DNA Microarray Study of Pancreas Cancer

Pancreas cancer and precancerous cysts can be difficult to diagnose. Sometimes biopsies do
not show cancer when cancer is actually present. We hypothesize that genetic differences
exist in tissue that is malignant compared to nonmalignant. When patients present with a
pancreas mass or cyst, we biopsy it by fine-needle aspiration during upper endoscopy with
ultrasound guidance. We would like to use tissue obtained via endoscopic ultrasound guided
fine needle aspiration to perform DNA microarray analysis, and compare the differences in
gene expression level in the benign tissue compared to cancerous tissue in order to improve
our diagnostic capabilities. DNA microarray measures gene expression level rather than
germline mutations. The true diagnosis will be based on cytology, surgical pathology, or
clinical followup. The performance of the microarray test as a diagnostic test will be
compared to the performance of cytology.