Reply to L. Bourke et al and K.M. Winters-Stone et al
Authors: Steve F. Fraser, Jason R. Gardner, Patricia M. Livingston
Journal: Journal of Clinical Oncology (2014)

We thank Bourke et al 1 and Winters-Stone and Beer 2 for their welcome comments regarding our systematic review. 3 Both authors raised pertinent points with which we are generally in agreement.We would like to re-emphasize that in writing our review, 3 we aimed to provide a comprehensive and unbiased summary of the extent of the field of research on the effects of exercise in men with prostate cancer receiving androgen-deprivation therapy (ADT).It was anticipated that in doing so, we would not only identify the potential benefits of exercise for this population, but would also highlight gaps in current knowledge and flaws in the existing research.As such, our overall goals were to encourage clinicians to consider the benefits of exercise for their patients and to stimulate research activity in this emerging area.Both Bourke et al 1 and Winters-Stone and Beer 2 expressed concern regarding the inclusion of multiple study designs, as well as the inclusion of studies containing a subsample of participants treated with ADT.We agree that high-quality randomized controlled trials provide the strongest evidence from which to draw conclusions about the efficacy of exercise on specific end points and to establish specific recommendations or guidelines around exercise prescription.Given that few high-quality randomized controlled trials have been published in this area to date, we believed that it would be more informative to include all relevant studies, despite their limitations, to stimulate discussion and highlight the need for further, more rigorous research.It certainly was not our intention to suggest that all included evidence was of equal quality, and to this end we provided a risk of bias assessment (Table 2 3 ) to assist the reader in evaluating the quality of evidence from each included study.Bourke et al 1 suggested that a meta-analysis would have added to the review, but because of the heterogeneity of study end points, measurement tools, and exercise prescription parameters, a meta-analysis was unlikely to provide meaningful information beyond what was already presented.As Winters-Stone and Beer 2 suggested, additional high-quality trials are required to replicate current findings as well as to investigate specific exercise programming variables (frequency, intensity, type, duration, timing) that can then inform the development of specific exercise prescription guidelines.We also note the comment by Bourke et al 1 concerning the need to engage treating urologists and oncologists regarding the benefits of exercise in usual care for prostate cancer survivors.Our recently completed cluster randomized controlled trial to determine the efficacy of a referral and physical activity program for survivors of prostate cancer (ENGAGE) 4 will also provide valuable data on the potential benefits of clinicians referring their patients to an exercise program, as well as on fitness and dosing impact of exercise for prostate cancer survivors, including those undergoing ADT.It is encouraging to note that additional studies have been published since our systematic review was performed. [5]6][7][8] We are also aware of other trials that are currently underway and are focused on other end points such as disease progression, as mentioned by Bourke et al. 1 There are also ongoing studies that aim to optimize exercise and nutrition recommendations, including our own study, IMPACT (Improving Musculoskeletal HealthDuringProstateCancerAndrogenDeprivationTherapy),whichis evaluating the effects of a year-long exercise program with nutritional supplementation on musculoskeletal health and body composition in men with prostate cancer receiving ADT.We share the enthusiasm of Bourke et al, 1 Winters-Stone and Beer, 2 and Parsons et al 9 for the important role exercise may have in improving thehealthofmenwithprostatecancerreceivingADT.Welookforwardto furtheradvancesinknowledgeinthisareaandsharethebeliefthatexercise hasasignificantroletoplayintheclinicalcareofmenwithprostatecancer, especially those undergoing ADT.