The tetrad BMI, leptin, leptin/adiponectin (L/A) ratio and CA 15-3 are reliable biomarkers of breast cancer.

Background: Several studies have reported that leptin levels, the leptin/adiponectin (L/A) ratio and carbohydrate antigen (CA) 15-3 are especially elevated in breast cancer patients with high body mass index (BMI). The purpose of this study was to evaluate BMI, leptin, L/A ratio and CA 15-3 all together as reliable biomarkers for breast cancer.

Methods: Serum levels of leptin, adiponectin and CA 15-3, as well as anthropometric and biochemical parameters were analysed in 88 female patients who participated in a mammography study. Predictive values of BMI, leptin, L/A ratio and CA 15-3 were determined with a 95% confidence interval.

Results: Women were diagnosed with either breast cancer (n = 40) or benign breast lesions (n = 48). Among anthropometric parameters, age (P ≤ 0.001), weight (P ≤ 0.05) and waist circumference (P ≤ 0.02) were higher in patients with breast cancer than in patients without this pathology. The 75th percentile values for BMI, leptin, L/A ratio and CA 15-3 were 29.24 kg/m(2), 26.65 ng/ml, 2.37 and 18.45 IU, respectively. The suggested odds ratio for breast cancer patients with the values that were above the 75th percentile of the tetrad was 6.7 (0.7505-60.0665 confidence interval).

Conclusion: When the four variables were analysed together, a sensitivity of 83.3%, specificity of 80%, positive predictive value of 83.3% and negative predictive value of 80% were obtained. Results indicate that using the 75th percentile set points for BMI, leptin, L/A ratio and CA 15-3 together could offer a reliable approach to determine which women are at high risk for developing breast cancer.