Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Lung Cancer Health Center

Font Size

Lung Cancer Screening (PDQ®): Screening - Health Professional Information [NCI] - Overview



Based on solid evidence, some lung cancers detected by screening chest x-ray and/or sputum cytology appear to represent overdiagnosed cancer. Because of comorbidities, harms of diagnostic procedures and treatment may be most frequent among long-term and/or heavy smokers.

Magnitude of Effect: When calculated as the ratio of all lung cancer cases in the intervention arm to those in the control arm (percent excess cases), the magnitude of overdiagnosis ranges from 6% to 17% .

  • Study Design: Randomized controlled trials.
  • Internal Validity: Good.
  • Consistency: Good.
  • External Validity: Good.


  1. Oken MM, Hocking WG, Kvale PA, et al.: Screening by chest radiograph and lung cancer mortality: the Prostate, Lung, Colorectal, and Ovarian (PLCO) randomized trial. JAMA 306 (17): 1865-73, 2011.
  2. Marcus PM, Bergstralh EJ, Zweig MH, et al.: Extended lung cancer incidence follow-up in the Mayo Lung Project and overdiagnosis. J Natl Cancer Inst 98 (11): 748-56, 2006.

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

WebMD Public Information from the National Cancer Institute

Last Updated: May 28, 2015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Today on WebMD

Broken cigarette
Do you know the myths from the facts?
man with a doctor
Our health check will steer you in the right direction.
sauteed cherry tomatoes
Fight cancer one plate at a time.
Lung cancer xray
See it in pictures, plus read the facts.
15 Cancer Symptoms Men Ignore
Lung Cancer Risks Myths and Facts
cancer fighting foods
Improving Lung Cancer Survival Targeted Therapy
Lung Cancer Surprising Differences Between Sexes
Pets Improve Your Health
Vitamin D
Lung Cancer Surgery Options