Predictors of cancer in patients with suspected pancreatic malignancy without a tissue diagnosis.

BACKGROUND: The aim of this study was to identify predictive factors for malignancy in patients undergoing surgery for suspected pancreatic cancer without a preoperative tissue diagnosis. METHODS: Patients were identified by International Classification of Diseases Ninth Revision and current procedural terminology codes, respectively, for pancreatic cancer and pancreaticoduodenectomy at a single tertiary referral center between January 1998 and May 2004. Data were collected retrospectively by chart review. Multivariate analysis of potential predictive factors was performed. RESULTS: A total of 150 patients underwent surgery for documented or suspected pancreatic malignancy; 102 did not have a preoperative tissue diagnosis of cancer. Of these, 75 had neoplastic disease at surgery. Average weight loss was greater for those with malignancy (13.5 vs. 4.8 lbs; P = .014) as was mean bilirubin (6.1 vs. 3.3 mg/dL; P = .006). In multivariate analysis, a combination of weight loss >20 lbs, bilirubin >3 mg/dL, and CA 19-9 >37 U/mL had both a specificity and positive predictive value of 100% for predicting malignancy regardless of bile duct abnormalities or mass lesions on endoscopic retrograde cholangiopancreatography or endoscopic ultrasound, respectively. The positive predictive value decreased to 89.5% when any 2 of these findings were present. The presence of a mass on CT or EUS alone had a sensitivity of 84%; however, no other single finding had a sensitivity >65%. CONCLUSIONS: In patients suspected of having a pancreatic malignancy, weight loss, hyperbilirubinemia, and increased CA 19-9 level may be predictive of a final cancer diagnosis. Surgical exploration should be considered in these patients even in the absence of a preoperative tissue diagnosis.

A circulating ligand for galectin-3 is a haptoglobin-related glycoprotein elevated in individuals with colon cancer.

BACKGROUND & AIMS: Galectin-3 is a beta-galactoside-binding protein implicated in tumor progression and metastasis of colorectal cancers. To determine whether circulating galectin-3 ligands are related to the presence of colon cancer, we sought to identify and quantify ligands in serum that bind to galectin-3. METHODS: Sera from patients with colon cancer, adenomas, and normal individuals were desialylated, reduced, and separated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) and blots probed with biotinylated galectin-3. RESULTS: In colon cancer sera, the major galectin-3 ligand was a 40-kilodalton band distinct from mucin, carcinoembryonic antigen, and Mac-2 binding protein. Serum 40-kilodalton ligand was 10- to 30-fold higher in patients with colon cancer than in healthy subjects. Ligand was purified by gel filtration, affinity precipitation on galectin-3/agarose, and SDS-PAGE. When tryptic peptides were analyzed by matrix-assisted laser-desorption ionization mass spectrometry and protein database searching, the 40-kilodalton ligand was identified as haptoglobin beta subunit. In confirmation of this finding, depletion of haptoglobin by immunoprecipitation also eliminated the 40-kilodalton ligand. Colon cancer sera had only a modest increase in total haptoglobin as compared with healthy subjects, suggesting that the structure rather than the amount of haptoglobin is altered in patients with colon cancer. Immunohistochemical staining confirmed the absence of haptoglobin in normal colon and the ectopic expression of haptoglobin in colon cancers and adenomatous polyps. CONCLUSIONS: A major circulating ligand for galectin-3, which is elevated in the sera of patients with colon cancer, is a cancer-associated glycoform of haptoglobin.