The SISTER Study is the first national randomized trial to focus on improving outcomes for Black/African-American (AA) women with endometrial cancer (EC). Black women have much higher mortality from EC compared with other groups in the United States, as they tend to have more high-risk, aggressive EC. High-risk EC requires chemotherapy and/or radiation, but Black/AA women have less success with treatment compared with White women, likely due to treatment delays or not receiving all prescribed treatment. Social isolation during treatment can affect cancer outcomes through physiologic changes that lead to cancer progression and lower survival rates. Black/AA women are uniquely at risk for social isolation due to cultural, socioeconomic, and physical stressors. The Endometrial Cancer Action Network for African-Americans (ECANA) has identified social support as a priority research area. Studies show that social support interventions, including peer-led support groups and one-on-one peer support, decrease social isolation and improve the likelihood of patients completing treatment. Despite professional organizations’ recommendations that comprehensive cancer centers include social support programming, actual practice varies. No studies have tested peer support strategies for Black women with EC. There is a critical need to identify the most effective social support intervention for Black women undergoing adjuvant EC treatment. The SISTER Study meets this need.
Our study has three main goals: (1) compare the effects of two virtual evidence-based interventions (group-based support and one-on-one peer support) on social isolation during cancer treatment among Black/AA women with high-risk EC to understand which is more effective; (2) determine if these interventions improve treatment completion; and (3) evaluate whether patients, healthcare staff, and peer support providers find these interventions acceptable.
To meet these goals, we will conduct a pragmatic randomized-controlled trial, meaning participants will be assigned by chance to one of three groups: one-on-one peer support, facilitated support groups, and usual care enhanced with a mailed ECANA support package. We call the study “pragmatic” because it is happening in real-world conditions so we can test if the programs will work in practice. We will enroll 252 Black women with high-risk endometrial cancer who will be undergoing radiation, chemotherapy, immunotherapy, or a combination across nine large cancer centers in the United States. Potential participants will talk to clinic staff and watch an introductory video. If they decide to participate, they will be assigned randomly to one of the three study groups. If they are assigned to one-on-one peer support (which will occur one to three weeks immediately before, during, or after treatment visits) or weekly support groups, interventions will occur entirely virtually and will be facilitated by Black EC survivors. Weekly groups will also include professionals with relevant areas of expertise, including nutrition and psychotherapy. The intervention will last for six months.
The primary outcome we will measure is social isolation (aim 1), as reported by patients, using a survey called the Social Provisions Scale, which will let us assess components of social support related to health outcomes. We will explore other outcomes that may influence this primary outcome, including (1) emotional distress and anxiety, (2) heightened racial vigilance, (3) financial stress, (4) physical and functional quality of life, and (5) satisfaction with patient care. The next outcome of interest (aim 2) is patient completion of prescribed treatment. Finally, we will also conduct in-depth interviews with a subset of 15 participants from each group to understand patient experience, which will give us important context beyond the survey results. Interviews will occur at the beginning and end of the study. We will also interview clinicians and cancer center leadership at each site as well as ECANA peer support facilitators to identify what resources will be needed to scale these support strategies to more treatment centers.
The study has been designed and will be conducted with close collaboration of ECANA ambassadors and other stakeholders—individuals and groups to whom outcomes of Black women with EC matter. The input of all stakeholders, and especially patients, will be essential during each phase of the study to ensure The SISTER Study is truly patient centered. We will share what we learn from study results through many avenues, including recommendations for clinical guideline and cancer center programming changes, reports and webinars for patients, and webinars and summaries for clinicians and researchers.
*All proposed projects, including requested budgets and project periods, are approved subject to a programmatic and budget review by PCORI staff and the negotiation of a formal award contract.