Patients with triple-negative breast cancer (TNBC) account for approximately 15% of all breast cancer diagnoses but are disproportionately burdened with metastatic disease and breast cancer death due to high rates of recurrence and a lack of risk-reducing treatment options in the surveillance phase. The transition to surveillance is marked with distress and prognostic uncertainty regarding fears of cancer recurrence at a time when contact with the oncology team decreases. Patients with TNBC are at greater risk for poor psychosocial outcomes as TNBC frequently occurs in younger patients and in patients harboring high-risk genetic mutations. Despite the dire needs of patients with TNBC, no coping and supportive care interventions currently exist for this population. To address this gap, the proposed study details a five-year plan to develop, refine, and pilot-test a nurse-led, coping, and supportive care intervention (TRANSITIONS) to address the needs of patients with TNBC as they transition from curative therapy to surveillance at Massachusetts General Hospital and three community affiliates. The aims of this project are to (1) to develop and refine TRANSITIONS based on preliminary data with patients with TNBC, stakeholder feedback, as well as patient feedback from an open pilot study (N=5-8), (2) to evaluate the feasibility and acceptability of TRANSITIONS by conducting a pilot randomized controlled trial (RCT) (N=75), and (3) to estimate the preliminary effects of TRANSITIONS for improving psychosocial outcomes in the pilot RCT. The candidate, Dr. Kathryn Post, assembled a mentor team comprised of internationally recognized investigators in behavioral interventions, patient-reported outcomes, cancer care (Joseph Greer, PhD), TNBC (Leif Ellisen, MD, PhD), and supportive care trials in patients with breast cancer (Jamie Jacobs, PhD). A scientific advisory committee will provide guidance on: qualitative data methods (Lara Traeger, PhD); breast cancer clinical care (Beverly Moy, MD, MPH); nurse-led interventions in cancer survivorship (Teresa Hagan Thomas, PhD, BA, RN); and biostatistics (Dustin Rabideau, PhD). Dr. Post will achieve her short-term goals through a coordinated research and training plan in (1) behavioral and cognitive-behavioral-therapy-based intervention development, (2) RCT design, testing, and conduct, and (3) longitudinal assessment and analysis. In addition to regular mentorship meetings and experiential training included in the research plan, Dr. Post will complete advanced coursework and didactic training, attend and present at seminars and national conferences, and publish findings in peer-reviewed journals. This K08 proposal details Dr. Post’s plans to gain mentorship, didactic training, and career development to facilitate her transition to research independence. Dr. Post’s long-term goal is to become an independent investigator and a leading nurse scientist in supportive oncology. With the additional training and mentorship...