The Role of Adiponectin in Breast Cancer: A Meta-Analysis

<div><p>Published results suggests that high adiponectin level may decrease the risk of breast cancer. However, available evidence on breast cancer is conflicting. Therefore a meta-analysis was performed to assess the association between blood adiponectin and breast cancer risk. PubMed database, Web of Science, Elsevier Science, Springer Link and bibliographies of retrieved articles were searched for epidemiological studies published up to March 2013. Meta-analysis was performed on the combined effect values (OR) as well as standardized mean difference (SMD) including 17 studies. Fixed or random effect pooled measure was selected on the basis of homogeneity test among studies. The publication bias was assessed by the Egger’s regression asymmetry test and Begg’s rank correlation test with Begg’s funnel plot. Subgroup analyses and sensitivity analysis were also performed. A total of 13 studies involving 3578 breast cancer cases and 4363 controls contributed to the OR analysis. The high adiponectin level did not significantly affect breast cancer risk (OR=0.902, 95% CI=0.773–1.053). After excluding articles that were the key contributors to between-study heterogeneity, the OR of high adiponectin level was associated with decreased breast cancer risk (OR=0.838, 95% CI=0.744–0.943). There was a significantly association between high adiponectin level and postmenopausal breast cancer women (OR=0.752, 95%CI=0.604-0.936); and it was not associated with premenopausal breast cancer women (OR=0.895, 95%CI=0.638-1.256). The result of pooled measure on SMD was that the high adiponectin level was associated with decreased breast cancer risk (SMD= -0.348, 95% CI= -0.533--0.614) after excluding articles which were the key contributors to between-study heterogeneity. Our findings indicate that high adiponectin level might decrease the risk of postmenopausal breast cancer. More randomized clinical trials and observational studies are needed to confirm this association with underlying biological mechanisms in the future.</p> </div

Begg’s funnel plot (with pseudo 95% confidence intervals) to detect any publication bias.

<p>Begg’s funnel plot (with pseudo 95% confidence intervals) to detect any publication bias.</p

Flow diagram of the study selection process.

<p>Flow diagram of the study selection process.</p

The effect of adiponectin on postmenopausal breast cancer.

<p>The effect of adiponectin on postmenopausal breast cancer.</p

The effect of adiponectin on breast cancer (OR).

<p>The effect of adiponectin on breast cancer (OR).</p

The effect of adiponectin on breast cancer (SMD).

<p>The effect of adiponectin on breast cancer (SMD).</p

The investigation involved face-to-face interviews based on self-designed structured questionnaires and subsequente clinical breast examinations.

<p>And subjects with suspected positive physical signs would receive further ultrasonic and X-ray examinations and possible biopsies. After the above proceeds, breast cancer cases were identified. In total, 124,758 were collected in the study, and because of information loss, 122,058 cases were included in the final analysis.</p

Pathological information on cases of breast cancer.

<p>Pathological information on cases of breast cancer.</p

Explanation of terms used in the questionnaire.

<p>Explanation of terms used in the questionnaire.</p

Detailed distributions of the breast cancer cases from the four survey areas by age are shown in this figure.

<p>Overall, breast cancer cases identified in this study were primarily diagnosed in the 40–45 and 45–50 year age groups.</p