Low Yield and High Cost of Gastric and Duodenal Biopsies for Investigation of Symptoms of Abdominal Pain During Routine Esophagogastroduodenoscopy.

BACKGROUND: Esophagogastroduodenoscopy (EGD) referrals for symptoms of abdominal pain are common. Current guidelines for dyspepsia recommend biopsies of gastric mucosa for Helicobacter pylori in all patients referred for EGD. Our study aimed to determine the clinical yield and cost-effectiveness of gastric and duodenal biopsy in EGDs performed for abdominal pain. METHODS: Three hundred and ninety-one outpatient EGDs performed at a single academic tertiary care center were studied. For each procedure, endoscopic as well as pathologic findings from the stomach and duodenum were then recorded. Charge of biopsy was calculated using the increased charges for professional fees, forceps, and pathology fees when a biopsy was performed. RESULTS: Gastric biopsies were obtained on 304 EGDs performed with 13 (4.2%) patients diagnosed with H. pylori. In patients with abnormal gastric mucosa on EGD, 11 of 167 (6.5%) were positive for H. pylori compared to 2 of 137 (1.4%) with normal appearing mucosa (p = 0.02). Charge per diagnosis of H. pylori for normal mucosa was calculated to be $43,073. Duodenal biopsies were performed in 263 cases. Celiac disease was diagnosed in 4 of 263 cases (1.5%). Of patients with abnormal duodenal mucosa on EGD, 1 of 36 (2.7%) were positive for celiac disease compared to 3 of 227 (1.3%) with normal mucosa (p = 0.57). Charge per diagnosis of celiac disease for normal mucosa was calculated to be $47,580. CONCLUSION: Routine biopsy during EGD for symptoms of abdominal pain has low yield with high costs. Practice of routine biopsies of normal appearing tissue and the present guidelines should be reconsidered in the investigation of abdominal pain with EGD.

Heterochromatin Protein 1 Binding Protein 3 Expression as a Candidate Marker of Intrinsic 5-Fluorouracil Resistance.

BACKGROUND: Despite receiving post-operative 5-fluorouracil (5-FU)-based chemotherapy, approximately 50% of patients with stage IIIC colon cancer experience recurrence. Currently, no molecular signature can predict response to 5-FU. MATERIALS AND METHODS: Mouse models of colon cancer have been developed and characterized. Individual tumors in these mice can be longitudinally monitored and assessed to identify differences between those that are responsive and those that are resistant to therapy. Gene expression was analyzed in serial biopsies that were collected before and after treatment with 5-FU. Colon tumors had heterogeneous responses to treatment with 5-FU. Microarray analysis of pre-treatment biopsies revealed that Hp1bp3, a gene encoding heterochromatin protein 1 binding protein 3, was differentially expressed between sensitive and resistant tumors. CONCLUSION: Using mouse models of human colorectal cancer, Hp1bp3 was identified as a candidate marker of intrinsic 5-FU resistance and may represent a potential biomarker for patient stratification or a target of clinical importance.

Improved Detection of Microsatellite Instability in Early Colorectal Lesions.

Microsatellite instability (MSI) occurs in over 90% of Lynch syndrome cancers and is considered a hallmark of the disease. MSI is an early event in colon tumor development, but screening polyps for MSI remains controversial because of reduced sensitivity compared to more advanced neoplasms. To increase sensitivity, we investigated the use of a novel type of marker consisting of long mononucleotide repeat (LMR) tracts. Adenomas from 160 patients, ranging in age from 29-55 years old, were screened for MSI using the new markers and compared with current marker panels and immunohistochemistry standards. Overall, 15 tumors were scored as MSI-High using the LMRs compared to 9 for the NCI panel and 8 for the MSI Analysis System (Promega). This difference represents at least a 1.7-fold increase in detection of MSI-High lesions over currently available markers. Moreover, the number of MSI-positive markers per sample and the size of allelic changes were significantly greater with the LMRs (p = 0.001), which increased confidence in MSI classification. The overall sensitivity and specificity of the LMR panel for detection of mismatch repair deficient lesions were 100% and 96%, respectively. In comparison, the sensitivity and specificity of the MSI Analysis System were 67% and 100%; and for the NCI panel, 75% and 97%. The difference in sensitivity between the LMR panel and the other panels was statistically significant (p<0.001). The increased sensitivity for detection of MSI-High phenotype in early colorectal lesions with the new LMR markers indicates that MSI screening for the early detection of Lynch syndrome might be feasible.