糖尿病惡化癌症術後的死亡率
作者：Janis C. Kelly
出處：WebMD醫學新聞
April 8, 2010 — 研究者在4月份糖尿病照護(Diabetes Care)期刊中的報告指出，新診斷的癌症病患，特別是大腸直腸癌或食道腫瘤患者，如果有第2型糖尿病，則術後死亡機率比沒有第2型糖尿病者高出50%。
馬里蘭州巴爾的摩約翰霍普金斯公共衛生學院流行病學系Bethany B. Barone等研究者，對於初次癌症治療之後的短期術後死亡率，進行了一個系統性回顧與統合分析，他們檢視了8,828篇前瞻文章，其中20篇符合質化系統性回顧的納入規範。
其中有15篇研究、病患樣本數從70- 32,621(中位數為427名病患)，有足夠的資訊納入統合分析；結果顯示，原本就有的糖尿病與癌症病患短期術後死亡率風險增加51%有關，納入干擾因素與出版偏見之後也是如此。
作者們報告指出，原本就有的糖尿病與各類型癌症的術後死亡率增加都有關(勝算比為1.85，95%信心區間 1.40- 2.45)。
共同作者、約翰霍普金斯醫學院流行病學與一般內科助理教授Hsien-Chieh "Jessica" Yeh博士表示，糖尿病患進行癌症手術時，他們的腫瘤科醫師與外科醫師應提高警覺。
她在聲明中表示，糖尿病患的術前、術中與術後照護都很重要，術前即應納入討論。
【風險為何增加？】
資深作者、Frederick L. Brancati醫師向Medscape Oncology表示，這篇研究與最近一篇顯示長期死亡風險增加40%的統合分析(JAMA. 2008 17;300:2754-2764)，兩者都提出了時間的問題。
約翰霍普金斯醫學院一般內科主任Brancati醫師表示，是否只是因為糖尿病導致心血管風險，而與癌症無關？這篇術後短期死亡率研究指出，有立即的風險，與癌症治療時機有關。
在目前的報告中，研究者提出原本就有的糖尿病影響癌症術後死亡率風險的兩個可能方式：敗血症或其他嚴重感染(此風險因為手術前後高血糖而增加)以及心肌梗塞。
他們寫道，糖尿病是多處血管床，包括冠狀動脈之粥狀動脈硬化慢性風險因素，也是一般人心肌梗塞和心血管疾病死亡的強力預測因子。
作者們指出，此研究有許多限制，包括人口統計資料有較大的異質性以及評估的干擾因素。
研究者發現，沒有研究評估糖尿病對乳癌或子宮內膜癌婦女術後死亡率風險的影響，因此，他們不確定這些研究發現是否可運用到有這些癌症的婦女。
Brancati醫師解釋，這些癌症患者的整體死亡率較低，所以難以發現警訊，因此，研究者未加以探究。
最後，研究者未能比較糖尿病對接受和未接受手術之癌症病患短期存活的影響，這個資料特別重要，因為已知糖尿病會影響治療決策，且讓某些病患決定進行非手術治療。
這次分析增加了對於「較佳的手術前後糖尿病照護是否可減少癌症術後死亡風險」的疑慮，但是，作者們指出，外科加護病房之密集胰島素治療的隨機控制試驗獲得的結果各異。
作者們結論表示，我們研究的主要意涵在於，腫瘤科醫師、外科醫師與癌症病患，在考慮治療選項時，都應對和糖尿病有關的術後死亡率風險增加有所警覺，但改善手術前後糖尿病照護是否可減少此一風險則尚屬未知。
研究作者皆宣告沒有相關財務關係。
Diabetes Worsens Postop Mortality in Cancer
By Janis C. Kelly
Medscape Medical News
April 8, 2010 — Newly diagnosed cancer patients, particularly those with colorectal or esophageal tumors, are 50% more likely to die after surgery if they have type?2 diabetes than if they do not, researchers report in the April issue of Diabetes Care.
Researchers, led by Bethany B. Barone, ScM, from the Department of Epidemiology, Johns Hopkins School of Public Health in Baltimore, Maryland, conducted a systematic review and meta-analysis of short-term postoperative mortality after initial cancer treatment. They identified 8828 prospective articles, of which 20 met the inclusion criteria for qualitative systematic review.
Fifteen studies, ranging in size from 70 to 32,621 patients (median, 427 patients), reported sufficient information to be combined in a meta-analysis. This showed that preexisting diabetes was associated with a 51% greater risk for short-term postoperative mortality in cancer patients, even after confounders and publication bias were accounted for.
Preexisting diabetes was associated with increased odds of postoperative mortality across all cancer types (odds ratio, 1.85, 95% confidence interval, 1.40?- 2.45), the authors report.
"Diabetic patients, their oncologists, and their surgeons should be aware of the increased risk when they have cancer surgery," said coauthor Hsien-Chieh "Jessica" Yeh, PhD, assistant professor of general internal medicine and epidemiology at the Johns Hopkins University School of Medicine.
"Care of diabetes before, during, and after surgery is very important. It should be part of the preoperative discussion," she said in a statement.
How Is Risk Increased?
Senior author Frederick L. Brancati, MD, told Medscape Oncology that this study and a recent meta-analysis that showed a 40% increased risk for death in the long-term (JAMA. 2008 17;300:2754-2764) both raise the question of timing.
"Was it just diabetes leading to cardiovascular risk 'on its own,' independent of cancer? This study of short-term mortality postop indicates that there's immediate risk, related in time to cancer treatment," said Dr. Brancati, chief of the Division of General Internal Medicine at Johns Hopkins School of Medicine.
In the current paper, the researchers suggest 2 ways that preexisting diabetes might influence postoperative mortality risk after cancer surgery: sepsis or other serious infections (with risk heightened by perioperative hyperglycemia), and myocardial infarction.
"Diabetes is a chronic risk factor for atherosclerosis in multiple vascular beds, including the coronary arteries, and is a strong predictor of myocardial infarction and cardiovascular disease death in the general population," they write.
This study has several limitations, the authors note, including "great heterogeneity in population demographics and in assessment of confounders."
The researchers found no studies evaluating the effect of diabetes on postoperative mortality in women with breast or endometrial cancer and, therefore, say they "are uncertain whether our findings apply to women with these cancers."
"Overall mortality is lower for these cancers, so it's harder to 'find the signal.' Therefore, researchers don't look there," Dr. Brancati explained.
Finally, the researchers were not able to compare the effect of diabetes on short-term survival in cancer patients who did and who did not undergo surgery. "This gap may be especially important because diabetes is known to influence treatment decisions and might steer some patients toward nonsurgical treatment," the authors write.
The analysis raises the question of whether better perioperative diabetes care would reduce the risk for postoperative mortality after cancer surgery, but the authors note that randomized controlled trials of intensive insulin therapy in surgical intensive care units "have yielded mixed results."
"The main implication of our study is that oncologists, surgeons, and cancer patients should be aware of the excess postoperative mortality risk related to diabetes when considering treatment options. Whether improvements in perioperative diabetes care can reduce this excess risk is uncertain," the authors conclude.
The researchers have disclosed no relevant financial relationships.
Diabetes Care. 2010;33:931-939.
