FitEx for Endometrial Cancer Survivors

Uterine cancer is the leading form of gynecologic malignancy in the United States. Currently, there are more than 600,000 EC survivors in the United States, and that number is expected to grow. Endometrial cancer (EC) is caused by excess estrogen, which acts as an oncogenic signal. Postmenopausal women with obesity have increased production of estrogen and are at an increased risk of developing type I EC.

Endometrial cancer was one of the first types of cancer to have an established relationship with body mass index (BMI). This relationship is linear and dose-dependent with BMI and can be explained by excess estrogen production . In women, adipose tissue is able to generate a form of estrogen known as estrone. Excess adipose tissue leads to increased production of estrone, which proliferates endometrial growth. For every five unit increase of BMI, the production of excess estrogen drives a 50% increased relative risk of developing EC.

Approximately 62% of American women are overweight or obese, putting them at increased risk of developing EC, the sixth most common cancer type in women in the United States. As the obesity rate in America continues to rise, the incidence of EC cases follows similar patterns. Between 2003 to 2015, the number of new EC diagnoses has increased by 13%, and continues to increase by 1% in following years. The National Cancer Institute predicts that nearly 60,000 new cases of EC will be diagnosed in 2021 and estimates that nearly 3% of women will be diagnosed with EC in their lifetime.

Fortunately, EC patients have relatively strong outcomes compared to other cancer types, as patients have an approximately 80% 5-year survival rate. However, a vast majority (70 - 90%) of type 1 EC survivors are obese. Five years after diagnosis, women with EC are more likely to die from cardiovascular disease and its risk factors, such as obesity and type 2 diabetes, than from EC. EC survivors with obesity report higher rates of depression and lower quality of life outcomes (sleep quality, self-esteem, fatigue, daily stress, etc.) than their non-obese counterparts. These outcomes worsen as BMI increases.

Addressing the role of obesity in EC survivors by encouraging physical activity is critical to improving optimal longitudinal care to survivors suffering from declining quality of life. Regular physical activity is associated with decreased levels of circulating estrogens in post-menopausal women and moderate physical activity in adulthood has been associated with reduced rates of developing endometrial cancer. As measured by a meta-analysis of physical activity interventions in participants with cancer, physical activity has established improvements to quality of life, fatigue, and physical functioning.

The connection between physical activity and BMI, morbidity, mortality, and improved quality of life outcomes is well supported. Despite this connection, only 1% of EC survivors meet all of the American Cancer Society guidelines for diet, exercise, and smoking recommendations. To increase the number of EC survivors meeting these guidelines, various exercise interventions have been developed to encourage EC survivors to increase physical activity and ultimately, improve their BMI.

However, existing interventions for EC survivors, geared towards improvements in BMI, have not been found to be efficacious in eliciting long-term changes in behavior with respect to weight loss. Because targeting weight loss was not effective in prior interventions, a successful intervention should target increasing physical activity rather than explicitly decreasing BMI. In breast cancer survivors, a similar demographic, many existing physical activity interventions are unsuccessful due to their focus on high intensity activities and due to the burden on participants to exercise together in person. In order to address pitfalls in prior physical activity studies, an ideal intervention should also target improvements to physical activity using lighter, ergonomically sound movements in a remote setting.

While participants report in-person physical activity as a barrier, various exercise studies have demonstrated that increasing social support is a powerful motivator of long-term behavior change, including adherence to physical activity. EC survivors surveyed in Canada report wanting a program that incorporates social support into an intervention. In breast cancer survivors, a group-dynamics based intervention achieved improvements in physical activity outcomes that persisted six months post-intervention.

Prior successful interventions have utilized social support but often require substantial physician engagement. While patients are more likely to engage with an exercise intervention if encouraged by their physician, oncologists noted barriers to promoting healthy behaviors in patients with obesity include lack of training in health promotion and even fear of overwhelming patients with health-promoting advice. Past ECS research that has shown successful and lasting improvements to behavior include weekly 1-on-1 physician calls and personalized telehealth communication, and cancer center exercise classes. In these interventions, an implicit cost is associated with staffing or availability (both for the participant and for the intervention facilitator). Taken together, an intervention that can facilitate the sense of groupness and be delivered virtually is optimal due to budget constraints on healthcare centers, geographical constraints of participants, and the current COVID-19 pandemic.

