Passage: The majority of cases of cholangiocarcinoma present as inoperable (unresectable) disease in which case people are generally treated with palliative chemotherapy, with or without radiotherapy. Chemotherapy has been shown in a randomized controlled trial to improve quality of life and extend survival in people with inoperable cholangiocarcinoma. There is no single chemotherapy regimen which is universally used, and enrollment in clinical trials is often recommended when possible. Chemotherapy agents used to treat cholangiocarcinoma include 5-fluorouracil with leucovorin, gemcitabine as a single agent, or gemcitabine plus cisplatin, irinotecan, or capecitabine. A small pilot study suggested possible benefit from the tyrosine kinase inhibitor erlotinib in people with advanced cholangiocarcinoma.

Question: A pilot study indicated patients with advanced cholangiocarcinoma may benefit from what chemotherapy agent?
the tyrosine kinase inhibitor erlotinib