|
Advertisement |
|
|
||
 |
|
|||||
|
|||||
|
 |
||||||
|
||||||
|
||||||
|
© 2001 American Society for Clinical Oncology Structured Exercise Improves Physical Functioning in Women With Stages I and II Breast Cancer: Results of a Randomized Controlled TrialFrom the Department of Medical Oncology and Oncology Rehabilitation Program, Ottawa Regional Cancer Centre, Ottawa, Canada. Address reprint requests to Roanne Segal, MD, FRCP(C), Department of Medical Oncology, Ottawa Regional Cancer Centre–General Site, 501 Smyth Rd, Ottawa, Ontario K1H 8L6, Canada; email: roanne_segal{at}cancercare.on.ca
PURPOSE: Self-directed and supervised exercise were compared with usual care in a clinical trial designed to evaluate the effect of structured exercise on physical functioning and other dimensions of health-related quality of life in women with stages I and II breast cancer. PATIENTS AND METHODS: One hundred twenty-three women with stages I and II breast cancer completed baseline evaluations of generic and disease- and site-specific health-related quality of life, aerobic capacity, and body weight. Participants were randomly allocated to one of three intervention groups: usual care (control group), self-directed exercise, or supervised exercise. Quality of life, aerobic capacity, and body weight measures were repeated at 26 weeks. The primary outcome was the change in the Short Form-36 physical functioning scale between baseline and 26 weeks. RESULTS: Physical functioning in the control group decreased by 4.1 points, whereas it increased by 5.7 points and 2.2 points in the self-directed and supervised exercise groups, respectively (P = .04). Post hoc analysis showed a moderately large (and clinically important) difference between the self-directed and control groups (9.8 points; P = .01) and a more modest difference between the supervised and control groups (6.3 points; P = .09). No significant differences between groups were observed for changes in quality of life scores. In a secondary analysis of participants stratified by type of adjuvant therapy, supervised exercise improved aerobic capacity (+3.5 mL/kg/min; P = .01) and reduced body weight (-4.8 kg; P < .05) compared with usual care only in participants not receiving chemotherapy. CONCLUSION: Physical exercise can blunt some of the negative side effects of breast cancer treatment, including reduced physical functioning. Self-directed exercise is an effective way to improve physical functioning compared with usual care. In participants not receiving chemotherapy, supervised exercise may increase aerobic capacity and reduce body weight compared with usual care.
IN THE YEAR 2000, the most frequently diagnosed cancer in North American women will be breast cancer. One in nine women will develop breast cancer over their lifetime, and one in 24 will die from it.1 Early-stage breast cancer has an excellent prognosis, with a 5-year survival rate of around 70%. Important advances in the treatment of women with breast cancer include the development of adjuvant therapy for those with localized disease. Adjuvant therapy is any therapy that is used once the primary tumor has been removed surgically and may include radiation treatment, chemotherapy or hormonal therapy, or very commonly, combinations of these therapies. Breast cancer is staged I to IV according to tumor mass, node status (negative or positive), and the presence or absence of distant metastases. Stage I patients have small, localized tumors, no discernible metastases, and the best prognosis. Stage IV patients may have tumors of any size, with the presence of documented metastases to other tissues or sites. Typically, they have the poorest prognosis. Patients considered for adjuvant therapy are most often women for whom the risk of micrometastatic disease may be favourably influenced by therapy. The form of adjuvant therapy chosen for an individual patient is dependent on tumor prognostic factors including stage, age, surgical approach, menopausal status, and pre-existing comorbidities.2 Women receiving adjuvant therapy for breast cancer, in addition to the usual toxicities of the drug or radiation treatment, may feel fatigued, nauseous, anxious, depressed, and in a low mood state.3-12 Many women become fearful of overexertion and are uncertain of what they can do.13 This often means that most physical activity ceases. Physical inactivity further contributes to the debilitation of the person with cancer13 and compounds the fatigue attributable to adjuvant therapy.14 Studies involving women with breast cancer have shown that many of the physical and psychologic components of quality of life are responsive to increased levels of exercise, including the following: state anxiety, depression, general mood, self image, functional capacity, and degree of nausea.13-19 Many patients perceive exercise as a stress-controlling mechanism that can help them cope with cancer and maintain a sense of control over their lives.13 In a recent review of the association between exercise and rehabilitation among patients with cancer, Friedenreich and Courneya20 concluded that exercise seems to improve breast cancer patients’ physiologic and psychologic well-being. However, the available research has many methodologic limitations, and these results should be considered as preliminary evidence only. Additional well-designed, experimental investigations involving exercise in women with breast cancer receiving adjuvant therapy are required. Questions remain concerning the need for supervised versus self-directed exercise, exercise type and intensity level, and the appropriate program duration. The purpose of this study was to evaluate the effect of exercise on physical functioning and other dimensions of health-related quality of life in women with breast cancer during the time they were receiving adjuvant therapy. Two approaches, self-directed and supervised exercise, were compared with usual care in a controlled clinical trial.
