New screening protocol for pancreatic cancer is better than standard means
Using the serum CA 19-9 tumor marker followed by an endoscopic ultrasound is more likely to detect stage 1 pancreatic cancer in persons at high risk for the disease than is the tumor marker alone, according to a study recently published in GIE: Gastrointestinal Endoscopy (2011;74:87-95).
Abdominal pain, jaundice, and/or weight loss may indicate the presence of pancreatic cancer, but often do not manifest until the tumor is locally advanced or metastatic, at which point effective treatment options are limited. In stage 1 disease, however, resection of the pancreas improves overall survival, making early detection critical.
Employing the tumor marker CA 19-9 to screen for pancreatic cancer has met with limited success, so screening protocols focus on high-risk populations—persons who have or had a parent, sibling, or child (first-degree relative) with pancreatic cancer. The current study enrolled 546 such participants, aged 50 to 80 years. All were given a serum CA 19-9 test; if the level was elevated (greater than 37 units/mL), the person also underwent targeted endoscopic ultrasound (EUS).
CA 19-9 was elevated in 27 patients (4.9% of the group), with neoplastic or malignant findings detected in 5 (0.9%) and pancreatic adenocarcinoma (stage 1 disease) in one (0.2%). No additional patients in the CA 19-9/EUS study had developed the disease at 1-year follow-up. The cost to detect one pancreatic neoplasia was $8,341, and the cost to detect one pancreatic adenocarcinoma was $41,133.
In a comparison group of 124 patients who received a diagnosis of pancreatic cancer at the same facility but were not part of the CA 19-9/EUS study, one patient (0.9%) presented with stage 1 disease, 52 (45.6%) with stage 2, 20 (17.5%) with stage 3, and 41 (36%) with stage 4. Although only one patient each in the intervention group and in the comparison group had stage 1 disease, the difference was statistically significant because the detection of stage 1 cancer in the comparison group was so rare.
The investigators concluded that potentially curative pancreatic adenocarcinoma could be identified with the CA 19-9/EUS screening protocol, and that stage 1 cancer is more likely to be detected by this protocol than by standard means of detection.