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DHN 510: Advanced Nutrition
Literature Review
Author: Chloe Sapienza
Affiliation: Dietetics Student, University of Kentucky, Lexington, Kentucky
Date: April 18, 2016
Title: The Correlation Between Exercise and Risk for Prostate Cancer
Across the globe prostate cancer is the second most frequently diagnosed
cancer. The CDC estimates that as of 2012 177,489 men in the United States were
diagnosed with prostate cancer. 27,244 men in the United States died from prostate
cancer. With regards to the United States, alongside non-melanoma skin cancer,
prostate cancer is the most common cancer among men in the United States with it
being one of the leading causes of cancer death among men of all races. Each day
more than 500 men are diagnosed with prostate cancer.
Prostate cancer can be addressed using treatment methods such as
prostatectomy, radiation therapy, hormone therapy, chemotherapy, cryotherapy,
and other emerging therapies. Androgen deprivation therapy is a hormone therapy
method used commonly and specifically throughout all five reviews during the
course of this paper. This therapy focuses on the reduction of androgens, which are
key factors in the growth of prostate cancer cells. With this therapy come many side
effects such as decreased bone mass, total lean mass, muscle strength, increased risk
for skeletal fractures and fat mass, and more not mentioned. [1] It is also likely to
develop metabolic conditions such as diabetes, cardiovascular disease, abdominal
obesity, and osteoporosis. [2] Because of the effects mentioned above exercise has
become a focal point for prostate cancer research. It is also important to note other
effects that come with the cancer itself such as decreased quality of life, depression,
decreased cognitive function, and cardiovascular fitness. It is also with these effects
that exercise is important.
The objectives in the present review are to provide an integrated overview of
current knowledge regarding the link between exercise and prostate cancer. In
addition it is proposed that this subject has potentially promising avenues for future
research.
The literature research articles were found using PubMed. Articles were
narrowed down using key words such as exercise and prostate cancer, correlation
between exercise and prostate cancer, and effects of exercise on prostate cancer.
Studies were conducted on humans, specifically males. Additional information was
found using the CDC and Prostate Cancer Foundation. The specific articles were
chosen based on date published, within the last 6 years, and relativity to purpose of
the review.
The studies conducted over the five reviews focused on resistance exercise
training as well as aerobic exercise training. It is also important to note that
nutrition intervention was used in the studies but will not be addressed in this
review.
A study by Buffart examined the effects of a 12-month resistance and
endurance exercise program on cancer-specific, health related quality of life with
regards to older long-term survivors of prostate cancer. The study conducted is
referred to as RADAR (randomized androgen deprivation and radiology therapy
study). The participants were separated in two randomized groups one being (EX)
which consisted of six months supervised resistance and aerobic exercise followed
by six months of home-based exercise and the other being (PA) which focused on
printed material. Through this study it was found that supervised aerobic and
resistance exercise improved quality of life and maintained physical and social
function. It was found that patients, who were married, started exercising sooner
after diagnosis and previously used bisphoshonates had larger intervention effects
on health related quality of life. The beneficial effects of health related quality of life
could be partially explained by the exercise-induced improvements in lower body
functional performance. [1]
A similar study conducted by Teleni used seven randomized controlled trial
groups to evaluate the effect of exercise on quality of life, androgen deprivation
symptoms, and or metabolic risk factors. Four of the studies were intervention
groups that combined resistance training with aerobic exercise training, two studies
using only resistance exercise training, one study using only aerobic training and
one study using football training sessions. It was found that exercise intervention
over 12-24 weeks with two to three days per week of resistance and aerobic
training had significant improvements with health and disease related quality of life.
With that being said this specific study found no significant improvements with lipid
profiles, blood glucose levels, blood pressure, body weight or body composition. It is
important to note that with this study it is possible that no improvements were
shown in those specific areas due to few studies in the current analysis as well as
intervention periods being too short to capture the effects. [2]
While the previous two studies focused on the effects of exercise a study
conducted by Craike focused on adherence to programs and factors that influence.
This study was done as a secondary analysis to the ENGAGE study, which aimed to
determine efficacy of clinician referral and exercise program to improve exercise
levels and quality of life for men with prostate cancer. Through this study a positive
correlation was found between vigorous-intensity exercises, meeting exercise
guidelines, improved cognitive function and reduced symptoms of depression.
