Quitting smoking is a key route people take to avoid cancer. For smokers who end up with the disease however, researchers say many feel it’s too late to quit. Despite this perception, a new study finds it’s never too late to add years to your life, even if you have lung cancer.

A team from the International Agency for Research on Cancer, part of the World Health Organization, says those who quit smoking after a lung cancer diagnosis live longer and spend more years without suffering a reoccurrence of their illness. The team adds that about half of all smokers keep smoking after developing lung cancer.

“Lung cancer is the leading cause of cancer death in the United States, expected to claim nearly 132,000 lives in 2021 despite recent treatment advances that have accelerated a decline in lung cancer mortality rates,” says Dr. Nancy Rigotti from Massachusetts General Hospital and Harvard Medical School in a media release.

Moreover, study authors say 80 percent of non-small cell lung cancer patients have a history of smoking. About half of these individuals are current smokers at the time of their diagnosis. Despite these findings, researchers note there are few studies examining the impact of actually quitting smoking on survival rates among lung cancer patients. As a result, the team believes many smokers may feel it’s just too late for them to kick the habit.

Adding Years of Life to Cancer Patients

The WHO team collaborated with the N.N. Blokhin National Medical Research Centre of Oncology in Russia to recruit 517 smokers diagnosed with lung cancer during this study. After gathering information on their lifestyles, tumor characteristics, and smoking habits, researchers followed the group for seven years — recording any changes in their health, treatment schedules, and smoking frequency.

During the study, just under half of the participants quit smoking completely (44.5%), with very few of these individuals relapsing. Overall, quitting smoking literally added nearly two years of good health to lung cancer patients.

Patients who quit smoking lived longer overall (6.6 years vs. 4.8. years), lived longer without a reoccurrence of lung cancer (5.7 vs. 3.9 years), and lived longer from the time of their diagnosis until death from the disease (7.9 vs. 6 years).

“Only 21% of patients with lung cancer survive 5 years, primarily because 57% of lung cancer is metastatic at the time of diagnosis,” explains Dr. Rigotti, who did not take part in the study.

The study authors add that lung cancer need not be a death sentence for smokers, noting the evidence shows there’s still a lot of good that can come from quitting at any time.