What Causes Lung Cancer?

What Causes Lung Cancer?

High-risk factors around us that lead to lung cancer

Lung cancer is basically defined as cancer that starts in the lungs.

According to scientists, there are two basic types of lung cancers – those that start from outer parts of the lungs called non-small cell lung cancer (NSCLC), and extremely aggressive tumors from lung substance named small cell lung cancer (SCLC).

Of these two, NSCLC accounts for 80-85% of reported cases. The two subsets of NSCLC are adenocarcinomas and squamous cell carcinomas of cells that line the respiratory tract. Adenocarcinoma in situ is a rare but benign form of adenocarcinoma that starts from alveoli (air sacs) and may not require urgent treatment. Faster growing NSCLC include large cell carcinoma and large cell neuroendocrine cancers.

The other 15% -20% of lung tumors originate from SCLC. This tumor is aggressive and invasive. But since it contains more dividing and immature cells, response to chemo is positive, although the chance of cure is minimal.

Sometimes lung cancers are mixed containing both NSCLC and SCLC cells.

Carcinogenic materials are substances that have the potential to cause cancers. An example is asbestos exposure that results in mesothelioma. Carcinoid tumors affect hormone-producing cells (neuroendocrine)

As many lung cancers in early stages present with similar symptoms to a common cold, many people don’t go to get checked, and the tumor grows exponentially. By the time it is noticed, it is already too late.

Many women, men, and children die each year as a result of lung cancers. One way of arresting lung cancer is to know its signs and symptoms, which include:

  • Recurrent chest infections like pneumonia and bronchiectasis
  • Fatigue and shortness of breath
  • Blood tinged mucus or hemoptysis
  • Gradually worsening excessive coughing
  • Chest pain due to compression of tissues in your chest
  • Difficulty swallowing
  • New-onset wheeze and cough, especially in smokers
  • Dull chest pain with no apparent origin
  • General body weakness and weight loss

Some factors increase the likelihood of developing lung cancer. Such include a family history of lung cancer, occupational hazards, genetic predisposition, lifestyle, and age.

Below are some risks that can lead to the development of lung cancer:

Smoking tobacco

Almost 80 percent of lung cancer patients smoked at one point in their lives. The risk of lung cancer is increased in people who smoke pipes or strongly-flavored cigars. Inhaling smoke profoundly and holding it for too long in the lungs allows tar and soot to settle in alveoli, and this drastically reduces oxygen absorption into your system.

Tobacco has more than 70 carcinogens, which is why it’s the leading cause of lung cancer. While chain-smoking is thought to cause mostly lung cancer, such habits badly damage your lungs, and before you know it, you will need to go everywhere with an oxygen tank because of irreversible lung damage.

All smoking is harmful; E-cigarettes, menthol versions, lower tar content, and ‘mild’ cigarettes can result in malignancy. Nonsmokers take in 2nd hand smoke with more toxins and can lead to lung cancer if this smoke is inhaled over a long time.

Radon exposure

Radon is a deadly radioactive gas that increases lung cancer and its fatalities. It affects both radon smokers and nonsmokers in equal measure. Exposure to radon-contaminated soil, water, and rocks kill many people annually. Experts note that more harm is done if radon accumulates inside residences. This is a silent killer as not many people are aware of the calamitous effects radioactive materials have on body cells.


Asbestos was once a commonplace in housing, textiles, milling, mining, and shipbuilding because of its resilience to heating. Many workers who were exposed to it developed lung cancer. Dangerous exposure leads to mesothelioma, a rare cancer of the pleural membrane.

Mesothelioma is aggressive and metastasizes rapidly. Houses with asbestos insulation pose a higher risk during a breakdown—smoking and working around asbestos double the risk of lung cancer than non-smoking workers.

Industrial occupational carcinogens

Here are factors that can trigger lung cancer in people:

  • Exposure to radioactive ingredients and wastes
  • Exposure to dangerous elements such as cadmium, silica, arsenate, nickel, chromium derivatives, pepper products, coal gas, and mustard gall, which in high concentration are carcinogenic
  • Exposure to gases and effluents in rubber, iron, and steel factories
  • Inhalation of automobile gases and industrial pollutants in industrial areas
  • Air pollution

Big cities usually have slow traffic with immense pollution from vehicles. Though this contributes to environmental degradation, car exhaust increases the risk of lung cancer. Both indoor and outdoor pollution is harmful and damages the respiratory system.

Polluted water

Access to safe drinking water in public areas is not guaranteed. In some places, water pollution by industrial wastes, especially arsenate, has been linked to a higher incidence of lung cancer.

Use of radiation in the treatment

There are some tumors affecting the lymphatic system. To treat these tumors, patients are exposed to therapeutic radiations, although this sometimes can predispose one to lung cancer. Breast cancer irradiation can also trigger lung cancer.

Family history of cancer

If your parents, grandparents, or siblings developed lung cancer while young, you will likely get same cancer as they did. Some of these tumors are attributed to poor lifestyle choices and genetic defects that bring about lung malignancies.

Previously Affected

Patients cured of NSCLC or SCLC are not out of the woods yet as there’s a chance of relapse. Close to 5% of all patients will experience a relapsing tumor.

Inconsiderate use of beta-carotene supplements

Study trials have proven that higher doses of beta carotene taken by active smokers increase the chance of developing lung cancer. Sources of beta-carotene include carrots, cantaloupe, papaya, mangoes, pumpkin, and sweet potato, all of which should be avoided.

While many of these factors are clinically unproven, they are also thought to cause lung cancer:


Marijuana and cigarette smoking both deposit the same amount of tar in the lungs. Sporadic use reduces risk.


Talcum powder occasionally used in cosmetic products is safe if asbestos is wholly eliminated.

Don’t hesitate to talk to us if your situation worsens or suspect you have lung cancer.