Cancer of the esophagus
Esophagus Cancer, Esophageal Cancer, Oesophageal cancer
What is the esophagus?
The esophagus is what many people refer to as the 'gullet' and is the tube connecting the mouth to the stomach, down which food and drink travel when they are swallowed. It has its own nerves and muscles so when something is swallowed, a ripple-like action moves along the esophagus pushing the food or liquid towards and into the stomach. For this reason, and the fact that there is a one-way valve mechanism at the entry to the stomach, even if someone is upside down when they swallow, the food will still move into the stomach without coming out again.
One important fact is that, although the lining of the stomach is designed to be able to cope with the acid conditions required for digestion, the lining of the esophagus does not have such protection and can be damaged by contact with the stomach acids. This may be significant in the development of some cases of cancer of the esophagus as will be explained more fully below.
How common is cancer of the esophagus?
For reasons that are not currently understood, the number of cases of oesophageal cancer is on the increase. It is thought that this increase may be connected to lifestyle factors such as the increase in obesity and reduction in fibre in the normal diet.
Who gets cancer of the esophagus?
Although almost anyone can get esophageal cancer, there are certain groups who are at higher risk than the average population. Firstly, it is mainly a disease of older age with two thirds of cases occurring in people over 65 years of age. Men are twice as likely to develop cancer of the esophagus as women and the disease is more common in people who are obese, smoke and have little raw fruit or vegetables in their diet.
Smoking and the consumption of alcohol seem to each be related quite strongly to the development of this cancer and it seems that if someone does both, their risk is even higher than simply adding the risk of each of these together..
Another group of people who are at higher than average chance of developing esophageal cancer are those with something called gastro-esophageal reflux diseases (called GORD by doctors). This is where the valve-like mechanism, mentioned above, between the esophagus and the stomach fails to work so acid from the stomach is allowed to regurgitate into the esophagus. The lining of the esophagus, unlike the lining of the stomach, is not designed to be able to stand the very acidic nature of the stomach contents and is therefore damaged by this fluid.
Most adults get the occasional bout of acid reflux which we tend to call indigestion or dyspepsia, but if this becomes a regular problem, the damage to the lining of the esophagus can lead to an increased likelihood of cancer. The risk increases with the length of time that the reflux has occurred.
Often the tissues lining the lower end of the esophagus (near where it joins the stomach) will change from the normal esophageal tissue to tissue which is more like that which lines the stomach. In some ways this is the body's attempt to protect the esophagus from the burning acids of the stomach as they wash up into it and is called 'Barrett's esophagus'. However, this alteration can unfortunately eventually change again into cancerous cells with the result that people with Barrett's esophagus run a higher than average risk of eventually developing cancer of the esophagus. The longer the length of esophagus that is affected by this tissue change, the higher the risk of cancer.
Finally, about one to five per cent of esophageal cancer cases are due to an inherited tendency to the condition, but in general cancer of the esophagus does not run in families.
How is cancer of the esophagus diagnosed?
Anyone can get cancer. In most cases there is no particular reason why a particular person develops it.
It is estimated that more than one in three of us will develop cancer at some stage. Although this sounds very frightening it must be remembered that cancer is more common in the elderly, ie we unfortunately must all die of something and heart disease and cancer are the two most common causes in developed countries. Also, not all cancers are fatal since advances in treatment mean many types of cancer can be controlled or even cured.
Obviously there are some people who are more likely to develop cancer. As mentioned, cancer is more likely to occur the older you get probably because the DNA inside the cells becomes corrupted and increasingly likely to send out the 'wrong signals' which then lead to uncontrolled cell multiplication. Exposure to certain substances also makes an individual more liable to develop certain types of cancer. Hence a cigarette smoker is at greater risk of not only lung cancer but also a large number of other cancers including cancer of the throat, stomach and tongue. People who have been exposed to asbestos are at greater risk of a type of malignancy of the lining of the lung called 'mesothelioma'. It is now well known that high doses of radiation can increase the chances of blood disorders such as leukaemia (cancer of the blood) and over exposure of the skin to the sun is a factor in the development of skin cancer.
How is cancer diagnosed?
One of the problems of esophageal cancer is that it can be hard to diagnose in the early stages as it may not give any symptoms and, even when it does, the symptoms can be mistaken for indigestion or dyspepsia. The symptoms it can give include:
- Persistent difficulty in swallowing ie food 'getting stuck' on the way down. Doctors call this symptom 'dysphagia'.
