Overseas Care and Cancer Survivorship in Small Island Developing States of the Eastern Caribbean: Protocol for a Multicountry Mixed Methods Study (CaSIDEC Study).

Background: Small island developing states (SIDS) are home to approximately 65 million people worldwide. SIDS have some of the highest rates of cancer mortality burden in the developing world. Disparities in cancer mortality could be attributed to reliance on services overseas, which is a common feature across SIDS due to limited resources for comprehensive cancer care on the islands. However, overseas travel for cancer care remains largely understudied in SIDS, and epidemiological data on the implications on cancer survivorship are lacking. Objective: We aim primarily to map patterns of overseas travel for cancer care among cancer survivors in Caribbean SIDS and examine the lived experiences of cancer survivors and caregivers. Additionally, we will explore how overseas travel may affect key domains of cancer survivorship. Methods: We will conduct a multicountry, cross-sectional study using a convergent mixed methods design. We will establish a sample of 900 cancer survivors residing in the islands of Antigua, Dominica, Grenada, Saint Kitts, Saint Lucia, and Saint Vincent. Eligible participants will be adult cancer survivors who have accessed health services in their island of residence due to cancer. Sites for recruitment will be cancer support groups and hospitals. Surveys will be conducted face-to-face. For every country visited for diagnosis and/or treatment, we will record the services accessed and motives for the choice of country. We will compute the proportions of patients traveling for cancer care by country of destination. We will use regression models to explore associations with time to treatment and lifestyle factors (after treatment). In-depth interviews (n=24) and focus groups (n=54 participants) will be conducted with cancer survivors and caregivers to learn about overseas travel with an emphasis on social support systems. Open-ended questions and prompts will assess aspects of the day-to-day logistics and travel arrangements and experience living overseas. We will use an inductive thematic analysis approach to identify and interpret patterns. Results: Planning and development to implement the logistics for data collection were started in February 2023. We started with pilot testing in September 2024, and we have recruited 113 cancer survivors as of May 31, 2026. We envisage active patient recruitment and data collection until March 31, 2029, across all participating countries. Conclusions: This is the first multicountry study on overseas travel on cancer care in Caribbean SIDS. Our work will produce evidence that will inform recommendations to fill performance gaps in transnational systems for cancer care in the Eastern Caribbean that will improve patients' lives. It is an important first step to developing data resources for high-quality research in understudied SIDS.