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A research conducted by the UC Davis Cancer Center has found that if smokers don’t give up smoking before radiation therapy for throat, mouth and other head and neck cancers then patients may show only mediocre results.

It was found that there is a poorer 5-year overall survival and increase in the occurrence of disease amongst those patients who have not quit smoking during radiation therapy although diagnosed with head-and-neck cancer than those who quit prior to treatment.

“I always tell patients, ‘You should really stop smoking,’ but I had no tangible evidence to use to convince them that they would be worse off if they continued to smoke,” Allen Chen, an assistant professor in the Department of Radiation Oncology at the UC Davis Cancer Center, said. “I wanted concrete data to see if smoking was detrimental in terms of curability, overall survival and tolerability of treatment. We showed continued tobacco smoking contributed to negative outcomes with regard to all of those.”

The research was conducted by reviewing the medical records of 101 patients by Chen and his colleagues. These patients were newly diagnosed by squamous cell carcinoma of the head and neck. The medical reports of those patients who continued to smoke and those who quitted were analyzed together keeping in mind the primary disease site, gender, smoking history, stage of disease, other treatment (surgery and chemotherapy) and date of initiation of radiation therapy.

The research supposedly found that five years later 55 percent of patients were still alive as they had quit smoking prior to the treatment but 23 percent persistent smokers had poorer outcomes as they continued to smoke. There was no significant difference of the incidence of secondary cancers following radiation therapy between the two study groups. It was found that there was a disease recurrence faced by 53 patients as they still continued to smoke. Also more complications of radiation therapy, such as scar tissue development, hoarseness and difficulties with food intake may be faced by active smokers.

“A diagnosis of cancer is emotionally devastating, and a lot of patients are reluctant to entertain the idea of smoking cessation. Many patients can’t or won’t connect the dots, and, unfortunately, our data shows that by continuing to smoke, they are more likely to gamble away the possibility of cure.”

However, one theory suggests that smoking deprives the body of much-needed oxygen. Hence,Chen emphasis the need for additional research to explain the differences in outcomes for patients with head and neck cancers.

“Radiation therapy requires oxygenation for the production of free radicals, which attack cancer cells,” he said.

The research and its findings are however, based on an observational analysis so it fails to show a cause-effect relationship between smoking during radiation therapy and poorer outcomes, reveals Chen. The actual cause of death of each patient was also poorly determined by the scientists.

“In addition, patients unable to quit may also have non-cancer-related medical and psychosocial problems that could possibly contribute to inferior survival,” Chen said. “Those who continue to smoke even after a diagnosis of head and neck cancer are likely to be at higher risk for alcohol abuse, have less social support and have lifestyles associated with high-risk health behaviors.”

It was further concluded by Chen that regardless of the underlying reasons, the findings may provide both clinicians and patients alike with compelling evidence supporting the role of smoking cessation in such a setting. He also adds that counseling these patients on its importance, both at UC Davis and in the community is a must.

The study was published online recently in the International Journal of Radiation Oncology, Biology and Physics.