This study aims to investigate the role of a mobile health app, Outcomes4Me, in the navigation of care for people with breast cancer.

This protocol is a single arm pilot study of a novel breast cancer navigation app that is intended to assist patients with breast cancer understand their diagnosis and treatment options (both as part of standard of care practice and clinical trials) and manage their care, through treatment and symptom tracking. Patients will also be able to share information and get news via the app relevant to their cancer subtype. Results from this intervention will inform future clinical integration efforts, improve patient-centeredness of such an app-based health content and data platform, and inform the design of a larger, randomized study to demonstrate an improvement in patients' outcomes as well as enhanced Real-World Evidence (RWE) data collection.

Inclusion Criteria:

• 18 years or older, with histologically or cytologically confirmed invasive breast cancer stage I-IV
• Must be on, or planning to be on within 4 weeks of registration, active therapy, with the intent to receive some element of active therapy > 28 days after registration
• Must be able to understand, read, and write in English and be able to sign informed consent
• Must have an Apple or Android smart phone that they are able to use and download the Outcomes4Me app on
• Must have the ability to access the internet at least once per week via their smart phone (having a computer is not required)

Exclusion Criteria:

• Participations seen for consultation opinion only and are not planning to receive some element of active treatment from an MGH medical or radiation oncology provider at MGH (Boston or Waltham sites) during the 12-week study period