The goal of this study was to clarify these associations in patients with advanced cancer.
We retrospectively reviewed 560 charts and identified 300 consecutive advanced cancer patients who completed a comprehensive smoking questionnaire. Data including the Edmonton Symptom Assessment System, Cut down/Annoyed/Guilty/Eye opener (CAGE) alcoholism screening questionnaire, illicit drug use history, and daily opioid requirements—morphine equivalent daily dose—were collected.
Among 300 patients, 119 (40%) were never smokers, 148 (49%) former smokers, and 33 (11%) current smokers. The most common malignancies were gastrointestinal (28%) and lung (20%). Current smokers were more likely to be single (P < 0.01) and significantly younger than former smokers (P < 0.001) but did not differ in age from never smokers. Never smokers were more likely to be female (P < 0.001). Current smokers reported significantly higher pain expression than former and never smokers (median 7 vs. 5.5 vs. 5, respectively, P = 0.02), higher CAGE positivity (42% vs. 21% vs. 3%, P < 0.001) and were more likely to have a history of illicit drug use (33% vs. 16% vs. 3%, P < 0.001). The morphine equivalent daily dose was not significantly different according to smoking status.
In advanced cancer, patients who were former or current smokers were significantly more likely to have a history of CAGE positivity and illicit drug use compared with never smokers. Current smokers expressed significantly higher pain. A smoking history may be a marker of an increased risk of opioid misuse.