One-half of cancer patients continue to smoke after diagnosis

Nov 28 2005

A pair of articles from The University of Texas M. D. Anderson Cancer Center makes the case that patients would receive better care if physicians and researchers would address the issue of tobacco use after a cancer diagnosis and monitor tobacco use during clinical trials that test new agents.

One study, to appear in the January issue of the journal Cancer but available online Nov. 28, suggests that the time to help tobacco users quit is the moment they are diagnosed with cancer.

It notes that, without help, up to one-half of cancer patients either continue to smoke after diagnosis or relapse after stopping for a short time.

The other report, a commentary published in October in Cancer Epidemiology, Biomarkers & Prevention, argues that researchers conducting clinical trials should assess whether patients are using tobacco while participating in the study because the detrimental health effects of smoking could negatively influence overall results. The authors are not suggesting that patients who use tobacco should be excluded from these studies, but that smoking should be seen as another critical variable that could have an impact upon study outcome.

Both reports highlight the growing connection between tobacco use after cancer diagnosis and poorer treatment outcome. It has long been known that one-third of all cancers are associated with tobacco use, but new research demonstrates that if patients quit before treatment or participation in a clinical trial, their success rates, quality of life and chances of not developing a second primary cancer greatly improves.

"Tobacco use after cancer diagnosis has now become the elephant in the room, a huge issue in oncology that many in the field are ignoring," says the lead author of both papers, Ellen R. Gritz, Ph.D., professor and chair of the Department of Behavioral Science.

"We now need to realize that it is to the benefit of cancer patients that we address both of these issues by promoting tobacco cessation efforts and collecting data in clinical trials on tobacco use," she says.

In the Cancer study, the researchers say an ideal time to help patients quit smoking is at the time they are diagnosed with cancer. "One thing we want people to realize is that many cancer patients are highly motivated and interested in quitting smoking at diagnosis," says co-author Michelle Cororve Fingeret, Ph.D., a postdoctoral fellow in the Department of Behavioral Science. "This creates a teachable moment in which patients are more receptive to smoking cessation treatment and therefore are more likely to successfully quit."

According to Gritz, the studies she and other researchers have conducted demonstrate that using this "teachable moment" can help up to 70 percent of patients quit using tobacco, whereas the typical success rate for tobacco cessation in the general population is only about 20 percent.

"This demonstrates that the diagnosis of cancer is a wake-up call to many patients, one which demands our support if we want to provide the best outcomes possible," says Gritz.

"Patients want to live, and they want to take an active part in their treatment," says co-author Damon Vidrine, Dr.P.H., a postdoctoral fellow in the Department of Behavioral Science. "This is a way to help them do that and to improve their chance for a better outcome."

Despite such studies, the "teachable moment" that can help patients stop smoking is not being used nearly enough in the service of patient health, Gritz says. While many doctors ask if their cancer patients smoke, "they don't have the resources or the background to do more than to urge the patients to stop."

"Most physicians are not trained in treating behavioral dependencies, and when cancer is diagnosed, doctors and patients are immediately focused on treating the malignancy," she says. "Because smoking is so damaging to patients' health, it needs to be addressed in the treatment plan."

The issue is now vitally important, Gritz says, because research shows that smoking-related complications can be significantly reduced when patients stop smoking before surgery, and that the longer the interval between smoking cessation and initiation of cancer treatment, the better the prognosis.

Evidence from research studies cited in the article also demonstrates that for two of the major cancer treatment modalities - radiation therapy and surgery - smoking has been found to diminish treatment effectiveness, exacerbate side effects and interfere with wound healing. These adverse effects are found both in patients with smoking-related cancers and in those with nonsmoking-related cancers. Similar adverse effects are likely to occur with chemotherapy, but data are lacking.

She says that many oncologists at M. D. Anderson, especially those treating cancers known to be strongly associated with tobacco use (head and neck, lung), recommend that patients quit smoking before starting treatment.

The interventions that have been tested need not be expensive, nor do they have to rely on the physician alone, Vidrine says. "There are a growing number of resources, such as several forms of nicotine replacement, anti-depressant drugs and behavioral intervention," he says. "It might only require brief advice from the physician and cessation programs that can be administered by hospital-based nurses or other health-care workers."

In the Cancer Epidemiology, Biomarkers & Prevention commentary, the flip side of the coin is discussed - how ignoring tobacco use in patients participating in a clinical trial can affect conclusions on the effectiveness of an experimental agent or treatment.

"Now that we know that smoking produces detrimental effects on treatment outcomes, it makes sense that this is a contributing factor that could affect the success of a clinical trial," says Gritz.

But despite the critical relevance of smoking to cancer outcomes, most oncology clinical trials do not collect data on smoking history and status unless the malignancy is widely acknowledged to be smoking related, she says.

These data often are collected only when the patient registers for the clinical trial, the researchers say. Subsequent changes in smoking status for all patients during treatment or follow-up are monitored in very few trials and are not often reported in discussions about the outcome of the study, Gritz says.

"We can't ignore the obvious anymore," she says. "Tobacco use is a critical variable that affects cancer treatment and outcome, and it needs to be addressed."