Breast cancer survivors who pick up the exercise habit are healthier overall and report a better quality of life than other survivors who are inactive, according to researchers at USC and UCLA.
Researchers interviewed 374 breast cancer patients more than a decade after their initial diagnosis about their exercise routines and physical and mental health.
Results of the study, one of the longest follow-up studies done on life after breast cancer, will appear in an upcoming issue of the journal Quality of Life Research, but findings were published early on the journal’s Web site.
“Millions of women are surviving breast cancer today, and the issues facing these survivors are complex,” said Leslie Bernstein, holder of the and AFLAC Chair in Cancer Research in the Keck School of Medicine of USC and the study’s senior author.
“If we can come to better understand the factors that successfully improve survivorship, we may be able to make better recommendations for living life after cancer,” said Bernstein, who is also a professor of preventive medicine.
The research team collected information from hundreds of breast cancer patients in Los Angeles County who were first diagnosed between 1983 and 1988 at ages 40 years or younger.
The women participated in a case-control study of risk factors for breast cancer during the 1980s and were part of the study that first identified physical activity as a means for reducing breast cancer risk.
At that time, researchers collected detailed information on lifetime physical activities before breast cancer diagnosis, weight history and other potential breast cancer risk factors.
Women were interviewed again about 13 years after cancer diagnosis.
Interviewers asked women about their history of exercise after breast cancer, determining the type of activity they typically did, as well as how often they participated and how long activities lasted.
The interviewers also asked about weight and whether women had been diagnosed with any diseases (cardiovascular problems or diabetes, for example) or if they had dealt with mental-health issues. Finally, they also asked about quality-of-life issues: level of energy and fatigue, bodily pain and emotional well-being, for example.
Researchers found that survivors’ quality of life was nearly comparable to that of American women as a whole. They also saw that many women became more active after breast cancer.
About 51 percent of the women were consistently inactive before diagnosis, but only 44 percent remained inactive after diagnosis. Before diagnosis, women exercised an average of 1.8 hours a week, while they were active for 2.7 hours weekly in the years afterward.
In addition, more women started exercising after diagnosis than quit exercising. The most popular types of activity included aerobics, brisk walking, general walking, jogging and weightlifting.
“We were somewhat surprised that this cohort of breast cancer survivors were more active following diagnosis than prior to diagnosis, as studies conducted within two to three years after diagnosis suggest that women become less active,” Bernstein said.
When the researchers compared exercise levels to survivors’ quality of life, they found that women who were inactive before diagnosis but who became active after diagnosis scored the highest on measures of mental and physical health.
“In this group, we saw that women who increased their activity after diagnosis � compared to their activity level before diagnosis � scored higher on quality-of-life measures, even 10 years after diagnosis,” Bernstein said.
Women who increased their exercise activities reported less bodily pain and better general health.
Bernstein noted that researchers cannot be certain whether exercise activity actually improved quality of life, or if women with a better quality of life tended to do more exercise. Also, women in the study were diagnosed at young ages, before menopause, so exercise findings might not necessarily apply to older women.
However, the results confirm that the quality of life of long-term breast cancer survivors is quite similar to that of women of the same ages who have not had breast cancer, and that exercise is associated with quality-of-life improvements.
Future studies will further elaborate on physical activity’s potential role in maintaining and improving health for cancer patients after diagnosis.
The National Cancer Institute funded the research. The American Cancer Society also supported the research through a clinical research professorship award.