pfizer Inc (C); Joseph C. Cappelleri, Pfizer Inc (C); Andrew Bushmakin, Pfizer Inc (C); Claudie Charbonneau, Pfizer Inc (C); Sindy T. Kim, Pfizer Inc (C); Isan Chen, Pfizer Inc (C) Consultant or Advisory Role: David Cella, Pfizer Inc (C) Stock Ownership: Jim Z. Li, Pfizer Inc; Joseph C. Cappelleri, Pfizer Inc; Andrew Bushmakin, Pfizer Inc; Sindy T. Kim, Pfizer Inc; Isan Chen, Pfizer Inc Honoraria: None Research Funding: David Cella, Pfizer Inc; Robert J. Motzer, Pfizer Inc Expert Testimony: None Other Remuneration: None
Conception and design: Jim Z. Li, Sindy T. Kim, Isan Chen, Robert J. Motzer Administrative support: Sindy T. Kim Provision of study materials or patients: Sindy T. Kim, Robert J. Motzer Collection and assembly of data: Sindy T. Kim, Isan Chen Data analysis and interpretation: David Cella, Jim Z. Li, Joseph C. Cappelleri, Andrew Bushmakin, Claudie Charbonneau, Sindy T. Kim, Isan Chen Manuscript writing: David Cella, Jim Z. Li, Joseph C. Cappelleri, Andrew Bushmakin, Claudie Charbonneau, Isan Chen Final approval of manuscript: David Cella, Joseph C. Cappelleri, Sindy T. Kim, Isan Chen, Robert J. Motzer
We thank the patients and their families for participation in this study. Editorial assistance was provided by ACUMED (Tytherington, United Kingdom) with funding by Pfizer Inc.
Supported by Pfizer Inc. Presented in part at the 42nd Annual Meeting of the American Society of Clinical Oncology, June 2-6, 2006, Atlanta, GA, and the 5th International Kidney Cancer Symposium, September 22-23, 2006, Chicago, IL. Authors disclosures of potential conflicts of interest and author contributions are found at the end of this article. Clinical Trials repository link available on www.JCO.org.
1. Mickisch G, Carballido J, Hellsten S, et al: Guidelines on renal cell cancer. Eur Urol 40:252-255, 2001[CrossRef][Medline] 2. National Comprehensive Cancer Network: The NCCN clinical practice guidelines in oncology: National Comprehensive Cancer Network, 2006. http://www.nccn.org/professionals 3. Linehan WM, Walther MM, Zbar B: The genetic basis of cancer of the kidney. J Urol 170:2163-2172, 2003[CrossRef][Medline] 4. Motzer RJ, Bander NH, Nanus DM: Renal-cell carcinoma. N Engl J Med 335:865-8675, 1996 5. Lam JS, Belldegrun AS, Figlin RA: Advances in immune-based therapies of renal cell carcinoma. Expert Rev Anticancer Ther 4:1081-1096, 2004[CrossRef][Medline] 6. Linehan WM, Zbar B: Focus on kidney cancer. Cancer Cell 6:223-228, 2004[CrossRef][Medline] 7. National Institute for Clinical Excellence: Improving outcomes in urological cancers: National Institute for Clinical Excellence, 2002. http://www.nice.org.uk 8. Motzer RJ, Murphy BA, Bacik J, et al: Phase III trial of interferon alfa-2a with or without 13-cis-retinoic acid for patients with advanced renal cell carcinoma. J Clin Oncol 18:2972-2980, 2000 9. Motzer RJ, Hutson TE, Tomczak P, et al: Sunitinib versus interferon alfa in metastatic renal-cell carcinoma. N Engl J Med 356:115-124, 2007 10. Cella D, Yount S, Du H, et al: Development and validation of the Functional Assessment of Cancer Therapy-Kidney Symptom Index (FKSI). J Support Oncol 4:191-199, 2006[Medline] 11. Cella D, Yount S, Brucker PS, et al: Development and validation of a scale to measure disease-related symptoms of kidney cancer. Value Health 10:285-293, 2007[CrossRef][Medline] 12. Bonomi AE, Cella DF, Hahn EA, et al: Multilingual translation of the Functional Assessment of Cancer Therapy (FACT) quality of life measurement system. Qual Life Res 5:309-320, 1996[CrossRef][Medline] 13. Cella D, Hernandez L, Bonomi AE, et al: Spanish language translation and initial validation of the functional assessment