Project Summary Given advances in screening and treatment, the number of people in the U.S. living with lung cancer is expected to increase by 25% (from 571,340 to 724,610) by 2030. Nearly all (95%) patients diagnosed with lung cancer report experiencing stigma (i.e., the perception and internalization of negative appraisal from others attributed to one’s lung cancer), which is perhaps the most prominent psychosocial issue in this population and contributes to poor psychological and physical health outcomes. A critical gap in the field of cancer control science is the lack of empirically supported patient-focused interventions that target the reduction of lung cancer stigma for this growing patient population. The goals of this K99/R00 are to adapt the existing Mindful Self-Compassion (MSC) psychosocial intervention to address anticipated delivery challenges and target the reduction of lung cancer stigma as well as to seek preliminary evidence for the efficacy of the adapted MSC intervention in reducing lung cancer stigma. The K99 study will involve a two-phase process of 1) conducting stakeholder focus groups to guide the iterative adaptation of MSC intervention activities and materials and 2) conducting in-depth interviews with lung cancer patients to explore patients’ reactions to intervention content and preferences for format and delivery. The R00 study will involve a two-phase process of 1) conducting a pilot RCT (n=60) to test preliminary efficacy of the adapted MSC intervention on primary (lung cancer stigma) and secondary outcomes (depressive symptoms, quality of life) and 2) conducting interviews with purposively sampled high responders (n=10) and non-responders (n=10) from the MSC condition (assessed post-intervention) to examine participants’ reactions to study participation. The overall objective of this K99/R00 is to provide Dr. Williamson with additional training and mentorship to become an independent cancer control investigator translating findings from basic behavioral scientific research into the development of tailored psychosocial interventions for cancer patients. Training aims include: 1) Psychosocial intervention development and adaptation in cancer; 2) advanced qualitative and mixed-methods design and analysis; 3) translational psychological research (synergy between basic and applied health science); 4) delivery of mindfulness- and compassion-based interventions in cancer care; and 5) professional development. Dr. Williamson is mentored by Dr. Jamie Ostroff at Memorial Sloan Kettering Cancer Center along with expert support from co-mentors (Drs. Lisa Carter-Harris and Jun Mao) and other significant contributors (Dr. Christopher Germer, Ms. Kathleen Lynch), who are all committed to Dr. Williamson’s career development. The proposed training plan will facilitate Dr. Williamson’s transition to independence as a cancer control investigator conducting a programmatic line of research that 1) characterizes disease-specific chall...