In an era of increased treatment options for high-grade tumors, failure to accurately identify tumor types exposes patients to avoidable risk. Patients with tumors classified as occult, or cancer of unknown primary, might receive inappropriate therapy or miss out on potentially beneficial treatment.
Rondell Graham, M.B.B.S., an anatomic and molecular pathologist at Mayo Clinic, co-led a molecular oncology tumor board session at CAP19, and subsequently spoke with CAP Today. Focusing on immunohistochemistry, Dr. Graham outlined a "safe, stepwise approach" to the workup of occult cancer:
The five most common occult primaries identified at autopsy are lung cancer, pancreatobiliary malignancy, other gastrointestinal tumors, breast cancer, and ovarian carcinoma, Dr. Graham reported. “You want to make sure that when you finish your workup and you are ready to sign it out as a cancer of unknown primary, that you considered or excluded these possibilities as much as possible,” he said.