Symptoms of Lung Cancer in Non-Smokers

How It Differs From Smokers

hand refusing a cigarette illustrating lung cancer symptoms differ in nonsmokers

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The symptoms of lung cancer in non-smokers may be different from those in people who smoke, and this isn't surprising as the types of lung cancer (and the most common locations of these cancers) differ. Often times the symptoms are more subtle, such as shortness of breath with activity, or hard to define, such as fatigue. For this reason, and because there isn't a screening test available for never smokers, lung cancers are frequently diagnosed in more advanced stages of the disease.

Understanding lung cancer symptoms in non-smokers has never been more important, as the majority of people diagnosed with lung cancer today are not active smokers (they are either former smokers or never smokers). Roughly 20 percent of women in the U.S. (and 50 percent worldwide), are lifelong non-smokers, and lung cancer in never smokers is thought to be the sixth leading cause of cancer-related deaths in the U.S. While lung cancer has begun to decrease in incidence in older adults, there has actually been a significant increase in one group of people: young, never-smoking women.

Why Might Symptoms of Lung Cancer in Non-Smokers Differ From Those in People Who Smoke?

One of the reasons that the symptoms of lung cancer in non-smokers and smokers may differ is that the most common types of lung cancer vary depending upon smoking status–-and different types of lung cancer tend to have different symptoms.

Another reason may be that women who develop lung cancer are more likely than men to have never smoked–-and the types of lung cancer found commonly in women and men can differ.

Symptoms of Lung Cancer in Non-Smokers Related to Lung Cancer Type

There are two main types of lung cancer. Non-small cell lung cancer accounts for roughly 80 percent of lung cancers and is broken down into three subtypes that vary among non-smokers and people who smoke. Small cell lung cancer is responsible for around 20 percent of lung cancer and is found more commonly among people who have smoked.

Non-Small Cell Lung Cancers

The three main types of non-small cell lung cancer include:

The most common type of non-small cell lung cancer in non-smokers is adenocarcinoma. Lung adenocarcinomas tend to grow in the outer regions of the lungs. Due to their location away from the large airways, these tumors often grow quite large or spread before they cause any symptoms.

Lung Adenocarcinoma Symptoms

Since these cancers often grow in the periphery of the lungs, they don't usually begin to cause symptoms until they are quite large. At that time, they are still often far from the airways, so less likely to cause a cough, coughing up blood, or wheezing. Common symptoms include:

  • Shortness of breath: The gradual onset of shortness of breath is often first dismissed as being due to age or inactivity. Only later, when it begins to cause difficulty breathing at rest as well is it seen as a concern.
  • Back and shoulder pain: Pain in the back or shoulder can be caused by pressure on nerves in the chest due to the tumor. It sometimes occur when the cancer spreads to bones in these regions as well.
  • Chest pain that worsens with a deep breath: Tumors that lie near the outer regions of the lungs can irritate the membranes (the pleura) that line the lungs. This can cause pain with breathing. The pain may also be positional, and more uncomfortable in certain positions or when lying down.
  • Fatigue: Worsening fatigue is actually a fairly common first symptom of these cancers.
  • Symptoms due to lung cancer spread (metastasis) Common areas that lung cancer spreads to include bones and the brain.

Even when these cancers metastasize, symptoms may be different. According to a 2017 study, lung cancers in never smokers are twice as likely to spread to the pleura, which may result in pain with deep breathing (pleuritic chest pain).

Squamous Cell Carcinoma of the Lungs

In contrast, squamous cell carcinoma of the lungs is much more common in people who have smoked. These tumors tend to grow in or near the large airways of the lungs and often cause symptoms early on in the disease. These symptoms may include coughing up blood, a persistent cough, and infections (such as recurrent bronchitis or pneumonia) due to obstruction of the airways by the tumor.

Small Cell Lung Cancers

Small cell lung cancers occur more often in men and people who smoke. These tumors frequently begin near the large airways causing a persistent cough or coughing up blood, and spread early, often to the brain.

Common Symptoms of Lung Cancer in Both Non-Smokers and Smokers

It is helpful to review common symptoms of lung cancer that are found in both non-smokers and in people who smoke. These may include:

Less Common Symptoms of Lung Cancer in Non-Smokers

As noted above, the most common types of lung cancer in smokers tend to grow near the central airways. These tumors tend to cause symptoms earlier on in the course of the disease, with symptoms related to the presence of the tumor near the airway. As such, coughing up blood, obstruction leading to lung collapse (atelectasis), and coughing might be seen earlier in lung cancers found in smokers than they would be in non-smokers.

Another group of symptoms that are seen occasionally with lung cancer is something called paraneoplastic syndrome. Paraneoplastic syndrome is a group of symptoms caused by hormone-like substances secreted by tumors and is seen most often with small cell lung cancers, squamous cell lung cancers, and large cell carcinomas –- cancers that are found more often in people who smoke.

Paraneoplastic symptoms may include an elevated calcium level in the blood, a low sodium level, weakness in the upper limbs, loss of coordination and muscle cramps among other symptoms.

Diagnosis in Non-Smokers

Unfortunately, due to a lack of awareness of symptoms and an effective screening test, as well as the disease being low on physicians' radar screens, people who have not smoked tend to be diagnosed in the higher stages of the disease than those who smoked. People who have never smoked tend to seek care later than those who have smoked. It's not always a lack of making an appointment, however, as many non-smokers are misdiagnosed and treated for conditions such as asthma or bronchitis before the diagnosis is made.

Chest X-rays are inadequate to diagnose lung cancer and may miss as many as 25 percent of these cancers.

A Word From Verywell

Just as we've learned that the pain associated differs between men and women, we're learning that symptoms of other conditions can vary between different people. This appears to be true with lung cancer in people who smoke versus those who have never smoked, and even between older and younger people with lung cancer. The importance of lung cancer symptoms in nonsmokers can't be stressed enough, as lung cancer rates are actually increasing significantly in one group of people: young, never-smoking women.

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