糖尿病可使乳腺癌风险增加27%

圣安东尼奥——一项纳入40项已发表研究、56,111例女性乳腺癌患者的Meta分析显示，糖尿病是乳腺癌的独立危险因素，可使乳腺癌风险增加27%，不过二者的关联仅限于绝经后的2型糖尿病患者。而且恶性肿瘤风险与血清胰岛素水平、胰岛素生长因子1水平、空腹血糖水平和C肽浓度均无关。

法国里昂国际预防研究所的Peter Boyle博士在圣安东尼奥乳腺癌研讨会上指出，上述结果提示，需要对高胰岛素血症参与乳腺癌发生的理论进行再评估，以解释为何风险增加仅限于绝经后患者而且与代谢控制指标无关。

这项Meta分析显示，乳腺癌的关键危险因素为肥胖和缺乏运动。而这两项早已被公认为糖尿病的危险因素。基于这项Meta分析的结果，Boyle博士认为，应将努力避免超重和增加体力活动作为预防糖尿病和乳腺癌的公共卫生策略的基础。

高水平的体力活动，不论是职业性的还是休闲性的，与绝经前女性被诊断为乳腺癌的相对风险降低17%独立相关，与绝经后女性的风险降低12%有关。肥胖与乳腺癌的关联则没有这么明确。超重或肥胖的绝经前女性罹患乳腺癌的风险显著低于较瘦者，而肥胖的绝经后女性则具有更高的乳腺癌风险。具体而言，体重指数(BMI)增加5 kg/m2——相当于身高1.7米的女性体重增加14.5 kg——与绝经后女性乳腺癌风险增加11%和绝经前女性风险降低10%相关。

Boyle博士及其同事还报告了另一项相关的Meta分析。在这项Meta分析中，作者观察了接受甘精胰岛素(来得时)治疗的女性的乳腺癌风险。之所以进行这项分析，是由于近期有证据显示吡格列酮与膀胱癌、利拉鲁肽与胰腺癌、胰岛素与肺癌、以及艾塞那肽与胰腺癌之间存在关联。

这项Meta分析纳入了3年来发表的18项流行病学研究，共对903,675例患者进行了270万人年的随访，涉及4,080例乳腺癌患者。分析结果显示，甘精胰岛素使用者的乳腺癌风险并不高于其他胰岛素使用者。事实上，甘精胰岛素使用者的癌症总风险降低了9%，具有统计学意义。这一差异主要来自结直肠癌风险的下降(14%)。作者还发现，延长甘精胰岛素治疗时间并不会增加乳腺癌风险。

这2项Meta分析均由赛诺菲-安万特公司(甘精胰岛素的生产商)资助。Boyle博士报告称无相关利益冲突，但有多位合著者是赛诺菲-安万特公司和其他胰岛素生产商的顾问。

爱思唯尔版权所有  未经授权请勿转载

SAN ANTONIO – Diabetes is independently associated with a 27% increased risk of breast cancer, but this elevated risk is confined to postmenopausal type 2 diabetic patients, a large meta-analysis has shown.

The meta-analysis, which included 40 published studies and 56,111 women with breast cancer, found no association between risk of the malignancy and circulating serum insulin level, insulin growth factor–1 level, fasting blood glucose level, or C-peptide concentration.

These findings suggest that the hyperinsulinemic theory of the pathogenesis of breast cancer may need to be reevaluated in order to account for the increased risk being confined to postmenopausal patients and unrelated to indices of metabolic control, Dr. Peter Boyle said at the annual San Antonio Breast Cancer Symposium.

The key risk factors for breast cancer that emerged from the meta-analysis were adiposity and lack of physical activity. Both are also well established as risk factors for diabetes.

Based on the findings from this meta-analysis, efforts to avoid overweight and increase physical activity should form the basis of a common public health strategy simultaneously aimed at preventing diabetes and breast cancer, according to Dr. Boyle of the International Prevention Research Institute in Lyon, France.

High levels of physical activity, whether occupational or recreational, were independently associated with a 17% reduction in the relative risk of being diagnosed with breast cancer in premenopausal women and a 12% decrease in the postmenopausal population.

The relationship between adiposity and breast cancer was less straightforward. Premenopausal women who were overweight or obese had a significantly lower breast cancer risk than did leaner women, while breast cancer risk was increased in adipose postmenopausal women. More specifically, a 5-U increase in body mass index – equivalent to an extra 14.5 kg in a woman 1.7 m tall – was associated with an 11% increased risk of breast cancer in postmenopausal women but a 10% reduction in risk in premenopausal women.

Dr. Boyle and coworkers also presented a related meta-analysis looking at breast cancer risk in women using insulin glargine (Lantus). The study was prompted by recent evidence linking pioglitazone to a possible increase in bladder cancer, liraglutide and pancreatic cancer, insulin use and lung cancer, and exenatide and pancreatic cancer.

This meta-analysis included 18 epidemiologic studies published within the past 3 years. Collectively the studies involved 4,080 cases of breast cancer in 903,675 patients followed for 2.7 million person-years.

The meta-analysis demonstrated no increase in breast cancer risk in insulin glargine users, compared with users of other insulins. Indeed, the risk of all forms of cancer was 9% lower in insulin glargine users, a statistically significant reduction. This was driven by a 14% reduction in the relative risk of colorectal cancer.

Another reassuring finding was that breast cancer risk did not increase with longer use of insulin glargine, as would be expected if a causal relationship existed, he added.

Both meta-analyses were funded by Sanofi-Aventis, which markets glargine. Dr. Boyle reported having no relevant financial conflicts, although several of his coinvestigators have served on advisory boards for Sanofi-Aventis and other insulin manufacturers.

学科代码：内分泌学与糖尿病 肿瘤学 妇产科学　　　关键词：EJC新闻 EJC
来源： EGMN