本帖最後由 goodcat1111 於 2009-5-7 22:34 編輯
作者：Zosia Chustecka
出處：WebMD醫學新聞
April 23, 2009(科羅拉多州丹佛) — 耶魯醫學院流行病學與公共衛生副教授Melinda Irwin博士表示，腫瘤科醫師應建議癌症病患運動；有越來越多證據顯示運動可以改善預後以及生活品質。
不過，華盛頓大學Fred Hutchinson癌症中心的Cornelia Ulrich博士表示，有關維他命、礦物質、抗氧化劑的證據，還不足以對癌症病患提出有證據力的使用建議。
兩篇演講都發表於美國癌症研究協會第100屆年會中有關癌症生存的討論會中。
Irwin博士表示，運動益處的最佳證據來自乳癌病患的研究，顯示可以降低復發與癌症和其他各種原因之死亡率風險。她向Medscape Oncology表示，前列腺癌和大腸直腸癌也有一些類似益處的證據，但是我強烈認為，運動、特別是生活品質改善的好處，可以擴展到所有的癌症病患。
在回顧運動益處的研究中，Irwin博士引述一篇她們最近發表的文獻(J Clin Oncol. 2008:24;3958-3964)─「Health, Eating, Activity and Lifestyle (HEAL)」這個包括了933名乳癌病患的研究，結果顯示，適當強度運動可以降低診斷後兩年仍存活婦女67%的死亡風險；這包括了乳癌死亡以及其他死因，如心血管疾病和糖尿病。
其他研究認為，運動減少乳癌死亡率達40%至55%，她表示，這個程度和標準治療一樣多。
她表示，這些研究有關運動的建議各異 —有些目標是每週90分鐘、有些是每週2至3小時，但是HEAL研究顯示，任何運動量都有好處。在一些研究中，診斷時開始運動且到治療後都持之以恆。
Irwin博士表示，任何運動量都比沒有運動好。
她向Medscape Oncology解釋，腫瘤科醫師有獨特的機會提出運動建議，在介入治療結束時有最佳機會提出，因為屆時病患急欲知道可以為自己做些什麼。
Irwin博士表示，當然，腫瘤科醫師沒有時間討論運動處方的細節，但確實可以提出此一建議，由他們這些癌症專家提出的建議別有價值。
她表示，我們的研究顯示，腫瘤科醫師建議代表著病患的高接受度，但研究中只有半數病患表示他們的腫瘤科醫師有提出運動建議。
美國癌症協會以及美國運動醫學會在2009年1月發起確保癌症運動運動課程(Certified Cancer Exercise Training course)，美國由這個腫瘤科醫師將癌症病患轉介到體適能專業人士的新發展，帶來實現的可能性。
Irwin博士指出，這使腫瘤科醫師更容易提出建議。他們建議運動之後，將病患轉給訓練專員。
【有關補充品的證據不足】
Ulrich博士向與會聽眾表示，相較於運動，目前無法建議癌症病患使用補充品；沒有足夠證據提出有科學基礎的建議。
她表示，有些研究認為有好處，但是也有研究認為有副作用。舉例來說，有一篇研究認為，抗氧化劑干擾了頭頸部癌症病患的放射線治療，而有別的研究顯示，金絲桃科、聖約翰草因為顯著影響irinotecan代謝而降低了其效果。
Ulrich博士表示，儘管缺乏證據，大部份癌症病患有在使用補充品。最近的回顧發現，美國有64%至81%的成年癌症病患使用補充品，其中14%至32%在診斷後開始服用。當問到何以服用時，病患表示他們服用補充品是為了較佳的感覺、促進治癒機會，以及確保適當營養。
她表示，另一篇研究發現，31%至68%癌症病患與長期存活者服用補充品但是未告知醫師。
Irwin博士以及Ulrich博士宣告沒有相關財務關係。
美國癌症研究協會(AACR)第100屆年會。2009年4月21日舉辦的研討會。
AACR 2009: Oncologists Should Recommend Exercise, But Not Supplements
By Zosia Chustecka
Medscape Medical News
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 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. John'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. |
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