Most People with Lung Cancer Smoked

When people hear “lung cancer,” they might automatically connect it with smoking tobacco. But anyone can get lung cancer, and not everyone who develops lung cancer has a history of smoking. Research that’s focused on people who never smoked may inform how doctors check for risk factors of lung cancer other than smoking, such as exposure to secondhand smoke, occupational exposures, exposures to radon and/or air pollution, and genetic factors.

Researchers from the American Cancer Society (Ahmedin Jemal, DVM, PhD, and Stacey Fedewa, PhD) and the US Centers for Disease Control and Prevention (CDC) published results of a study of people in the United States with lung cancer who never smoked. Previous studies were based on small population sizes from hospital data, but this study had a much larger number of people to study, as it used population-based data from multiple state cancer registries.

Here’s an overview of their findings.

People Who Currently Smoke or Formerly Smoked (collectively known as “ever smokers”)

• More than 84% of women and 90% of men with a new diagnosis of lung cancer either smoke or used to smoke.
• Half of the patients ages 20 to 64 said they currently smoke.
• Among patients ages 65 to 79, about 86% to 91% had smoked at some point in their lives or still smoke.
• For all ages combined, the number of people who said they currently smoke was higher for Black people than for White or Hispanic people with lung cancer.

People Who Never Smoked (known as “never smokers”)

• Almost 16% of women and almost 10% of men with a new diagnosis of lung cancer had never smoked.
• Of more than 129,000 patients with lung cancer, 12.5% of men and women combined had never smoked.
• The highest number of people who have never smoked was for people ages 20 to 49.
• More women with lung cancer had never smoked, compared with men.
• People with adenocarcinoma of the lung had a higher proportion of never smoking than those with small cell or squamous cell carcinomas of the lung.

Data were only included for states and years where the status of cigarette use was “unknown” for less than 15% of cases: Alaska, Colorado, Florida, Idaho, Louisiana, North Carolina, and Rhode Island.