Introduction
When lung cells are frequently exposed to a carcinogen (cancer-causing factor), the cells’ DNA and metabolic processes may be damaged; as a result, creating abnormal cells within the organs. These cells do not function properly like normal cells. They also multiply at a faster rate than normal cells and form tumors, or clumps of cancerous cells, inside the lungs. Cancerous tumor cells will start demolishing healthy cells near it. Ultimately, it will start metastasizing or spreading to organs near the lungs, like the bones, adrenal glands, liver, kidneys, and even the brain. This will be adverse to the body’s metabolism since these cancer cells do not aid the lungs like normal, healthy cells and can cause death. There are two types of lung cancer, small cells (the more aggressive type) and non-small cells. The majority of lung cancer cases are non-small cell lung cancer (84%). As for 2020, the American Cancer Society estimated that there are approximately 228,820 new cases of lung cancer and 135,720 deaths from lung cancer. About 1 in 17 women and 1 in 15 men will get lung cancer in their life, both smokers and non-smokers, although smokers will have a higher chance of having lung cancer. Its survival rate is measured in a relative survival rate method: 5-year relative rate by the American Cancer Society. It compares patients with identical stages and types of cancer to the rest of the population. For instance, people with localized lung cancer have a 5-year relative survival rate of 61%. This means that the people who have this type of cancer usually are about 61% more likely to live 5 years longer than those who don’t have this type of lung cancer. ACS also uses the SEER (Surveillance, Epidemiology, and End Result) database, which divides lung cancer into three stages: localize (the cancerous cells still resides within the lungs), regional (cancer had spread to neighboring structures from the lung), and distant (cancer metastasized to other organs). This chart is from the American Cancer Society that shows 5-year relative survival rate for non-small cell lung cancer from 2009 to 2015:
| SEER stage | 5-year relative survival rate |
| Localized | 61% |
| Regional | 35% |
| Distant | 6% |
| All stages combined | 24% |
This chart from American Cancer Society shows the 5-year relative survival rate for small-cell lung cancer between 2009-2015:
| SEER stage | 5-year relative survival rate |
| Localized | 27% |
| Regional | 16% |
| Distant | 3% |
| All stages combined | 6% |
Keep in mind that these numbers show an overall statistic; patients may have a better or worse chance of survival, for there are other personal factors that contribute. These numbers also only apply to the first time a patient is diagnosed.
Causes
Tobacco is the most common cause of lung cancer. It is also a highly significant risk factor for lung cancer. As many as 80-90% of patients diagnosed are smokers or former smokers. The carcinogens in tobacco products can cause and hasten the process of lung cancer. It can further make your lungs more affected by hazardous chemicals such as radon and asbestos. Those who are exposed to smokes from these tobacco products (secondhand smoking) can be at risk of lung cancer. Adding on, if a smoker can quit smoking, the chances of getting lung cancer significantly reduces, although never diminishes. Therefore, it is always optimal to quit smoking.
Another risk factor of lung cancer is carcinogens. These are chemicals that, when consumed, can have the ability to cause cancer. Radon, asbestos, tar, arsenic, thorium, chromium, nickel, soot, are all carcinogens, just to name a few. The longer a person is exposed to these carcinogens, the higher the risk for lung cancer. These carcinogens can also be carried in the air (if polluted). Cooking with kerosene fuels, biomass, etc. can also contribute to lung cancer.
People of 65 and older are also at higher risk for lung cancer. Also, people with a history of lung diseases (like COPD and pulmonary fibrosis) may also be at a higher risk of getting this kind of cancer. Adding on to the last point, the people with a family history (immediate members) suffering from lung cancer are also at higher risk of getting the disease. This can be passed down through genetic mutation (extremely rare) or by being exposed to the same environmental risk factors (such as smoke from tobacco products and carcinogens).
Radiation therapy can contribute to the chances of getting lung cancer. People being treated for breast cancer and Hodgkin lymphoma. Although the current medical advances that can minimize this risk factor, it is still a concerning aspect not to be overlooked.
Diet can also affect the likelihood of getting lung cancer. Unsafe water sources that contain arsenic can cause damage to the lungs and potentially cause lung cancer. People who take many beta-carotene pills over the year can increase their likelihood of getting lung cancer. However, foods that contain beta-carotene are considered safe.
Please keep in mind that all these factors have the CHANCE of causing cancer. Other factors such as the amount of time a person is exposed to these risk factors may determine if they will get cancer or not. Getting exposed to charcoal’s smoke will not give you cancer immediately. The dose is the poison.
Symptoms and Diagnosis
Before reading on, please keep in mind that this article is not meant for medical advice or diagnosis. Please consult your physician if you suspect you have cancer or any other medical issues.
Symptoms of lung cancer don’t usually manifest until the later stages of this disease. However, in many cases, these symptoms do manifest early on; as a result, the patient will have a higher chance of survival. Symptoms of lung cancer can be confused with other lung diseases and disorders. Therefore, it is important to consult your physician if you are concerned that the symptoms listed below may signal lung cancer. Several symptoms of lung cancer includes:
- Constant and worsening coughs
- Blood or sputum-coughing
- Hoarseness
- Constant chest pain that gets more painful when performing activities that involves the lung (laughing, coughing, deep breathing, etc.)
