CA 19-9 nonproduction is associated with poor survival after resection of pancreatic adenocarcinoma

Background: Carbohydrate antigen (CA) 19-9 is the most common serum biomarker used in pancreatic adenocarcinoma (PC). Elevated preoperative levels have been shown to correlate with more advanced stage, greater risk of unresectability, and overall worse survival. The prognostic value of CA 19-9 nonproduction, which is present in an estimated 5% to 15% of the population, is unclear. We sought to determine whether CA 19-9 nonproduction was associated with worse survival after PC resection.

Methods: We retrospectively reviewed our institution's prospective pancreatic database for all PC patients with documented preoperative CA 19-9 values who underwent resection with curative intent from March 1992 to August 2009. After excluding 10 perioperative deaths, 200 patients remained for analysis.

Results: Mean and median follow-up was 23.3 and 16.1 months, respectively. Median survival in months for patients with preoperative CA 19-9 levels in U/mL by category was as follows: normal (5.1 to 36.9): 32, nonproduction (r5): 21, mildly elevated (37 to 99.9): 35, highly elevated (100 +): 16. Factors significantly associated with worse overall survival were: nonwhite race, nonproduction or highly elevated preoperative CA 19-9 (≥100 U/mL), estimated blood loss ≥1L, tumor size (≥2 cm), lymph node-positivity, and advanced (3/4) histologic grade. On multivariate analysis, only CA 19-9 nonproduction or highly elevated production, estimated blood loss ≥1 L, advanced histologic grade, and node positivity remained significant in the final model.

Conclusions: CA 19-9 nonproduction is not associated with improved survival after pancreatic cancer resection, as has previously been asserted, when compared with patients with normal and elevated levels.