大肠癌发病的相关因素

Clinical significance of expression of hMLH-1 and hMSH-2 in sporadic colorectal carcinoma in Chinese Han patients in Xinjiang

AIM: To investigate the clinical significance of expression of hMLH-1 and hMSH-2 in sporadic colorectal carcinoma (SCC) in Chinese Han patients in Xinjiang.

METHODS: Expression of hMLH-1 and hMSH-2 was detected by immunohistochemistry in 95 cases of SCC specimens collected from Chinese Han patients in Xinjiang and 65 cases of normal colorectal mucosa (NCM) specimens.

RESULTS: The positive rates of hMLH-1 and hMSH-2 expression in NCM were both 100%. The negative rates of hMLH-1 (31.6%) and hMSH-2 (18.9%) expression were significantly higher in SCC than in NCM (both P < 0.05). The negative rates of hMLH-1 and hMSH-2 protein expression were significantly higher in right-sided tumors than in left-sided and rectal tumors (P = 0.006, 0.002), and in poorly differentiated tumors than in well differentiated tumors (P = 0.014, 0.008). There was a positive correlation between the expression of hMLH-1 and hMSH-2 proteins in SCC.

CONCLUSION: Loss of expression of hMLH-1 and hMSH-2 proteins in SCC was observed in some Chinese Han patients in Xinjiang. Loss of expression of hMLH-1 and hMSH-2 proteins correlates with tumor differentiation and location. Combined detection of hMLH-1 and hMSH-2 expression may be used for evaluating the severity and prognosis of colorectal cancer.

Clinical significance of expression of YB-1 and P53 in colorectal tumors

AIM: To investigate the expression of YB-1 and P53 in colorectal carcinoma (CRC) of different stages and to analyze their correlation with clinicopathological features of CRC.

METHODS: Expression of YB-1 and P53 proteins in normal colorectal mucosa (NCM, n = 20), low-grade colorectal intraepithelial neoplasia (LGIN, n = 30), high-grade colorectal intraepithelial neoplasia (HGIN, n = 30), and colorectal carcinoma (CRC, n = 50) was detected by immunohistochemistry.

RESULTS: The strong positive rate of YB-1 expression in NCM was significantly lower than those in LGIN, HGIN, and CRC (0% vs 76.7%, 80.0%, 80.0%, all P < 0.05). The strong positive expression of YB-1 was statistically correlated with lymph node metastasis and TNM stage in CRC (both P > 0.05). The positive rate of P53 in NCM was significantly lower than those in LGIN, HGIN, and CRC (0% vs 6.7%, 40.0%, 60.0%, all P < 0.05). The positive expression of P53 was statistically correlated with degree of tumor differentiation, lymph node metastasis and TNM stage in CRC (all P < 0.05). The expression of YB-1 was positively correlated with that of P53 in CRC (r = 0.306, P < 0.05).

CONCLUSION: YB-1 and P53 play an important role in the development and metastasis of colorectal carcinoma. Combined detection of YB-1 and P53 proteins may be useful for judging the severity and prognosis of colorectal cancer.

Significance of KLF6 and WWOX protein expression in colorectal carcinoma

AIM: To investigate the expression of Kruppel-like factor 6 (KLF6) and WW domain-containing oxidoreductase (WWOX) proteins in colorectal carcinoma and to analyze their clinicopathological significance.

METHODS: The expression of KLF6 and WWOX proteins was detected by immunohistochemistry in 40 colorectal carcinoma specimens and 40 normal colorectal mucosa specimens.

RESULTS: The positive rates of KLF6 and WWOX protein expression differed significantly between colorectal carcinoma and normal colorectal mucosa (KLF6: 45.0% vs 82.5%, WWOX: 37.5% vs 90.0%, both P < 0.05). The expression of KLF6 and WWOX proteins was found to be associated with tumor differentiation, lymph node metastasis, and tumor invasion in colorectal carcinoma (all P < 0.05). A positive correlation was noted between the expression of KLF6 and that of WWOX in colorectal carcinoma (r = 0. 320, P < 0.05).

