168 Background: Cancer self-management (SM) is individuals’ engagement in tasks related to the medical, physical, spiritual, and emotional management of cancer. Reports of SM interventions often focus on efficacy and do not detail processes of development and evaluation. We delineate our creation of a patient-oriented and informed cancer SM intervention, Managing Cancer Care: A Personal Guide (MCC), and share lessons learned to improve intervention efficacy and fidelity. Methods: We developed and evaluated MCC in 5 stages: needs assessment interviews (n=25); development of MCC; focus group (n=6); pilot testing with metastatic breast cancer patients (n=23); and population testing with non-metastatic breast cancer patients (n=110). We performed content analysis on qualitative data and used descriptive statistics to analyze module ratings and frequency of use in the pilot and population tests. Results: We identified cancer SM practices, preferences, facilitators, and barriers, and designed MCC based on interview data, related literature, and SM theory. The MCC prototypeconsisted of 7 magazine-style modules designed to be user-friendly, concise, and personalized. Although well-received, we made substantial changes based on focus group data, with additional revisions after the pilot test. Module ratings and frequency of use differed between pilot and population samples. Among metastatic patients, median ratings (1-10, low/high) for MCC as a whole on both content and format were 8 (range 2-10). The most popular module was Care Options, which tied with Managing Transitions as most frequently used. Among non-metastatic patients, median ratings were 8 (range 1-10) and 9 (range 2-10) on content and format, with the Managing Your Symptoms module being most popular and most frequently used. Conclusions: Data from our metastatic and non-metastatic samples suggest differing SM priorities. Lessons learned in creating patient-oriented cancer SM interventions include acknowledging that there are no “one size fits all” solutions, resisting assumptions about reception of potentially emotional content, maintaining flexibility, and negotiating the tension between research and real world settings.