Abstract 3562: Overweight, inflammation of normal colorectal mucosa, and cancer risk.
Authors: Roncucci Luca , Mariani Francesco , Sena Paola , Palumbo Carla , Pedroni Monica 
Published: August 2012

Introduction: The relationship between chronic inflammation and risk of cancer is strongly supported by several observations on cancer in many tissues and organs. On the other hand, also an excess weight, resulting in accumulation of body fat, may be a risk factor for the development of some types of cancer. Several epidemiological studies have confirmed that an increase in Body Mass Index (BMI) is related to an increased risk of colorectal cancer. Some studies have shown that obesity can be considered a disease with a low-grade of inflammation. Myeloperoxydase (MPO) is one of the main enzymes characterizing polymorphonuclear cell activation, and may link the inflammatory response to metabolic alteration and neoplastic transformation. Aim: This study aimed at evaluating whether some anthropometric and clinical parameters in patients who underwent colonoscopy were related to the presence of colorectal tumors, and whether this relation may be explained by the level of inflammation of normal colorectal mucosa, assessed through the count of MPO-positive cells. Methods: We collected 210 samples of normal colorectal mucosa from 90 patients during colonoscopy, and fixed them in formalin and embedded in paraffin for histology. Thirty-four patients had colonic or rectal carcinoma, or one or more colorectal adenomas, 56 subjects had normal colonoscopy and were used as controls. For each patient, we measured: waist circumference, body mass index, blood pressure, and fasting glycemia. For each samples, we counted, after immunohistochemistry, the mean number of myeloperoxidase positive cells in at least twenty 100x optic fields on biopsies of normal colorectal mucosa. Results. Patients with waist circumference and BMI above or equal the threshold (for waist: 102 cm for men and 88 cm for women, for BMI 25) had higher percentages of colorectal tumors than subjects with parameters below the threshold (45% vs 33% for waist, and 42% vs 33% for BMI). Similar increases in percentages of lesions was observed according to blood pressure (41% above 140/90 and 35% below 140/90) and even more evident according to fasting glicemia (64% above or equal to 110mg/dl and 36% below). The mean number of MPO-positive cells in colorectal mucosa was strongly related to waist circumference, (2.7 ± 0.2, mean ± SEM, for waist equal or above the threesold according to sex vs 1.7 ± 0.2 for waist below the threesold, P&lt;0.001), expecially in women. Similar results were obtained for BMI (2.5 ± 0.2 for BMI equal or above 25 vs 1.8 ± 0.2 for BMI below 25, P&lt;0.001). No significant difference was observed according to blood pressure and fasting glicemia. Conclusions: Some anthropometric parameters related to overweight and body fat distribution are related to colorectal cancer risk and to the degree of mucosal inflammation. Thus, these easily measurable parameters may be useful for the identification of patients at high colorectal cancer risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3562. doi:1538-7445.AM2012-3562