1. Health

Symptoms of Lung Cancer in Non-Smokers

Why Do They Differ From Those in Smokers?

By

Updated March 30, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Symptoms of lung cancer in non-smokers may be different from lung cancer in people who smoke. Sometimes the symptoms may be more subtle, such as shortness of breath with activity, or hard to define, such as fatigue. What are some common symptoms of lung cancer in non-smokers and why might they be different from those in smokers?

As a quick aside, talking about lung cancer in non-smokers is more important than ever. Currently 20% of women who develop lung cancer in the United States are lifelong non-smokers. In addition, the majority of people, both men and women, who develop lung cancer at this time are former, not current smokers.

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% 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% 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. Initial symptoms may include:

  • Shortness of breath -– The gradual onset of shortness of breath may first be dismissed as being due to age or inactivity
  • Back and shoulder pain -– Due to pressure on nerves caused by the tumor
  • Chest pain that worsens with a deep breath (pleuritic chest pain) -– Tumors near the outer regions of the lungs can irritate the membranes that line the lungs. This can cause pain with breathing
  • Fatigue
  • Symptoms due to lung cancer spread (metastasis) -- Common areas that lung cancer spreads to include bones and the brain

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.

More About Symptoms of Lung Cancer in Non-Smoking Women

One form of non-small cell lung cancer is seen more commonly in young women and people who have never smoked, and appears to be increasing in incidence in the United States. Bronchioloalveolar Carcinoma (BAC) may cause symptoms similar to other lung cancers, but it has also been coined the “masquerader.” It is not uncommon for BAC to be misdiagnosed first as pneumonia or other lung disease.

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.

Further Reading:

Sources:

Bryant, A. and R. Cerfolio. Differences in epidemiology, histology, and survival between cigarette smokers and never-smokers who develop non-small cell lung cancer. Chest. 2007. 132(1):185-92.

Rudin, C. et al. Lung cancer in never smokers: molecular profiles and therapeutic implications. Clinical Cancer Research. 2009. 15(18):5646-61.

Samet, J. et al. Lung cancer in never smokers: clinical epidemiology and environmental risk factors. Clinical Cancer Research. 2009. 15(18):5626-45,

Scagliotti, G. et al. Nonsmall cell lung cancer in never smokers. Current Opinion in Oncology. 2009. 21(2):99-104.

Subramanian, J. and R. Govindan. Molecular genetics of lung cancer in people who have never smoked. Lancet Oncology. 2008. 9(7):676-82.

Wakalee, H. et al. Lung cancer incidence in never smokers. Journal of Clinical Oncology. 2007. 25(5):472-8.

Yano, T. et al. Non-small cell lung cancer in never smokers as a representative ‘non-smoking-associated lung cancer’: epidemiology and clinical features. International Journal of Clinical Oncology. 2011. 16(4):287-93.

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.