Comparison of Blood Leptin Concentration and Colonic Mucosa Leptin Expression in Colon Adenoma Patients and Healthy Control / 대한소화기학회지

BACKGROUND/AIMS: Obesity increases the risk of colorectal cancer and adenomatous polyp, and one of the underlying mechanisms of this increase is considered to be due to the growth promoting effects of adipokines, such as leptin. In order to investigate this finding, leptin expression in the colonic tissue and blood leptin concentration of the colonic adenoma patients were compared to those of the control group. METHODS: Colonic adenoma tissues were obtained by polypectomy (n=60). In these patients, normal colonic mucosa at remote areas from the polyp was also obtained and blood samples were collected as well. Age and sex matched control subjects were selected among those who showed normal colonic mucosa in health screening colonoscopy (n=60). RESULTS: There was no significant difference in serum leptin concentration between the colonic adenoma patients and control subjects. Leptin expression was noted in 43.3% of the colonic adenomas, but only in 6.7% of normal colonic mucosa from the control subjects (p<0.01). There were ten cases of concurrent adenocarcinoma in situ in adenoma patients, eight cases of which expressed leptin (p=0.01). In adenoma group, leptin expression rate was significantly high in larger adenomas and in obese patients (p<0.05). However, there was no statistically significant relationship between leptin expression in colonic mucosa and serum leptin level. CONCLUSIONS: Leptin expression was more frequently observed in colonic adenomas, especially in larger adenomas associated with adenocarcinoma in situ, but blood leptin level was not related to tissue leptin expression. Leptin expression was more frequently observed in obese patients from the adenoma group. Therefore, leptin may play an important role in colonic tumorigenesis and progression, especially in obese patient.

Comparison of Blood Leptin Concentration and Colonic Mucosa Leptin Expression in Colon Adenoma Patients and Healthy Control / 대한소화기학회지

BACKGROUND/AIMS: Obesity increases the risk of colorectal cancer and adenomatous polyp, and one of the underlying mechanisms of this increase is considered to be due to the growth promoting effects of adipokines, such as leptin. In order to investigate this finding, leptin expression in the colonic tissue and blood leptin concentration of the colonic adenoma patients were compared to those of the control group. METHODS: Colonic adenoma tissues were obtained by polypectomy (n=60). In these patients, normal colonic mucosa at remote areas from the polyp was also obtained and blood samples were collected as well. Age and sex matched control subjects were selected among those who showed normal colonic mucosa in health screening colonoscopy (n=60). RESULTS: There was no significant difference in serum leptin concentration between the colonic adenoma patients and control subjects. Leptin expression was noted in 43.3% of the colonic adenomas, but only in 6.7% of normal colonic mucosa from the control subjects (p<0.01). There were ten cases of concurrent adenocarcinoma in situ in adenoma patients, eight cases of which expressed leptin (p=0.01). In adenoma group, leptin expression rate was significantly high in larger adenomas and in obese patients (p<0.05). However, there was no statistically significant relationship between leptin expression in colonic mucosa and serum leptin level. CONCLUSIONS: Leptin expression was more frequently observed in colonic adenomas, especially in larger adenomas associated with adenocarcinoma in situ, but blood leptin level was not related to tissue leptin expression. Leptin expression was more frequently observed in obese patients from the adenoma group. Therefore, leptin may play an important role in colonic tumorigenesis and progression, especially in obese patient.

Early changes in carcinogenesis of colorectal adenomas / Cambios tempranos en la carcinogénesis de los adenomas colorectales

OBJECTIVES: Adenocarcinoma of the colon and rectum is the third most common cause of cancer deaths and the sixth most common cancer in the world. Adenomas are benign neoplastic lesions which can be transformed into carcinomas, but this is usually not the case. There should be some risk factors which lead to the development of carcinomas into adenomas. The aim of this study is to find out the early changes and high risk factors related to carcinogenesis in colonic polyps. METHODS: IIn this study, we reviewed nearly 1000 colonoscopic biopsies and chose 72 biopsies. We developed three groups (tubular adenomas group 1, villous adenomas group 2, normal mucosa group 3); each group had 24 different biopsies. P53, Ki-67, bcl-2, cyclin D1, E-cadherin, c-erb B2 immunohistochemistry and human papillomavirus (HPV) in-situ hybridization were used for analysis. RESULTS: Five of the seventy-two cases were positive in HPV in-situ analysis. Four of them were villous adenomas and one was a tubular adenoma. Ki-67 expression was limited only to crypts in group 3 but in groups 1 and 2, Ki-67 expression was seen both in crypt epithelium and surface epithelium. Cyclin D1, c-erb B2, bcl-2 expression was significantly increased in neoplastic polyps. CONCLUSION: Ki-67 expression, both in the crypt and surface epithelium, and cyclin D1, c-erb B2, bcl-2 over-expression may be a clue of dysplastic epithelium and if the role of HPV is elucidated and shown to be important in colonic carcinogenesis, then vaccination might prevent carcinogenesis caused by HPV.

OBJETIVOS: El adenocarcinoma del colon y recto es la tercera causa más común de muertes por cáncer y el sexto tipo de cáncer más común en el mundo. Los adenomas son lesiones neoplásicas benignas que pueden transformarse en carcinomas, pero éste normalmente no es el caso. Debe haber algunos factores de riesgo que conducen al desarrollo de carcinomas en adenomas. El objetivo de este estudio es averiguar los cambios tempranos y los factores de alto riesgo relacionados con la carcinogénesis en los pólipos colónicos. MÉTODOS: En este estudio, revisamos casi 1000 biopsias colonoscópicas y escogimos 72 biopsias. Desarrollamos tres grupos (grupo 1: adenomas tubulares, grupo 2: adenomas vilosos, grupo 3: mucosa normal); cada grupo tuvo 24 biopsias diferentes. Para el anílisis se utilizaron la inmunohistoquímica de P53, Ki-67, bcl-2, ciclina D1, E-cadherina, y c-erb B2, así como la hibridación in situ para la detección del virus del papiloma humano (VPH) RESULTADOS: Cinco de setenta y dos casos resultaron positivos en el análisis del VPH in-situ. Cuatro de ellos fueron adenomas vilosos, de los cuales uno era un adenoma tubular. La expresión Ki-67 está limitada sólo a las criptas en el grupo 3, pero en los grupos 1 y 2, la expresión Ki-67 se observó tanto en el epitelio de la cripta como en el epitelio de la superficie. La expresión de la ciclina D1, c-erb B2, y bcl- 2 se halla significativamente aumentada en los pólipos neoplásicos. CONCLUSIÓN: La expresión de Ki-67 tanto en el epitelio de la cripta como de la superficie, y la sobre-expesión de la ciclina D1, c-erb B2, bcl-2 puede ser una clave para el epitelio displásico, y si se aclara y demuestra que el papel del VPH es importante en la carcinogénesis colónica, entonces la vacunación podría prevenir los carcinogénesis inducidos por el VPH.