Colorectal cancer epidemiology and prevention study in China

MicroRNA expression profiles identify biomarkers for predicting the response to chemoradiotherapy in rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) following surgery significantly improves the survival rate of patients with rectal cancer. However, nCRT is associated with significant adverse symptoms and high medical costs. Therefore, it is important to investigate potential biomarkers for the prediction of the response to nCRT in patients with rectal cancer. The present study identified candidate biomarkers for predicting a complete response (CR) to nCRT in patients with rectal cancer and investigated the associated mechanisms. Microarray data (accession no. GSE29298) was downloaded from the Gene Expression Omnibus database. Differentially expressed microRNAs (miRNAs/miR) were screened between the pathological CR (pCR) group and no pCR (incomplete response) group. miRNA target genes were predicted using the miRWalk 2.0 online tool and subjected to Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Furthermore, a miRNA co‑regulatory network was constructed and disease‑associated genes were predicted. The results demonstrated that a total of 36 upregulated and 5 downregulated miRNAs were identified between the two groups. Among these differentially expressed miRNAs, miR‑548c‑5p, miR‑548d‑5p and miR‑663a were significantly associated with a CR to nCRT. The co‑regulatory network and pathway analysis indicated that miR‑548c‑5p and miR‑548d‑5p may function together through stem cell pluripotency and ubiquitin‑mediated proteolysis signaling pathways. Furthermore, the prediction of disease‑associated genes demonstrated that miR‑548c‑5p/miR‑548d‑5p and miR‑663a may regulate genes associated with rectal cancer, including mutated in colorectal cancers (MCC) and adenomatous polyposis coli (APC), and colorectal neoplasms, including interleukin‑6 signal transducer (IL6ST), cell cycle checkpoint kinase 2 (CHEK2), marker of proliferation Ki‑67 (MKI67), cadherin 7 (CDH7), calreticulin (CALR) and transforming growth factor β1 (TGFB1). Therefore, miR‑548c‑5p, miR‑548d‑5p and miR‑663a are promising candidate biomarkers for predicting a CR to nCRT. miR‑548c‑5p/miR‑548d‑5p may be associated with a CR by regulating IL6ST, CHEK2, MKI67 and MCC. In addition, it may function through the pluripotency of stem cells and ubiquitin‑mediated proteolysis signaling pathways. miR‑663a may be associated with a CR to nCRT by targeting CDH7, CALR, APC and TGFβ1. Thus, the miRNA biomarkers investigated in the present study may represent novel therapeutic targets for the prediction and eventual improvement of the response to nCRT in patients with rectal cancer.

Effects of dual modified resistant indica rice starch on azoxymethane-induced incipient colon cancer in mice

In this study, the effects of different doses of dual modification-treated (DMT) indica rice resistant starch (IR-RS) on azoxymethane (AOM)-induced early colon cancer in mice were investigated. The investigated factors included body weight, gastrointestinal emptying rate, the number and morphology of aberrant crypt foci (ACFs) and the specific expressions of adenomatous polyposis coli (APC), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and cytochrome c genes. The results demonstrated that DMT IR-RS controlled the increase in the body weights of the mice, increased the gastrointestinal emptying rates and reduced the numbers of ACFs and aberrant crypts. Reverse transcription-polymerase chain reaction revealed that DMT IR-RS promoted the expression of APC, Bax and cytochrome c and inhibited the expression of Bcl-2. These results demonstrate that a DMT IR-RS diet may induce apoptosis and has beneficial health effects in AOM-induced early colon cancer in mice.

β1 integrin modulates tumor growth and apoptosis of human colorectal cancer

We aimed to ascertain whether β1 integrin (ITGB1) induces apoptosis of colorectal cancer (CRC) through regulation of the mitochondrial pathway in vitro and in vivo. We generated lentiviral vectors expressing ITGB1 or ITGB1-specific RNAi and an unrelated control vector. After infection of the HT29 cells, we used western blot analysis and flow cytometric analysis to validate the patterns of ITGB1 expression. Proliferation and apoptosis were evaluated by colony formation assay, flow cytometry and western blot analysis. Upregulation of ITGB1 significantly increased the proliferation of HT29 cells; however, the levels of Bcl-2 and cyclin D1 proteins were upregulated while Bax, caspase-3, caspase-9 and p21 were downregulated in the HT29-ITGB1 cells compared to these levels in the controls. Hoechst 33258 staining and flow cytometric analysis showed that ITGB1 may play a significant role in the apoptosis of CRC cells. Moreover, ITGB1 promoted the proliferation of cells in a xenograft tumor mouse model. TUNEL staining revealed a marked increase in the percentage of positive cells in the HT29-RNAi group (84.3 ± 4.0%), which were more significant than in the HT29-ITGB1 group (48.3 ± 2.9%) and the other two control groups, HT29 (52.0 ± 3.6%) and HT29-NC (49.7 ± 4.5%). These results suggest that ITGB1 regulates the growth and apoptosis of human colorectal cancer cells.

