Women are familiar with breast cancer as a common health condition. They are also noticing that many of their female friends and relatives have been diagnosed with lung cancer. In fact, over the last 20 years, while lung cancer rates have fallen for men, they have increased in women.

Why is lung cancer more common in females?

While the exact reason is not clear, we believe there are several possible explanations:

  • It appears that female smokers are more likely to develop lung cancer than male smokers from the same cigarette exposure.
  • Women are more likely to develop lung cancer among those who have never smoked.  
  • The decrease in smoking prevalence is more dramatic in men than in women, which makes the drop in male lung cancer risk more dramatic.

Taken together, it makes sense that lung cancer appears to be setting its sights on women as the overall cloud of tobacco smoke lifts from our society.

Why do people who never smoke get lung cancer?

A 2018 study in the New England Journal of Medicine reports that 15 percent of those diagnosed with lung cancer are non-smokers. For women who are diagnosed with lung cancer, however, 24 percent were non-smokers. So why are women who never smoked diagnosed with lung cancer more than men?

We don’t have a good understanding of why the disease happens in never-smokers.  I tell my never-smoking patients that it happened, “by accident,” but they are always curious if there was an identifiable risk factor.

The truth is the very act of breathing brings the lungs in constant contact with our environment. Things like environmental tobacco smoke (secondhand smoke), radon gas, inhaled particles, pollution, and even viruses may contribute to lung cancer risk.

It is just speculation, but the immune system in women is designed to tolerate babies, which are immunologically distinct. This may leave women more susceptible to early lung cancers which might otherwise be cleared by the immune system.

As smoking prevalence continues to fall in our society, the overall death rate from lung cancer will continue to fall dramatically, and we will notice the disease more in patients who never smoked. 

Lung cancer screening

The best test we have to screen for lung cancer is a computed tomography (CT) scan. Unfortunately, it is not sensitive enough, or specific enough, to apply to patients with very low risk. The risk of developing lung cancer is so low in a never-smoker that there is no need to be screened. In fact, CT scans would probably be harmful by finding benign lung nodules in never-smokers, prompting further intervention.

Although women smokers are more likely to develop lung cancer than men who smoke (independent of exposure), the difference is not large enough to impact recommendations for screening, or prevention.

If you are an active smoker between the ages of 55 and 80, or a former heavy smoker who quit within the past 15 years, you should speak to your doctor about whether you qualify for lung cancer screening.

Early signs of lung cancer

Unfortunately, the most common symptoms of lung cancer are the same as the symptoms of upper respiratory infections, which are incredibly common. They can include:

  • new persistent cough or changes in a chronic cough
  • shortness of breath or wheezing
  • hoarseness
  • tiredness or weakness

So, it is hard to ask healthy patients to watch out for symptoms they get from a common cold. However, upper respiratory infections get better in a week or two. Anyone who is sick for too long, too severely, and/or without explanation, should seek medical attention.

Lung cancer awareness

Building awareness of the growing prevalence of lung cancer in non-smokers is key so that lung cancer is never thought of as self-inflicted, or unworthy of compassion or resource allocation. In fact, a smoker may still have developed his or her lung cancer having never smoked.

“Never-smoking” lung cancer affects about 30,000 Americans per year. A good comparison is pancreas cancer, which is diagnosed in about 60,000 Americans per year. Cigarettes also cause pancreas cancer, and about 20 percent of cases are directly attributable to smoking. But no one ever thinks of pancreas cancer as self-inflicted.

Like lung cancer in never-smokers, there is no screening test for pancreas cancer. So, the best thing to do is get rid of cigarettes in society because they are the main cause. But we must also advocate for all people when they are sick with equal compassion and fight all cancers with equal passion.

The good news for never-smokers

The good news is that lung cancer in never-smokers tends to be caused by specific genetic changes in genes (EGFR, ALK, ROS1, etc.) for which there are targeted drugs which are more reliable than chemotherapy, or immune therapies. We test all patients with advanced non-small cell lung cancer for these gene mutations, smokers and non-smokers alike.

More good news is that we are well on our way to a smoke-free society. Currently, about 500,000 Americans die every year from tobacco-related disease, including lung cancer, emphysema, heart disease, and stroke. Even if cigarettes were to disappear from the face of the earth, we would still have millions of Americans at risk of smoking-related disease from prior exposure, and thousands of Americans who develop lung cancer having never smoked.

We need to be more compassionate toward lung cancer patients, and more passionate about developing better treatments and finding  cures.

The Thoracic Multidisciplinary Clinic, part of the Lifespan Cancer Institute, is entirely dedicated to the compassionate care of patients with lung cancer. Learn more about our program on our website or call 401-222-2881.

Christopher Azzoli, MD

Dr. Christopher Azzoli is an oncologist and the director of thoracic oncology at the Lifespan Cancer Institute. He specializes in the care of patients with lung cancer and mesothelioma.