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We Know: The Facts About Lung Cancer
What is lung cancer?
Lung cancer is the deadliest form of cancer worldwide. According to the
American Cancer Society, six out of ten people will die within one year of diagnosis, and seven
out of eight people are likely to die within two years of diagnosis. The average age of onset for lung
cancer is 70 years of age.
The lungs control respiration and include the right and left lung, the pleura, windpipe,
and bronchi. The majority of all lung cancers start in the bronchi and takes years to develop. It is
usually caused by smoking, and may start as a pre-cancerous area that grows into a cancerous mass. By the
time lung cancer is detected, it is usually at an advanced stage and may have metastasized to other
parts of the body. Treatment and prognosis depend on when the cancer is detected.
What are the different types of lung cancer?
Lung cancer comes in two distinct types:
- Small Cell Lung Carcinoma (SCLC)
- responsible for 13% of all lung cancer cases
- caused by the l-myc oncogene
- starts in the bronchi
- often metastatic and carries a poor prognosis
- Non-small Cell Lung Carcinoma (NSCLC)
- responsible for the majority of all lung cancer cases
- there are three subtypes
- Squamous cell carcinoma - caused by smoking and occurs in the center of the lung
- Adenocarcinoma - occurs in the gas exchange areas in the outer area of the lung
- Large Cell Undifferentiated Carcinoma - occurs in the surface of the lung, is hard
to treat, and spreads rapidly.
A rarer form of lung cancer is carcinoid cancer. This form of cancer is slow growing and can be treated
surgically.
What causes lung cancer?
The biggest risk factor of lung cancer is smoking. According to the American
Cancer Society, eight out of ten cases of lung cancer is attributed to smoking, and the more a person smokes,
the higher the risk for lung cancer. Non-smokers who are exposed to smoking environments have
a higher risk of developing lung cancer than non-smokers who are not exposed.
Other factors include:
- Asbestos
- Radon
- Exposure to cancer-causing agents
- Marijuana
- Radiation treatments to the lung
- Hereditary and family history of lung cancer
- Low fruit and vegetable diets
- Air pollution
What are the symptoms of lung cancer?
Symptoms associated with lung cancer include:
- Shortness of breath or difficulty breathing
- Coughing up blood - this may be due to leakage of blood from the new vessels that
feed cancerous cells
- Chronic coughing and wheezing
- Chest pain
- Appetite loss
- Hoarseness of voice
As cancer cells grow, blockage of the airways can occur, leading to pneumonia and metastasis that
results in:
- Bone pain
- Weakness in the limbs
- Dizziness
- Jaundice
How is lung cancer diagnosed?
If a person is suspected of having lung cancer, the first test performed will be the chest X-ray.
If the chest X-ray proves inconclusive, a battery of other tests will be performed. These include:
- Brochoscopy and CT scan
- MRI
- PET scan to determine if the cancer has spread
- Bone scan to determine if patients with SCLC has experienced metastasis to the bone
- Sputum cytology to examine the contents of phlegm
- Mediastinoscopy takes tissue samples from the lymph nodes along the windpipes
- Thoracentesis to determine if there is fluid in the lungs
- Bone marrow biopsy if metastasis has occurred
- Blood tests to measure complete blood count (CBCs)
What treatments are available for lung cancer?
Treatment depends entirely on the stage, type, and degree of cancer. Before settling on
one mode of treatment, your best bet is to get a second opinion to confirm that the prognosis is correct.
Once this has been determined, the treatment modalities for lung cancer include:
- Surgery - good for NSCLC and non-metastatic tumors
- Wedge resection - part of the lobe is removed
- Lobectomy - entire lobe is removed
- Pneumonectomy - entire lung is removed
- Chemotherapy - best suited for SCLC
- Radiotherapy - for patients who can't have surgery; offered in conjunction with
chemotherapy
- Targeted therapy - targets cancerous cells and leaves non-cancerous cells alone. May not
be effective on certain types of cancers
What is the survival rate for those diagnosed with lung cancer?
The survival rate for lung cancer victims is low. The five-year survival rate for those with Stage I
lung cancer is 47%. The five-year survival rate for those diagnosed with Stage IV lung cancer
decreases to 2%.
How can one prevent lung cancer?
The best prevention against lung cancer is to avoid smoking.
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