What Is the Survival Rate for Lung Neuroendocrine Cancer?

Lung neuroendocrine tumors are a rare and aggressive type of pulmonary neoplasms that accounts for less than two percent of all lung tumors. These tumors can spread to other areas such as the liver and bones. Neuroendocrine tumors are mostly seen in the digestive system; the lungs are the second most commonly affected organ.

The neuroendocrine tumors of the lungs are classified into four variants, which are as follows:

1. Typical carcinoid
2. Atypical carcinoid
3. Large cell neuroendocrine carcinoma
4. Small-cell lung carcinoma

Typical carcinoid tumors

These are slow-growing tumors that usually appear in the center of the lungs or the windpipe. They rarely spread beyond the lymph nodes and do not respond well to radiotherapy or chemotherapy. Approximately 9 out of every 10 lung carcinoids are typical carcinoids.

Atypical carcinoid tumors

These are much rarer than typical carcinoid tumors but grow faster than typical carcinoids, which makes them spread more quickly beyond the lungs. They may show signs of cell death and fast division of cells. About 50 percent of atypical carcinoids spread to nearby lymph nodes and into bones and the liver. Atypical carcinoids are highly treatable than other types of lung cancers.

Based on their location, lung carcinoids are divided into the following two types:

1. Central carcinoids (located in the walls of the large airways of the lungs)
2. Peripheral carcinoids (found closer to the edges of smaller airways)

Carcinoid tumors of the lungs are a rare form of cancer that accounts for only one to two percent of all cases of lung cancer. In the United States, about 2,000 to 4,500 new carcinoid tumor cases are diagnosed yearly. Carcinoid tumors develop mostly in young people.

The exact cause of lung carcinoid tumors is unknown. Air pollutants, smoking, or exposure to chemicals do not seem to be the cause of carcinoids of the lung, but they increase the risk of tumors.

The following are the risk factors for carcinoid tumors of the lung:

• Female gender (women are at a higher risk than men)
• Fair complexion
• Having a rare inherited disorder called multiple endocrine neoplasia type I

About 25 percent or more people with lung carcinoids do not show any symptoms. These tumors are seen when diagnostic tests are done for some other illnesses, such as a chest X-ray for a lung infection.

If the symptoms are predominant, the affected person may experience severe cough and wheezing, and the cough may produce blood in the phlegm or sputum. When the tumor size is large, they block air passage and may develop an infection called post-obstructive pneumonia.

Other symptoms of carcinoid tumors include:

• Facial warmth and redness
• Asthma-like symptoms, such as wheezing and shortness of breath
• Increased blood pressure
• Weakness
• Weight gain
• An increased amount of body and facial hair

Lung neuroendocrine tumors can be classified into the following five stages:

1. Stage 0: Also called carcinoma in situ, which means the tumor is in place and has not spread to nearby tissues or organs.
2. Stage I: Indicates that the tumor has not spread to lymph nodes.
   • Stage I tumors can be divided into:
     • Stage IA: The tumor is 3 cm or lesser in size. Stage 1A is further divided into stages IA1, IA2, and IA3 based on the tumor size.
     • Stage IB: The tumor is more than 3 cm in size but not more than 4 cm.
3. Stage II: Is divided into stages IIA and IIB.
   • Stage IIA: The tumor is larger than 4 cm but lesser than 5 cm in size and does not spread to nearby lymph nodes.
   • Stage IIB: A tumor of 5 cm or less that has spread to the lymph nodes. Stage IIB can also refer to a tumor that is larger than 5 cm in diameter but has not spread to the lymph nodes.
4. Stage III: Stage III is further classified as IIIA, IIIB, and III C. This staging is based on the size of the tumor and the spread of cancer to the lymph nodes. Stage III tumors do not spread to distant parts of the body. They are the most difficult ones, and sometimes it is impossible to remove them surgically. When these tumors spread to nearby lymph nodes or when the tumor has grown into nearby structures, surgical removal of the tumor becomes extremely difficult.
5. Stage IV: These tumors have spread to more than one area in the opposite lung, the fluid surrounding the lung or heart, and/or distant body parts via the bloodstream. Cancer cells can spread throughout the body once they enter the bloodstream. The tumor has a higher risk of spreading to the brain, bones, liver, and adrenal glands.
   • Stage IV is divided into the following two substages:
     • Stage IVA cancer has spread within the chest, opposite lung, or the lining of the heart or lung, and/or has spread to only one area outside the chest.
     • Stage IVB has spread outside the chest, with more than one metastasis outside the lung, in one or more organs.

The following are the ways to diagnose lung neuroendocrine cancer:

• CT scan takes pictures of internal organs using X-rays from different angles.
• Chest X-rays help locate carcinoid tumors.
• MRI uses magnetic and radio waves to take pictures of the lungs.
• A biopsy involves the removal of a small tissue sample from the tumor using a needle. It is then checked under a microscope for signs of malignancy and the type of tumor.
• Blood and urine tests are done to detect abnormal hormonal changes.

The following are the ways to treat lung neuroendocrine cancer:

• Surgery: Involves the surgical removal of the tumor and the involved tissues and lymph nodes.
• Radiation therapy: Uses powerful rays to kill cancer cells. Usually, radiation therapy is done after the surgical removal of cancer cells.
• Chemotherapy: A cancer treatment that uses powerful medications to kill fast-growing cancer cells and stops them from growing. Chemotherapy drugs can be given orally or intravenously. Both radiation therapy and chemotherapy are done when the cancer cells grow very aggressively.
• Palliative Care: A specialized medical care in which doctors, nurses, and other specialists can support symptom relief. They can offer additional assistance to supplement the care individuals receive from regular providers. Palliative care helps improve the quality of life and can be combined with other treatments.

The prognosis of lung neuroendocrine cancer is good, with a five-year survival rate. Maintaining regular follow-ups with your healthcare team is important as these tumors may recur.