Ca 19-9 tells you about which cancer?

Pancreas: Common exocrine pancreatic cancer. To detect the disease, it is neither sensitive nor specific. However, if the tumor makes it, its reappearance in the blood is a sign that the tumor has recurred.

Usually pancreas: While many cancers can express ca19-9, it is usually used to evaluate a patient for and follow pancreatic cancers. An elevated serum level however, is not diagnostic of cancer and a tissue biopsy is necessary to establish a diagnosis. It can be elevated in benign process though the higher the value the more worrisome for cancer.

First, it is NOT: A screening tool. It can rise with injury or obstruction of any bile duct. Where it is most used is in exocrine pancreas duct cancer after diagnosis to monitor response to treatment.