Exercise as it relates to Disease/Benefit of Exercise During Androgen Deprivation Therapy for Prostate Cancer

Background of Androgen Deprivation Therapy (ADT) and Prostate Cancer
Androgen Deprivation Therapy or ADT is a form of hormonal treatment for advanced prostate cancer sufferers which was produced by Huggins and Hodge in early 1940s. Driven by Androgens, (natural or synthetic hormones) which are produced by the body, androgens increase the growth of cancerous cells of the prostate. By removing androgens such as Dihydrotestosterone (DHT), ADT can aid in the overall management of the advanced prostate cancer stage by localising the disease.

Prostate Cancer
Often considered one of the most common forms of non-related skin cancer, prostate cancer is a leading cause of death amongst the male population. The prostate is an organ, in the male reproductive system which is located just under the bladder and is responsible for producing fluid to protect sperm. The development of prostate cancer is associated with abnormal cell growth, where the prostate cells mutate and form a tumor. The tumor can then spread to other parts of body, including the bones and lymph nodes. Early symptoms are often unclear but further related symptoms may replicate that of old age due to the slow developing process. Prostate cancer patients have recorded a higher survival rate of 76.5% at five year post-diagnosis. The high survival rate is somewhat due to the early detection and treatment options available to the patients, such as surgical removal, ADT and radiation therapy.

Androgen
Androgen is responsible for the development of male characteristics such as reproductive organ development and enlargement of muscles. The most common and important hormone to a males development is testosterone, which is categorised as an anabolic steroid. Prostate cells as well as cancer cells grow based on amount of male hormone (androgen) available in our body

Androgen Deprivation Therapy
Androgen Deprivation Therapy (ADT) has been recognised as a common treatment strategy with as many as 50% of prostate cancer patients receiving this treatment. The main aim of ADT is to reduce the tumor in the prostate, further increasing the survival rate by reducing the amount of testicular androgen production via Luteinizing-hormone-releasing hormone (LHRH). Research showed 79.7% decline in serum testosterone concentration, which relates to a decrease in lean mass and increase in fat mass, and also 89.4% reduction in serum prostate specific concentration after 48weeks of the treatment.

Benefit
Benefits of Androgen deprivation therapy are best described with a comparison of early and late on set of treatment. In particular there was no survival advantage to an early treatment with ADT, but for those individuals who are in the advanced stage of prostate cancer ADT may provide some quality of life benefits. These benefits may include, a reduction in bone pain, a decompression of the spinal cord, and the prevention of a ureteral obstruction. ADT does not provide a cure for the cancer but it can reduce levels of testosterone significantly which suppresses cancer growth. Such benefits of a treatment like ADT rely on the choice of treatment, duration and cycle prescribed by the specialist. ADT is closely linked with patients' survival rate and also it is used for prostate volume control.

Risk
Gonadal steroids have a large influence on growth rate and body composition, therefore a castration of such important hormones will have detrimental effects on the musculoskeltal system, endocrine and cardiovascular system. Testosterone is associated with the body's ability to remain lean and re-distribute fat. A reduction in testosterone can result in weight loss, and an increase in fat mass. The composition and quality of cortical bone is significantly diminished leaden to the onset of osteoporosis and osteopenia. Other less reported risks of ADT patients include sexual disfunction, reduction in sexual desire, tiredness, breast enlargement, depression and liver problems. ADT has both short and long term side effects, but further research in this area will help to weigh the benefits against the morbidity and help to optimise and manage these adverse risks.

Exercise benefit to Prostate Cancer patients with ADT Treatment
Pharmaceutical treatment is expensive and does little to no improve physical functional so exercise is important. A recent amount of scientific evidence suggests resistance training as the most effective form of exercise to improve overall muscle strength, physical function and counteract osteopenia in the older adults.

Exercise Type
Men receiving ADT should undertake a high intensity progressive resistance training, twice a week for a number of weeks. Initially beginning with training machines, which provide concentric muscle contractions. Such exercises could include chest press, seated row, shoulder press, lat pull down, triceps extension, bicep curl, leg press, squats and abdominal crunches. Exercises should be altered as weeks progress. It's important to also consider in every session general flexibility exercises and adequate warm up and warm down. The strategy of such exercises is to help muscle function, balance, body composition, and the thickness of muscles.

Activity Level
Exercise should be a progression from 12-6 repetition maximum and 2-4 sets per exercise. The activity level should be designed to increase in repetitions and sets of exercises as the weeks progress. This is based on the model proposed by the American College of Sports Medicine, resistance exercise for adult males. To ensure the safety of participants, exercises should be supervised, be at the proper intensity and the correct technique should be shown to complete the exercise.

Benefit of Exercise
Androgen Deprivation Therapy affects a patient's quality of life, resistance exercises have been reported to have a positive approach in reversing such effects. In a particular a case study involving 3–5 weeks of walking, stretching and light resistance exercises at home, 60 minutes of grouped-based booster session every 2 weeks, walking speed, heart rate and RPE after the exercises were improved and resting heart rate (RHR) dropped significantly. Further positive outcomes included muscular power and endurance, stimulation of bone formation from resistance training, and the enhancement of the immune system as exercise improves the innate immune system response.

Conclusion
Androgen Deprivation Therapy treatment for prostate cancer patients has been related to patient's positive survival rate, despite decreasing the quality of life. ADT prevents the amount of testosterone available in the body which has known side effects, but hormonal therapy may delay the progression of growth, and lengthen survival.

Many cancer patients on ADT can tolerate moderate to heavy resistance exercise training, under proper medical assistance and supervision. Strength training as well as general exercises, such as walking and stretching, may counteract the side effects of prostate cancer treatment. However, the exercise level should be kept high, and always monitored.