HBF report part 2: Intro

Cancer Survivorship

Every year, more people are surviving cancer.²¹ However, side effects from acute and ongoing treatments continue to diminish physical function and quality of life (QOL) for years after treatment completion.^46,67,78 These complications often lead to a restriction of physical activity. Recent research found that as many as 70% of cancer survivors do not perform sufficient physical activity to achieve the basic health guidelines.⁶ It has also been found that the majority of cancer survivors significantly decrease their level of physical activity after diagnosis, with a return to pre-diagnosis physical activity levels to be highly unlikely.⁵⁵

Side Effects of Treatment

Direct side effects of cancer treatments, especially chemotherapy, radiation therapy, and hormone therapy, include cardiotoxicity, loss of bone mineral density, loss of muscle mass, and increases in fat mass and fatigue.^{18,35,53,67,75} The reduction in physical activity exacerbates these side effects, especially fatigue, which creates a vicious cycle between continued loss of physical function and decreasing exercise.⁴ This puts cancer survivors at a huge risk for developing secondary diseases, such as cardiovascular disease, osteoporosis, diabetes, and chronic fatigue; having a reoccurrence of their cancer; or developing another cancer.

Health Burden of Cancer

Cancer is Australia’s leading burden of disease, accounting for 19% of the total burden² and costing the country $16 million per year in health care for breast cancer alone.⁷² Currently, there are over 300,000 cancer survivors in Australia, with 20,000 more men being diagnosed each year just with prostate cancer.²¹ With the growing population of survivors needing further medical treatment for secondary diseases, the health burden on these patients and subsequently the health care system is becoming astronomical. The main reason there are more survivors are improvements in cancer screening and treatment. However, the improvements in medical treatment to keep people alive does not necessarily mean that people are living well. Studies have shown that cancer treatment severely diminishes cancer survivors’ QOL.^37,76 As this evidence has become more widely known, improving cancer survivors’ QOL has become as important an outcome as physical rehabilitation. Quality of life is defined as the combination of a persons’ physical, psychological, and social well being.⁵¹

Interventions to Help Cancer Survivors

Exercise has been proven effective at improving cancer survivors’ health and QOL.^23,35,67 Beyond diminishing the physiological impact of treatment side effects, cancer survivors can improve their fitness to a greater level than they enjoyed before treatment. Exercise has been shown to improve the psychological dimension of QOL, and group exercise classes provide social support for cancer survivors.^{12,13,16,38,44,48,49} However, some researchers have called into question the validity of these findings, citing that the measured improvement in these areas may be more superficial, and not dealing with deeper psychological issues.³⁰ To address these issues, psychological interventions are needed, and have had great success at helping with depression, anxiety, and QOL.^62,63,69 Despite the success of both approaches, few studies have employed a multi-modal design to optimally improve cancer survivors’ QOL.^13,45,50,78 These studies have many limitations, including poorly delivered exercise, limited sample sizes, and not following up the participants to determine the long term impact of their interventions.

An additional limiting feature of exercise oncology research to date is that it has been biased toward breast cancer survivors,²³ though there is still a large body of research into exercise amongst male cancer survivors. However, there is a lack of research on psychological interventions amongst men. A recent systematic literature review on psychological interventions for prostate cancer survivors identified 21 studies total, all of which were poor quality, and few which included psychotherapy components.¹¹ There is a general belief and stigmata, supported by research, that men are not interested in participating in psychotherapy based interventions.^{20,34,40,52,56,68,70,74}

Approach to the Problem

The intervention tested in the present study aimed to improve the health and QOL of Western Australian breast and prostate cancer survivors. This is a novel intervention, which combined group exercise and supportive group psychotherapy (SGP), grounded within the transtheoretical model of behaviour change (TTM) to help improve exercise behaviour and adherence.⁵⁹ The same intervention was delivered to both breast and prostate cancer survivors to determine if it would be suitable for both populations, and therefore more economically feasible to roll out into the larger community.