In theory, cancer can occur in any organ of the human body. Individual cells begin to reproduce in greater numbers than normal, the surrounding tissue cannot control their growth and these cells escape and establish themselves in other tissue or organs. Cancer commonly occurs as a result of congenital or acquired genetic defects. It is still not known in many cases what causes these defects. Untreated cancer will grow out of control and destroy the functions of the organ. It will also invade other organs nearby. Of greatest danger is the fact that cancer cells can be transported to other organs via bloodstream and lymphatic system (i.e. formation of metastases).
The goal of any surgical treatment is the complete removal of the cancer. Doctors use the term 'curative surgery'. If surgery is performed primarily to relieve symptoms (e.g. to reduce pain or to remove blocked passages), the term 'palliative surgery' is used. Cancer cells may remain in the body even if curative surgery is performed, as some cancerous cells may have spread (or "metastasised") to surrounding tissue or other organs undetected. These cells often remain concealed during surgery. If doctors suspect that cancerous cells have escaped detection, chemotherapy or radiotherapy is recommended. This will usually suppress any such cells. This is known as 'adjuvant therapy'.
If a tumour cannot be completely removed, chemotherapy or radiotherapy may also be recommended to slow malignant growth or to reduce the symptoms caused by remnants of the tumour. Serious side effects, such as nausea, vomiting and hair-loss, once quite common, are now much more infrequent. This was achieved by breakthroughs in chemotherapy and radiotherapy.
Clinical research must be conducted to achieve further advancement in cancer treatment. Patients are separated into groups according to form of treatment (i.e. traditional vs. experimental treatment). Thus results can be evaluated as to their success. The best care for the patient will always have the highest priority.
Picture of the main duct of the pancreas with different forms of cancer. (ERCP picture)
This malignant tumour usually develops in the ducts of the pancreas head. Its growth will usually lead to a malfunctioning of the pancreas or to a blocking of the bile flow in the liver. Gradually the tumour will affect the surrounding blood vessels, nerves and lymph nodes. When reaching this phase, cancerous cells will migrate and metastases will be found in other organs. The cancer has reached a generalised state that cannot be removed locally.
Cancerous growth depends on many factors. Some cells are very aggressive and fast growing, some have clearly identifiable characteristics and grow much more slowly. The patient's age, general health and immune system (which can be damaged by smoking and excessive drinking) play an important role. Usually pancreas cancer patients are 60 and over, however in rare cases younger people can be affected.
A tumour in the head of the pancreas can also block the main pancreatic duct, preventing the digestive enzymes which are normally produced in the pancreas from reaching the intestines. This leads to poor digestion, weight loss and diarrhoea. These symptoms can be relieved by taking pancreatic enzyme supplements in tablet form, or by clearing the obstruction in the main pancreatic duct. Often the symptoms of diabetes mellitus appear before pancreatic cancer is diagnosed. Diabetes mellitus can however appear both after the diagnosis of cancer and after a pancreas operation. The most common form of pancreatic cancer arises in the duct cells in the head of the pancreas. Most patients are over the age of 60, but younger people may also develop the disease.
The disease takes a similar course if the cancer does not originate in pancreatic tissue, but in the deep-seated bile duct (which also traverses the pancreas head), or in the papilla (draining channel for pancreatic fluid and bile leading into the duodenum). These cancer forms have one redeeming factor: they can be detected early through icterus (typical eye discoloration indicating the presence of jaundice). Finally we need to mention the cystic forms of pancreatic cancer. They are not easily differentiated from benign tumours or pseudo cysts, which can be observed with chronic pancreatitis patients. Considerable experience before and after surgery is required to determine the appropriate therapy.
In recent years, fundamental research using methods based on molecular biology has lead to a significant extension to our knowledge about the genesis of pancreatic cancer.
Scientists have increasingly observed the presence of growth stimulating factors (growth factors), as well as alterations (mutations) of certain hereditary genes. These would control cell growth and cell death (apoptosis) under normal circumstances. However, when mutation occurs, pancreatic cancer cells tend to grow more rapidly than healthy tissue. These changes are probably responsible for the resistance of the tumour to chemotherapy and radiotherapy. Further research into pancreatic cancer is necessary to pinpoint the exact character of those changes that could serve as basis for the development of new therapies. This research will develop improved methods to combat pancreatic cancer.
Pancreatic cancer unfortunately has no characteristic symptoms in its early stages. Most often, deterioration in general well-being is observed and the patient will suffer from loss of appetite and weight.
Often patients complain about unusual pains in the upper abdomen, these can sometimes spread to the back; and gradually increase in intensity as the disease advances. Tumours located in the pancreas head can disrupt bile flow. This leads to jaundice, which can be accompanied by colourless stool, dark urine and itchy skin. Absence of pain and fever with this type of jaundice must be interpreted as a clear danger signal. Diabetes mellitus developing for the first time is another common sign of pancreatic cancer.
The exact causes of pancreatic cancer remain unknown at this time. The only known risk factor is smoking. Excessive coffee consumption and/or a penchant for fatty meals have not been established as causes of pancreatic cancer. Whether increased alcohol consumption leads to a higher risk for developing the disease is also an open question. It has however been established that genetic predispositions exist, as the disease is more frequent in some families.
Regrettably it is often impossible to detect pancreatic cancer in its early stages at this time. Basic medical procedures for early detection do not exist. However, intensive research is being carried out to improve the chances of early detection, and this will certainly lead to new and improved diagnostic procedures in clinical practice.
