There is a disease, a cancer, that kills more people than cervical cancer and whose incidence is rising in the UK and most of the industrialised world. However, most people have never heard of this cancer, and even amongst most doctors, the rising death toll from this disease is unknown. This disease is called “cholangiocarcinoma”, or CC, and unless you or someone you care about has been affected by this cancer, it is unlikely you’ll have come across this term before. I believe this is a disease whose profile needs to be raised and I would like to take this opportunity to tell you about CC.
As a liver specialist, I am continually amazed at the liver’s incredible diversity. It has, literally, hundreds of different functions in the body. One of these is to make bile, a green to yellowish fluid, which aids the digestion of fats and also carries away potentially harmful toxins into the gut for excretion from the body. The bile ducts are a system of tube like structures which carry this bile from the liver to the gut. Cholangiocarcinoma is a fatal cancer arising in these bile ducts. This particular form of cancer kills almost 2000 people per year in this country, and affects both men and women. Most people who get CC will die from the disease. Moreover, studies from around the world suggest that CC is increasing. The reasons for this are unknown.
So what causes CC and why might it be increasing? CC is believed to occur due to a combination of factors, including other illnesses that damage the liver and/or bile ducts over a prolonged period of time. Some chemical toxins have also been linked to CC and there may be a small genetic predisposition, although CC is not a directly inherited disease. In Thailand and other parts of Southeast Asia, CC is relatively common and this is thought to be due to liver flukes which are endemic in that part of the world. However, in the Western world, the majority of cases of CC have no known risk factor. Studying the cause(s) of CC is an important area of on-going research in this field, as only by understanding the underlying mechanisms can effective treatments be developed.
CC is a difficult cancer to treat as the only cure currently available is to surgically remove the whole cancer. It is also difficult to diagnose this disease in the early stages and by the time most patients present with symptoms, the cancer has spread too far for surgery to be effective.
So how does CC present itself and how do we go about diagnosing it? CC, as with several other diseases in and around the liver, typically causes blockage to the flow of bile, leading to the symptoms of jaundice (yellowing of the skin and eyes), pale stools and dark urine. Patients may also complain of malaise, fatigue and weight loss. Severe pain is not a typical feature. As many other diseases can present in a similar way, it can be difficult to confirm the diagnosis of CC. There is no single test that proves a diagnosis of CC. Specialists rely on a combination of the patient’s history, a clinical examination, blood tests for cancer “markers”, imaging scans (ultrasound, CT and MRI), and endoscopy techniques (to get bile and tumour samples from within the bile ducts) to investigate a case of possible CC. An important area of CC research is the development of new techniques to get an accurate and early diagnosis of CC.
Aside from surgery, there are other treatments which, although not curative, can help control symptoms such as jaundice and may delay progression of the cancer and/or its fatal effects. These treatments include placing “stents” into the bile duct to allow bile to flow again, and combinations of chemotherapy drugs. Several new treatments are being researched and developed to tackle CC. These include new cancer drugs; better stents and ways to directly visualise and kill cancer cells inside the bile ducts.
CC is a devastating cancer. It presents late in its course, is difficult to diagnose accurately and early, and in most cases cannot be cured. Furthermore, CC seems to be increasing and we don’t know why. Most of us haven’t even heard of it. This is a disease about which we need to raise awareness, and it’s essential we find out the causes of CC so we can develop better diagnostic tests and more effective treatments for the future.
Dr Shahid A Khan is a Consultant Physician & Senior Lecturer at Imperial College London; &advisor to AMMF, the UK’s only Cholangiocarcinoma Charity