The study was conducted at the Ottawa Regional Cancer Centre. One hundred twenty-three women with stages I and II breast cancer were recruited through medical oncologists within 2 weeks of the initiation of their prescribed adjuvant therapy (radiotherapy, hormonal therapy, or chemotherapy). We excluded patients receiving only alternative or dose-intensive chemotherapy regimens, those with severe cardiac disease or uncontrolled hypertension (> 160/95 blood pressure), and those for whom the treating oncologist believed that exercise was not indicated. At a prescreening session, the nature of the study was explained and informed consent was obtained. Height and weight were recorded. A medical questionnaire, as well as generic21 and cancer site-specific22 measures of health-related quality of life, was completed. To determine aerobic capacity, participants completed the modified Canadian Aerobic Fitness Test (mCAFT).23 A description of this test and the meaning of the scores derived from it is provided in the Appendix. Before assignment to a study group, we stratified participants by type of adjuvant therapy (chemotherapy v no chemotherapy) to ensure that groups were balanced on this factor. Stratum 1 included patients who were to receive chemotherapy, either alone or in combination with other adjuvant therapies. Stratum 2 included patients who were to receive any adjuvant therapy other than chemotherapy (ie, hormone and/or radiation). We then randomly assigned participants to one of three groups using a random numbers table: usual care (control group), a self-directed exercise intervention, or a supervised exercise intervention. A study coordinator revealed group assignment after baseline testing. Usual care involved general advice from the oncologist about the benefits of exercise and a suggestion to participants to exercise if they felt well enough. This advice was given during the referral visit, 1 to 4 weeks before the beginning of adjuvant treatment. For participants in the self-directed and supervised exercise intervention groups, an exercise specialist provided detailed information regarding their fitness assessment during a return visit, within seven days of the baseline testing. Instructions for monitoring exercise intensity and completing an exercise diary were provided. Participants were shown a standardized series of warm-up and cool-down exercises and were provided a progressive walking program at an exercise intensity of 50% to 60% of the predicted maximal oxygen uptake. Participants in the self-directed exercise group received a home exercise prescription and were asked to exercise five times per week for a 26-week period. They received an interim fitness evaluation at 13 weeks and were contacted by telephone every 2 weeks during the 26-week training period. During the call, the exercise specialist checked on progress and worked with the participants to overcome any barriers to exercise they were experiencing. Supervised exercise group participants received a supervised exercise program three times per week for 26 weeks in the rehabilitation area of the Ottawa Regional Cancer Centre.24 During each exercise class, the exercise specialist led a 7- to 10-minute warm-up. Participants then completed walking exercise at their prescribed pace. The exercise specialist then led a standard cool-down. Patients were also expected to exercise at home on at least 2 other days each week. Generic and disease-specific health-related quality of life, aerobic capacity, and body weight measures were repeated 26 weeks after the baseline assessment. Participants not returning for follow-up appointments were contacted by telephone by the study coordinator. Generic health-related quality of life was measured using the Medical Outcomes Survey Short Form-36 (MOS SF-36).21 The SF-36 is a 36-item, self-administered, generic health-related quality of life assessment constructed to measure eight health attributes: physical functioning; role limitations resulting from physical health problems; bodily pain; general health; vitality (energy/fatigue); social functioning; role limitations resulting from emotional problems; and mental health (psychologic distress and psychologic well-being). Each of the scales has a maximum score of 100, with higher scores indicating more positive health states. Cancer site-specific quality of life was measured using the