If you have been physically active during the year leading up to a breast cancer diagnosis, and you were overweight, your chances of surviving are significantly greater, say researchers from the University of North Carolina, Chapel Hill, USA.

Study leader, Page Abrahamson, said the benefits were more acute for women who are overweight or obese at around the time of diagnosis.

You can read about this study in the journal Cancer.

Before the study the team had noted that most epidemiologic studies had reported a lower risk of developing breast cancer among women with higher levels of recreational physical activity. However, little was known about what effects exercise might have on prognosis.

The team examined data on 1,264 women, aged 20-54. They had all been diagnosed with invasive breast cancer during the period 1990-92. They were interviewed within several months of diagnosis and information was gathered on their level and frequency of physical activity when they were 13 and 20 years old, as well as during the year leading up to their breast cancer diagnosis. They were all followed up eight and ten years after diagnosis.

They found that women who partook in regular physical activity in the year leading up to their diagnosis had a much better survival rate, especially those whose BMI (body mass index) was over 25. The 25% of women who did the most exercise during this period had a survival rate 21% higher than those who did very little or no exercise.

The researchers are not sure why the benefit was especially so for overweight women. They suggested that perhaps their finding is a fluke, and that improved survival may apply equally to all women with breast cancer who have been exercising regularly. Abrahamson said. “Once women receive radiation or chemotherapy after diagnosis, they no longer produce hormones from their ovaries. Therefore, lower-weight women wouldn’t necessarily gain extra benefit from exercise. However, for overweight women, they are still getting hormones from their excess fat tissue and are at a higher risk of dying. It is possible that overweight women who are exercising are lowering their hormone levels through exercise and increasing their odds of surviving. Previous studies have shown exercise to significantly decrease estrogen levels in overweight women.”

Frequency and intensity of exercise before the year leading up to diagnosis had no significant effect on survival rates, say the researchers.

“Recreational physical activity and survival among young women with breast cancer”
Page E. Abrahamson, PhD, Marilie D. Gammon, PhD, Mary Jo Lund, PhD, Julie A. Britton, PhD, Stephen W. Marshall, PhD, Elaine W. Flagg, PhD, Peggy L. Porter, MD, Louise A. Brinton, PhD, J. William Eley, MD, MPH, Ralph J. Coates, PhD
Cancer DOI 10.1002/cncr.22201
Click Here To View Abstract Online

Written by: Christian Nordqvist
Editor: Medical News Today