The CA-19.9 test is typically recommended for individuals with suspected pancreatic cancer, bile duct cancer, or other gastrointestinal cancers. It may be ordered when there are symptoms suggestive of these cancers, such as jaundice, abdominal pain, or unexplained weight loss. Additionally, individuals undergoing treatment for these cancers may have the CA-19.9 test done to monitor treatment response or detect cancer recurrence.