Lianne B. Dolan

Effects of Exercise Dose and Type During Breast Cancer Chemotherapy: Multicenter Randomized Trial

BACKGROUND Exercise improves physical functioning and symptom management during breast cancer chemotherapy, but the effects of different doses and types of exercise are unknown. METHODS A multicenter trial in Canada randomized 301 breast cancer patients to thrice-weekly supervised exercise during chemotherapy consisting of either a standard dose of 25 to 30 minutes of aerobic exercise (STAN; n = 96), a higher dose of 50 to 60 minutes of aerobic exercise (HIGH; n = 101), or a combined dose of 50 to 60 minutes of aerobic and resistance exercise (COMB; n = 104). The primary endpoint was physical functioning assessed by the Medical Outcomes Survey-Short Form (SF)-36. Secondary endpoints were other physical functioning scales, symptoms, fitness, and chemotherapy completion. All statistical tests were linear mixed model analyses, and the P values were two-sided. RESULTS Follow-up assessment of patient-reported outcomes was 99.0%. Adjusted linear mixed-model analyses showed that neither HIGH (+0.8; 95% confidence interval [CI] = -0.8 to 2.4; P = .30) nor COMB (+0.5; 95% CI = -1.1 to 2.1; P = .52] were superior to STAN for the primary outcome. In secondary analyses not adjusted for multiple comparisons, HIGH was superior to STAN for the SF-36 physical component summary (P = .04), SF-36 bodily pain (P = .02), and endocrine symptoms (P = .02). COMB was superior to STAN for endocrine symptoms (P = .009) and superior to STAN (P < .001) and HIGH (P < .001) for muscular strength. HIGH was superior to COMB for the SF-36 bodily pain (P = .04) and aerobic fitness (P = .03). No differences emerged for body composition or chemotherapy completion. CONCLUSIONS A higher volume of aerobic or combined exercise is achievable and safe during breast cancer chemotherapy and may manage declines in physical functioning and worsening symptoms better than standard volumes.

Hemoglobin and Aerobic Fitness Changes with Supervised Exercise Training in Breast Cancer Patients Receiving Chemotherapy

Background: Aerobic exercise training (AET) is known to increase RBC production; however, this has not been evaluated in breast cancer patients undergoing adjuvant chemotherapy. The purpose of this study was to examine the changes in hemoglobin (Hb) levels in the Supervised Trial of Aerobic versus Resistance Training (START) and to determine its association with changes in VO2peak. Methods: Two hundred and forty-two breast cancer patients initiating chemotherapy were randomized to usual care (n = 82), resistance exercise (RET, n = 82), or AET (n = 78) groups for the duration of their chemotherapy (median, 17 weeks). Supervised exercise was thrice weekly based on standard AET and RET prescriptions. Aerobic fitness (VO2peak) and Hb concentration were measured at baseline and end of chemotherapy. Results: Regardless of the exercise group, Hb declined over the course of chemotherapy (13.4 ± 10.0 to 11.8 ± 11.5 g/dL, P < 0.01). Both AET and RET groups had significant, moderate correlations between the change in VO2peak and Hb (AET: r = 0.49, P < 0.001; RET: r = 0.39, P = 0.001). Conclusion: The results indicate that regular exercise does not protect against the decline in Hb associated with chemotherapy in breast cancer patients, but resulted in a stronger association between Hb and VO2peak. Impact: Even with the chemotherapy-induced decline in Hb, breast cancer patients can maintain their aerobic capacity by participating in regular aerobic exercise. Further studies are required to determine safe intensity levels that may stimulate the maintenance of Hb levels in breast cancer patients. Cancer Epidemiol Biomarkers Prev; 19(11); 2826–32. ©2010 AACR.

