CA 19-9
췌장암에서 종양표지자로 많이 사용 되어지는 CA 19-9는 종양과 연관성이 있는 항원으로 정상 췌장 또는 담관 세포에서 합성되어지며 그 외에도 위장, 대장, 자궁점막, 침샘의 상피에서도 만들어지는 것으로 알려져 있습니다. 즉, 췌장과 담관 이외의 악성종양에서도 증가할 수 있고 양성질환인 경우에도 증가할 수 있다는 얘기입니다.
종양표지자인 CA19-9는 위암 (40-50%), 대장암 (30%), 췌장암 (80%) 에서 증가할 수 있습니다. 그러나, 췌장암 환자임에도 CA 19-9가 증가하지 않는 경우도 10-15% 정도로 보고되고 있어 현재 췌장암을 진단하기 위한 단일 표지자 검사는 없습니다.
CA 19-9 수치 상승을 일으킬 수 있는 양성질환인 산부인과 질환 (난소 낭종, 자궁내막염, 자궁 경부염 등), 내분비대사 질환 (당뇨, 갑상선 기능 항진증 및 저하증, 갑상선 결절 등), 호흡기 질환 (기관지 확장증, 폐결핵 등), 췌장 및 담도계 염증, 건강보조 식품이나 한약제 복용 등의 유무를 확인하여야 합니다.
How is it used? CA 19-9 is not sensitive or specific enough to use as a screening test for cancer, and it is not diagnostic of a specific type of cancer. Its main use is as a tumor marker:
To help differentiate between cancer of the pancreas and other conditions, such as pancreatitis To monitor a person's response to pancreatic cancer treatment and/or cancer progression To watch for pancreatic cancer recurrence CA 19-9 can only be used as a tumor marker if the cancer is producing elevated amounts of it. Since CA 19-9 is elevated in about 65% of those with bile duct (hepatobiliary) cancer, it may be ordered to help evaluate and monitor people with this type of cancer.
When is it ordered? CA 19-9 may be ordered along with other tests, such as carcinoembryonic antigen (CEA), bilirubin, and/or a liver panel, when a person has symptoms that may indicate pancreatic cancer. Those symptoms include abdominal pain, nausea, weight loss, and jaundice.
If CA 19-9 is initially elevated in pancreatic cancer, then it may be ordered several times during cancer treatment to monitor response and on a regular basis following treatment to help detect recurrence.
CA 19-9 may sometimes be ordered when a doctor suspects hepatobiliary cancer and/or bile duct obstruction. Non-cancerous causes of bile duct obstruction can cause very high CA 19-9 levels, which fall when the blockage is cleared. In these cases, it is a good idea to wait at least a week or two after the blockage is removed to re-check CA 19-9 levels.
What does the test result mean? Low amounts of CA 19-9 can be detected in healthy people, and many conditions that affect the liver or pancreas can cause temporary elevations.
Moderate to high levels are found in pancreatic cancer, other cancers, and in several other diseases and conditions. The highest levels of CA 19-9 are seen in cancer of the exocrine pancreas. This cancer arises in the tissues that produce food-digesting enzymes and in the ducts that carry those enzymes into the small intestine. About 95% of pancreatic cancers are of this type.
Serial measurements of CA 19-9 may be useful during and following cancer treatment. Rising or falling levels may give the doctor important information about whether the treatment is working, whether all of the cancer was removed successfully during surgery, and whether the cancer is recurring.
Is there anything else I should know? Unfortunately, early pancreatic cancer gives few warning signs. By the time a person has symptoms and significantly elevated levels of CA 19-9, pancreatic cancer is usually at an advanced stage.