The Caddo County Sheriff's Office issued a Silver Alert for a missing woman Thursday afternoon.
The woman has been identified as 55-year-old Dawn Sherrill.
Authorities said Sherrill was last seen at 6 p.m. Wednesday near the intersection of State Highway 8 and County Road 1377 in Anadarko.
Sherrill was last seen wearing gray shoes, tan capri pants and a smoky gray scrub top that reads "Anadarko Vet."
The sheriff's office said Sherrill was diagnosed with brain cancer. Sherrill recently underwent brain surgery which could play a role in whether or not she is confused and if she knows where she is going.
While authorities said they are unsure of the direction she is traveling, Sherrill is driving a red and black 2007 Ford F-150 with the Oklahoma license plate DLN579.
This is a developing story.