Predictors of adherence to different types and doses of supervised exercise during breast cancer chemotherapy

BackgroundExercise is beneficial for breast cancer patients during chemotherapy but adherence to different types and doses of exercise is a challenge. The purpose of this study was to examine predictors of adherence to different types and doses of exercise during breast cancer chemotherapy in a multicenter randomized controlled trial.MethodsBreast cancer patients in Edmonton, Vancouver, and Ottawa, Canada receiving chemotherapy (N = 301) were randomized to a standard dose of 25–30 minutes of aerobic exercise (STAN), a higher dose of 50–60 minutes of aerobic exercise (HIGH), or a higher dose of 50–60 minutes of combined aerobic and resistance exercise (COMB). Predictors included demographic, medical, fitness, and quality of life variables. Exercise adherence was measured as the percentage of supervised exercise sessions completed.ResultsOverall adherence to the supervised exercise sessions was 73% (SD = 24%). In a multivariate regression model, six independent predictors explained 26.4% (p < 0.001) of the variance in exercise adherence. Higher exercise adherence was achieved by breast cancer patients in Vancouver (p < 0.001), with fewer endocrine symptoms (p = 0.009), randomized to STAN (p = 0.009), with fewer exercise limitations (p = 0.009), receiving shorter chemotherapy protocols (p = 0.015), and with higher VO2peak (p = 0.017). Disease stage (p for interaction = 0.015) and body mass index (p for interaction = 0.030) interacted with group assignment to predict adherence. For disease stage, patients with stage I/IIa disease adhered equally well to all three exercise interventions whereas patients with stage IIb/III disease adhered better to the STAN intervention than the two higher dose exercise interventions. For body mass index, healthy weight patients adhered equally well to all three exercise interventions whereas overweight patients adhered best to STAN and worst to COMB; and obese patients adhered best to STAN and worst to HIGH.ConclusionsDeterminants of exercise adherence in breast cancer patients receiving chemotherapy are multidisciplinary and may vary by the exercise prescription.

A Multicenter Randomized Trial of the Effects of Exercise Dose and Type on Psychosocial Distress in Breast Cancer Patients Undergoing Chemotherapy

Background: Exercise may improve psychosocial distress in patients with cancer; however, few studies have examined the effects of different types or doses of exercise, or whether exercise effects are related to baseline depression levels. Methods: In a multicenter trial in Canada, we randomized 301 patients with breast cancer initiating chemotherapy to thrice weekly, supervised exercise consisting of either a standard dose of 25 to 30 minutes of aerobic exercise (STAN; n = 96), a higher dose of 50 to 60 minutes of aerobic exercise (HIGH; n = 101), or a combined dose of 50 to 60 minutes of aerobic and resistance exercise (COMB; n = 104). The primary endpoint was depression assessed by the Center for Epidemiological Studies-Depression scale at baseline, twice during chemotherapy, and postchemotherapy. Secondary endpoints were anxiety, perceived stress, and self-esteem. Results: Repeated measures ANOVA indicated that neither HIGH [mean difference = −0.9; 95% confidence interval (CI), +0.0 to −1.8; P = 0.061] nor COMB (mean difference = −0.4; 95% CI, +0.5 to −1.3; P = 0.36) was superior to STAN for managing depressive symptoms. In a planned subgroup analysis, there was a significant interaction with baseline depression levels (Pinteraction = 0.027) indicating that COMB and HIGH were effective for managing depressive symptoms in patients with clinical levels of depressive symptoms at baseline. Conclusions: Compared with a standard volume of aerobic exercise, higher volumes of exercise did not help manage depressive symptoms in unselected patients with breast cancer receiving chemotherapy, but they were effective in patients with clinical levels of depressive symptoms at baseline. Impact: A phase III exercise trial targeting depressed patients with breast cancer is warranted. Cancer Epidemiol Biomarkers Prev; 23(5); 857–64. ©2014 AACR.

