Lung cancer risk factors

Lung cancer is the deadliest cancer in the world. In the United States alone, 0.23 million people are diagnosed with lung cancer, annually. Even though cigarette smoke is the number one risk factor for lung cancer, it is not the only one. Read on to know more about the risk factors for lung cancer, according to experts like Pulmonologist in Lahore.

What are the risk factors for lung cancer?


About 90 percent of the lung cancer cases diagnosed are due to cigarette smoke. In fact, 80 to 90 percent of deaths secondary to lung cancer, in the United States, alone, are linked to cigarette smoke. This risk factor is also extended to other kinds of smoke—such as that of cigar and pipes. There are more than 7000 chemicals in the tobacco smoke and most of these are known carcinogens.

Even second hand smokers—people who don’t smoke themselves but are exposed to cigarette smoke—are at risk for lung cancer. Inhalation of second hand smoke also reaches the lungs and has the potential to cause disease. In the United States, one out of every four people were second hand smokers, many of which were children.

The risk of lung cancer rises as the cigarettes consumed per day increase. In comparison to people who don’t smoke, smokers are 15 to 30 times more likely to die from lung related complications. People who quit cigarette smoking lower their risk of lung cancer, but the risk of other chronic lung diseases persists despite smoking cessation.

Cigarette smoke is full of carcinogens, which is why it can cause cancers of mouth, esophagus, throat, bronchus, larynx, stomach, rectum, colon, liver, pancreas, renal pelvis, kidney, urinary bladder, leukemia and cervical cancer as well.

Family history

The risk of non-small cell lung cancer is associated with positive family history and genetic link. For people having a blood relative with lung cancer, the risk of acquiring lung cancer is twice as high, compared to people with no family history. Therefore, someone with positive family history should not smoke as there is no such thing as a safe level of smoking exposure.


Asbestos is a known risk factor for a particular type of lung cancer, known as mesothelioma. Asbestos was used previously, in insulation, building material and construction. People with excessive exposure to asbestos include those working in shipbuilding, construction industry, mining industry as well as firefighters. In retrospective studies, 70 to 80 percent mesothelioma cases included exposure to asbestos. The risk multiples if such workers also smoke.


Radon is a naturally occurring gas, found in old buildings and houses. It is a by-product of uranium breakdown in the rocks and soil. It is usually odorless, and needs testing by radon kits for detection.

Exposure to radon gas has been determined by United States Environmental Protection Agency, as the leading cause of small-cell lung cancer in the non-smokers, which is why precautions must be taken seriously. People are advised to check their homes for radon, as high radon levels can be remedied easily.

Industrial exposure

Apart from asbestos and radon, inhalation of many toxic chemicals in the industrial sector, such as nickel, soot, radioactive ores, vinyl chloride, beryllium, silica, tar, chromium and arsenic all are associated with increased risk of non-small cell lung cancer. Whoever works in such industries should get regular checkups and seek help from their healthcare provider if they have suspicious symptoms.

History of previously treated cancer

Previously treated cancers, especially with radiation therapy, puts one at risk for lung cancer. Examples of such cases include, women who get radiation therapy to the chest for breast cancer, or patients of Hodgkin’s disease. This is the reason cancer survivors need regular checkups even after their cancer is gone to rule out other diseases. As with other risk factors, the chance of lung cancer in such people escalates if they also smoke cigarettes.

Metastasis from another cancer

Cancer in any other part of the body can also metastasize to the lungs. In case metastasis has occurred, it is known as stage IV disease, and is generally incurable at this point. Stage IV cancer is managed symptomatically to decrease the pain and discomfort of the patient as per the advice of an expert like Pulmonologist in Karachi.

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