Quitting smoking during radiation treatment for lung and head and neck cancer significantly enhances treatment efficacy, yet many patients will not give up the habit even though the benefits are very obvious.
In fact, “the magnitude of improved response rates from smoking cessation may be even greater than seen with chemotherapy or radiosensitizers,” said Larry Pan, MD, a clinical fellow in radiation oncology at Memorial Sloan-Kettering Cancer Center in New York.
During his residency at Juravinski Cancer Centre at McMaster University in Hamilton, Ontario, Dr. Pan conducted a two-phase study to determine tobacco use in patients receiving radiation therapy for lung or head and neck (H&N) cancer. He also looked at tobacco use and barriers to quitting in this patient population as well as the success of cessation counseling.
He found significant barriers to quitting, with patients caving to cravings or outright refusing to give up the calming effect of smoking. Dr. Pan, along with other radiation oncologists, shared with Oncology News International some of the more successful intervention techniques.
Smoking to relieve stress
Dr. Pan built on research done by George P. Browman, MD, and colleagues that evaluated the influence of cigarette smoking during radiotherapy in 115 patients with locally advanced H&N cancer. Response was assessed 13 weeks after completion of treatment. They found that the rate of complete response for the 53 patients who continued to smoke was 45%, compared with 74% for the 62 patients who stopped smoking. The two-year survival rate was 39% for the smokers and 66% for those who quit.
Mortality rate was influenced by the length of time between quitting smoking and beginning cancer treatment, with a risk reduction of 40% for patients who had quit less than 12 weeks before diagnosis and 70% for those who had quit more than one year before.
After adjustment for other variables, smoking remained an independent prognostic factor, and the results could not be explained by type of chemotherapy, presence of coexisting morbidity, and differences in the adverse effects of radiation, Dr. Browman’s group wrote (N Engl J Med 328:159-163, 1993).
For his study, Dr. Pan obtained data via self-administered questionnaires and/or structured interviews. The study included 134 patients whose charts were reviewed to determine their smoking status (as documented by physicians) and any cessation counseling offered.
According to the results, 31% of the patients with H&N cancer continued to smoke, while 12% quit shortly before starting treatment. Of those with lung cancer, 11% continued to smoke and 23% quit before beginning therapy (RSNA 2008 abstract SSE24-06). “The percentage of patients who continued to smoke during radiotherapy was higher for H&N cancer than for lung cancer, and more lung cancer patients actually quit,” Dr. Pan said. He speculated that patients were aware of the association between smoking and lung cancer and that it was likely that smoking caused their cancer. The association between smoking and H&N cancer was less well known.
Patients who continued to smoke cited a variety of reasons why they were unable to quit, including overwhelming cravings, inability to cope with stress, and lack of support from their treatment center for smoking cessation (see Figure).