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* American Association for Cancer Research (AACR) 100th Annual Meeting

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From <http://www.medscape.com/news>Medscape Medical News

AACR 2009: Oncologists Should Recommend Exercise, But Not Supplements

Zosia Chustecka

April 23, 2009 (Denver, Colorado) ­ Oncologists

should recommend exercise to cancer patients;

there is accumulating evidence to show that it

can improve both prognosis and quality of life,

according to Melinda Irwin, PhD, MPH, associate

professor of epidemiology and public health at

the Yale School of Medicine, in New Haven, Connecticut.

However, the evidence for supplements, such as

vitamins, minerals, and antioxidants, is

insufficient to make any science-based

recommendations on their use in cancer patients,

according to Cornelia Ulrich, MS, PhD, from the

Fred Hutchinson Cancer Center, University of Washington, in Seattle.

Both were speaking at a symposium on cancer

survivorship here at the American Association for

Cancer Research 100th Annual Meeting.

The best evidence for the benefits of exercise

comes from studies of breast cancer patients,

where it has been shown to reduce the risk for

relapse and mortality ­ both from cancer and all

causes, Dr. Irwin said. There is also some

evidence of a similar benefit in prostate and

colorectal cancer. " But I would strongly

hypothesize that the benefits from exercise ­

particularly for improving quality of life ­

would extend to all cancers, " she told Medscape Oncology.

In reviewing studies showing benefits from

exercise, Dr. Irwin cited 1 that her own group

published recently (J Clin Oncol.

2008:24;3958-3964). The Health, Eating, Activity

and Lifestyle (HEAL) study of 933 breast cancer

patients showed that moderate-intensity physical

activity reduced the risk for death by 67% in

women who remained active 2 years after

diagnosis. This was both breast cancer mortality

and deaths from other causes, mostly

cardiovascular disease and diabetes, she added.

Other studies have suggested that exercise

reduces the risk for breast cancer mortality by

40% to 55%, " which is as much as standard treatments, " she said.

These studies have varied in their

recommendations for exercise ­ some aimed for 90

minutes a week, others for 2 to 3 hours a week,

but the HEAL study showed a benefit from any

amount of exercise, she said. In some of the

studies, exercise started at diagnosis and

continued throughout and after the treatment.

" Any amount of exercise is better than none, " Dr. Irwin said.

" Oncologists are uniquely placed to recommend

exercise, and they have the perfect opportunity

to intervene as treatment is ending, because

patients are then eager to learn what else they

can do to help themselves, " she explained to Medscape Oncology.

" Of course, oncologists do not have the time to

discuss exercise regimens in detail, " Dr. Irwin

acknowledged, but the fact that the

recommendation is made by them, as cancer specialists, is " very valuable. "

" Our study showed that oncologist recommendation

is a strong predictor of uptake, " she said, " but

only half the patients in the study said that

their oncologist had mentioned exercise. "

A new development may make it possible soon for

oncologists in the United States to refer their

cancer patients to physical-fitness professionals

that are specifically trained for this work. The

American Cancer Society and the American College

of Sports Medicine launched a

<http://www.acsm.org/Content/NavigationMenu/Certification/Certifica%20tionHome/H\

ealth_Fitness_and_.htm>Certified

Cancer Exercise Training course in January 2009.

" This would make it much easier for oncologists, "

Dr. Irwin noted. " They could recommend exercise,

and then refer the patient to a trained professional. "

Insufficient Evidence on Supplements

In contrast to exercise, the use of supplements

by cancer patients cannot be recommended at

present; there is insufficient evidence to make

science-based recommendations, Dr. Ulrich told the audience.

Some studies have suggested a benefit, but there

have also been some that suggested adverse

effects, she said. For example, 1 study suggested

that antioxidants interfere with radiation

therapy in patients with head and neck cancer,

whereas another showed that the popular herbal

remedy St. 's wort significantly reduced the

efficacy of irinotecan by interfering with its metabolism.

Despite the lack of evidence, supplements are

used by the majority of cancer patients, Dr.

Ulrich said. A recent review found that 64% to

81% of all adult cancer patients in the Untied

States take supplements, and 14% to 32% of them

started taking them after diagnosis. When asked

why, patients said they took supplements " in

order to feel better, to enhance their chance of

a cure, to retain a sense of control, and to ensure adequate nutrition. "

Another study found that 31% to 68% of cancer

patients and long-term survivors take supplements

but don't tell their doctors, she said.

Dr. Irwin and Dr. Ulrich have disclosed no relevant financial relationships.

American Association for Cancer Research (AACR)

100th Annual Meeting. Symposium held April 21, 2009.