The goal of the study is to understand the meaning of progression-free survival for women with metastatic breast cancer and to use this understanding to create and distribute a new questionnaire to assess the effect progression has on a woman's functioning and well-being.

This study is being conducted in three stages. Stages I and II are complete. Participation in Stage III requires the completion of an online survey. The survey may be accessed at the following link:

https://www.surveymonkey.com/s/mbc3survey

Compensation options for eligible participants are listed at the end of the survey.

Eligibility will be confirmed in follow-up call/email by study staff.

Inclusion Criteria:

• Female
• Age 18 and older
• Clinical diagnosis of metastatic breast cancer
• U.S. resident
• Able to speak and read English
• Willing to sign and informed consent
• Willing to self-administer one online questionnaire that will take approximately 15 minutes to complete

Female 18 and older U.S. resident Clinical diagnosis of metastatic breast cancer