Exercise linked to lower mortality with early prostate cancer

(Reuters Health) - Men with prostate cancer that hasn’t spread may have longer survival the more they exercise, a recent study suggests.

For these men, regular moderate or vigorous physical activity was associated with 31 percent to 37 percent lower likelihood of death during the study, compared to more modest amounts of exercise.

“This confirms and expands on previous work that shows an inverse association between recreational physical activity after diagnosis and risk of prostate cancer-specific mortality,” said lead study author Ying Wang of the American Cancer Society in Atlanta, Georgia, in email to Reuters Health.

Prostate cancer is the third leading cause of cancer death among U.S. men, according to the American Cancer Society. The country’s 3.3 million prostate cancer survivors account for 21 percent of all cancer survivors.

Wang and colleagues pulled data from a large, long-term study group established by the American Cancer Society in 1992, focusing on 7,000 men who were diagnosed with prostate cancer between 1992 and 2011.

The average age at cancer diagnosis was 71, and there were 2,700 deaths through 2012, including 450 due to prostate cancer and 750 due to heart disease. The average time from diagnosis to death was about eight years for those who died from cancer and 10 years for those who died from other causes.

Men who were more active before diagnosis were more likely to have lower-risk cancer tumors and a history of prostate screenings. They were also leaner, more likely to be nonsmokers and vitamin users and they ate more fish.

Both before and after diagnosis, walking accounted for 73 percent of the physical activity that men did, followed by 10 percent for cycling and 5 percent for aerobic exercise, according to the report in European Urology.

After standardizing the men’s weekly exercise times and intensity levels, the researchers compared mortality rates among all the men to those who did some physical activity but not much. They wanted to avoid comparisons to the least active men, who were likely also the sickest overall, because their sedentary lifestyles were potentially due to other reasons.

Based on exercise levels before diagnosis, moderate to vigorous exercise, including walking, was linked to lower risk of death from prostate cancer, but only for men with lower-risk tumors.

But after the diagnosis, the same levels of exercise were linked to lower risk of death from prostate cancer for all men, although the apparent benefit of walking was no longer statistically meaningful.

The rising rage of prostate cancer “keeps the conversation going” regarding efforts to prevent and treat it, said Dr. Antony Wekesa of Eurofins Lancaster Laboratories in Cork, Ireland, who wasn’t involved in the study.

A limitation of the study is that it used self-reported data about the men’s exercise and other lifestyle details, Wekesa told Reuters Health by email. The low number of minority participants also obscures possible differences among groups that often have higher prostate cancer rates.

Three clinical trials at the University of California, San Francisco are focused on the effects of physical activity in men with prostate cancer, noted Erin Van Blarigan of UCSF, who wasn’t involved in the current study.

The American Cancer Society and American College of Sports Medicine recommend at least 150 minutes of moderate physical activity or 75 minutes of vigorous exercise each week.

That guideline “is a good starting goal for men who have been diagnosed,” Van Blarigan told Reuters Health by email. “However, men with prostate cancer should work toward continuing to increase their physical activity . . . likely twice that amount.”

SOURCE: European Urology, online July 12, 2017.