Physical health scores predict breast cancer outcomes

Survivors of breast cancer who had poor health scores were 27 percent more likely to experience either a recurrence of their cancer or a new breast cancer. Physical health also impacted survival quite strongly; risk of death from any cause was 65 percent greater among those with poorer health scores.

Researchers from UC San Diego Moores Cancer Center used data from three of the four cohorts included in the After Breast Cancer (ABC) Pooling Project to analyze the association of poor physical health and survival, along with a cluster of comorbidities. The physical health score has been shown in smaller studies to be an important predictor of future breast cancer events and overall survival in women with breast cancer.

"Here we see a single metric that predicts risk," said John P. Pierce, Ph.D., who is the Sam M. Walton professor for cancer prevention and associate director for population sciences at Moores Cancer Center. "Variables cluster together and are summarized in the physical health score. The question becomes how to improve the physical health status of this particular group of breast cancer survivors."

Physical health scores were measured for a total of 9,387 early-stage breast cancer survivors, using the SF-36 -- a multipurpose, short-form health survey taken after diagnosis, with follow-up occurring on average seven years later. The physical health score includes information about how an individual perceives their own physical functioning, bodily pain and limitations caused by physical problems.

About half the women in the sample had a physical health score that met the survey definition of poor physical health. Low physical health scores were strongly associated with a higher body mass index. The women with low scores were less physically active and were 64 percent more likely to have sleep difficulties. They also had 50 percent higher rates of high blood pressure and diabetes and were twice as likely to have arthritis.

By addressing this cluster of health concerns, clinicians can help women improve their health, feel better about their lives and reduce associated breast cancer risks, according to Pierce.

"Instead of looking at breast cancer survivors as a whole, we need to focus on the women with low physical health scores, those most at risk," he said. "An increase of 5 percent in their physical health score can reduce their risk. We can empower them to take charge of their health and thereby improve their chance of survival as well as their quality of life."