People with PSC have an increased risk of getting some cancers (bile duct cancer, gallbladder cancer, liver cancer and colorectal cancer) 1 than the general population and are therefore carefully monitored by their doctors.
Regular screening by colonoscopy with biopsies is recommended for people with PSC and IBD 1,4,58. Recent advances in endoscopic imaging techniques using high definition endoscopes and chromoendoscopy have improved the early detection rate for bowel cancer 65.
In PSC patients without confirmed IBD, many doctors order colonoscopies with biopsies every 5 years 48 and this is supported by the BSG/UK-PSC Guidelines 58 (Recommendation 27) to ensure that colitis has not developed.
Watch: The PSC Colonoscopy: why it is needed and what's involved. Dr Kate Lynch (née Williamson) University of Oxford at a PSC Support Information Day:
Biliary tract (hepatopancreatobiliary, HPB) cancers are cancers that affect the bile duct (cholangiocarcinoma, CCA), gallbladder and liver (hepatocellular carcinoma, HCC). All patients with advanced fibrosis or cirrhosis of the liver, regardless of the cause of their liver disease, are at increased risk of liver cancer 1.
What is the lifetime risk of bile duct cancer for people with PSC?
The overall risk (incidence) of bile duct cancer over the lifetime of an individual with PSC is 10-15% 7. However, the majority of cases occur within the first 1-2 years of PSC diagnosis 7,66. After those two years, bile duct cancer is very rare; less than 1% per year develop the cancer after that time 7. The medical term for bile duct cancer is ‘cholangiocarcinoma’.
The average age of a bile duct cancer diagnosis in people with PSC is younger (in the 30s) than in the general population (in the 60s) 66.
Currently, there is no proven beneficial form of surveillance strategy for cholangiocarcinoma, and research studies are ongoing to address this issue 5. EASL/ESGE recommend that bile duct cancer should be suspected in any patient with ‘worsening cholestasis, weight loss, raised serum CA19-9, and/or new or progressive dominant stricture’ 67.
According to the EASL and AASLD there is currently no consensus about the best way to screen for bile duct cancer:
The European Association for the Study of the Liver (EASL) states: ‘'There is at present no biochemical marker or imaging modality which can be recommended for early detection of cholangiocarcinoma. ERCP with brush cytology (and/or biopsy) sampling should be carried out when clinically indicated.' 4.
The position of the American Association of the Study of Liver Diseases (AASLD) is that ‘in the absence of evidence based information, many clinicians screen patients with an imaging study plus a CA19-9 at annual intervals.’ 68
CA19-9 is a blood test to measure the level of tumour markers found in the blood. However, it is not specific enough to be used on its own to screen for bile duct cancer, especially in a disease like PSC because a third of people with CA19-9 at 129U/mL are free of cancer long-term 66. CA19-9 fluctuates in PSC and levels increase with bacterial cholangitis, other gastroenterological and gynaecological cancers, and smoking 66. Furthermore, some people can’t make CA19-9 (the so-called ‘non-secretor’), so in around 5-7% of people the test cannot be performed 135.
The BSG/UK-PSC Guidelines recommend that while increased CA19-9 may support a diagnosis of suspected bile duct cancer, it has a low diagnostic accuracy and that routine measurement of blood CA19-9 is not recommended for surveillance for cholangiocarcinoma in PSC 58 (Recommendation 23).
If you have PSC, you should discuss your cancer risk and available screening options with your PSC doctor.
Gallbladder cancer and liver cancer (HCC) are also more common in PSC than in the general population 69. Gallbladder cancer develops in only around 2% of people with PSC, although more than 50% of gallbladder polyps detected by ultrasound scans could be malignant. A polyp is like a small soft but solid growth on the gallbladder wall, usually in the order of 2-10mm diameter. It is thought to be a potential precursor for gallbladder cancer. Usually they are benign, but as mentioned, there is increased risk for polyps being pre-malignant and/or developing to cancer in people with PSC.
Once someone has cirrhosis (severe scarring of the liver), it is recommended that the ultrasound scan frequency increases to every 6 months, to monitor for liver cancer 1. If a suspect liver lesion is suspected, further imaging (i.e. MRI or CT scan) may be required to confirm the diagnosis.