- Persistent indigestion particularly in people over the age of 55, especially if they haven't tended to suffer before from indigestion.
- Loss of appetite.
- Weight loss.
On examination of the patient the physician may feel a mass (lump) in the upper abdomen, but this is unusual.
If the physician suspects that cancer of the esophagus may be a possibility or at least wants to rule it out as a cause of the patient's symptoms, they will arrange for the individual to have a test called an endoscopy. This involves the passing of a flexible telescope called an endoscope down the patient's esophagus and into the stomach and allows the specialist to 'see inside' these organs with the aid of fibre-optic technology. Biopsies (small samples of tissue) can be taken through the endoscope and examined under the microscope to look for abnormal tissue.
Will any other tests be done?
Once the diagnosis of cancer of the esophagus has been made, further tests may be done in order to 'stage' the cancer. Staging means trying to determine the exact make up of the cancer and how far advanced it is and allows the doctors to plan treatment and give some idea of the outlook for the patient.
These further tests may include CT (computerised tomography) or MRI (magnetic resonance imaging) scanning, a chest x-ray, a bronchoscopy and/or sometimes a laparoscopy. CT and MRI scans both provide very clear images of the inside of the body to look for any spread of the cancer. A bronchoscopy involves passing a special telescope into the lungs to see if the cancer has spread into the upper breathing tubes, and a laparoscopy examines the inside of the abdomen with a fibre-optic tube passed through the abdominal wall.
Blood tests may also be done to check if the patient is anaemic and to see if there is any sign of spread of the cancer to the liver.
What is the treatment for cancer of the esophagus?
The treatment depends on the type of cancer cells involved in the cancer and the how far the cancer has spread at the time of diagnosis. It also depends on the age of the patient and whether or not they have other health problems since not everyone will be fit enough for major surgery. Some of the treatment options are set out below.
Surgery: In suitable patients, surgery to remove the cancer may be recommended. It has the advantage that it generally leads to a better long-term outlook for the patient. However, this may be because it is only suitable for the treatment of about 20 per cent of people with cancer of the esophagus and tends to be those whose cancer was detected early and who are otherwise well.
Removal of the cancer usually involves removing most of the esophagus which is then replaced either by joining the stomach to what is left of the esophagus or by replacing the esophagus with a piece of bowel or an artificial tube. This is a major operation, which carries risks of complications that will be explained to the patient beforehand.
Chemotherapy: Chemotherapy (the use of powerful cancer-killing drugs) is sometimes used on its own to treat esophageal cancer where surgery is not suitable or sometimes in addition to surgery to try to prevent the cancer from coming back once it has been removed. Chemotherapy can improve the quality of life of the individual by shrinking the tumour and relieving some of the symptoms, but it can also lead to side effects such as nausea and hair loss.
Radiotherapy: As with chemotherapy, radiotherapy (the use of carefully measured doses of radiation directed at the cancer site) can be used in addition to surgery to prevent the cancer returning; or on its own in patients not suitable for surgery. It can be very helpful in shrinking the tumour, which will relieve the swallowing difficulty, that is one of the most distressing symptoms of the condition.
esophageal dilation: Another method of relieving swallowing difficulty due to esophageal cancer is to dilate (stretch open) the hole in the middle of the cancer with a special dilator instrument passed down the esophagus. Unfortunately the swallowing problems tend to return as the cancer continues to grow. Dilation is not without its potential problems, for example perforation of the esophagus that can be potentially serious.
Attempts are sometimes made to keep the passage through the esophagus open by dilating the esophagus and then inserting a metal or plastic tube called a 'stent' into the channel. Although not a permanent solution, this can relieve the problems with swallowing for some time.
Laser therapy: Lasers are sometimes used to 'burn' a hole through the tumour to re-establish the ability to swallow.
Palliative treatment: There may come a point where further treatment with the aim of curing the cancer may not be possible and attempts to keep the cancer at bay are failing. However, a host of different treatments now exist with the aim of treating the symptoms of the cancer and improving the quality of life of the individual. This sort of treatment is called palliative therapy and is now a specialist area in itself with doctors and nurses who have particular training in palliative care.
Last updated 18 June 2011