Glucagonoma is a malignant tumor in the pancreas that grows from A cells. Functionally active glucagonomas produce hormones and potentially cause a variety of symptoms, while functionally inactive glucagonomas may remain symptom-free. If surgical removal is not possible, chemotherapy may be considered.
What is a glucagonoma?
A glucagonoma is a malignant tumor in the pancreas, which is located in the upper abdomen. Its secretions contain enzymes that help digest carbohydrates, proteins, and fats in the duodenum. It also produces the hormones insulin, glucagon, somatostatin, ghrelin, and pancreatic polypeptide. One of the hormones, glucagon, regulates blood glucose levels and is produced in pancreatic A cells; tumor growth in glucagonomas also originates from these cells. Depending on the behavior of the tumor, medicine distinguishes between functionally active and functionally inactive glucagonomas. The latter can be benign as well as malignant and do not lead to the expression of symptoms in every case. In contrast, functionally active glucagonomas are often malignant and manifest themselves in a variety of symptoms. The disease is extremely rare overall: Only about one percent of pancreatic tumors are glucagonomas, and most of these are functionally inactive.
Causes
Multiple endocrine neoplasia type I can lead to the development of functionally inactive glucagonomas. This underlying condition, also known as Wermer syndrome, is a hereditary disease. A gene on the eleventh chromosome is affected, which usually prevents the development of tumors. Multiple endocrine neoplasia type I can cause not only glucagonomas, but also other pancreatic tumors such as insulinomas and gastrinomas. Neoplasms in the parathyroid glands, pituitary gland, and other organs are also possible. Regardless, glucagonomas can occur without preexisting disease; the exact cause of uncontrolled cell growth in the tumor often cannot be determined in individual cases.
Symptoms, complaints, and signs
Functionally active and functionally inactive glucagonomas are each characterized by different signs. Possible symptoms of functionally active glucagonoma include necrotizing migratory eczema (erythema necrolyticum migrans), anemia, and diabetes mellitus. Sweet-smelling urine, increased urine output, intense thirst, fatigue, subjective lack of energy, pruritus, dermatitis, slowed wound healing, and neurologic symptoms may indicate diabetes. In addition, patients often lose body weight because the body’s cells cannot use sugar despite adequate glucose levels in the blood. Functionally inactive glucagonomas can develop without any noticeable symptoms because they do not produce any additional glucagon and accordingly do not interfere with the metabolism of the human body. However, depending on its location and size, the tumor may indirectly cause discomfort by displacing healthy tissue, partially obstructing the common bile duct (choledochal duct), causing jaundice (icterus), provoking (pressure) pain, or affecting blood vessels, leading to bleeding. Metastases in other organs such as the liver may cause additional symptoms.
Diagnosis and progression
Symptoms that may be present provide initial clues about the glucagonoma. Imaging techniques allow direct viewing of the tumor, which is also necessary for subsequent removal. Ultrasound sonography, computed tomography (CT), or magnetic resonance imaging (MRI) are preferably used. In many cases, the glucagonoma is discovered by chance during such examinations. In the blood, an increased glucagon concentration can be detected, especially in the case of a functionally active glucagonom: The value can be ten to a thousand times above the normal range. In addition, laboratory examination of the blood specifically searches for the tumor marker chromogranin A, the occurrence of which is typical for glucagonomas.
Complications
Because glucagonoma is a malignant tumor, its subsequent course depends largely on the spread and extent of the tumor. In most cases, diabetes occurs as a result of the glucagonoma, which places a heavy burden on the daily life of the affected person. The urine also has a strong sweet smell and the patient suffers from increased thirst.There is a constant feeling of fatigue, which cannot be compensated with the help of sleep. Likewise, itching occurs in different parts of the body and wounds heal only slowly. If the metastases spread to other regions of the body, discomfort may also occur in other places and organs. In the worst case, this can lead to death. The tumor is usually treated either by surgery or chemotherapy. In the process, nausea, vomiting and also hair loss occur. However, it cannot be predicted whether the tumor can be completely cured and whether it will recur. In most cases, the glucagonoma reduces life expectancy.
When should you see a doctor?
If symptoms such as a sweet urine odor, severe thirst, or fatigue are noticed, a physician should be consulted. Glucagonomia must be detected and treated early to allow for a positive healing process. Persons who feel physically or mentally unwell and, for example, are constantly tired or experience unusual itching, should have this clarified immediately. Only a physician can answer whether this is a glucagonom. Patients suffering from multiple endocrine neoplasia type I are particularly susceptible to the development of a glucagonoma. If mentioned symptoms are noticed, often accompanied by signs of diabetes mellitus or anemia, medical advice is needed. If unusual symptoms occur during treatment, it is best to inform the appropriate physician. In case of serious complications, such as bleeding or severe pressure pain, the affected person should be taken to the nearest hospital.
