[The difference of clinicopathologic features according to leptin expression in colorectal adenoma]

Colorectal adenoma and cancer are known to be associated with obesity. Leptin, an adipocyte-derived hormone that plays a crucial role in obesity has been suggested as a growth factor in colon cancer. However, the association between adenoma and leptin remains controversial. We evaluated the leptin expression in human colorectal adenoma and its correlation to clinicopathologic factors.

Leptin expression was assessed by immunohistochemistry in 91 samples of colorectal adenoma larger than 5 mm, which were removed by endoscopic polypectomy. All patients underwent colonoscopy for cancer screening at Seoul Paik Hospital from 2007 to 2008 and we only included the patients less than 50 years of age. Leptin expression and its relationship with clinicopathologic features were analyzed.

Eighty samples were available for the interpretation of leptin expression and showed positive in 42 (52.5%) cases and negative in 38 (47.5%) cases. As body mass index (BMI) increased based on World Health Organization (WHO) classification the positivity of leptin expression also increased (ptrend=0.02). In leptin positive group, the correlation of leptin expression with adenoma size and histological showed positive tendency without statistical significance.

Leptin expression of colorectal adenoma was associated with BMI. The question of whether leptin contributes to colorectal adenoma development is unresolved and will require additional studies.