Functional Assessment of Cancer Therapy-General (FACT-G) and Functional Assessment of Cancer Therapy-Breast (FACT-B) scales.22 The FACT-G is intended for all patients with cancer and the FACT-B is intended for patients with breast cancer. The primary outcome of interest in this study was the change between baseline and 26 weeks measured by the physical functioning scale of the SF-36. Although the reliability of each of the SF-36 scale scores has been found to be acceptable for group comparisons,21 the physical functioning scale most consistently meets the reliability standard (> 0.90) for comparison of repeated measures within individual patients. The physical functioning scale consists of 10 items that evaluate various aspects of physical functioning and a range of severe and minor physical limitations. Secondary outcomes of interest included changes in the remaining seven scales of the SF-36 (physical role, bodily pain, general health, vitality, social functioning, emotional role, and mental health), as well as changes in FACT-G, FACT-B, aerobic capacity, and body weight. All eligible participants, regardless of compliance with the protocol, were included in the analysis. The sample size was calculated to detect whether at least one form of structured physical activity (ie, self-directed or supervised) would have an average difference of at least 10 points (a moderately large difference) compared with the control group for the change in the physical functioning scale of the SF-36 over 26 weeks. A two-sided test was used with alpha = .05, 1-beta = 0.8. Based on a pilot study, the sample size was determined using sigma2 = 300 points. The sample size for each treatment was 41 patients based on the method for designing multiple comparisons with a control suggested by Bristol.25
Baseline subject characteristics in the three groups were compared using one-way analysis of variance for continuous variables and
A total of 378 eligible patients were approached during the recruitment period, and 123 (32.5%) agreed to participate in the study. Of the 255 patients who declined to participate in the study, 62 (24.3%) said they were not interested, 34 (13%) believed that work would interfere with their participation, 32 (12.5%) said that their physician would not permit them to participate, eight (3.1%) said they had other medical conditions that made exercise difficult, and six (2.4%) were unwilling to be randomly assigned to treatment. The remaining 113 (44.3%) did not provide a reason for their refusal. No participants were excluded during the prescreening procedures, and 123 participants were randomly allocated to the control group (n = 41), the self-directed exercise group (n = 40), and the supervised exercise group (n = 42) ( Fig 1). Baseline demographic, body weight, aerobic capacity, prior level of physical activity, and disease treatment characteristics of the subjects did not differ among the three groups ( Table 1). There were no baseline differences among groups for the eight SF-36 scales ( Table 2). The chemotherapy regimens of the 83 participants receiving chemotherapy are summarized in Table 3.
End-of-intervention (26-week) data were obtained for 99 participants (80.4%) . Twenty-four participants dropped out during the treatment. The dropout rate did not differ among the three groups (17.5% v 17.5% v 23.1% in the control, self-directed, and supervised groups, respectively). If data were missing because of dropout, data from the participant’s most recent observation were used in the intent-to-treat analysis. Changes in physical functioning between baseline and 26-weeks in the three groups for all participants and when stratified by type of adjuvant therapy are listed in Table 4. Figure 2 illustrates in graph form changes in physical functioning over treatment by group. In the control group, the physical functioning scale decreased by 4.1 points, whereas it increased by 5.7 points and 2.2 points in the self-directed and supervised exercise groups, respectively (P = .04), when all 123 participants were considered. Post hoc analysis with Dunnett’s t test revealed a significant mean difference between the self-directed and control groups (9.8 points; P = .01). The mean difference between the supervised and the control groups, although showing a trend in favor of the exercise intervention, did not achieve significance (6.3 points; P = .09).