Treatment and therapy
Removal of glucagonoma is the standard treatment. If surgery is not possible or not reasonable, chemotherapy may also be considered. In this case, the patient usually receives strong intravenous drugs that inhibit cell growth. The effect not only affects the tumor, but also all other cells. Treated patients therefore typically suffer from hair loss, since hair cells also divide very frequently and are particularly affected by the chemotherapeutic agent. One possible active ingredient is streptozotocin, to which pancreatic cells react first and foremost. Common side effects of streptozotocin are nausea, diarrhea, vomiting, liver and kidney failure. In addition, the active ingredient itself may have a carcinogenic effect and promote the development of tumors; however, scientists have so far only been able to observe this effect in animals. In particular, untreated, functionally active glucagonomas can have fatal consequences. The tumor produces glucagon, which promotes the release of glucose. Insulin, which the organism also produces in the pancreas, acts like a key on the body’s cells, allowing them to take up the glucose. An excess of glucagon thus has the effect of inhibiting the action of insulin – the result is, on the one hand, an excess of glucose in the blood and, on the other, cells that suffer from a lack of energy and eventually starve to death. This condition corresponds to the metabolic disease diabetes mellitus. The diabetes may need to be treated as well; the same applies to other symptoms. After removal of the tumor and if the prescribed hormone substitutes are taken, the consequences may disappear. Regular follow-up examinations ensure that the tumor does not return or invade other organs because of metastasis.
Outlook and prognosis
The prognosis of glucagonoma is tied to disease progression at diagnosis and initiation of treatment. If left untreated, the malignant tumor of the pancreas leads to premature death of the patient. Alternative cures that lead to freedom from symptoms are currently unknown and spontaneous recovery is not expected in these cases. Glucagonoma requires surgical intervention and, depending on the individual circumstances, the use of chemotherapy. If the cancer cells in the organism have already spread beyond the pancreas and affected other organs, the prospect of cure decreases dramatically. In these patients, the treatment plan is aimed at alleviating the existing symptoms. This is to ensure that the affected person experiences as little impairment as possible and is not subjected to unnecessary pain.If the tumor can be successfully removed in an operation, the prospect of relief from the symptoms increases. With subsequent follow-up treatment and further cancer screening, a cure can be achieved. Nevertheless, cancer therapy is necessary in the further course, which leads to severe restrictions in lifestyle. Overall, the life expectancy of the patient with a glucagonoma is significantly reduced despite all current medical possibilities. Recurrence of the tumor disease is to be expected in many affected individuals, and numerous complications as well as secondary diseases are possible.
Prevention
General preventive measures that can help prevent glucagonoma and other cancers include avoiding radioactive radiation, ultraviolet radiation, chemical carcinogens, and other factors. Personal lifestyle also exerts an influence on individual cancer risk. Smoking, obesity and poor dietary habits are among the most important factors in this area. In addition, doctors and health insurers recommend regular screening for certain types of cancer to detect tumors early.
Follow-up care
The options for follow-up care are usually very limited in the case of a glucagonoma. In this case, the affected person is primarily dependent on medical treatment by a physician to prevent and limit further complications and discomfort. Self-healing does not occur with a glucagonoma. In the worst case, the affected person dies as a result of this disease. The earlier the tumor is detected, the better the further course. For this reason, early diagnosis and treatment is of great importance. The treatment itself is usually carried out by chemotherapy. Those affected depend on the support of friends and family, whereby they need not only physical but also psychological support. Furthermore, a healthy diet and generally a healthy lifestyle can also have a positive effect on the course of this disease. Frequently, those affected are dependent on taking medicines, whereby care must be taken to ensure that they are taken regularly and, above all, correctly. Even after successful treatment, regular examinations of the body are necessary in order to detect further tumors at an early stage. Furthermore, contact with other sufferers of this disease can also have a positive effect on the further course.
What you can do yourself
If a glucagonoma has been diagnosed, medical treatment is required. However, those affected can also do a few things themselves to alleviate the symptoms and promote recovery. The first step is to treat the side effects individually. Measures such as bed rest, warm compresses and a gentle diet help against nausea, diarrhea, vomiting and other side effects of the prescribed medication. Hair loss is usually not permanent. However, if it is found to be bothersome, a hairpiece or a gentle hair restorer is recommended. The latter should, however, be discussed with the responsible physician beforehand in order to exclude interactions with the prescribed medication. In addition, the triggering disease must be treated. If the glucagonoma is caused by diabetes, the diet must be changed. Any excess weight should also be reduced and regular exercise should be taken. This also helps against accompanying symptoms such as fatigue, lack of energy and slower wound healing. Physiotherapeutic measures, such as physiotherapy, Pilates or yoga, help against neurological complaints. Since the appropriate self-help measures vary from case to case, regular consultation with the physician is recommended. The medical professional can give further tips with which recovery can be promoted independently.
