Detecting Early Stage Pancreatic Cancer
Combination of CA 19-9 tumor marker level and endoscopic ultrasound may aid in early detection in high-risk individuals.
Pancreatic cancer is likely at or near the top of the list of most-feared cancers. With a life expectancy of only 5-8 months from the time of diagnosis, it would be wonderful if this cancer could be detected earlier, when there is a greater chance of cure or long-term control of the disease.
Abdominal pain, jaundice, and weight loss are signs and symptoms of pancreatic cancer, but often do not occur until the cancer is no longer in its early stage. Pancreatic cancer has been described as a “silent” cancer until it 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. Early detection is therefore critical.
The tumor marker CA 19-9 has been used to help diagnosis pancreatic cancer for many years. However, using this tumor marker has a screening tool has met with limited success. Researchers at the University of Chicago hoped to identify a way to detect pancreatic cancer in its earliest stage. They conducted a study of 546 people, ages 50-80, that had a first-degree relative with pancreatic cancer. First-degree relatives included parents, siblings, and children. 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 levels were elevated in 27 patients (5% 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. In the comparison group of 124 patients who received a diagnosis of pancreatic cancer at the same facility but were not part of the study, one patient (0.9%) presented with stage 1 disease, 52 (46%) with stage 2, 20 (17%) 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 researchers 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.
Zubark R, Gordon SR, Lidofsky SD et al. Screening for pancreatic cancer in a high-risk population with serum CA 19-9 and targeted EUS: a feasibility study. GIE: Gastrointestinal Endoscopy. 2011;74(1):87-95.