My sister has had severe lower back pain for about 10 days and has been undergoing chemotheraphy with immunotherapy as she has metastatic triple negative breast cancer. she is taking steriods now, as well as cbd oil, and tylenol but suffering still?

Sorry but your question is not clear. I assume that you sister has metastatic breast cancer which involves the spines and it causes back pain. Steroids will help but it take time, she may need narcotic med and local radiation therapy if pain persists. Tylenol is not strong enough.

If there has been no recent injury or strain, metastatic involvement of the spine or a compression fracture of the spine are definite possibilities. Both are very painful conditions.Her oncologist should be notified, evaluate her and prescribe adequate pain relieving medication.