36 The qualitative part of our research landscape analysis included interviews with experts from various sectors relevant to MBC research, including advocacy and nonprofit organizations, academic and medical institutions, government agencies, pharmaceutical and biotechnology organizations, professional societies, and clinical trials cooperative groups (a complete list can be found in Appendix 2). All Alliance members were asked to suggest experts they believed we should interview, including members of their organization’s medical and scientific advisory boards or external scientists believed to be leaders in metastatic research. In addition, we identified experts to be interviewed from those listed as the principal investigator on multiple awards from the MBC Grants Dataset. The experts interviewed had expertise in basic laboratory research, clinical trial design and execution, health care and research policy, patient-reported outcomes, and quality of life research. Seven questions were asked of each KOL interviewed: 1. What exciting scientific opportunities do you see for advancing our understanding of metastasis? 2. What do you think is the most promising target for developing new therapeutics aimed at metastasis? a. Cancer stem cells in tumors b. Cell invasion from the breast c. Tumor dormancy d. Tumor cell avoidance of immune surveillance (“immune escape”) e. End-organ microenvironment f. Cell signaling and proliferation g. Other 3. What gaps or roadblocks exist that hinder advances in MBC research? 4. What role do you see for markers or circulating tumor cells, circulating tumor DNA, or other? a. Companion diagnostics (for new agents) 5. Can you describe MBC clinical trials you are involved with conducting? a. Challenges in designing and conducting trials for MBC b. Current pipeline of trials or products planned for MBC trials 6. Are there other aspects of MBC research we should discuss? 7. Whom else should we interview? Each interview was conducted by 2 Alliance staff. Each interview was recorded and the interviewee was de-identified. All responses and interviewer notes were manually logged in a spreadsheet. The final spreadsheet was reviewed by 2 Alliance staff to identify and extract common topics: any topic noted by 3 or more respondents is included in the results section. Interviews with Key Opinion Leaders