Mediators of physical exercise for improvement in cancer survivors' quality of life.

OBJECTIVE: Mediating mechanisms of a 12-week group-based exercise intervention on cancer survivors' quality of life (QoL) were examined to inform future exercise intervention development. METHODS: Two hundred nine cancer survivors ≥ 3 months posttreatment (57% breast cancer) aged 49.5 (± 10.4) years were assigned to physical exercise (n = 147) or wait-list control (n = 62). QoL, fatigue, emotional distress, physical activity, general self-efficacy and mastery were assessed at baseline and post-intervention using questionnaires. Path analysis was conducted using Mplus to explore whether improved physical activity, general self-efficacy and mastery mediated the effects of exercise on fatigue and distress and consequently QoL. RESULTS: The intervention was associated with increased physical activity (ß = 0.46, 95% confidence interval (CI) = 0.14;0.59), general self-efficacy (ß = 2.41, 95%CI = 0.35;4.73), and mastery (ß = 1.75, 95%CI = 0.36;2.78). Further, the intervention had both a direct effect on fatigue (ß = -1.09, 95%CI = -2.12;0.01), and an indirect effect (ß = -0.54, 95%CI = -1.00;-0.21) via physical activity (ß = -0.29, 95%CI = -0.64;-0.07) and general self-efficacy (ß = -0.25, 95%CI = -0.61;-0.05). The intervention had a borderline significant direct effect on reduced distress (ß = -1.32, 95%CI = -2.68;0.11), and a significant indirect effect via increased general self-efficacy and mastery (ß = -1.06, 95%CI = -1.89;-0.38). Reductions in fatigue (ß = -1.33, 95%CI =-1.85;-0.83) and distress (ß = -0.86, 95%CI = -1.25;-0.52) were associated with improved QoL. Further, increased physical activity was directly associated with improved QoL (ß = 3.37, 95%CI = 1.01;5.54). CONCLUSION: The beneficial effect of group-based physical exercise on QoL was mediated by increased physical activity, general self-efficacy and mastery, and subsequent reductions in fatigue and distress. In addition to physical activity, future interventions should target self-efficacy and mastery. This may lead to reduced distress and fatigue, and consequently improved QoL of cancer survivors.

Cancer patients' view on rehabilitation and quality of life: a programme audit.

An existing 12-week cancer rehabilitation group programme, combining physical training and psychosocial sessions, was recently tested in a quantitative longitudinal cohort study (n = 658) among adult patients who have problems coping with cancer. Results showed improvements in all quality of life domains. The objective of the present study was to explore patients' perspectives on how and to what extent the rehabilitation programme had met their needs in order to optimize the programme. Patients who participated in the programme no longer than 5 years ago were interviewed in three focus groups (n = 23). Participants saw rehabilitation as provided by the programme as an important steppingstone in their ongoing recovery process and identified the integrated physical training, psychosocial sessions and patient-to-patient contacts as a powerful and supportive combination. Recommendations for improvements to the programme mainly concerned the psychosocial module. Information needs varied strongly among participants and, in this respect, it was hard to satisfy all of them. Participants suggested that the programme should focus more on developing skills to cope with cancer, its consequences and emerging problems after rehabilitation. In conclusion, participants valued the group-based multi-modal cancer rehabilitation programme and recommended to focus more on developing coping skills.

Myocardial force development and structural changes associated with monocrotaline induced cardiac hypertrophy and heart failure.

In this study alterations are characterized which occur, in myocardial force development morphological appearance and protein composition, during the development of cardiac hypertrophy and heart failure in monocrotaline (MCT) treated rats. The transition from cardiac hypertrophy to heart failure was studied by comparing the results from control (CON) and two MCT groups (40 and 44 mg/kg body weight). The three experimental groups consisted of at least five animals each. Parameters studied were: body weight (measured daily), lung/body weight ratio, right ventricular wall volume and thickness, and force development in thin right ventricular trabeculae at 27 degrees C, using different extracellular calcium concentrations and pacing frequencies. MCT injection resulted in marked right ventricular hypertrophy and heart failure as evidenced by an up to 2-fold increase in lung/body weight ratio and a 1.7-fold increase in wall volume. The MCT groups showed a negative force-frequency relation and maximum force was up to 2-fold less than in the CON group. Protein analysis by means of one- and two-dimensional gel electrophoresis revealed a marked (7-fold) up-regulation of the slow myosin heavy chain isoform as well as a 4.5-fold increase in the content of the cytoskeletal protein desmin, whereas the mitochondrial protein ATP-synthase content was reduced. Hence MCT-induced cardiac hypertrophy and heart failure result in altered cellular calcium handling, depression of maximum force output, an increase in the economy of myocardial contraction and changes in cytoskeletal structure and energy supply.