Carcinoid Tumor

21.03.2024

CARCINOID TUMOR DIAGNOSIS AND TREATMENT

Carcinoid tumors are a rare type of tumor that can occur in different parts of the body. These tumors occur especially in organs such as the intestines, stomach, lungs and pancreas. Carcinoid tumors arise from endocrine cells and usually grow slowly. These tumors can produce hormones and biochemical compounds, which can lead to a variety of symptoms. A condition called carcinoid syndrome may include these symptoms and present with symptoms such as flushing, diarrhea, and fatigue. Treatment of carcinoid tumors may include a variety of methods, such as surgery, radiation therapy, chemotherapy, or targeted drugs, depending on the type, size, stage of the tumor, and the patient's overall health. It may be possible to control carcinoid tumors with early diagnosis and appropriate treatment.

WHAT ARE THE RISK FACTORS?

Although the exact causes of carcinoid tumors are not fully known, some risk factors have been identified. However, these risk factors do not definitively explain the formation of carcinoid tumors, and many people may not develop this type of tumor even if they have these factors. Potential risk factors for carcinoid tumors may include:

Age: Carcinoid tumors usually occur in middle age and later, so the risk may increase with age.

Gender: Some types of carcinoid tumors may occur more frequently in a certain gender. For example, carcinoid tumors arising from the ECL cells of the stomach are generally more common in men, while intestinal carcinoids are slightly more common among women.

Family History: Family history may increase the risk of carcinoid tumors. Genetic diseases, especially multiple endocrine neoplasia (MEN) syndromes, may increase the risk of developing carcinoid tumors.

Chronic Stomach Problems: Stomach problems, such as chronic gastroenteritis or high acidity, may increase the risk of carcinoid tumors that arise from the ECL cells of the stomach.

Nicotine and Alcohol Use: Some studies show that smoking and excessive alcohol consumption may specifically increase the risk of lung carcinoid tumors.

Chronic Infections: Chronic infections, such as Helicobacter pylori, may increase the risk of carcinoid tumors arising from the ECL cells of the stomach.

Risk factors for carcinoid tumors may vary from person to person and may not be an underlying risk factor for all carcinoid tumors. However, taking these risk factors into account is important to support early diagnosis and treatment of the disease.

Image 1: Carcinoid tumors can occur in different organs in the body, such as the lung, pancreas, and small intestine.

WHAT ARE THE SYMPTOMS?

Symptoms and signs of carcinoid tumors may vary depending on factors such as tumor type, size, location, and hormone production. Some carcinoid tumors may be silent and asymptomatic, while others may cause symptoms.

Possible findings of carcinoid tumors:

Hot Flashes: A condition called carcinoid syndrome may include symptoms such as hot flashes. This symptom is characterized by sudden and severe flushing of the face, sweating, and rapid heartbeat.

Diarrhea: Carcinoid tumors can sometimes cause diarrhea. Diarrhea is usually chronic and recurrent.

Stomach ache: Abdominal pain may occur as a result of the growth or spread of carcinoid tumors.

Shortness of breath: Carcinoid tumors in the lungs can cause shortness of breath.

Bronchial Obstruction: Carcinoid tumors in the lungs can block the airways, causing cough and breathing problems.

Weight Loss: Symptoms of carcinoid syndrome may also include weight loss and loss of appetite.

Tiredness: Hormonal changes caused by carcinoid tumors can lead to fatigue and weakness.

Rare Cases: Carcinoid tumors can cause rare symptoms throughout the body, which may include changes in skin color, irregular heartbeats, or muscle weakness.

Symptoms of carcinoid tumors are often related to hormone production, so symptoms may vary depending on the type and amount of hormones. If a carcinoid tumor is suspected, it is important to be evaluated and diagnosed by an oncologist.

HOW IS IT DIAGNOSED?

Carcinoid tumors are diagnosed using a series of clinical, laboratory and imaging tests. Diagnostic stages may include: First, the patient's symptoms and medical history are evaluated. Hormone levels are then examined with blood tests, because carcinoid tumors can cause hormonal changes. An important step in diagnosis is radiological imaging tests. Imaging methods such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) help determine the location and spread of the tumor. For definitive diagnosis, tissue biopsy can be performed. This allows tumor cells to be examined under a microscope and determines the type and characteristics of the carcinoid tumor. The diagnostic process may require the involvement of many different specialists and is customized based on the patient's symptoms, test results, and medical history.

WHAT ARE THE PATHOLOGICAL TYPES?

Carcinoid tumors can be divided into different pathological types according to their histopathological features and the tissue from which they originate. Pathological types of carcinoid tumors can be:

Typical Carcinoids: These types of tumors usually have low-grade malignancy and grow slowly. They consist of well-differentiated cells and often show low mitotic activity.

Atypical Carcinoid: Atypical carcinoid tumors are tumors that have a more aggressive course and a high degree of malignancy. The cells are more abnormal and may show more mitotic activity.

Gastroenteropancreatic Carcinoid: Such tumors arise in the gastrointestinal tract (intestines, stomach, pancreas) and arise from the endocrine cells of these organs. They may produce hormones and show typical or atypical features.

Lung Carcinoid: Lung carcinoid tumors occur in the lungs and can be typical or atypical. Although lung carcinoids are generally less malignant, they can sometimes be invasive.

