Prolonged Response to Osimertinib in EGFR-Mutated Metastatic Urothelial Carcinoma, a Case Report.

A 48-year-old woman without obvious environmental risk factors was diagnosed with metastatic urothelial carcinoma harboring a mutation in EGFR typical of driver mutations for non-small cell lung cancer. Within a year, her cancer progressed on four standard therapies for urothelial cancer, including cancer in lungs, liver, bone, and brain. As fifth-line therapy, she received osimertinib, leading to a complete response in the brain and improvement elsewhere, and the cancer remained controlled for six months. Targeted therapy for rare driver mutations can be effective in urothelial cancer and should be considered prior to exhausting standard therapies.