Subgroup effects in a randomised trial of different types and doses of exercise during breast cancer chemotherapy

Background:The Combined Aerobic and Resistance Exercise Trial tested different types and doses of exercise in breast cancer patients receiving chemotherapy. Here, we explore potential moderators of the exercise training responses.Methods:Breast cancer patients initiating chemotherapy (N=301) were randomly assigned to three times a week, supervised exercise of a standard dose of 25–30 min of aerobic exercise, a higher dose of 50–60 min of aerobic exercise, or a higher dose of 50–60 min of combined aerobic and resistance exercise. Outcomes were patient-reported symptoms and health-related fitness. Moderators were baseline demographic, exercise/fitness, and cancer variables.Results:Body mass index moderated the effects of the exercise interventions on bodily pain (P for interaction=0.038), endocrine symptoms (P for interaction=0.029), taxane/neuropathy symptoms (P for interaction=0.013), aerobic fitness (P for interaction=0.041), muscular strength (P for interaction=0.007), and fat mass (P for interaction=0.005). In general, healthy weight patients responded better to the higher-dose exercise interventions than overweight/obese patients. Menopausal status, age, and baseline fitness moderated the effects on patient-reported symptoms. Premenopausal, younger, and fitter patients achieved greater benefits from the higher-dose exercise interventions.Conclusions:Healthy weight, fitter, and premenopausal/younger breast cancer patients receiving chemotherapy are more likely to benefit from higher-dose exercise interventions.

Optimal Mode for Maximal Aerobic Exercise Testing in Breast Cancer Survivors

Purpose. To determine which mode of exercise is preferred by breast cancer survivors and to evaluate this response between graded exercise testing on a treadmill and on a cycle ergometer. Methods. Twelve breast cancer survivors completed 2 maximal aerobic stress tests on separate days. The women completed a ramp protocol on an electronically braked cycle ergometer and an incremental step protocol on a treadmill to volitional fatigue. Test order was randomized. Expired gases were collected for the determination of peak aerobic capacity (Vo2peak). Results. Exercise mode had a significant effect on the graded exercise response in breast cancer survivors, P = .003. Treadmill Vo2peak was significantly greater than bike Vo2peak (28.7 ± 4.7 vs 23.9 ± 4.7 mL/min/kg, respectively, P = .003) and VEmax was equivalent between exercise modes (P = .731). Maximal heart rate was significantly higher by 11 bpm during the treadmill protocol (P = .004), and Ve/VCo2 exhibited possible mode dependency (P = .018). Conclusion. This patient population felt more comfortable and produced significantly greater Vo2peak values using the treadmill protocol. These results discuss the potential implications concerning the design and interpretation of exercise interventions for breast cancer survivors.

Is there enhanced lymphatic function in upper body trained females

BACKGROUND Chronic physical activity results in adaptations in many aspects of human physiology, while specific training can directly influence structural changes. It remains unknown if habitual exercise influences upper extremity lymphatic function in females; thus, the purpose of this cross-sectional study was to compare different exercise stresses on lymphatic function in ten upper body trained females with ten untrained females. METHODS AND RESULTS Participants underwent a maximal upper body aerobic test on an arm crank ergometer before undergoing three randomly assigned lymphatic stress tests. Lymphoscintigraphy was used to quantify lymphatic function. (99m)Tc-antimony colloid was injected into the third web space of each hand, followed by 1 min spot views taken with a gamma-radiation camera. The maximal stress test required individuals to repeat their initial maximal exercise test. The subjects were then imaged every 10 min until 60 min were reached. The submaximal stress test involved arm cranking for 2.5 min at 0.6 W x kg(-1), followed by 2.5 min of rest, repeated for 60 min. The final stress test was a 60 min seated resting session. The clearance rate (CR) and axillary uptake (AX) were determined. Only AX post maximal exercise was significantly different between trained and untrained, p=0.009. All other measures of lymphatic function between groups were similar. CONCLUSION This study demonstrates no significant difference in lymphatic function between upper body trained and untrained females.