Kirstin Lane

Effects of Aerobic and Resistance Exercise in Breast Cancer Patients Receiving Adjuvant Chemotherapy: A Multicenter Randomized Controlled Trial

PURPOSE Breast cancer chemotherapy may cause unfavorable changes in physical functioning, body composition, psychosocial functioning, and quality of life (QOL). We evaluated the relative merits of aerobic and resistance exercise in blunting these effects. PATIENTS AND METHODS We conducted a multicenter randomized controlled trial in Canada between 2003 and 2005 that randomly assigned 242 breast cancer patients initiating adjuvant chemotherapy to usual care (n = 82), supervised resistance exercise (n = 82), or supervised aerobic exercise (n = 78) for the duration of their chemotherapy (median, 17 weeks; 95% CI, 9 to 24 weeks). Our primary end point was cancer-specific QOL assessed by the Functional Assessment of Cancer Therapy-Anemia scale. Secondary end points were fatigue, psychosocial functioning, physical fitness, body composition, chemotherapy completion rate, and lymphedema. RESULTS The follow-up assessment rate for our primary end point was 92.1%, and adherence to the supervised exercise was 70.2%. Unadjusted and adjusted mixed-model analyses indicated that aerobic exercise was superior to usual care for improving self-esteem (P = .015), aerobic fitness (P = .006), and percent body fat (adjusted P = .076). Resistance exercise was superior to usual care for improving self-esteem (P = .018), muscular strength (P < .001), lean body mass (P = .015), and chemotherapy completion rate (P = .033). Changes in cancer-specific QOL, fatigue, depression, and anxiety favored the exercise groups but did not reach statistical significance. Exercise did not cause lymphedema or adverse events. CONCLUSION Neither aerobic nor resistance exercise significantly improved cancer-specific QOL in breast cancer patients receiving chemotherapy, but they did improve self-esteem, physical fitness, body composition, and chemotherapy completion rate without causing lymphedema or significant adverse events.

Progressive resistance training in breast cancer: a systematic review of clinical trials.

BackgroundProgressive resistance training (PRT) may be effective for targeting the sequelae of breast cancer and its treatment given the unique anabolic nature of this exercise modality. Therefore, our objectives were: (1) to systematically review studies that have prescribed PRT after breast cancer surgery, (2) to summarize the efficacy of PRT in this cohort, and (3) to delineate areas for future investigations.MethodA systematic review using computerized databases was performed.ResultsThe systematic review located 10 trials: Four uncontrolled trials, one controlled trial and five randomized controlled trials (RCTs). PRT was prescribed with aerobic training in 8/10 trials reviewed, and in isolation in 2/10 trials reviewed. Upper body PRT was prescribed in 7/10 trials, including 4/5 RCTs. No exacerbation of objectively measured or subjectively reported lymphedema symptoms was reported in any of these trials. Adverse events were rare, generally musculoskeletal in nature, and were managed effectively by conservative means. Overall, the studies we reviewed suggest that women surgically treated for breast cancer can derive health-related and clinical benefits by performing PRT after breast cancer surgery. Further research may be required to stimulate greater advocacy for PRT among oncologists, and in community care settings.ConclusionsRobustly designed RCTs prescribing targeted PRT regimens throughout various phases of breast cancer treatment are warranted. RCTs with thorough, standardized reporting of interventions and adverse events are required to establish the efficacy of this intervention for the post-treatment management of breast cancer patients and survivors as a means to improve health status and quality of life.

Predictors of supervised exercise adherence during breast cancer chemotherapy.

