Exercise as it relates to Disease/The Effects of Resistance Training on Prostate Cancer Patients undergoing treatment

This is an analysis of the journal article “Resistance Training and Reduction of Treatment Side Effects in Prostate Cancer Patients” by Galvão, Nosaka, Taaffe, Spry, Kristjanson, Mcguigan et al. (2006).



What is the background to this research?
Prostate cancer is a disease caused by abnormal cell growth in the male prostate gland. Currently in Australia, prostate cancer is the third most common cancer diagnosed, and the second leading cause of death in males.

One of the most common forms of treatment for prostate cancer is through androgen-deprivation therapy (ADT). ADT aims to either stop the production of testosterone, or block the action of testosterone on somatic cells. It is undeniable ADT is very effective in treating and managing the prostate cancer, however the treatment itself is accompanied by a wide-range of adverse side-effects (i.e. reduced muscle strength, reduced lean and bone mass, and decreased physiological function). Inevitably, exercise interventions have the ability to alleviate these side-effects through improving physical functioning and mitigating ADT-induced fatigue, and therefore improve the overall health of sufferers. Whilst most literature examines the role aerobic exercise plays during breast cancer treatments, annual statistical evidence suggests that mortality rates are higher in men with prostate cancer as opposed to women with breast cancer. Consequently, the article evaluated grants insight into a new area of research; the potential of resistance training as an effective intervention strategy to reduce ADT-related side-effects.

Where is the research from?
The study was supported by numerous grants and scholarships and was primarily carried out at the Edith Cowan University, with research being conducted throughout Perth.

A number of authors of this publication are currently working on a related project regarding the effects of endurance and strength training modes on a variety of factors. Professor Daniel Galvão's research in particular focuses on the role exercise plays in managing cancer. His research profile can be found here.

What kind of research was this?
This study is a non-randomized clinical trial, which compares baseline measures to final results. Non-randomized trials are vulnerable to bias, and hence are predominantly used for exploratory purposes.

What did the research involve?
The study examines the effects of a 20-week high-intensity progressive resistance training program for older men undergoing ADT.

91 prostate cancer patients were either referred or responded to advertisement and were initially screened for participation. Specific exclusion criteria points included - off ADT within next 5 months; any disorder/disease that may inhibit exercise; inability to walk 400m and/or undertake resistance training; and recent/current resistance training (past 12-months).

10 subjects undertook 20-weeks of resistance training (2x/week). Both upper-body and lower-body exercises were implemented to target major muscle groups. The initial 10-week introductory phase utilized hydraulic machines to exclusively provide concentric muscle contractions. The following 10 weeks involved isotonic resistance, eliciting concentric and eccentric muscle contractions using similar exercises on different equipment. The training program was based on the ACSM position stand on progression models in resistance training, and therefore progressed subjects from 12- to 6RM for 2-4 sets per exercise.

Assessment Methods
The following assessment measures were recorded at baseline, week 10, and week 20:

Limitations
Several limitations exist with regards to the methodology. Firstly, the low number of subjects described as ‘well-functioning, motivated individuals’, accompanied with the study being a non-randomized trial limits the potential for variation between individuals to occur. Additionally, the short duration of this study disregards the long-term effects of resistance training for men receiving ADT.

What were the basic results?
As expected, considerable improvements were achieved:
 * Increased muscle strength of 40-96% and muscle endurance → comparable with individuals not on ADT.
 * Improved functional performance and balance → may contribute to a reduction in falls, and a decreased fracture risk during GnRH administration.
 * Body composition measures were preserved → reduced risk of suffering from other chronic conditions.
 * Quadriceps thickness increased by 15% despite a reduced anabolic hormone environment.
 * Serum-free testosterone and PSA were unaltered → training can be undertaken safely without compromising the therapeutic purpose.
 * Haemoglobin was unaltered → reduced levels of fatigue.

Interpretation
The researchers interpreted these results to express positive implications of resistance training for individuals receiving ADT. This claim is supported by the results and prior research, however it is possible that the results of this study have over-emphasised the implications of resistance training due to the specific exclusion criteria owing to the generalisability of the findings.

What conclusions can we take from this research?
This study indicates that resistance training should be considered for preserving body composition and reducing musculoskeletal side-effects for older men receiving ADT. These findings extend on prior research which expressed that resistance training increased quality of life and decreased fatigue for ADT sufferers. In order for future studies to build on current findings, it is crucial they incorporate larger study groups, provide longer exercise periods, and train during intermittent regimens of ADT. In conclusion, whilst further research is required to establish recommendations for individuals, resistance training has the ability to be an effective intervention for men receiving ADT.

Practical advice
The research highlights that resistance training can be safely undertaken for older men receiving ADT to achieve common training adaptations. It is important for individuals not familiar with weight-bearing activities to seek professional advice in ensuring the establishment and monitoring of an individualised, multi-component exercise program, which warrants a suitable progression of intensity, load, and duration, to reduce the risk of an adverse event and/or injury occurring.

For more practical advice, click here.

Further information/resources
Additional information/resources can be found below:
 * https://en.wikipedia.org/wiki/Prostate_cancer
 * http://www.cancer.org.au/about-cancer/types-of-cancer/prostate-cancer.html
 * https://www.andrologyaustralia.org/androgen-deprivation-therapy/
 * http://www.prostate.org.au/media/770549/2014-Prostate-Cancer-and-Exercise-FULL.pdf