Surgery, (removal of the tumour) is the only procedure that can bring about a cure. Surgery can only be carried out if cancer cells have not spread to other organs, such as the liver, the lungs or the surrounding vessels, in which case it is impossible to remove it outright. Experience shows that only 25% of all patients with pancreatic cancer can be treated with surgery. Besides the actual tumour, the adjoining healthy part of the pancreas needs to be removed as well. Other organs or parts thereof will be removed if the position of the tumour makes this necessary.
At an advanced stage of the disease, complete removal of the tumour is often impossible. Therapy will then aim to relieve the patient's symptoms. The flow of bile must be restored if the bile duct is blocked and the patient is suffering from jaundice. This can be done endoscopically by inserting a tube into the bile duct, or by a surgical procedure, known as biliodigestive anastomosis, during which a piece of the intestine is sewn on to the bile duct, to ensure the flow of bile.
If the tumour grows into the duodenum, it will obstruct the passage of food, i.e. food cannot pass easily or not at all from the stomach into the intestine. To bypass this predicament, surgery known as gastroenterostomy, will be performed (this procedure joins the stomach to the small intestine).
The benefits of radiotherapy and/or chemotherapy in the treatment of pancreatic cancer have not been convincing. Efforts are being made to develop new and more effective forms of treatment for pancreatic cancer. A range of new procedures is undergoing clinical tests at present.
Many patients suffer from diabetes mellitus before pancreatic cancer is diagnosed. The condition will usually stabilise after surgery, sometimes however it can improve or deteriorate. In most cases insulin therapy is required.
The removal of a part of the pancreas will lead to a reduced production of digestive enzymes, which in turn will cause weight loss, bloating or diarrhoea. This condition can be treated quite easily with medication containing pancreatic enzymes.
After surgery, patients must be regularly monitored by medical checks, lab tests and medical imaging (ultrasound, CAT, MRT). Problems arising from surgery can thus be corrected and resurging tumours can be detected early. Further therapy can be applied if necessary.
These tests are conducted in consultation with the GP. Often, additional therapy, e.g. chemotherapy, can be carried out as part of clinical studies and organised on a case-by-case basis with patient, surgeon, oncologist (cancer specialist) and family doctor.
In recent years, pancreas surgery has become a very safe procedure. Nevertheless, very few patients survive the first 5 years after the operation, as surgery would have been performed too late. In cases where the tumour cannot be removed, patients seldom survive for more than two years. The amount of research being carried out gives rise to hope that this situation will improve significantly in years to come.
Genetic therapies are of special interest for pancreatic cancer research. Knowledge of the complex factors that cause pancreatic cancer has improved considerably in recent years.
This knowledge, combined with genetic therapies can raise hopes for a new start.
A realistic assessment of the situation shows however that actual therapies have not materialised at this time. Additional studies have lead to a better understanding of changes observed in the molecular-biological structure of pancreatic cancer and have thus established the basis of a new approach to genetic therapies. However, early surgery is still the most promising therapy at this time.
Patients who have had a part or the whole of their pancreas removed may experience a reduction in the functioning of their pancreas, dependent on how much of the organ has been lost. This leads to two problems, above all:
- Too few pancreatic enzymes (leading to digestion problems)
- Too little insulin (leading to high blood-sugar levels)
These deficiencies can be rectified by taking suitable medication.
Pancreatic Enzyme Substitution
Nowadays there are excellent, modern preparations on the market which contain substances that replace the pancreatic enzymes (e.g. Creon, Fig. 7). These preparations must be taken with all meals, including fat- or protein-rich snacks. The required dosage varies from patient to patient and is determined by the nature of the food and the symptoms of the patient. It is essential that the therapy eliminates the patient's bloated feeling and the foul-smelling diarrhoea with the fatty deposits. Typically, 2-3 capsules have to be taken with main meals and 1-2 capsules with snacks. It is important that the pancreatic enzymes reach the food so that they can fulfil their function. For this to happen, from 6-12 capsules need to be taken every day. These numbers may be significantly higher or lower, dependent on how well the remaining part of the pancreas functions.
These enzyme preparations are normally easily digestible and have virtually no side-effects. In very rare cases, they can cause an allergic reaction.
If the pancreatic disorder or operation lead to high blood sugar levels being recorded, the patient will require an appropriate form of blood sugar therapy. To start with, and where the blood sugar levels are not particularly high, the situation can be controlled by following a suitable diet and taking tablets which influence the sugar level. However, where extensive resectioning of the pancreas has been carried out, direct insulin replacement treatment is sometimes required. Various forms of insulin are now available for this treatment. These either come from animals or are manufactured using gene technology. For the most part, these are identical to human insulin and are therefore described as human insulin. All forms of insulin must be injected. The large variety of insulin types allow the therapy to be tailored to the needs of the patient and special attention can be paid to eating habits. The aim of any therapy is to ensure that the patient feels well and the blood sugar levels are kept under control. By doing this, serious damage to the health can be avoided, both in the short and the long term. It is particularly important in the initial phase of treatment that the patient is closely monitored by his family doctor or specialists in the field.
Sometimes the spleen is also removed as part of an operation on the pancreas.
It is quite possible to live without a spleen. The spleen plays a certain role in the human immune system. If it is removed, a person is more susceptible to bacterial infections. To provide protection against infection after removal of the spleen, the patient should be given certain inoculations after the operation. According to current guidelines, these inoculations should be repeated every 3 to 5 years. In addition, the patient should always seek medical help if he contracts a serious infection, and tell the doctor that he or she no longer has a spleen. The doctor can then decide whether treatment with antibiotics is required.
The removal of the spleen can also lead to a build-up of blood platelets (thrombocytes). It is important to have this situation regularly monitored. If the number of platelets is too high, this can lead to the thickening of the blood and a possible thrombosis. If the level is too high, your doctor will prescribe a temporary course of medication to thin the blood, in order to reduce the risk of thrombosis.