Cancer Diagnosis May Not Generate Healthy Living

By Todd Neale
HALIFAX, Nova Scotia 30 april 2008-- Many cancer survivors don't follow healthy lifestyles, according to epidemiologists here.They are more likely to be non-smokers (82.6% to 91.6%) than adults in the general population (79.5%) but not more prone to exercise to recommended levels or to consume healthy diets, defined as having at least five servings of fruits and vegetables a day.In a study of more than 9,000 patients with a history of prostate, breast, colorectal, bladder, uterine cancer, or melanoma, 80.9% to 85.2% were not following the dietary recommendation of eating at least five servings of fruits and vegetables a day, Chris Blanchard, Ph.D., of Dalhousie University here, and colleagues reported in the May issue of the Journal of Clinical Oncology
And only 29.6% to 47.3% were getting the recommended 150 minutes of moderate-to-strenuous exercise or 60 minutes of strenuous physical activity a week, they said.
Only about one in 20 patients (3.6% to 5.8%) was following all three recommendations (smoking, diet, and exercise), and 7.3% to 12.5% were not following any.
This is concerning, the researchers said, because health-related quality of life increased significantly (P<0.001) across all cancer groups for each additional healthy behavior the patients had adopted.
The fact that most cancer survivors are not making the lifestyle changes necessary to improve their long-term outcomes illustrates the need to find ways to promote adherence to recommendations like those from the American Cancer Society, the researchers said.
Also, past studies have shown that physical activity is linked to health-related quality of life in cancer survivors, but more information is needed on the relationship between quality of life, smoking, and the consumption of recommended amounts of fruits and vegetables, they said.
Dr. Blanchard and colleagues analyzed self-reported and registry-based data on 9,105 patients with a history of cancer from the society's Study of Cancer Survivors-II. Breast, prostate, colorectal, bladder, uterine, and skin cancers were chosen because of their relatively lengthy long-term survival rates.
Health-related quality of life was assessed on the basis of eight physical and mental domains. Scores could range from 0 (worst) to 100.
Across all six cancer groups, those who were getting the recommended amount of exercise had higher health-related quality-of-life scores than those who were not, after controlling for age, race, education, marital status, disease stage, and comorbidities (P<0.05).
Patients with a history of breast, prostate, or colorectal cancer who ate the recommended amounts of fruits and vegetables and who did not smoke had significantly higher health-related quality-of-life scores than those who did not meet those criteria (P<0.05).
Melanoma survivors had higher health-related quality-of-life scores if they followed the fruits and vegetables recommendation (P<0.05), but no significant difference was found in regards to smoking.
No significant differences were found in the health-related quality-of-life scores in patients with a history of bladder or uterine cancer for either of the recommendations on fruits and vegetables or smoking.
There was an increasing trend for higher health-related quality-of-life scores among patients in all six cancer groups for each additional recommendation that was met (P<0.001 for all).
There was a difference of about eight points (on the scale of 100) between those who followed all three recommendations and those who did not follow any, a clinically significant change, according to study co-author Kevin Stein, Ph.D., of the American Cancer Society in Atlanta.
It would be challenging to implement an interventional program that considers multiple behaviors, the researchers said, but "doing so may provide an important opportunity to maximize the potency of the intervention from an outcomes perspective."
"Importantly," they said, "such an intervention should rely on a sound theoretical framework that takes multiple levels (i.e., intrapersonal, interpersonal, institutional, community, and policy) into account."
The authors acknowledged that the study was limited by the use of self-reported assessments of lifestyle behaviors, the lack of information on behaviors before the cancer diagnosis and the low overall response rate.
Also, the cross-sectional study design could not determine a causal relationship between these behaviors and an improved quality of life.
Finally, adding together the effects of various comorbidities may not account for the varying strengths of their effects on health-related quality of life.
The study was supported by intramural funding from the ACS.
One of Dr. Blanchard's co-authors, Kevin Stein, Ph.D., is an employee of the cancer society.
Primary source: Journal of Clinical OncologySource reference:Blanchard C, et al "Cancer survivors' adherence to lifestyle behavior recommendations and associations with health-related quality of life: Results from the American Cancer Society's Studies of Cancer Survivors (SCS-II)" J Clin Oncol 2008.