PURPOSE Exercise adherence is difficult during cancer treatments, but few studies have examined the predictors of such exercise. Here, we report the predictors of adherence to supervised exercise training during breast cancer chemotherapy. METHODS Breast cancer patients (N = 242) initiating adjuvant chemotherapy in Edmonton, Ottawa, and Vancouver were randomly assigned to usual care (n = 82), supervised resistance exercise (n = 82), or supervised aerobic exercise (n = 78) for the duration of their chemotherapy. Baseline data on standard demographic, medical, behavioral, fitness, and psychosocial variables as well as motivational variables from the Theory of Planned Behavior were collected. Adherence was assessed by objective attendance records. RESULTS Adherence to supervised exercise was 70.2%. Univariate analyses indicated significant or borderline significant associations between exercise adherence and location/center (r = 0.30; P < 0.001), V[spacing dot above]O2peak (r = 0.21; P = 0.008), muscular strength (r = 0.21; P = 0.008), percent body fat (r = -0.21; P = 0.012), disease stage (r = 0.17; P = 0.031), education (r = 0.15; P = 0.053), depression (r = -0.14; P = 0.073), and smoking (r = -0.14; P = 0.081). In multivariate analysis, location/center (beta = 0.28; P = 0.001), V[spacing dot above]O2peak ([beta] = 0.19; P = 0.016), disease stage (beta = 0.18; P = 0.015), and depression (beta = -0.16; P = 0.033) remained significant and explained 21% of the variance in exercise adherence. Participants in Vancouver, with higher aerobic fitness, more advanced disease stage, and lower depression, achieved better adherence. CONCLUSION Adherence to supervised exercise training was predicted by unique aspects of the location/center, disease stage, aerobic fitness, and depression but not motivational variables. Location/center in our trial may have been a proxy for the amount of one-on-one attention received during supervised exercise. These findings may have implications for improving adherence during breast cancer chemotherapy.

Six-Month Follow-up of Patient-Rated Outcomes in a Randomized Controlled Trial of Exercise Training during Breast Cancer Chemotherapy

Background: Few exercise trials in cancer patients have reported longer-term follow-up. Here, we report a 6-month follow-up of exercise behavior and patient-rated outcomes from an exercise trial in breast cancer patients. Methods: Breast cancer patients initiating adjuvant chemotherapy (n = 242) were randomly assigned to usual care (n = 82), resistance exercise training (RET; n = 82), or aerobic exercise training (AET; n = 78) for the duration of their chemotherapy. At 6-month follow-up, participants were mailed a questionnaire that assessed quality of life, self-esteem, fatigue, anxiety, depression, and exercise behavior. Results: Two hundred one (83.1%) participants provided 6-month follow-up data. Adjusted linear mixed-model analyses showed that, at 6-month follow-up, the RET group reported higher self-esteem [adjusted mean difference, 1.6; 95% confidence interval (95% CI), 0.1-3.2; P = 0.032] and the AET group reported lower anxiety (adjusted mean difference, −4.7; 95% CI, −0.0 to −9.3; P = 0.049) compared with the usual care group. Moreover, compared with participants reporting no regular exercise during the follow-up period, those reporting regular aerobic and resistance exercise also reported better patient-rated outcomes, including quality of life (adjusted mean difference, 9.5; 95% CI, 1.2-17.8; P = 0.025). Conclusions: Improvements in self-esteem observed with RET during breast cancer chemotherapy were maintained at 6-month follow-up whereas reductions in anxiety not observed with AET during breast cancer chemotherapy emerged at 6-month follow-up. Moreover, adopting a combined aerobic and resistance exercise program after breast cancer chemotherapy was associated with further improvements in patient-rated outcomes. Exercise training during breast cancer chemotherapy may result in some longer-term and late effects for selected patient-rated outcomes. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2572–8)

Barriers to Supervised Exercise Training in a Randomized Controlled Trial of Breast Cancer Patients Receiving Chemotherapy

BackgroundExercise adherence is a challenge for breast cancer patients receiving chemotherapy but few studies have identified the key barriers.PurposeIn this paper, we report the barriers to supervised exercise in breast cancer patients participating in a randomized controlled trial.MethodsBreast cancer patients initiating adjuvant chemotherapy (N = 242) were randomly assigned to usual care (n = 82) or supervised resistance (n = 82) or aerobic (n = 78) exercise. Participants randomized to the two exercise groups (n = 160) were asked to provide a reason for each missed exercise session.ResultsThe two exercise groups attended 70.2% (5,495/7,829) of their supervised exercise sessions and provided a reason for missing 89.5% (2,090/2,334) of their unattended sessions. The 2,090 reasons represented 36 different barriers. Feeling sick (12%), fatigue (11%), loss of interest (9%), vacation (7%), and nausea/vomiting (5%) accounted for the most missed exercise sessions. Disease/treatment-related barriers (19 of the 36 barriers) accounted for 53% (1,102/2,090) of all missed exercise sessions. Demographic and medical variables did not predict the types of exercise barriers reported.ConclusionsBarriers to supervised exercise in breast cancer patients receiving chemotherapy are varied but over half can be directly attributed to the disease and its treatments. Behavioral support programs need to focus on strategies to maintain exercise in the face of difficult treatment side effects.

