The intent of NOT-CA-21-026 is to “assess [stigma’s] impact on cancer control and prevention, and develop stigma-reduction interventions to improve cancer outcomes in low- and middle-income countries (LMICs)”. Thailand definitely qualifies under this criterion, and is the focus of an ongoing molecular epidemiology study on hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), in which Drs. Wang and Loffredo (MPIs of the proposed administrative supplement) have active collaborations. The proposed pilot project results would be used to inform the design of interventions to lower stigma associated with liver malignancies and thereby improve cancer outcomes. The parent grant (P30 CA51008) has a strong population science component, the Cancer Prevention and Control Program, with depth of expertise in prevention sciences. Cancer disparities is a cross-cutting theme of the program, and the proposed work will deepen our engagement in global oncology in Asia, specifically in Thailand. This will provide added value to the parent grant in providing a population-based assessment of stigma in liver cancers that can serve as a model for work in Asians (who have high risk of liver cancers) living in our catchment area and LMICs. Study findings will also lay the groundwork for interventions to reduce stigma and improve outcomes. In Thailand, both HCC and CCA occur at high levels: its rate of CCA is the world’s highest. To address knowledge gaps about risk factors, our existing consortium was formed in 2010 among five major cancer referral centers in Thailand, covering about 80% of the country, which recruit HCC and CCA cases and age-, gender- and region-matched controls. Results identified hepatitis B and C viral infections as the major risk factors for HCC, and consumption of fish infested with the liver fluke, Opisthorchis viverrini, as the main risk factor for CCA. With this infrastructure, newly diagnosed cases can be identified for our proposed stigma research. Importantly, the consortium also recruits two high-risk groups with pre- malignant disease: those with chronic liver disease and those with liver fluke infestation, both of which will be included in our stigma project. Thus, the information from HCC and CCA patients will deepen the understanding of the stigma that they experience and the consequences for screening, treatment, and survivorship programs, while the inclusion of the pre-malignant groups affords an unparalleled opportunity to explore their stigma experiences and to plan for future interventions to prevent cancer. In Specific Aim 1, we will examine associations of liver cancer stigma with depression and use of ultrasound screening among liver cancer patients and high risk, pre-malignant patients. Specific Aim 2 is to conduct qualitative interviews with samples of patients from Aim 1, and with community health workers and healthcare providers to understand causes of cancer stigma and their prevention. The results will reveal ways to ...