Lung cancer is the leading cause of cancer-related death and is responsible for more than a quarter of all deaths due to cancer in the United States. Patients whose cancer is diagnosed early, before it spreads, have a 5-year survival rate of 52%; however, just 15% of lung cancers are diagnosed at this stage. Overall, the 5-year survival rate for small cell lung cancer (6%) is lower than for non-small cell lung cancer (18%).
Integrative interventions like vitamin D, melatonin, and soy isoflavones have been shown in studies to affect survival rates in lung cancer patients.
Causes and Risk Factors
- Smoking and tobacco smoke, which are implicated in approximately 85% of all lung cancers
- 50‒80% increased risk of lung cancer if first-degree relative or sibling has the disease
- Emphysema increases risk 2.44-fold and chronic bronchitis 1.47-fold
- Exposure to asbestos, diesel engine exhaust, air pollution, pesticides, and heavy metals are associated with lung cancer development
Note: Recent evidence suggests e-cigarettes can harm the lungs. In one study, never-smokers and regular smokers demonstrated a significant increase in airway resistance in response to e-cigarettes. Lab studies have also shown that the nicotine vapor from e-cigarettes enhanced the “aggressive” behavior of epithelial lung tissue that already contained mutations.
Signs and Symptoms
- chest discomfort or pain, persistent cough, trouble breathing, wheezing, bloody sputum
- loss of appetite, unexplained weight loss
- hoarseness, trouble swallowing
- swelling in the face and/or veins in the neck
Diagnosis and Staging of Lung Cancer
A number of tests and diagnostic tools may be used to identify lung cancer and determine how advanced it is, including:
- Imaging: X-rays, magnetic resonance imaging (MRI), chest computed tomography (CT), and positron emission tomography (PET) scans
- Staging: The extent of the cancer is determined by tumor size, whether cancer cells have spread to nearby lymph nodes, and whether additional metastatic events have occurred.
Note: Annual screening with low-dose computed tomography (LDCT) is recommended in current smokers with a 30 pack per year smoking history and most former smokers ages 55 to 80.
- Lung cancer treatment depends on the subtype of the cancer and its stage, but can involve surgery, chemotherapy, and radiation.
Novel and Emerging Strategies
- Vaccines, with several in late-stage trials
- Quantitative circulating tumor cell (CTC) analysis counts the number of CTCs in a patient’s blood.
- Metformin, with studies showing that people with type 2 diabetes who use it have a significantly lower risk of developing lung cancer
Dietary and Lifestyle Changes
- Smoking cessation
- Controlling glucose levels, as studies find that people with diabetes and lung cancer have a worse prognosis
- Adhering to a Mediterranean diet may reduce lung cancer risk
- Vitamin D: An epidemiological study found that patients with lung cancer who underwent surgery during the summer and had higher vitamin D intake (greater than 596 IU daily) had a significantly longer period of recurrence-free survival and overall survival than those who underwent surgery during the winter and had low vitamin D intake (less than 239 IU daily and no vitamin D supplements).
- Melatonin: A study of lung cancer patients found significantly higher 5-year survival rates and tumor regression rates in those who received melatonin each evening while undergoing chemotherapy compared with those who received chemotherapy alone.
- Soy Isoflavones: A study of women with lung cancer found that those whose diets were highest in soy products and isoflavones (average 31.4 g of soy foods and 53.5 mg isoflavones daily) before diagnosis had mortality rates at the 2-year follow-up that were 81% lower than those with the median intake (average 16 g soy foods and 26.5 mg isoflavones daily).
- Vitamin E: A large study on male smokers found that those whose blood levels of alpha-tocopherol were in the top 20% had a 19% reduction in the risk of developing lung cancer compared with those whose levels were in the bottom 20%.
- Zinc: A study of lung cancer patients compared with an equal number of healthy individuals found that those with the highest dietary intake of zinc (greater than about 12 mg daily) had a 43% lower risk of lung cancer.