Surveyed EC survivors prefer gentle, group-based, walking exercises that function as support groups and exercises that they can do from home, but note barriers to adherence include access, fatigue, and pain. Yoga has been shown to decrease cancer-related fatigue, improve mobility, and increase mindfulness among cancer patients. Weekly yoga is a potential target to address barriers of exercise but has not been explored in detail in the EC patient population. In a focus group of sixteen gynecologic cancer survivors, yoga was viewed favorably by survivors and is a newly developing target for increased physical and psychological well-being. Yoga improvements have been shown in a range of health conditions including post-menopausal symptoms, cancer, heart disease, and even long-term improvements to BMI. The most common demographic for yoga practitioners is White, middle-aged women and practitioners strongly endorse the benefits of yoga on mindfulness, social support, and coping with stress. Prior work in EC survivorship has demonstrated that increased BMI has a negative impact on quality of life, an outcome that yoga has improved in similar populations such as breast cancer survivors.

Goal setting and behavior tracking are two key behavioral psychology principles that encourage and promote improvements in exercise and dietary habits in obese adults, and successful interventions should incorporate these principles as components to see greater success. FitEx is a virtual, scalable, evidence-based walking program that can be easily modified to include other exercises such as yoga. FitEx has shown significant maintenance of physical activity changes six months post-intervention. FitEx participants join a team, led by regional facilitators and local team captains, and set a physical activity and dietary goals throughout the eight week intervention. Participants have the opportunity to meet with others weekly for remote, guided exercise demonstrations. Participants are able to see if their goals are being met each week as self-monitoring is built into the FitEx interface, creating a sense of real time feedback. The program was developed for community-dwelling adults and its impact on cancer survivors has yet to be tested. Thus, FitEx is an intervention that meets the five dimensions of RE-AIM: Reach, Effectiveness, Adoption, Implementation, and Maintenance, such that small changes to FitEx do not diminish any of these dimensions and overall program success. Because FitEx is a validated program of measuring daily physical activity adherence which incorporates a low-dose of social support, it can easily be modified to target specific populations. Additionally, FitEx can be modified to include different exercises, such as yoga, which are viewed favorably by ECS. The present study seeks to determine whether a modified FitEx intervention geared towards survivorship or yoga improves outcomes in physical activity adherence and in quality of life in EC survivors.

As measured through FitEx, the yoga intervention will provide a remote workout regimen led by a registered yoga instructor. The control FitEx condition will include standard weekly meetings that currently take place in FitEx. Both arms incorporate walking as the predominant form of exercise and may include any other exercises of the participant's preference according to their goals. As a modified, tailored intervention for ECS, FitEx has the potential to improve physical activity adherence and quality of life in ECS.

The overall objective of this work is to tailor FitEx for ECS, with the goal of improving physical activity, as measured by step count, for both groups. Participants will be randomized to EC- tailored FitExEc (control) or FitExEC+yoga (intervention). The study hypotheses are (1) FitExEC and FitExEC+ yoga are feasible and acceptable (2) participants in both conditions will have improved weekly step count compared to baseline and (3) participants in the yoga-tailored condition will have greater improvements in quality of life compared to the ECS control condition.

The study's primary aims are feasibility and acceptability. The investigators will assess using recruitment statistics.

The study's secondary aims are efficacy related to physical activity improvement (measured through pedometers (step count) and subjectively through self report) as well as quality of life, fear of cancer recurrence, exercise preferences, social support, self-compassion, and exercise class satisfaction.

The investigators expect that both group-based programs will improve physical activity behaviors during the 8- week intervention, while the yoga-tailored group will exhibit improved secondary outcomes. The study's complementary aims will assess psychosocial factors, long-term outcomes, and barriers to implementation.