About 1,700 new cases of lung carcinoid tumors are diagnosed each year, so it is a fairly rare disease.
Many types of lung tumors can be prevented while many others can be treated successfully if detected early. Chemotherapy and radiation therapy have extended patients’ lives and increased survival rates.
Nearly 95% of patients with early stage typical lung carcinoids and 70% for atypical lung carcinoids lived five years after diagnosis. However, if the tumor is larger than 3cm, spread, or is atypical, the prognosis significantly worsens.
There are four main types of lung neuroendocrine tumors:
SMALL AND LARGE CELL LUNG TUMORS
Small-cell lung cancer (SCLC), also known as oat cell cancer, is common with smokers. This tumor is an aggressive tumor that tends to spread to other locations throughout the body.
Large cell neuroendocrine carcinoma is a very rare lung cancer. It characterized by the presence of anomalous, large cells that arise in the lungs’ outer edges.
CARCINOID LUNG TUMORS
Typical carcinoid lung tumors grow slowly and rarely spread beyond the tissues of the lungs.
Atypical carcinoid lung tumors advance more quickly than typical tumors. They are also more likely to spread beyond the lungs.
Carcinoids are also classified by where they form in the lungs:
Central: Near the center of the lung
Peripheral: Toward the edges of the lung
Most central carcinoids are typical; most peripheral carcinoids are atypical. Lung tumors represent just over one-quarter of all diagnosed cancers. It is the most common cause of cancer death in the U.S. in both men and women.
The following factors may influence lung tumor development:
- Ethnicity: Lung tumors are twice as likely to occur in whites than in blacks, Asians, and Hispanics.
- Gender: For unknown reasons, lung tumors occur in women more than in men.
- Tobacco Use: Typical lung carcinoids are usually not associated with smoking or chemicals, but atypical carcinoids have been. But, smokers over 60 years old are very susceptible to lung tumors.
- Chemical Exposure: Workplace exposure to second-hand smoke, asbestos, radioactive radon gas, diesel gas, and some industrial toxins like silica and beryllium may lead to lung tumor development.
- Certain Lung Disorders: Patients with recurring lung inflammations are also prone to lung tumors.
- Family History: Patients with family a history of lung carcinoid tumors are more likely to develop lung tumors themselves.
Stop Smoking. Early detection is the key to survival, as tumors can be treated in early stages.
Common Signs and Symptoms
Early stages of peripheral carcinoid tumors or small central carcinoid tumors rarely exhibit symptoms, leaving the patient at higher risk for the tumor to spread to other parts. However, these early stages are often detected in other routine medical tests.
Symptoms commonly associated with lung tumors include:
- Bloody Saliva / Sputum
- Wheezing or Asthma-Like Symptoms
- Erratic Heartbeat
- Weight Gain
- Secondary Diabetes
- Increased Body Hair
- Other Signs and Symptoms
- Post-Obstructive Pneumonia
- Associated Disorders
- Pneumothorax (collapsed lung)
Diagnosing Lung Tumors
Only 15% of lung tumors are diagnosed early enough to be removed. The following tests are used to diagnose lung tumors:
- Urinalysis: Detects carcinoid chemicals in urine.
- Chest X-rays: Preliminary tool to detect tumors.
- Spiral Computed Tomography (CT) Scan: To show in 3-D the location, size, and shape of the tumor. Often good for detecting smaller tumors.
- CT-Guided Needle Biopsy: Only certain method for identifying tumor.
- MRI: To detect if tumor has spread.
- Positron Emission Tomography (PET): Determines if mass is cancerous and progression.
- Somatostatin Receptor Scintography: uses radioactive hormone injection to locate carcinoid tumors and detect spreading.
- Meta-Iodobenzylguanidine (MIBG): Similar to Somatostatin Receptor Scintography.
Staging Lung Tumors
The system used for non-small cell lung cancer is used for all carcinoid tumors. This system is called the “TNM” staging system. The “T” represents the primary tumor’s size and spread. It has four substages: T1-T4. The “N” represents the spread to the lymph nodes. It has four stages: N0-N3. The “M” represents the spread to other organs. It has two stages: M0-M1.
STAGES OF LUNG TUMORS
Stage 0: Tumor only in layer of cells in air passage. No spread.
Stage IA: Cancer is less than 3 cm and no spread.
Stage IB: Cancer is greater than 3 cm or involves a main bronchus or has spread or has clogged airways, but has not spread to lymph nodes.
Stage IIA: Cancer is less than 3 cm, has not spread to surrounding membranes, and does not affect bronchi. Has spread to lymph nodes.
Stage IIB: Cancer is greater than 3 cm or involves bronchus or has spread to chest wall or diaphragm or has clogged airways, but has not spread to lymph nodes.
Stage IIIA: Any size cancer, involves bronchus and middle chest or has spread to chest wall or diaphragm or is closing airways or caused lung collapse or pneumonia. Has spread to lymph nodes on same side as tumor.
Stage IIIB: Any size cancer, involves bronchus and middle chest and lymph nodes on either side or has spread to chest wall or diaphragm or heart and is closing airways or caused lung collapse or pneumonia. May have two or more separate tumors in same lobe.
Stage IV: Spread to distant sites has occurred.
Nearly one-third of lung tumor patients can sustain resection surgery. However, older patients may not be strong enough for surgery.
COMMON TREATMENT OPTIONS
- Lobectomy: Removal of lobe of lung. Option for otherwise healthy patients.
- Segmental Resection / Wedge Resection: Removal of tumor and surrounding healthy tissue. Less lung function is affected. Only an option for early stage patients with tumor on edge of lung. Common for NSCLC patients, followed with chemotherapy to prevent spread to lymph nodes.
- Pneumonectomy: Removal of entire lung. Recurrent tumors are common.
OTHER TREATMENT OPTIONS
- Radiation Therapy: Uses external x-ray beams to kill or shrink tumor or to minimize spread to other areas. Can also relieve symptoms.
- Stereotactic Body Radio Therapy (SBRT): Multiple radiation beams focused on lung tumor. Used when surgery is not possible.
- Conformal Radiation Therapy: New technique using 3-D technology and CT scans to focuses and adjusts radiation beams on shape and size of the tumor.
- Brachytherapy: Radioactive seeds are put into the tumor to relieve symptoms but not cure disease.
- Chemotherapy: Uses intravenous drugs to kill tumor cells, to slow growth, and to minimize symptoms. Used at all stages of lung tumors.
- Immunotherapy: Uses drugs to bolster the patientsí immune system.
- Gene Therapy: Kills or slows cancerous growth.
- Angiogenesis Inhibitors: Prevents blood vessels from forming for tumors, shutting down blood supply to the tumor.