Moderators of the effects of exercise training in breast cancer patients receiving chemotherapy: a randomized controlled trial.

Exercise training improves supportive care outcomes in patients with breast cancer who are receiving adjuvant therapy, but the responses are heterogeneous. In this study, the authors examined personal and clinical factors that may predict exercise training responses.

Resting Energy Expenditure and Body Mass Changes in Women During Adjuvant Chemotherapy for Breast Cancer

Weight gain is a commonly reported side effect of adjuvant chemotherapy. A change in resting energy expenditure during treatment has been a suggested mechanism for weight gain. We prospectively measured resting energy expenditure, weight change, and body composition (dual-energy x-ray absorptiometry) in 10 women undergoing adjuvant chemotherapy for breast cancer. There was no change in resting energy expenditure across cycles of chemotherapy (P =.78) or from baseline to the end of treatment (1,189.68 ± 80.27 vs 1,205.76 ± 56.71 kcal/d; P =.74). Overall, participants did not gain weight across treatment. However, there was an overall trend toward weight gain (66.3 ± 5.1 vs 68.2 ± 5.0 kg; P =.09), and participants did show an increase in total fat mass (24.2 ± 3.8 vs 26.5 ± 3.2 kg; P =.04), whereas muscle mass remained the same. Although no change in resting energy expenditure was seen, the observed increase in total fat mass is consistent with a decrease in physical activity level commonly reported with adjuvant chemotherapy treatment of breast cancer, and these body composition changes may have important health implications for survivors.

Exercise and the Lymphatic System Implications for Breast-Cancer Survivors

AbstractThis article summarises the current research on the lymphatic system related to exercise and critically evaluates the implications for exercise performance by breast-cancer survivors. The primary role of the lymphatic system during exercise is to assist in the regulation of tissue volume and pressure by carrying fluid and plasma proteins that have leaked into the interstitial space from tissues back to the cardiovascular system. During steady-state exercise in humans, lymph flow has been shown to increase to levels approximately 2- to 3-fold higher than at rest. Although the lymphatic system does not typically limit exercise performance in the normal population, the function of this system can be impaired in 27–49% of women who have survived breast cancer.Breast cancer-related lymphoedema (BCRL) is a chronic swelling that can occur in the ipsilateral hand or arm of women treated for breast cancer and results in a number of physical and psychological sequelae. Exercise was once believed to be a factor in the development of BCRL as it was thought that the damage to the axillary lymphatics from breast-cancer treatment resulted in a primary obstruction to lymph flow. However, the exact aetiology and pathophysiology of BCRL appears to be multi-factorial and not as simple as a ‘stop-cock’ effect. Furthermore, recent studies have shown that participating in vigorous, upper-body exercise is not related to an increase in arm volume, which would indicate the development of BCRL. It is still not known, though, how long-term exercise affects lymphatic system function in breast-cancer survivors with and without BCRL.

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.

One session of interval work does not alter VO2max, peak power or plasma volume

Abstract We examined the effect of one high-intensity cycling workout on aerobic capacity (VO2max), peak cycling power, and estimated change in plasma volume on subsequent days. Eight healthy males (age=29.5±5.3 years, height=1.81±0.09 m, mass=81.5±7.5 kg) visited the laboratory on three occasions. The first visit (D1) included baseline measures of cycling VO2max, haematocrit, and haemoglobin. Following a brief rest, the participants performed a high-intensity cycling workout of six 30-s cycling intervals (modelled on the Wingate cycle test) with each repetition separated by 3 min rest. The final two visits (D2 and D3) included identical measures as the first visit and occurred 48 and 96 h after the interval workout. No significant differences were found for VO2max (53.4±5.3, 53.7±6.7, and 53.7±6.2 ml · kg−1 · min−1), peak power (386±35, 384±35, and 389±35 W) or estimated change in plasma volume [−0.8±8.5% (D1–D2), 1.5±11.5% (D2–D3), and −1.6±9.6% (D1–D3)] between any of the three test days. Our results show that one short-term high-intensity cycling workout does not alter VO2max, peak power or estimated change in plasma volume on subsequent days, and is therefore unlikely to benefit or hinder performance.