Prostate cancer is one of the most common cancers diagnosed among men worldwide (1). Of those diagnosed, approximately 10–20% will present with metastatic disease at the time of diagnosis, and an additional one in five will progress from localised to metastatic disease despite treatment (2, 3). Once prostate cancer has metastasized, the five year survival rate drops from 95–36% (4). Metastatic disease and the subsequent treatments cause considerable physical and psychological burden (5). Androgen deprivation therapy, radiotherapy and chemotherapy can result in increased fat mass, fatigue, and pain as well as reduced muscle mass, bone mineral density, physical function, and sexual function (2, 6). In addition, over 80% of individuals with advanced prostate cancer will develop bone metastases, which can result in significant bone pain, pathological fractures, and neurological impairments (5). Individuals in this population have also been found to exhibit higher levels of anxiety and depression than their age matched peers, including men diagnosed with localized prostate cancer (7–9). Given the high burden, there is a clear need to develop interventions that help combat side effects, improve physical function, and reduce overall burden in individuals with metastatic prostate cancer.
Research has demonstrated the beneficial effects from physical activity and more specifically, structured exercise interventions in individuals with prostate cancer (10, 11). Currently, it has been suggested that exercise can play an important role in symptom management, rehabilitation, and long term survival (5, 10, 11). While the physiological mechanisms behind this are yet to be elucidated, it is hypothesised that exercise improves immune function, modulates circulating factors (such as insulin and growth factors), reduces inflammation, and improves treatment efficacy (5). However, until recently, those with metastatic disease were discouraged from structured exercise for fear of exacerbation of symptoms or increased risk of skeletal-related events (12).
New evidence is now available to show that supervised multi-modal exercise can be safe, feasible, and clinically relevant in individuals with metastatic prostate cancer (12–15). Cormie et al. were the first to show that resistance training is both safe (no adverse events found) and tolerable (attendance 83% and compliance 93%) in this population using a pilot study (12). Galvão et al. then implemented a multi-modal (resistance, aerobic and flexibility training) intervention and found significant improvements in physical function (mean difference 3.2 points; 95% confidence interval (CI)=[0.4, 6.0]; P = 0.028) and muscular strength (mean difference of 6.6 kg (95% CI=[0.6, 12.7]; P = 0.033) after twelve weeks (14). Currently, the Movember GAP4 INTERVAL trial is examining overall survival in individuals completing a vigorous intensity face-to-face multi-modal exercise program (16).
Despite the mounting evidence regarding the benefits of supervised multimodal exercise for this population, many do not engage in sufficient physical activity to obtain health benefits. Zopf et al. found that only 20% of patients achieved 50–149 min per week of self-rated moderate to vigorous aerobic activity, and 29% of patients achieved ≥ 150 minutes (17, 18). This is despite evidence that 92% of individuals with advanced cancer being interested in becoming more active (19). Barriers to exercise in this population include general exercise barriers such as the lack of suitable facilities, remoteness, motivation, and access to experts, as well as disease-specific barriers such as significant fatigue, urinary incontinence, mood, high levels of other medical commitments, and lack of education regarding exercise for individuals with prostate cancer (8, 20). It is currently unknown how many Australian individuals with metastatic prostate cancer receive individualised exercise advice.
Home-based exercise programs offer a feasible alternative to counteract some of the obstacles to on-site exercise interventions because they may be able to reduce location constraints, financial, and time limitations (21, 22). However, current research indicates that these interventions produce smaller effect sizes in cancer populations on both quality of life and physical function when compared to face-to-face exercise (10, 23). Lack of supervision and personalised support, reduced intervention adherence, and limited individualisation are all possible causes of this discrepancy (10, 24, 25).
The use of technology in distance-based health care, otherwise known as eHealth, may help to improve the capacity of distance-based programs. For example, web-based platforms have the ability to prescribe and demonstrate tailored exercise plans, provide tailored behavioural change advice, facilitate self-monitoring, and support communication with health care professionals. Much of this can be achieved in an automated fashion using computer-tailoring techniques, thus allowing for personalization at a low-cost (26). Reviews of digital health interventions for behaviour change suggest that some level of human support is important for efficacy (27, 28). E-Health interventions utilizing some of these techniques to support prostate, colorectal, breast, and leukemia cancer populations have already been trialed with good effects in terms of improved physical activity levels and reduced sedentary behaviour (24, 29–32). However, the extent to which these techniques are acceptable, safe and potentially effective for supporting individuals with metastatic prostate cancer, given their unique needs and risk profile, is unknown. Our study seeks to address this gap by conducting a pilot evaluation of ExerciseGuide, a web-based and telephone supported personalised exercise intervention designed for individuals living with metastatic prostate cancer.
The primary objective of the trial is to assess key areas of uncertainty regarding the use of ExerciseGuide (and other similar programs) in future practice and research, including issues relating to feasibility, safety and potential for efficacy. Publication of this protocol aims to ensure transparency around pre-specified criterion for success, aid replication of study and intervention methods, and inform interested parties of the upcoming trial results.