When only the 83 participants receiving chemotherapy were considered, physical functioning in the control group decreased by 5.0 points, whereas it increased by 6.3 and 0.9 points in the self-directed and supervised exercise groups, respectively (P = .11). Post hoc analysis showed a significant mean difference between the self-directed exercise group and the control group (11.3 points; P = .03). When only the 40 participants not receiving chemotherapy were considered, physical functioning in the control group decreased by 2.1 points, whereas it increased by 4.3 and 5.0 points in the self-directed and supervised exercise groups, respectively (P = .19). Post hoc analysis of this relatively small subset of participants showed that the difference between the self-directed exercise group and the control group (6.4 points) was significant only at the .12 level, whereas the difference between the supervised exercise group and the control group (7.1 points) was significant at the .08 level. Changes in other SF-36 scales between baseline and 26 weeks in the three groups are listed in Table 5. There were no significant differences among the groups for changes in these scale scores. There were no significant differences among the groups for changes in the FACT-G (P = .29) or FACT-B (P = .17) scores over the 26-week intervention period.
Changes in aerobic capacity over the 26-week period among the three groups for all participants stratified by type of adjuvant therapy are listed in Table 6. Considering all study participants, aerobic capacity remained the same in the control group and increased by 3.5% and 2.4% in the self-directed and supervised exercise groups, respectively. These differences were not significant. When only participants receiving chemotherapy were considered, aerobic capacity in the control group increased by 0.2 mL/kg/min, whereas it increased by 0.9 mL/kg/min in the self-directed exercise group and decreased by 0.3 mL/kg/min in the supervised exercise group (P = .30). When only participants not receiving chemotherapy were considered, aerobic capacity in the control group decreased by 0.4 mL/kg/min, whereas it increased by 1.0 mL/kg/min in the self-directed exercise group and by 3.1 mL/kg/min in the supervised exercise group (P < .01). Post hoc analysis showed that the difference between the supervised exercise group and the control group (3.5 mL/kg/min) was significant at the .01 level.
Changes in body weight over the 26-week period among the three groups for all participants and when stratified by type of adjuvant therapy are listed in Table 7. Considering all participants, body weight decreased only in the supervised exercise group (-1.4 kg), although this decrease was not significant compared with the control group (+0.6 kg). When only participants receiving chemotherapy were considered, body weight in the control group increased by 0.4 kg, whereas it increased by 0.3 kg in the self-directed exercise group and decreased by 0.5 kg in the supervised exercise group (P = .78). When only participants not receiving chemotherapy were considered, body weight in the control group increased by 1 kg, whereas it increased by 0.9 kg in the self-directed exercise group and decreased by 3.8 kg in the supervised exercise group (P < .05). Post hoc analysis showed that the difference between the supervised exercise group and the control group (4.8 kg) was significant at the .01 level.
In this study of women with stages I and II breast cancer, self-directed exercise, compared with usual care, led to a moderately large and clinically significant 9.8-point improvement in physical functioning, as measured by the physical functioning scale of the SF-36. Supervised exercise led to a more moderate 6.3-point improvement in physical functioning. These women were able to participate in a program of structured physical activity while undergoing adjuvant therapy, with no adverse events recorded. Baseline differences in physical functioning may have accounted in some way for the magnitude and direction of changes observed over treatment. Although initial physical functioning scores in the self-directed and supervised exercise groups were similar, physical functioning at baseline was higher in the control group. This fact does not negate the results but provides context for their interpretation. The observed differences in physical functioning between the usual care and self-directed exercise groups have practical significance in that limitations in physical functioning may prevent work at a paying job.21 For example, at physical functioning scale scores of 70 to 79 (as observed in the control group at 26 weeks), 18.9% of patients in the MOS could not work at a paying job because of health problems. At physical functioning scale scores of 80 to 89 (as observed in the self-directed exercise group at 26 weeks), only 6.1% of patients in the MOS could not work because of health problems. To our knowledge, this is the largest randomized controlled trial (RCT) of structured exercise in breast cancer patients to be reported in the literature, with 40 or more participants allocated to each of the groups (one control group and two exercise intervention groups). There have been four RCTs of aerobic exercise in breast cancer patients previously reported,16,18,26,27 and one research team has conducted all of this research. The intervention group sizes reported in the present RCT are at least twice as large as those previously reported. Although the present study was not designed to directly compare supervised with self-directed exercise, we were surprised that participants in the self-directed exercise group improved their physical functioning to a somewhat greater degree than in the supervised exercise group. Before the study, we hypothesized that the supervised group would improve