JAMA: Men with a high fitness level in midlife appear to be at lower risk
for lung and colorectal cancer, but not prostate cancer, and that higher
fitness level also may put them at lower risk of death if they are
diagnosed with cancer when they’re older, according to a study published
online by JAMA Oncology.
While the association between cardiorespiratory fitness (CRF) and
cardiovascular disease (CVD) has been well-established, the value of CRF
as a predictor of primary cancer has gotten less attention, according
to background in the study.
Susan G. Lakoski, M.D., M.S., of the University of Vermont,
Burlington, and coauthors looked at the association between midlife CRF
and incident cancer and survival following a cancer diagnosis at the
Medicare age of 65 or older. The study included 13,949 men who had a
baseline fitness exam where CRF was assessed in a treadmill test.
Fitness levels were assessed between 1971 and 2009 and lung, prostate
and colorectal cancers were assessed using Medicare data from 1999 to
2009.
During an average 6.5 years of surveillance for the 13,949 men, 1,310
of them were diagnosed with prostate cancer, 200 with lung cancer and
181 men with colorectal cancer.
The authors found that high CRF in midlife was associated with a 55
percent lower risk of lung cancer and a 44 percent lower risk of
colorectal cancer compared to men with low CRF. However this same
association was not seen between midlife CRF and prostate cancer, and
authors note the exact reasons for this are unknown, although they
speculate men with high CRF may be more prone to undergo preventive
screenings and therefore have a greater opportunity to be diagnosed with
prostate cancer.
The study also found that high CRF in midlife was associated with a
32 percent lower risk for cancer death among men who developed lung,
colorectal or prostate cancer at Medicare age compared with men with low
CRF. And, high CRF in midlife was associated with a 68 percent
reduction in CVD death compared with low CRF among men who developed
cancer.
“To our knowledge, this is the first study to demonstrate that CRF is
predictive of site-specific cancer incidence, as well as risk of death
from cancer or CVD following a cancer diagnosis. These findings provide
further support for the effectiveness of CRF assessment in preventive
health care settings. Future studies are required to determine the
absolute level of CRF necessary to prevent site-specific cancer as well
as evaluating the long-term effect of cancer diagnosis and mortality in
women,” the study concludes.
(JAMA Oncol. Published online March 26, 2015. doi:10.1001/jamaoncol.2015.0226. Available pre-embargo to the media at http://media.jamanetwork.com.)
Editor’s Note:
Authors made conflict of interest and funding/support disclosures.
Please see the article for additional information, including other
authors, author contributions and affiliations, financial disclosures,
funding and support, etc.