of cancer therapy quality-of-life instrument. Med Care 36:1407-1418, 1998[CrossRef][Medline] 14. Cella DF, Tulsky DS, Gray G, et al: The Functional Assessment of Cancer Therapy scale: Development and validation of the general measure. J Clin Oncol 11:570-579, 1993 15. Brazier J, Jones N, Kind P: Testing the validity of the Euroqol and comparing it with the SF-36 health survey questionnaire. Qual Life Res 2:169-180, 1993[CrossRef][Medline] 16. de Boer AG, van Lanschot JJ, Stalmeier PF, et al: Is a single-item visual analogue scale as valid, reliable and responsive as multi-item scales in measuring quality of life? Qual Life Res 13:311-320, 2004[CrossRef][Medline] 17. Rabin R, de Charro F: EQ-5D: A measure of health status from the EuroQol Group. Ann Med 33:337-343, 2001[Medline] 18. The EuroQol Group: EuroQol: A new facility for the measurement of health-related quality of life—The EuroQol Group. Health Policy 16:199-208, 1990[CrossRef][Medline] 19. Fitmaurice G, Laird N, Ware J: Applied Longitudinal Analysis. Hoboken, NJ, John Wiley & Sons, Inc, 2004 20. Hedeker D, Gibbons R: Longitudinal Data Analysis. Hoboken, NJ, John Wiley & Sons, Inc, 2006 21. Singer J, Willett J: Applied Longitudinal Data Analysis: Modeling Change and Event Occurrence. New York, NY, Oxford University Press, 2003 22. Hedeker D, Gibbons RD: Application of random-effects pattern-mixture models for missing data in longitudinal studies. Psychol Methods 2:64-78, 1997[CrossRef] 23. Little RJA: A class of pattern-mixture models for normal incomplete data. Biometrika 81:471-483, 1994 24. Cohen J: Statistical Power Analysis for the Behavioral Sciences (ed 2). New York, NY, Academic Press, 1988 25. Cella D: Manual of the Functional Assessment of Chronic Illness Therapy (FACIT Scales), Version 4. Evanston, IL, Evanston Northwestern Healthcare & Northwestern University, Center on Outcomes, Research and Education, 1997 26. Brucker PS, Yost K, Cashy J, et al: General population and cancer patient norms for the Functional Assessment of Cancer Therapy-General (FACT-G). Eval Health Prof 28:192-211, 2005 27. Ozeki Z, Kobayashi S, Machida T, et al: Long-term survival in patients with metastatic renal cell carcinoma managed with conservative therapy: A report of two cases. Hinyokika Kiyo 50:621-624, 2004[Medline] 28. Pace KT, Dyer SJ, Stewart RJ, et al: Health-related quality of life after laparoscopic and open nephrectomy. Surg Endosc 17:143-152, 2003[CrossRef][Medline] 29. Atzpodien J, Kuchler T, Wandert T, et al: Rapid deterioration in quality of life during interleukin-2- and alpha-interferon-based home therapy of renal cell carcinoma is associated with a good outcome. Br J Cancer 89:50-54, 2003[CrossRef][Medline] 30. Watanabe J, Hattori T, Satoh M, et al: Combined immunotherapy using interferon-alpha, interleukin-2 and lymphokine-activated killer cells: Improvement of quality of life in patients with advanced renal cell carcinoma. Nippon Hinyokika Gakkai Zasshi 86:1156-1163, 1995[Medline] 31. Wild D, Grove A, Martin M, et al: Principles of good practice for the translation and cultural adaptation process for patient-reported outcomes (PRO) measures: Report of the ISPOR Task Force for Translation and Cultural Adaptation. Value Health 8:94-104, 2005[CrossRef][Medline] 32. Devine D, Parker PA, Fouladi RT, et al: The association between social support, intrusive thoughts, avoidance, and adjustment following an experimental cancer treatment. Psychooncology 12:453-4562, 2003[CrossRef][Medline] Submitted July 21, 2007; accepted April 15, 2008.
This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||
|
Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|