The pathological type of each carcinoid tumor is important in determining the tumor's behavior, aggressiveness and treatment approach. By studying biopsy or surgical samples, pathologists determine the pathological type of the tumor, and this information affects the treatment plan and the patient's prognosis. Important receptors in carcinoid tumors include somatostatin receptors (SSTRs), serotonin receptors, epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptors (VEGFRs), gastroenteropancreatic receptors (GPRs), insulin-like growth factor-1 receptor (IGF-1R) and In some cases, progesterone and estrogen receptors come to the fore. Some of these receptors may play an important role in the diagnosis, treatment and follow-up of carcinoid tumors. For example, somatostatin receptors can be targeted to slow tumor growth, while VEGFRs can guide treatment by influencing tumor blood vessel formation. The presence and activity of these receptors, depending on the characteristics of the tumor, can determine the course of the disease and treatment responses, therefore it is critical to examine these receptors in patients diagnosed with carcinoid tumors.

Image 2: In carcinoid tumors, complaints such as facial flushing, diarrhea and weight loss may be observed.

HOW IS TUMOR STAGING DONE?

Staging of carcinoid tumors helps determine the severity of the cancer by evaluating the tumor's size, spread, and other factors. Staging of carcinoid tumors is based on the following factors:

Tumor Size: The size of the tumor is an important factor in tumor staging. Generally, tumor size is classified as less than one centimeter (T1), between one centimeter and two centimeters (T2), between two centimeters and five centimeters (T3), or over five centimeters (T4).

Lymph Node Spread: It is examined whether the carcinoid tumor has spread to the surrounding lymph nodes. It is reported under category N (nodal invasion).

Distant Metastasis: It is evaluated whether the carcinoid tumor has metastasized to other parts of the body. In this case, the M (distant metastasis) category is used.

Differentiation of the Tumor: The degree of cellular differentiation of the tumor (typical or atypical) is determined.

These factors are used to determine the stage of the cancer, and staging is usually based on the TNM classification system. According to this system, the stage of cancer is determined by combining T (tumor size), N (lymph nodes) and M (distant metastasis) factors. Staging evaluates the extent and severity of the disease and helps determine the appropriate treatment plan. Staging results play an important role when creating a specific treatment plan for each patient.

HOW IS TREATMENT DONE ACCORDING TO STAGES?

Treatment of carcinoid tumors may vary depending on the stage and type of tumor and the patient's general health condition. Here are the treatment approaches according to different stages of carcinoid tumors:

Stage 1 and 2 Carcinoid Tumors: In these stages, the tumor is usually localized, meaning it has not spread to a limited area. Treatment usually involves surgical removal of the tumor. After surgical intervention, your doctor may recommend hormone therapy or follow-up, depending on the type and stage of the tumor.

Stage 3 Carcinoid Tumors: At this stage, the tumor has spread to surrounding tissues or lymph nodes. Treatment may include surgically removing the tumor, although this may be a more complex surgery. After surgery, additional treatment such as radiotherapy may be needed.

Stage 4 Carcinoid Tumors: In this most advanced stage, the tumor has metastasized to distant organs. Treatment may include surgical removal of distant metastases, radiotherapy, chemotherapy, or targeted therapies. Treatment options may vary depending on the metastasized organs and the patient's general health condition.

The treatment plan is determined according to the patient's medical condition, tumor characteristics and stage. A special treatment plan is created for each patient and the treatment process is guided by a multidisciplinary healthcare team. The patient's symptoms, quality of life and expectations are also taken into account when determining the treatment plan.

Image 3: Nuclear medicine applications can be used in the diagnosis and treatment process of carcinoid tumors.

WHAT ARE THE SYSTEMIC DRUGS USED IN TREATMENT?

Methods used in the treatment of carcinoid tumors may vary depending on the type and stage of the tumor and the specific condition of the patient. Some medications and treatment options used in the treatment of carcinoid tumors:

Chemotherapy drugs: Streptozocin is a drug used in the chemotherapy of carcinoid tumors.

Somatostatin Analogs: Somatostatin analogs such as octreotide and lanreotide are used in the control of carcinoid tumors. These medications may help relieve symptoms and slow tumor growth by reducing hormone production.

Smart Drug Therapies:

Everolimus: Everolimus is a targeted therapy drug used in the treatment of carcinoid tumors. It can control the growth and proliferation of tumor cells.

Sunitinib: Sunitinib is a targeted therapy drug used in the treatment of intestinal carcinoid tumors. It tries to prevent tumor growth.

Immunotherapies: Immune checkpoint inhibitors such as pembrolizumab and nivolumab have been an area of ​​research in the treatment of carcinoid tumors. These drugs work by encouraging the immune system to target cancer cells.

Carcinoid tumor treatment is individualized depending on the patient's unique situation and the characteristics of the tumor. The treatment plan is determined by an oncologist or a multidisciplinary oncology team, and the patient's response is monitored regularly. Medications and treatment methods may vary depending on the type of tumor, its stage, and the patient's general health condition.

HOW SHOULD FOLLOW-UP BE DONE AFTER RECOVERY?

After treatment of carcinoid tumors is completed, patients need regular follow-up and monitoring. Collaboration with an oncologist or specialist physician should be made for follow-up purposes. The follow-up period is determined by the type of tumor, its stage, treatment response and the general health status of the patient. Typically, follow-up may include: regular physical exams, blood tests (for example, chromogranin A levels), imaging scans (CT, MRI, or PET scans), and monitoring of symptoms. If the tumor re-grows or metastasizes during follow-up, rapid intervention is possible and alternative treatment options can be evaluated. Additionally, supportive treatment options should be considered to optimize patients' symptoms and quality of life. Monitoring carcinoid tumors may help improve patients' long-term health and quality of life.