Gene expression profiling identifies markers of ampullary adenocarcinoma

Ampullary adenocarcinoma is an aggressive cancer with a poor prognosis. Without surgical resection, ampullary adenocarcinomas can be difficult to distinguish from ampullary adenomas. The aim of this study was to identify differentially expressed genes in ampullary adenocarcinoma in order to identify candidate markers of the disease. The Affymetrix Human Genome U133 GeneChip set (HG-U133A and HG-U133B) was used to obtain gene expression profiles of 5 ampullary adenocarcinomas and 10 normal duodenal samples. Using fold change analysis we identified 235 fragments expressed at least fivefold higher in ampullary cancers than in normal duodenum. The expression profiles of eight candidate overexpressed genes (osteopontin, mesothelin, tissue inhibitor of metalloproteinases 1, mucin-1, mucin-5, fascin, heat shock protein 47, fibronectin 1) were confirmed by immunohistochemistry or in situ hybridization on tissue microarrays (TMA) containing 54 ampullary adenocarcinomas. One of these genes, osteopontin, was expressed 27-fold higher levels in ampullary adenocarcinomas compared to normal duodenum by genechip analysis. We therefore determined serum osteopontin levels in patients with ampullary neoplasms, patients with other periampullary diseases and in normal controls. Mean preoperative serum osteopontin levels as measured by competitive ELISA were 906 +/- 268 ng/ml in patients with ampullary cancer, 867 +/- 160 ng/ml in patients with an ampullary adenoma, 327.1 +/- 195.6 ng/ml in patients with nonmalignant periampullary diseases and 204 +/- 65 ng/ml in age-matched healthy controls (p < 0.001). Measurement of markers of ampullary cancer such as osteopontin may aid in the early detection and differential diagnosis of patients with periampullary lesions.

The need for a prophylactic gastrojejunostomy for unresectable periampullary cancer: a prospective randomized multicenter trial with special focus on assessment of quality of life

OBJECTIVE

To evaluate the effect of a prophylactic gastrojejunostomy on the development of gastric outlet obstruction and quality of life in patients with unresectable periampullary cancer found during explorative laparotomy.

SUMMARY BACKGROUND DATA

Several studies, including one randomized trial, propagate to perform a prophylactic gastrojejunostomy routinely in patients with periampullary cancer found to be unresectable during laparotomy. Others suggest an increase of postoperative complications. Controversy still exists in general surgical practice if a double bypass should be performed routinely in these patients.

METHODS

Between December 1998 and March 2002, patients with a periampullary carcinoma who were found to be unresectable during exploration were randomized to receive a double bypass (hepaticojejunostomy and a retrocolic gastrojejunostomy) or a single bypass (hepaticojejunostomy). Randomization was stratified for center and presence of metastases. Patients with gastrointestinal obstruction and patients treated endoscopically for more than 3 months were excluded. Primary endpoints were development of clinical gastric outlet obstruction and surgical intervention for gastric outlet obstruction. Secondary endpoints were mortality, morbidity, hospital stay, survival, and quality of life, measured prospectively by the EORTC-C30 and Pan26 questionnaires. It was decided to perform an interim analysis after inclusion of 50% of the patients (n = 70).

RESULTS

Five of the 70 patients randomized were lost to follow-up. From the remaining 65 patients, 36 patients underwent a double and 29 a single bypass. There were no differences in patient demographics, preoperative symptoms, and surgical findings between the groups. Clinical symptoms of gastric outlet obstruction were found in 2 of the 36 patients (5.5%) with a double bypass, and in 12 of the 29 patients (41.4%) with a single bypass (P = 0.001). In the double bypass group, one patient (2.8%) and in the single bypass group 6 patients (20.7%) required (re-)gastrojejunostomy during follow-up (P = 0.04). The absolute risk reduction for reoperation in the double bypass group was 18%, and the numbers needed to treat was 6. Postoperative morbidity rates, including delayed gastric emptying, were 31% in the double versus 28% in the single bypass group (P = 0.12). Median postoperative length of stay was 11 days (range 4-76 days) in the double versus 9 days (range 6-20 days) in the single bypass group (P = 0.06); median survival was 7.2 months in the double versus 8.4 months in the single bypass group (P = 0.15). No differences were found in the quality of life between both groups. After surgery most quality of life scores deteriorated temporarily and were restored to their baseline score (t = -1) within 4 months.

CONCLUSIONS

Prophylactic gastrojejunostomy significantly decreases the incidence of gastric outlet obstruction without increasing complication rates. There were no differences in quality of life between the two groups. Together with the previous randomized trial from the Hopkins group, this study provides sufficient evidence to state that a double bypass consisting of a hepaticojejunostomy and a prophylactic gastrojejunostomy is preferable to a single bypass consisting of only a hepaticojejunostomy in patients undergoing surgical palliation for unresectable periampullary carcinoma. Therefore, the trial was stopped earlier than planned.

Novel markers of pancreatic adenocarcinoma in fine-needle aspiration: mesothelin and prostate stem cell antigen labeling increases accuracy in cytologically borderline cases

The interpretation of pancreas fine-needle aspiration (FNA) is extremely difficult given the cytologic overlap of neoplastic and reactive processes. Using serial analysis of gene expression, we have discovered 2 new markers of pancreatic adenocarcinoma, mesothelin and prostate stem cell antigen (PSCA), and confirmed their specificity by immunohistochemical labeling. Here we evaluate the potential contribution of immunohistochemical labeling of mesothelin and PSCA to the interpretation of pancreas FNAs. Thirty pancreas FNAs with follow-up data were reviewed. Unstained cell block sections from these aspirates labeled for mesothelin and PSCA using immunohistochemistry were compared with initial cytologic diagnoses and with follow-up diagnoses. On follow-up, 19 patients proved to have cancer, and 11 did not. Initial cytologic diagnosis of malignancy correlated with carcinoma on follow-up in 12 of 12 cases, and initial benign cytologic diagnosis correlated with benign follow-up in 8 of 9 cases (sensitivity, 92%; specificity, 100%). Six of the 9 patients with suspicious cytology were found to have a carcinoma on follow-up. PSCA labeling was present in 16 of the 19 patients who ultimately were proven to have carcinoma; PSCA labeling was absent in 10 of the 11 lesions proven to be benign (sensitivity, 84%; specificity, 91%). Mesothelin labeling was present in 13 of the 19 patients who ultimately were proven to have carcinoma; mesothelin labeling was absent in 10 of the 11 lesions proven to be benign (sensitivity, 68%; specificity, 91%). Five of the 6 cytologically suspicious cases with malignant follow-up labeled for either PSCA or mesothelin (83%), and 2 of the 6 cases labeled for both markers. None of the 3 suspicious cases with benign follow-up labeled for either PSCA or mesothelin. Increasingly, molecular techniques are identifying potential cancer markers that may have diagnostic utility. In this study, immunohistochemical labeling for 2 of these markers, PSCA and mesothelin, appears highly specific for pancreatic adenocarcinoma in FNA specimens and useful in categorizing cytologically suspicious lesions.