FIG 1.

Disease courses for patients 1 (top) and 2 (bottom) aligned by date of diagnosis. The date when metastatic disease was first radiographically evident is indicated with an M in blue. CA19-9 test results are not shown because—for both patients—they were reproducibly approximately 90% lower than the 37 U/mL threshold for normal, even when the primary tumor was present. This result suggests a false negative result because of a Lewis^a-b- antigen phenotype, as is the case for 5%-10% of Caucasian patients with PDAC.⁶⁵