CONCLUSION: Reduced expression of KLF6 and WWOX proteins may be related with the development, progression, and prognosis of colorectal carcinoma. Combined detection of KLF6 and WWOX protein expression is helpful for diagnosis and evaluation of the prognosis of colorectal carcinoma.

Prognostic significance of CD83, CD1a and Ki-67 expression in colorectal carcinoma

AIM: To analyze the prognostic significance of CD83, CD1a, and Ki-67 expression in colorectal carcinoma.

METHODS: The expression of CD83, CD1a, and Ki-67 in 60 cases of colorectal cancer was detected by immunohistochemistry and flow cytometry (FCM). The correlations of CD83, CD1a, and Ki-67 expression with clinicopathological parameters and prognosis in colorectal cancer were analyzed.

RESULTS: Immunohistochemistry analysis showed that the positive rates of CD83 and CD1a in early-stage (Dukes' stage) colorectal cancer patients and those with a good prognosis were significantly higher than those in advanced-stage patients and those with a poor prognosis, respectively (all P < 0.05). FCM analysis showed that the positive rate of CD1a was significantly higher in early-stage colorectal cancer patients and those with a good prognosis than in advanced-stage patients and those with a poor prognosis, respectively (both P < 0.05). Both immunohistochemistry and FCM results showed that the positive rate of Ki-67 was significantly lower in early-stage colorectal cancer patients and those with a good prognosis than in advanced-stage patients and those with a poor prognosis, respectively (both P < 0.05).

CONCLUSION: CD83, CD1a, and Ki-67 expression is correlated with the Dukes' stage and prognosis of colorectal cancer and can therefore be used as a prognostic parameter for the disease.

Expression of SFRP2 and β-catenin in the carcinogenesis and progression of colorectal carcinoma

AIM: To investigate the role of Secreted Frizzled-related proteins 2 (SFRP2) and β-catenin in carcinogenesis and progression of colorectal carcinoma.

METHODS: Expression of SFRP2 and β-catenin proteins were examined immunohistochemically in 20 cases of normal colorectal mucosa, 20 cases of colorectal polyp, 36 cases of colorectal adenomas and 42 cases of colorectal carcinoma. The corresponding clinical data between the expression of SFRP2 and β-catenin proteins were analyzed retrospectively.

RESULTS: The positive expression rates of SFRP2 were significantly lower in colorectal carcinoma and colorectal adenoma than in normal colorectal mucosa and colorectal polyp (28.57% vs 100.0%, 95.0%; 36.11% vs 100.0%, 95.0%, all P < 0.05). The reduced membranous β-catenin expression rate was significantly higher in colorectal carcinoma than in normal colorectal mucosa, colorectal polyp and colorectal adenoma (52.4% vs 0%, 0%, 11.1%, all P < 0.05). The cytoplasmic and nuclear β-catenin expression rates were significantly higher in colorectal carcinoma and colorectal adenomas than in normal colorectal mucosa and colorectal polyp (64.3% vs 0%, 0%; 30.6% vs 0%, 0%, all P < 0.05), higher in colorectal carcinoma than in colorectal adenomas (P < 0.05). The positive expression of SFRP2, reduced membranous β-catenin expression and cytoplasmic and nuclear β-catenin expression in colorectal carcinoma were significantly correlated with the tumor differentiation, but not with the tumor position, morphology or size, lymph node metastasis or Duke's stage. Besides, the positive expression of SFRP2 was significantly correlated with the depth of invasion in colorectal carcinoma. The positive expression of SFRP2 was negatively correlated with the reduced membranous β-catenin expression (r = -0.452, P = 0.003) and cytoplasmic and nuclear β-catenin expression (r = -0.519, P = 0.000). There existed positive correlation between the reduced membranous β-catenin expression and cytoplasmic and nuclear β-catenin expression (r = 0.782, P = 0.000).

