Spontaneous smoking cessation before lung cancer diagnosis.

Introduction: We have observed that many patients with lung cancer stop smoking before diagnosis, usually before clinical symptoms, and often without difficulty. This led us to speculate that spontaneous smoking cessation may be a presenting symptom of lung cancer.

Methods: Patients from the Philadelphia Veterans Affairs Medical Center with lung cancer and for comparison, prostate cancer and myocardial infarction underwent a structured interview about their smoking habits preceding diagnosis. Severity of nicotine addiction was graded using the Fagerström Test for Nicotine Dependence. Among former smokers, dates of cessation, onset of symptoms, and diagnosis were recorded. Difficulty quitting was rated on a scale of 0 to 10. Distributions of intervals from cessation to diagnosis were compared between groups.

Results: All 115 patients with lung cancer had been smokers. Fifty-five (48%) quit before diagnosis, and only six of these (11%) were symptomatic at quitting. Patients with lung cancer who quit were as dependent on nicotine, when smoking the most, as those who continued to smoke, unlike the other groups. Despite this, 31% quit with no difficulty. The median interval from cessation to diagnosis was 2.7 years for lung cancer, 24.3 years for prostate cancer, and 10.0 years for patients with myocardial infarction.

Conclusions: These results challenge the notion that patients with lung cancer usually quit smoking because of disease symptoms. The hypothesis that spontaneous smoking cessation may be a presenting symptom of lung cancer warrants further investigation.