Twenty-four weeks of smoking cessation therapy with varenicline (Chantix) was more effective than 12 weeks of treatment with the drug in helping cancer patients kick the cigarette habit, according to results from a randomized, placebo-controlled trial.
Smokers being treated for breast, skin, lung, and other cancers were recruited for the smoking cessation study, designed to explore the efficacy of extended-use varenicline therapy delivered along with behavioral therapy.
Among patients who remained adherent with the assigned cessation protocol, those who received 24 weeks of varenicline therapy had higher cigarette quit rates at weeks 24 and 52, wrote Robert A. Schnoll, PhD, of the University of Pennsylvania in Philadelphia, and colleagues in Psycho-Oncology.
More than half of cancer patients who smoked before their diagnosis continue to smoke after. Smoking cessation is increasingly recognized as a highly effective strategy for improving outcomes and survival in a large percentage of cancer patients.
In 2017 and 2018, the National Cancer Institute funded initiatives to expand or begin smoking cessation programs at dozens of cancer centers across the country as part of the NCI’s “Cancer Moonshot” Program.
Co-author Brian Hitsman, PhD, of the Northwestern University Feinberg School of Medicine in Chicago, said the 42 centers participating in the initiative are contributing their own funding, and are committed to making tobacco treatment a core component of cancer care.
“It is now clear that quitting smoking has important benefits not just for the general health of the patient, but for the success of cancer treatment,” he told MedPage Today.
He said varenicline may be particularly well suited for use in cancer patients trying to quit smoking because, in addition to reducing nicotine cravings, it has been shown to have beneficial effects on mood and cognition.
The trial tested 12 weeks of varenicline plus 12 weeks of placebo (standard or ST) versus 24 weeks of varenicline (extended or ET) with seven counseling sessions in 207 cancer patients undergoing treatment at two cancer treatment centers.
Primary outcomes were 7‐day biochemically confirmed abstinence at weeks 24 and 52. Treatment adherence and side effects, adverse and serious adverse events, and blood pressure were also assessed.
Among all study participants, point prevalence and continuous abstinence quit rates at weeks 24 and 52 were not significantly different across treatment arms (P>0.05 for all).
Adherence (43% of sample) significantly interacted with arm for week 24 point prevalence (odds ratio 2.31, 95% CI 1.15‐4.63, P=0.02) and continuous (OR 5.82, 95% CI 2.66‐12.71, P<0.001) abstinence.
For both outcomes, adherent participants who received ET reported higher abstinence (60.5% and 44.2%) versus 12-week ST (44.7% and 27.7%). Differences in quit rates between arms were not significant for nonadherent participants (9.7% and 4.8% for ET; 12.7% and 10.9% for ST).
No significant differences were reported between the treatment groups in side effects, adverse and serious adverse events, and rates of high blood pressure (P>0.05 for all).
“Since cancer patients are at heightened risk for depression and may already be experiencing high rates of sleep problems or nausea, it was important to assess if extended treatment varenicline exacerbated such side effects,” the researchers wrote. “The potential effectiveness of extended treatment varenicline could be undercut if it worsened common symptoms experienced by cancer patients.”
The findings suggest that interventions designed to increase medication adherence by extending treatment to 24 weeks “would not risk increasing adverse events or side effects.”
“Compared with standard treatment, extended treatment varenicline does not increase patient risk and increases smoking cessation rates among patients who adhere to treatment,” the authors stated. “Studies are needed to identify effective methods to increase medication adherence to treat patient tobacco use effectively.”
The study was funded by the NIH.
Pfizer provided medication free of charge for this study. Schnoll and Hitsman disclosed relevant relationships with Pfizer. One co-author disclosed a relevant relationship with GlaxoSmithKline.