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For many long-time smokers, quitting may seem pointless. Smoking is a risk factor for many diseases, including lung cancer, and if the damage is already done, why stop now?

New research shows there is a good reason to kick the habit, no matter how long you have smoked.

Lung cancer makes up nearly 25% of all cancer deaths, with eight out of 10 lung cancer deaths linked to tobacco use. But a new study that will be presented at this year’s American Society of Clinical Oncology Annual Meeting explores how the timing of when a smoker quits affects lung cancer survival, especially as it relates for those who have smoked for decades.

The results suggest smoking cessation, even two years prior to lung cancer diagnosis, can improve a patient’s survival.

It seems obvious but quitting smoking – no matter when you do it – will improve your health.
Dr. Matthew Schabath, Associate Member, Cancer Epidemiology Department

“It seems obvious but quitting smoking – no matter when you do it – will improve your health,” said Dr. Matthew Schabath, co-author of the study and associate member of Cancer Epidemiology Department at Moffitt Cancer Center. “We find that many of those who have smoked for most of their lives feel like the damage is already done and there is no need to stop. Our study shows there is benefit.”

Former Smokers

Quit 5+ years before diagnosis = 20% survival benefit
Quit 2 to 5 years before diagnosis = 16% survival benefit
Quit within 2 years of diagnosis = 12% survival benefit

For the study, Schabath and his fellow researchers analyzed data from 17 International Lung Cancer Consortium studies, reviewing information for more than 35,000 lung cancer patients - 47.5% were current smokers, 30% were former smokers and 22.5% had never smoked at the time of diagnosis. The analysis showed the risk of death after lung cancer diagnosis decreased for former smokers.

“This information will allow us to create possible interventions to encourage smokers to quit, especially when they see a physician for lung cancer screening,” said Schabath.

Lung cancer screening is recommended for those ages 55 or older who are a current or former smoker with a 30-pack per year history equivalent to one of the following:

  • One pack a day for 30 years
  • Two packs a day for 15 years
  • Three packs a day for 10 years