physical functioning the most. One reason may be that the self-directed exercise program included many features thought to comprise effective home training, including the following: baseline fitness evaluation; written guidelines for home exercise; education about pulse checking/heart-rate guidelines; daily activity logs; bi-weekly telephone calls by the exercise specialist; and an interim fitness evaluation.28 It may also be that self-directed exercise performed at home or in community facilities is more convenient and that, therefore, participants were more adherent to the prescribed exercise program. We found, however, no differences in reported adherence to exercise prescription. Overall, this patient population demonstrated a high level of motivation to engage in structured exercise. The dropout rate for participants in the self-directed and supervised exercise groups was 17.5% and 23.1%, respectively, 6 months after the initiation of the exercise programs. Comparatively, previous studies in healthy populations of individuals consistently show that 50% of individuals who begin a structured exercise program will drop out within the first 6 months.29 We were also able to obtain a good level of adherence to the prescribed exercise prescription. Participants in the self-directed exercise group (not including those people who dropped out of the study) reported completing an average of 93 of 130 (71.5%) prescribed exercise sessions. Those in the supervised exercise group also reported completing an average of 93 sessions. A higher level of exercise intensity may have led to a greater improvement in physical functioning in the intervention groups. We provided participants in these groups with a progressive walking program at an exercise intensity of 50% to 60% of the predicted aerobic capacity. This relatively low intensity of training was used to ensure the safety of participants assigned to the unsupervised self-directed exercise group. Previous studies16,18,26,27 have used 60% to 85% of the aerobic capacity and have reported improvements in aerobic capacity of up to 40%. In our study, changes in aerobic capacity as measured by CAFT were modest (between 2.5% and 3.5%). This is likely a reflection of the lower exercise intensity. Nonetheless, it seems that significant improvements in physical functioning can occur even without large changes in physiologic fitness. The significant reduction in body weight in the supervised exercise group compared with that of the control group in the stratum of patients that were not receiving chemotherapy should be interpreted with caution. This secondary subset analysis was provided for hypothesis-generating purposes only. There were baseline differences in body weight between groups. One shortcoming of most of the previous RCTs of exercise16,18,26,27 has been the short duration of the exercise programs (typically 10 to 12 weeks). Our study provides evidence of a beneficial effect of structured exercise over a relatively long 26-week duration. The American College of Sports Medicine recommends that 15 to 20 weeks of regular exercise are necessary to realize important fitness benefits.30 Moreover, the exercise intervention used in the present study reflects true life circumstances, ie, moderate-level aerobic activity (primarily brisk walking) performed with or without direct medical supervision. It has been recommended that quality of life measures used in clinical trials should include the use of a core instrument to assess health-related quality of life in a generic manner along with disease and site-specific assessments.31 In the present study, we found the SF-36, a generic measure of health-related quality of life, to be more responsive to the effects of structured physical exercise than the FACT-G and FACT-B cancer- and cancer site–specific measures. The generalizability of these results is a consideration. Approximately one third of the patients who were approached agreed to participate in the study. An additional one third of those approached did not provide any reasons for their refusal. At this point, we may conclude that the results of this study pertain to the select group of patients with breast cancer who would be interested in participating in an exercise-based rehabilitation program soon after diagnosis. The 32.5% participation rate is somewhat higher, however, than the 15% to 25% participation rate for exercise-based rehabilitation programs after myocardial infarction.32 There is a need to examine in more detail the long-term effects of physical functioning changes occurring with an exercise intervention. With this in mind, we in the process of collecting follow-up data, having begun 6 months after termination of the formal intervention program. Physical exercise can blunt some of the negative side effects of breast cancer treatment, including reduced physical functioning. Self-directed exercise is an effective way to improve physical functioning compared with usual care. In participants not receiving chemotherapy, supervised exercise may increase aerobic capacity and reduce body weight compared with usual care.
APPENDIX The mCAFT is a submaximal test that can be used to predict maximal oxygen uptake. After resting measures of heart rate and blood pressure, the person steps up and down on a stepping ergometer at preset cadence. The stepping rate is age- and sex-specific, and the final stage demands approximately 85% of maximal aerobic power in a person of average fitness.33 In the present study, stages one to five of the mCAFT were performed sequentially.23 Stepping cadences for the five stages were 66, 84, 102, 114, and 120 beats per minute. After each 3-minute stepping stage, a standing postexercise heart rate was taken and blood pressure was measured. The next stage was initiated at 1 minute after exercise.