Because these interventions were found to have positive effects Craike and team
sought to examine demographic, clinical, behavioral, and psychosocial predictors of
adherence. It was found that men with hormonal symptoms that follow androgen
deprivation therapy might require additional physical and emotional support and
assistance with participation in exercise programs. With this study behavior change
techniques, clinician referral, setting program goals, prompting practice, and self
monitoring were incorporated which may also explain high levels of adherence to
exercise programs. [3]
Similar to the study by Craike and team a study by Livingston focused on the
importance of cancer clinician endorsement of physical activity recommendations.
Demark- Wahnefried W found only 20% of clinicians promote lifestyle changes to
their patients. Using intervention evaluation, Livingston and team found that 80% of
it’s participants reported that clinician’s referral influenced their decision to
participate in the exercise program, 75% reported that they would recommend the
exercise program to others living with prostate cancer, 91.5% stated that the
exercise program was rewarding, 88% reported that the program was extremely or
quite beneficial to their health and well-being, and 45% expressed an intention to
continue the program by joining a gym. “Engagement with medical and allied health
professionals in the establishment of a clinician referral pathway for exercise-based
programs could reduce the barriers to exercise among prostate cancer survivors.”
[4]
A study conducted by Havid took an approach at a larger time period of two
years focusing specifically on PSA (prostate specific antigen) doubling time. Studies
have shown that exercise training in prostate cancer patients specifically on
androgen deprivation therapy leads to increased fitness levels, reductions in body
weight by decreased fat mass, and also maintenance of muscle mass and functional
capacity. In this study it was aimed to find possible effects of PSA doubling time and
metabolic parameters of home-based endurance training in out-clinic patients who
have biochemical recurrence following radical prostatectomy or managed on active
surveillance. It was found that PSA doubling time was strongly correlated with
changes in VO2max but not body composition. The data from this study supports
the epidemiological finding that physical activity may delay cancer progression. This
has also provided insight that suggests intrinsic systemic change induced during
physical exertion, which give raise to improvements in VO2max are also involved in
the molecular suppression of tumor progression. All of these factors come together
to give support to the idea that increased level of physical activity leading to
improved fitness level may be a factor contributing to delay prostate cancer
progression. [5]
It was shown in two of the five studies that clinicians role, as health
promotion advocates are crucial in execution and adherence of exercise in patients.
While working to become registered dietitians, physicians, and other specializations
in the health field, it is important to hone in on this finding and implementing health
promotion in future endeavors. With prostate cancer being such a prominent cancer
among men more studies are being conducted to give relief and possible
preventions of the cancer. It is important to start studying the variety of exercise
techniques now to narrow down specifics with the most effect. It is with hope that
with these studies and more being conducted in the future exercise will become a
standard requirement in cancer treatment and prevention and health care providers
can show the overall benefits to patients and families.
1. 1. Li AW and Laurien M Buffart. The Effect, Moderators, and Mediators of
Resistance and Aerobic Exercise on Health-Related Quality of Life in Older
Long-Term Survivors of Prostate Cancer. Cancer. 2015; 16: 2821-2830.
2. Li AW Laisa Teleni. Exercise improves quality of life in androgen deprivation
therapy-treated prostate cancer: systemic review of randomized controlled trials.
Bioscientifica Ltd. 2015; 23: 101-112.
3. Li AW Melinda Craike. Predictors of adherence to a 12-week exercise program
among men treated for prostate cancer: ENGAGE study. Cancer Medicine. 2016;
Online early access: 1-8.
4. Li AW Patricia M. Livingston. Effects of a Clinician Referral and Exercise
Program for Men Who Have Completed Active Treatment for Prostate Cancer: A
Multicenter Cluster Randomized Controlled Trial (ENGAGE). Cancer. 2015; 15:
2646-2654.
5. Li AW Thine Hvid. Effect of a 2-year home-based endurance training
intervention on physiological function and PSA doubling time in prostate cancer
patients. Cancer Causes & Control. 2016; 27: 165-174.
6. Center for Disease Control and Prevention. Prostate Cancer Statistics. Updated
March 23, 2016. http://www.cdc.gov/cancer/prostate/statistics/index.htm
Accessed March 10, 2016.
7. Prostate Cancer Foundation. Faces of Prostate Cancer. Updated March 16, 2016.
http://www.pcf.org/site/c.leJRIROrEpH/b.5699537/k.BEF4/Home.htm Accessed
March 10, 2016.