Bronchial carcinoids are rare (1% to 2% of all lung cancers in adults), slow-growing neuroendocrine tumors that arise in the bronchial mucosa and usually involve patients in their 40s to 60s.
Types of bronchial cancer
There are a diverse number of tumors originating in the mucous glands and ducts of the bronchi. These are tumors with widely varying malignant (cancerous) potential, although most are low-grade malignancies, growing and spreading much more slowly than conventional lung cancer. The main ones are:
- Neuroendocrine (carcinoid) tumors – affect hormone-producing cells and nerve cells. They can form in the lungs or in other organs such as the stomach, intestines, pancreas, and lung;
- Cystic adenoid carcinomas (cylindromas) – usually start in the salivary glands in the mouth and throat. They can also affect the trachea, the lacrimal glands, the sweat glands, or a woman’s uterus, vulva, or breasts;
- Mucoepidermoid carcinomas – rare neoplasms that contain a variable proportion of squamous and mucus-secreting cells in addition to intermediate cells.
Mucous gland adenomas are the only truly benign (non-cancerous) bronchial tumors, with no potential to become malignant.
Symptoms and Signs of Bronchial Cancer
Half of the patients with bronchial cancer are asymptomatic and half develop symptoms of airway obstruction, including dyspnea and cough, which often leads to the misdiagnosis of asthma. Repeat pneumonia, hemoptysis, and chest pain are also common.
Symptoms of carcinoid tumor include:
- Coughing, sometimes with blood;
- Shortness of breath;
- Chest pain;
- Flushing of the face;
- Infections such as pneumonia.
Symptoms of adenoid cystic carcinoma include:
- A protuberance on the roof of the mouth, under the tongue, or at the bottom of the mouth;
- Difficulty swallowing;
- Hoarse voice;
- Numbness in the jaw, the roof of the mouth, face, or tongue.
Symptoms of mucoepidermoid carcinoma include:
- Swelling in the glands near the ears, under the jaw, or in the mouth;
- Numbness or weakness of the face; and
- Pain in the face.
Diagnosis of bronchial cancer
To diagnose the neoplasm, the doctor may order one or more tests. The most common are
- MRI/tomography – the main imaging tests used to diagnose bronchial cancer. They are methods that make images of organs and structures of the body, locating and measuring the tumor. If necessary, contrast – a liquid that can be drunk or injected into the vein – can be used to perform the MRI;
- Biopsy – a small piece of tissue is removed and analyzed by a specialist. The sample can be obtained using a bronchoscope (tube down the throat). Alternatively, the doctor may insert a needle through the chest wall to get the sample. A pathologist will examine the tissue taken under a microscope to determine if cancer cells are present.
Treatment
The treatment to be chosen depends on factors such as the type of cancer, stage of disease development, age, and the person’s overall health. Learn about the most common approaches:
Surgery – This is the main treatment for bronchial adenomas. The surgeon removes the cancer and some of the surrounding tissue. The lymph nodes around the tumor may also be removed, to prevent the disease from spreading.
Radiation – This treatment uses high-energy X-rays to kill cancer cells. It can be done before surgery, to reduce the size of the tumor, or after, to eliminate any cancer cells left behind.
Radiation can cause side effects such as:
- Fatigue;
- Redness of the skin in the area where treatment was done;
- Sore throat and mouth;
- Difficulty swallowing
- Coughing;
- Shortness of breath.
These side effects can persist for up to three months after the radiotherapy treatment is completed.
Chemotherapy – A systemic treatment that can destroy cancer cells throughout the body. Some chemotherapy drugs are given intravenously and others can be taken orally. Chemotherapy is sometimes used to reduce tumors before surgery or to destroy any remaining cancer cells after surgery.
Possible side effects of chemotherapy include:
- Fatigue;
- Nausea and vomiting;
- Hair loss
- Loss of appetite
- Diarrhea
- Increased risk of infection.
Immunotherapy – Often the body cannot fight the tumor because the cancer cells produce proteins that help the cancer to camouflage itself, to hide from the immune system. Immunotherapy drugs prevent this disguise and thus help the body’s own defense system fight the cancer.
Targeted therapy – Treatment that acts on proteins or genes that are unique to that cancer and help it grow. Targeted therapy then inhibits these growth factors preventing the cancer from spreading.
Prevention
The cause of bronchial adenoma is unknown, meaning that there is no clear guidance on how to prevent the neoplasm. Genes may play a role in some forms of this cancer.
People with an inherited disease called multiple endocrine neoplasia type 1 (MES) are more likely to develop carcinoid tumors. Radiation to the head and neck may increase the risk of mucoepidermoid carcinoma.