Because the exercise heart rate increases in a linear fashion from 50% to 100% of maximal oxygen uptake, the exercise heart rate measured after a known submaximal workload can be used to predict the maximal oxygen uptake using an equation.33 The equation for women is as follows:equationequation
Weller et al34 evaluated the predictive ability of the mCAFT. The linear relationship between measured maximal oxygen uptake score and those predicted by the mCAFT was strong (r = 0.88).
Normative maximal oxygen uptake data for North American women in the 50- to 65-year-old age group have been proposed.35 Scores of
Supported by the National Cancer Institute of Canada with funds from the Canadian Cancer Society (Grant in Aid of Research No. 7191), Ottawa, Ontario, Canada.
1. National Cancer Institute of Canada: Canadian Cancer Statistics 2000. Toronto, Canada, National Cancer Institute of Canada, 2000 2. Saunders CM: Current management of breast cancer. Br J Hosp Med 50: 588-590, 1993[Medline] 3. Aaronson NK: Assessment of quality of life and benefits from adjuvant therapies in breast cancer. Recent Results Cancer Res 127: 201-210, 1993[Medline] 4. Berglund G, Bolund C, Fornander T, et al: Late effects of adjuvant chemotherapy and postoperative radiotherapy on quality of life among breast cancer patients. Eur J Cancer 27: 1075-1081, 1991 5. Bliss JM, Robertson B, Selby PJ: The impact of nausea and vomiting upon quality of life measures. Br J Cancer Suppl 19: S14-S22, 1992[Medline] 6. Campora E, Naso C, Vitullo MT, et al: The impact of chemotherapy on the quality of life of breast cancer patients. J Chemother 4: 59-63, 1992[Medline] 7. Gelber RD, Goldhirsch A, Hurny C, et al: Quality of life in clinical trials of adjuvant therapies. International Breast Cancer Study Group (formerly Ludwig Group). Monogr Natl Cancer Inst 1992: 127-135, 1992 8. Graydon JE: Women with breast cancer: Their quality of life following a course of radiation therapy. J Adv Nurs 19: 617-622, 1994[Medline] 9. Gunnars BM: Quality of life during cancer chemotherapy treatment: An analysis of experience of cancer patients. Diss Abstr Int[c] 53: 500, 1992 (abstr) 10. Kurtz ME, Kurtz JC, Given CW, et al: Loss of physical functioning among patients with cancer. Cancer Pract 1: 275-281, 1993[Medline] 11. Maraste R, Brandt L, Olsson H, et al: Anxiety and depression in breast cancer patients at start of adjuvant radiotherapy. Relations to age and type of surgery. Acta Oncol 31: 641-643, 1992[Medline] 12. Stefanek ME: Quality of life and other psychosocial issues in breast cancer. Curr Opin Oncol 6: 583-586, 1994[Medline] 13. Winningham ML: Walking program for people with cancer. Getting started. Cancer Nurs 14: 270-276, 1991[Medline] 14. Winningham ML, Nail LM, Burke MB, et al: Fatigue and the cancer experience: The state of the knowledge. Oncol Nurs Forum 21: 23-36, 1994[Medline] 15. Winningham ML: Exercise and cancer, in Goldberg L, Elliot DL (eds): Exercise for Prevention and Treatment of Illness. Philadelphia, PA, F.A. Davis Co, 1994, pp 301-315 16. MacVicar MG, Winningham ML, Nickel JL: Effects of aerobic interval training on cancer patients’ functional capacity. Nurs Res 38: 348-351, 1989[Medline] 17. Mock V: The benefits of exercise in women with breast cancer, in Dow KH (ed): Contemporary Issues in Breast Cancer. Sudbury, MA, Jones and Bartlett, 1996, pp 99-106 18. Mock V, Burke MB, Sheehan P, et al: A nursing rehabilitation program for women with breast cancer receiving adjuvant chemotherapy. Oncol Nurs Forum 21: 899-907, 1994[Medline] 19. Young MS, Sexton DL: A retrospective investigation of the relationship between aerobic exercise and quality of life in women with breast cancer. Oncol Nurs Forum 18: 751-757, 1991[Medline] 20. Friedenreich CM, Courneya KS: Exercise as rehabilitation for cancer patients. Clin J Sport Med 6: 237-244, 1996[Medline] 21. Ware JE, Donald-Sherbourne C: The MOS 36-item short form health survey (SF-36): Conceptual framework and item selection. Med Care 30: 473-483, 1992[Medline]
22.
