Utility of tumor markers in determining resectability of pancreatic cancer.
OBJECTIVE
Despite advances in preoperative radiologic imaging, a significant fraction of potentially resectable pancreatic cancers are found to be unresectable at laparotomy. We tested the hypothesis that preoperative serum levels of CA19-9 (cancer antigen) and carcinoembryonic antigen will identify patients with unresectable pancreatic cancer despite radiologic staging demonstrating resectable disease.


METHODS
Academic tertiary care referral center.


METHODS
From March 1, 1996, to July 31, 2002, 125 patients were identified who underwent surgical exploration for potentially resectable pancreatic cancer based on a preoperative computed tomographic scan; in 89 of them a preoperative tumor marker had been measured.


METHODS
Preoperative tumor markers (CA19-9 and carcinoembryonic antigen) were correlated with extent of disease at exploration. As CA19-9 is excreted in the biliary system, CA19-9 adjusted for the degree of hyperbilirubinemia was determined and analyzed.


RESULTS
Of the 89 patients, 40 (45%) had localized disease and underwent resection, 25 (28%) had locally advanced (unresectable) disease, and 24 (27%) had metastatic disease. The mean adjusted CA19-9 level was significantly lower in those with localized disease than those with locally advanced (63 vs 592; P =.003) or metastatic (63 vs 1387; P<.001) disease. When a threshold adjusted CA19-9 level of 150 was used, the positive predictive value for determination of unresectable disease was 88%. Carcinoembryonic antigen level was not correlated with extent of disease.


CONCLUSIONS
Among the patients with resectable pancreatic cancer based on preoperative imaging studies, those with abnormally high serum levels of CA19-9 may have unresectable disease. These patients may benefit from additional staging modalities such as diagnostic laparoscopy to avoid unnecessary laparotomy.
Schlieman
Michael G
MG
Department of Surgery, Division of Surgical Oncology, UC Davis Cancer Center, Sacramento, CA 95817, USA.
Ho
Hung S
HS
Bold
Richard J
RJ
D000230:Adenocarcinoma / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000368:Aged; D018395:CA-19-9 Antigen / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen