Adenocarcinoma is by far the most common type of pancreas tumor. Ninety of the patients were treated at the University of Rochester Medical Center's Wilmot Cancer Institute; the others at Dana Farber/Brigham and Women's Cancer Center in Boston and Stanford Cancer Institute. In all cases after the tumors were removed, scientists extracted DNA from the cancerous tissue and nearby normal tissue, and conducted next-generation DNA sequencing on the specimens.
The analysis centered on the activity of the KRAS, CDKN2A, SMAD4, and TP53 genes. Results showed that patients who had three or four of the altered genes had worse disease-free survival (the time between surgery and when the cancer returns), and overall survival (from surgery to death), compared to patients with a single or two altered genes. A more detailed breakdown of survival and specific gene activity is available in the full study.