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 23. Jetté M, Sidney K, Landry F, et al: Blood pressure response to a progressive step test in normotensive males and females. Can J Appl Physiol 19: 421-431, 1994[Medline]
24.
Segal R, Evans W, Johnson D, et al: Oncology rehabilitation program at the Ottawa Regional Cancer Centre: program description. Can Med Assoc J 161: 282-285, 1999 25. Bristol DR: Designing clinical trials for two-sided multiple comparisons with a control. Control Clin Trials 10: 142-152, 1989[Medline] 26. Winnignham ML, MacVicar MG: The effect of aerobic exercise on patient reports of nausea. Oncol Nurs Forum 15: 447-450, 1988[Medline] 27. Winnignham ML, MacVicar MG, Bondoc M, et al: Effect of aerobic exercise on body weight and composition in patients with breast cancer on adjuvant chemotherapy. Oncol Nurs Forum 16: 683-689, 1989[Medline]
28.
DeBusk RF, Miller NH, Superko HR, et al: A case-management system for coronary risk factor modification after acute myocardial infarction. Ann Intern Med 120: 721-729, 1994 29. Dishman RK: Determinants of participation in physical activity, in Bouchard C, Shephard RJ, Stephens T, et al (eds): Exercise, Fitness and Health. Champaign, IL, Human Kinetics Books, 1990, pp 75-101 30. American College of Sports Medicine: The recommended quantity and quality of exercise for deleloping and maintaining cardiorespiratory and muscular fitness in healthy adults. Med Sci Sports Exerc 22: 265-274, 1991 31. Nayfield SG, Ganz PA, Moinpour CM, et al: Report from a National Cancer Institute (USA) workshop on quality of life assessment in cancer clinical trials. Qual Life Res 1: 203-210, 1992[Medline] 32. Agency for Health Care Policy and Research: Clinical Practice Guideline: Cardiac Rehabilitation. Rockville, MD, United States Department of Health and Human Services, 1995 33. Canadian Society for Exercise Physiology: Professional Fitness and Lifestyle Consultant: Resource Manual. Ottawa, Canada, Canadian Society for Exercise Physiology, 1993 34. Weller IMR, Thomas SG, Gledhill N, et al: A study to validate the modified Canadian Aerobic Fitness Test. Can J Appl Physiol 20: 211-221, 1995[Medline] 35. Katch FI, McArdle WD: Nutrition. Weight Control and Exercise ( ed 2 ). Philadephia, PA, Lea and Febiger, 1983 Submitted February 15, 2000; accepted September 14, 2000.
This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||
|
|||||||||||
|
|
Copyright © 2001 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|
TOP
ABSTRACT
INTRODUCTION
2 tests for categorical variables. For the primary analysis, the change in physical functioning scores between baseline and 26 weeks was calculated for each participant. Change scores between groups were compared using one-way analysis of variance. Post hoc analysis was conducted using Dunnett’s t test, where the two physical activity intervention groups were each compared against the control group. Secondary measures of quality of life (remaining SF-36 scales, FACT-G, FACT-B), aerobic capacity, and body weight were analyzed in the same way. A secondary analysis of each outcome measure was also performed with participants stratified by the type of adjuvant therapy (chemotherapy v no chemotherapy) that they were receiving. The Research Ethics Committee of the Ottawa Hospital approved the study protocol. 
21 mL/kg/min are low, 22 to 28 mL/kg/min are fair, 29 to 34 mL/kg/min are average, 35 to 40 mL/kg/min are good, and 
41 mL/kg/min are high. 
