Pharmacokinetically Guided Everolimus in Patients With Breast Cancer, Pancreatic Neuroendocrine Tumors, or Kidney Cancer

This phase II trial studies how well real-time pharmacokinetic therapeutic drug monitoring works in preventing stomatitis from developing in patients with hormone receptor positive breast cancer, pancreatic neuroendocrine tumors, or kidney cancer that are receiving a type of cancer drug called everolimus. Stomatitis is a common side effect of everolimus that causes inflammation of the mouth, with or without oral ulcers, and frequently leads to patients discontinuing the medication. Monitoring the blood levels of everolimus and making adjustments in a patient's dose may be able to decrease the incidence of stomatitis, while maintaining the effectiveness of everolimus to treat the cancer.