Lung Cancer In Non-Smokers: Causes, Symptoms, Treatment & More

Authored by Dr Trinanjan Basu, Senior Consultant-Radiation Oncologist, HCG Cancer Centre Borivali

Lung cancer is a serious health complication that can cause long-term harm and even fatality. In fact, according to the World Health Organization, lung cancer is the leading cause of cancer-related death around the globe.

Although smokers are at the most significant risk of contracting lung cancer, it is increasingly observed in non-smokers. Moreover, for smokers their risk of lung cancer increases every time they choose to smoke.

Lung cancers are usually categorized into two main types: non-small cell carcinoma (NSCLC) and small cell carcinoma (SCLC).  NSCLC is more prevalent between the two and tends to develop over a significant period of time, while SCLC is less common, although it is pretty aggressive.

So, what exactly is lung cancer?

The lungs are part of a person’s respiratory system and are on each side of the chest. These two spongy organs help inhale oxygen and release carbon dioxide.

It is called lung cancer when cancerous cells form in this organ and then spread to other body parts. 

What are the causes of lung cancer?

Although there is no specific reason as to why a person can be diagnosed with lung cancer in the future, there are some risk factors that can increase the likelihood of this disease. Some of these risk factors include the following:

Smoking: One of the most significant risk factors for lung cancer and a host of other diseases like cardiac issues, diabetes, infertility, high cholesterol, and persistent cough, among others, is smoking. 

No matter how little you smoke, it will impact your health negatively. There are no safe substances present in tobacco products, from acetone and tar to nicotine and carbon monoxide; all of them can negatively affect your overall health. 

Smoking leads to lung damage and tissue loss that cannot be reversed. Once damage is caused to the lungs, it can make a person more susceptible to lung infections like tuberculosis and pneumonia while also increasing the possibility of death from those illnesses.

Although not everyone who has lung cancer is a smoker, and not all smokers get lung cancer, there is no doubt that smoking is one of the most significant risk factors for respiratory illness. 

Radon: According to the American Lung Association, radon exposure is another significant risk factor for lung cancer. 

A radioactive gas, radon, is released into the air when uranium in rocks and soil breaks down. It can easily seep into the water and air supply and enter a person’s house through cracks in the floors, walls, or foundation. Over time, the amount of radon in a house can grow substantially. 

Further, a person’s chance of contracting lung cancer increases substantially when they breathe in hazardous substances that include asbestos, arsenic, cadmium, chromium, nickel, some petroleum products, and uranium.

Other risk factors include a family history of lung cancer, genetic mutations, increased exposure to radiation, an unhealthy diet, and lack of exercise. While certain factors like not smoking and exercise are modifiable factors, non-modifiable factors include family history and environmental factors. In the case of non-modifiable risk factors, the best way forward would be to go for regular screenings if you are in the risk category, as early detection can improve outcomes.

Does secondhand smoke increase your risk of lung cancer?

Secondhand smoke is another significant risk factor for lung cancer. It is the smoke from other people’s cigarettes or cigars and the smoke they exhale. When a person who does not smoke inhales this, it is called secondhand smoke, which is another risk factor for lung cancer. 

Although laws have reduced exposure to secondhand smoke in public, steps must be taken to avoid breathing in secondhand smoke at home and work as far as possible.

Further, secondhand smoke can also increase the risk of cardiac issues and stroke as well.

What are the symptoms of lung cancer?

In many cases, lung cancer does not show any symptoms. Some classical early symptoms can include shortness of breath, a lingering or worsening cough, coughing up phlegm or blood, chest pain that worsens when breathing deeply, laughing, or coughing, and hoarseness. It also includes wheezing, weakness, fatigue, loss of appetite and weight loss, and even recurrent respiratory infections such as pneumonia or bronchitis. 

Once the lung cancer spreads to other parts of the body, additional symptoms may occur, which include lumps in the neck or collarbone, bone pain, especially in your back, ribs, or hips, headaches, dizziness, balance issues, numbness in arms or legs, jaundice, drooping of one eyelid and shrunken pupils, lack of sweat on one side of your face, shoulder pain and muscle weakness. 

Further lung cancer can also lead to other health problems like high blood pressure, high blood sugar, and seizures. 

How is lung cancer treated?

The main goal of lung cancer treatment is to remove the tumor and cancer cells causing the disease. These can include surgery to remove the tumor and chemotherapy and radiation treatments to kill cancer cells. Depending on the specific case, specialists also recommend cancer treatments like targeted therapy and immunotherapy, although this happens at a later stage.

The treatment for NSCLC varies from patient to patient, depending on the specific details of their overall health and stage of cancer at the time of diagnosis.

The treatment options, depending on the stage of the lung cancer, include:

Stage 1: Surgery to remove a portion of the lung that is cancerous or high dose radiation (SBRT) to kill tumor cells. Generally stage 1 treatment remains single modality.

In most cases, cancer is entirely curable if detected at this stage.

Stage 2: Along with surgery, a patient in this stage will also require chemotherapy and/or radiation. At times high dose radiation (SBRT) with immunotherapy can also be an option.

Stage 3: Patients at this stage will require a multi-modality treatment comprising of chemotherapy, surgery, and radiation treatment.

Stage 4: Depending on the specific prognosis, options can include surgery, radiation, chemotherapy, targeted therapy, and immunotherapy. Lung cancer at this stage is proven to be more fatal.