It's a sad but familiar scene near the grounds of many medical campuses: hospital-gowned patients, some toting rolling IV poles, huddled in clumps under bus shelters or warming areas, smoking cigarettes.

Smoking causes 30 percent of all cancer deaths and 87 percent of all lung cancer deaths. Yet, roughly 50 percent to 83 percent of cancer patients keep smoking after a cancer diagnosis, through treatment and beyond, says Sonia Duffy, University of Michigan School of Nursing researcher. For patients who quit on their own, relapse rates (as in the general population) are as high as 85 percent.

Yet, continued smoking severely hampers cancer treatment, increases cancer recurrence and decreases survival, she says.

While it's easy to dismiss smoking as a lack of discipline or a disregard for one's own health, it's a much more complicated picture for these patients, says Duffy, lead researcher on the review paper, "Why Do Cancer Patients Smoke and What Can Providers Do About It," which appears in the journal Community Oncology.

"Ours is the first comprehensive review study to examine reasons why the very cause of the cancer, namely smoking, in many cases isn't treated," said Duffy, who said she wasn't prepared to find so many hurdles hindering smoking cessation in cancer patients.

"I think what surprised me when I did the review was the multitude of issues that cancer patients face, and that there are so many variables affecting why they don't get treatment, and if they do get treatment, why they may not respond. Nicotine addiction, health issues, emotional issues, psychological issues and system level issues are all in the way."

Other obstacles include limited access to quit-smoking programs, little social support, sleep deprivation, poor nutrition, lack of confidence in being able to quit and socioeconomic status. After back-to-back appointments and grueling chemotherapy or radiation protocols, many cancer patients simply lack time or energy to attend quit-smoking programs, Duffy says.

Depression is another big barrier to quitting smoking, and among cancer patients it's as high as 58 percent, compared to 10 percent in the general population, she says. And, while most lung cancer patients understand the relationship between smoking and their diagnosis, head-and-neck-cancer patients often don't make the connection.

Surprisingly, Duffy's research suggests that only 56 percent of family physicians urge their cancer patients to quit smoking. Most oncology providers suggest quitting, but the oncologist's main focus is on cancer treatment. Duffy's paper suggests that nurse-administered stop-smoking interventions may be the best way to reach cancer patients who smoke, yet many nurses are not trained to conduct cessation interventions. Duffy's next project will examine ways to specifically design quit-smoking programs for nurses to administer to cancer patients.

Duffy also has appointments at the Ann Arbor VA Center for Clinical Management Research and the U-M departments of Otolaryngology and Psychiatry. Other authors include Samantha Louzon of the Ann Arbor VA Center for Clinical Management Research and Ellen Gritz of the University of Texas MD Anderson Cancer Center.