CONCLUSION: The expression of SFRP2 and β-catenin are closely correlated with the carcinogenesis and progression of colorectal carcinoma, and may be an early event. The positive expression of SFRP2 is negatively correlated with the reduced membranous β-catenin expression and cytoplasmic and nuclear β-catenin expression. The former may inhibit carcinogenesis and latter may promote carcinogenesis.

Investigation on the risks of colorectal cancer in patients with diabetes mellitus

AIM: To investigate the influences of DM-associated factors on the pathogenesis of colorectal cancer (CRC), and clarify whether diabetes mellitus (DM) is a risk factor of CRC.

METHODS: A case-control study was performed to compare 364 colorectal cancer patients (198 colon cancer patients and 166 rectal cancer patients) with 733 controls (patients without cancer), with respect to their family history of CRC and DM, personal DM history, habits of smoking and drinking, cholesterol and triglyceride levels.

RESULTS: The value of odds ratio (OR) in patients with DM history was 1.72 and that in patients with family DM history was 1.64. The value of OR in DM patients with family CRC history was 3.23, significantly higher in DM patients without family CRC history (OR = 1.57). After further analysis, the rate of DM patients with/without family CRC history was always higher than that in the controls. Logistic analysis showed that the age, gender, DM history, coronary heart disease, hypertension, smoking, drinking, and blood lipid had no marked relationship with colorectal cancer, but DM and family CRC history were correlated with the occurrence of colorectal cancer (OR = 2.99, P < 0.01; OR = 1.79, P < 0.01).

CONCLUSION: DM is an independent risk factor of CRC. Routine examination for CRC is recommended for DM patients to make earlier diagnosis of CRC and improve the prognosis of patients.

Immunohistochemical expression of carcinoembryonic antigen, P53, nm23, Ki-67, multidrug resistance-associated protein and their correlations with the clinicopathology in colorectal carcinoma

AIM: To investigate the mechanism of cyclooxygenase-2 (COX-2), basic fibroblast growth factor (bFGF) in the carcinogenesis of colorectal carcinoma and adenoma.

METHODS: The expression of CEA, P53, nm23, Ki-67 and MRP protein were detected by SP immunohistochemistry in colorectal carcinoma (n = 73) admitted from January 2003 to July 2006, and their clinical data and follow-up documents were analyzed retrospectively.

RESULTS: The positive rates of CEA, P53, nm23, Ki-67 and MRP protein expression in colorectal cancer were 82.2%, 68.5%, 75.3%, 84.9% and 64.4%, respectively. CEA and MRP expression had no correlations with the patients'ages, sex, tumor size or location and differentiation types of tumor, depth of invasion and lymph node metastasis, while P53, Ki-67 and nm23 expression were significantly correlated with the depth of invasion and lymph node metastasis. The positive rates of P53 and Ki-67 expression was significantly higher in Dukes C, D stages than those in Dukes A, B stages (82.8% vs 59.1%, P < 0.05; 100% vs 75.0%, P < 0.05), while the positive rate of nm23 expression was markedly lower (58.6% vs 86.4%, P < 0.05). The expression of CEA had a negative correlations with that of nm23 (r = -0.296, P = 0.011) in colorectal carcinoma. However, the expression of P53 had a positive correlations with that of Ki-67 (r = 0.308, P = 0.008). P53, Ki-67 and nm23 expression were significantly related to the prognosis. The positive rate of nm23 expression was notably higher in patients survived over or equal to 3 years than that in ones survived less than 3 years (92.9% vs 71.2%, P < 0.05), but the positive rates of P53 and Ki-67 expression were just in the opposite situation (42.9% vs 74.6%, P < 0.05; 64.3% vs 89.8%, P < 0.05).

CONCLUSION: P53, Ki-67 and nm23 were significantly correlated with the invasion, metastasis and prognosis of colorectal carcinoma. CEA may be a stimulative factor in the invasion and metastasis of colorectal cancer and MRP-induced drug resistance may be relatively independent. CEA, P53, nm23 and Ki-67 can serve as effective markers ini reflecting the invasion, metastasis and prognosis of colorectal carcinoma.