Decline in CA19-9 during chemotherapy predicts survival in four independent cohorts of patients with inoperable bile duct cancer

Mie Grunnet, Ib J Christensen, Ulrik Lassen, Lars H Jensen, Magnus Lydolph, Jennifer J Knox, Mairead G McNamara, Mark Jitlal, Harpreet Wasan, John Bridgewater, Juan W Valle, Morten Mau-Sørensen