- Shortness of breath
- Lung infections such as bronchitis and pneumonia occur oftenly
- Wheezing
Some symptoms that manifest when the cancer spreads to other organs:
- Bone pain
- Swelling of the lymph nodes
- Seizures, headaches, dizziness, and other nervous system-related symptoms
- Jaundice (when the skin and eyes turn yellow)
- Blood clots
Doctors choses diagnosis based on factors like a patient’s medical history, symptoms, and physical exam results. As for the USC lung cancer screening program, patients must meet these criteria, as quoted from their website linked below:
- “You must be at least 55 years old; have smoked the equivalent of one pack of cigarettes a day for 30 years; and be either a current smoker or have quit within the past 15 years
- You must be older than 50; have smoked the equivalent of one pack of cigarettes a day for 20 years; and have at least one of the following risk factors:
- Significant chronic lung disease (chronic obstructive pulmonary disease [COPD], pulmonary fibrosis)
- Exposure to toxins such as radon, asbestos, coal and diesel fumes
- A first-degree relative with lung cancer
- A personal history of lung cancer, lymphoma or head and neck cancer”
Doctors may perform an imaging test on you for cancer signs. This means taking pictures of parts that are inside your body. One method that your doctor may use is CT scanning. CT scanning uses the typical donut-like machine with a table that pierces through the hole that you see in medical movies. It is an X-ray machine that takes several pictures of different parts of your body as you slide through the machine. Another method is PET scanning. This method is where the patient ingest a radioactive sugar that when a special camera takes pictures, the pictures show whether the cancer has metastasized to other organs or lymph nodes or not. Furthermore, bone scanning is where your doctor injects a safe amount of radioactive material in your veins. This substance would then gather up in the abnormal region of your bone and express themselves as a dense, gray to black shade, which can be cancerous. There are many other kinds of imaging methods out there.
Procedures that your doctor may perform includes but not limited to:
- Sputum cytology (where your doctor takes the phlegm, sputum or mucus from the lung to inspect them for cancer cells.)
- Bronchoscopy biopsy (your doctor inserts a long and flexible tube down to your airways in order to remove a sample from the region for inspection.)
- Endobronchial ultrasound (your doctor inserts a tube down your airways with ultrasound attached to it in order to look at nearby tissues, organs, and lymph nodes. Needles will pass through the bronchoscopy to get the biopsy sample. The patient will be numbed and will be under light sedation.)
- Thoracentesis (due to cancer, or some other medical conditions, your back may be filled with liquid. Your doctor will use a needle and inject it in the between your ribs to drain the fluids. The fluid then will be inspected for cancer cells.)
- And so on…
If you suspect that you have cancer, please consult your doctor and discuss your concern.
Treatment
When doctors have enough evidence to diagnose you with cancer, you will begin treatment. The most common three methods are surgery, chemotherapy, and radiation therapy. For small cell lung cancer, chemotherapy and radiation is more common. Another treatment method is targeted therapy. It is a subcategory of chemotherapy. However, unlike general chemotherapy, where the drug will eliminate all kinds of cells, healthy or cancerous, targeted therapy only attacks cancer cells. A new and emerging cancer treatment is immunotherapy. This means that doctors train your immune system to fight against cancer. Three types of immunotherapy includes: CAR T Cells (Chimeric Antigen Receptor T cells), where scientists generate a special kind of antigen receptors on the patient’s T-cells so they can easily bind to the cancer cell’s antigens and eliminate them. Another immunotherapy treatment is cancer vaccination. This is quite self-explanatory. The doctor injects harmless cancer cells into your body to prepare your body for defense when the real cancer hits. Thirdly, checkpoint inhibitors are basically drugs that disable the proteins that prevent your body from fighting cancer. Complementary and Alternative Medicine can go along with standard treatment. These include acupuncture, meditation, magnet therapy, herbal teas, and so on. These are only several treatment methods. Check with your physician for the most fitting treatment for you.
Conclusion
Overall, lung cancer is when your lung cells mutate and don’t function properly; it gets in the way of your normal organ functions. It can be divided into non-small cell lung cancer and small cell lung cancer. The three stages of cancer are localized, regional, and distant. Some causes of cancer include tobacco, exposition to carcinogens, family history of lung cancer, old age, etc. When lung cancer manifests in symptoms, these symptoms include constant and worsening cough, blood-coughing, wheezing, jaundice, bone pain, swelling of lymph nodes, etc. Your doctor can diagnose you through CT scans, PET scans, bronchoscopy biopsy, thoracentesis, and so on. When you are diagnosed with lung cancer, a team of doctors may treat you with surgery, chemotherapy, immunotherapy, radiation, and so on.
References
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Andrew Pham, Youth Medical Journal 2020
Youth Medical Journal 