Study of Screening Brain MRIs in Stage IV Breast Cancer

This trial is studying whether routinely checking for brain metastases (cancer that has spread to the brain) using MRI scans in people with stage IV (metastatic) breast cancer — even before symptoms appear — leads to better outcomes. Brain metastases are currently only detected when symptoms show up, but catching them earlier may allow earlier treatment. **You may be eligible if...** - You have been diagnosed with stage IV (metastatic) breast cancer, confirmed by biopsy - You know your ER, PR, and HER2 receptor status - For HR+/HER2- breast cancer: your disease must have progressed past first-line treatment - For HER2+ or triple-negative breast cancer: you must have confirmed stage IV disease - You are 18 or older with at least 6 months life expectancy - You have no prior brain metastases or treatment for brain cancer **You may NOT be eligible if...** - You have previously been diagnosed with or treated for brain metastases - You already have neurological symptoms that would normally prompt a brain MRI - You have advanced kidney disease that contraindicates MRI contrast dye - You have a medical condition that prevents MRI scanning Talk to your doctor to see if this trial is right for you.