Involvement of SET in the Wnt signaling pathway and the development of human colorectal cancer

The SET oncoprotein is involved in cancer progression by modulating multiple cellular processes, including the inhibition of the tumor suppressor, protein phosphatase 2 (PP2A). Based upon these multiple activities, we hypothesized that targeted inhibition of SET is likely to have multiple discrete and measurable effects on cancer cells. In the present study, the mRNA expression levels of SET, PP2A and β-catenin were examined in 31 pairs of human colorectal adenocarcinoma tissues and corresponding adjacent normal colorectal tissues by quantitative real-time polymerase chain reaction (qPCR). A small interfering RNA targeting SET was transfected into the human colon carcinoma cell lines, LS174T and SW480. The mRNA levels of SET, PP2A, β-catenin, c-Myc, E-cadherin and p53 were determined by qPCR analysis and the protein levels of SET, c-Myc, PP2A and β-catenin were examined by western blot analysis. mRNA expression levels of SET and β-catenin were found to be elevated in 22 (70.9%) samples, while PP2A expression levels were upregulated in eight (25.8%) samples. In addition, the knockdown of SET mRNA expression caused the upregulation of PP2A and c-Myc in the two cell lines, whereas β-catenin, E-cadherin and p53 mRNA expression was downregulated. Consistent with these results, the protein expression of β-catenin and c-Myc was found to be downregulated, whereas PP2A was upregulated at the protein level. Based on these results, we proposed that SET is essential in the carcinogenesis of human colorectal adenocarcinoma. In addition, it is suggested that SET promotes carcinogenesis through regulation of the Wnt signaling pathway.

hClock gene expression in human colorectal carcinoma

In this study, we aimed to investigate changes in the expression of human Clock (hClock), a gene at the core of the circadian gene family, in colorectal carcinomas (CRCs) and to discuss the possible effects. Previous studies have revealed that the disruption of circadian rhythms is one of the endogenous factors that contribute to the initiation and development of CRCs. However, the underlying molecular changes to the circadian genes associated with CRCs have not been explored. Immunofluorescence and quantitative polymerase chain reaction (qPCR) analysis of the hCLOCK protein and gene expression were performed in 30 cases of CRC. The hCLOCK protein was expressed in all specimens obtained from 30 CRC patients. Higher levels of hCLOCK expression were observed in human CRC tissues compared with the paired non-cancerous tissues. hCLOCK expression was significantly higher in poorly differentiated, or late-stage, Dukes' grade tumors and in 64.3% of tumor cases with lymph node metastasis. The hClock gene was expressed in all specimens. A significantly higher expression of hClock was found in human CRC cases compared with paired non-cancerous tissues. There was a strong positive linear correlation between hClock gene expression and protein expression in human CRCs. A strong positive linear correlation was also found between hClock gene expression and ARNT, HIF-1α and VEGF expression in human CRCs. There was no significant correlation between hClock and Bak, Bax, Bid, tumor necrosis factor receptor I (TNFR I) and TNFR II. The circadian gene hClock was stably expressed in human colorectal mucosa and was important in regulating the expression of downstream clock-controlled genes. hCLOCK may interact with HIF-1α/ARNT and activate VEGF to stimulate tumor angiogenesis and metastasis.

Role of FBXL20 in human colorectal adenocarcinoma

In the present study, in order to determine whether the FBXL20 gene plays a role in the carcinogenesis of human colorectal adenocarcinoma, the mRNA expression levels of FBXL20 were examined in 30 pairs of human colorectal adenocarcinoma tissues and corresponding adjacent normal colorectal tissues by quantitative real-time PCR (qRT-PCR). The pGPU/GFP/Neo-FBXL20 siRNA expression vector was transfected into the human colon carcinoma cell lines, SW480 and SW620. The mRNA levels of β-catenin, c-Myc, cyclin D1, p53, PP2A, SET and E-cadherin were determined by qRT-PCR, whereas the protein levels of β-catenin, c-Myc, caspase-3 and SET were examined by western blot analysis. MTT assay and flow cytometry were employed to assess cell proliferation, apoptosis and the cell cycle. As shown by qRT-PCR, FBXL20 mRNA expression was upregulated in 76.7% of the tumor samples. Cell proliferation was inhibited by 33.3% in the SW480-FBXL20 cells and by 22.7% in the SW620-FBXL20 cells, compared to the corresponding control cells. Furthermore, the percentages of apoptotic cells were 21.3 and 17.1% in the SW480-FBXL20 and SW620-FBXL20 cells, whereas the percentages of G1 phase cells in the two cell lines were 90.13 and 78.13%, respectively. In addition, the mRNA expression of SET and E-cadherin was upregulated in the SW480-FBXL20 and SW620-FBXL20 cells, whereas that of β-catenin, c-Myc, cyclin D1, p53 and PP2A was downregulated. Consistently, the protein expression of β-catenin and c-Myc was downregulated, whereas that of SET and caspase-3 was upregulated. Based on these results, we can conclude that FBXL20 plays an essential role in the carcinogenesis of human colorectal adenocarcinoma. Moreover, our data suggest that FBXL20 promotes carcinogenesis through the regulation of the Wnt signaling pathway and caspase activation.

Prognostic significance of MID1 expression in colorectal carcinoma

AIM: To detect the expression of midline 1 (MID1) in human colorectal carcinoma and to assess its prognostic significance.

METHODS: Immunohistochemistry was used to detect the expression of MID1 protein in colorectal carcinoma specimens (n = 109). The relationship between the survival of patients with colorectal cancer and the expression of MID1 was investigated. Survival analyses were performed using the Kaplan-Meier method and Cox regression model.

RESULTS: MID1 expression significantly affected the survival of patients with colorectal carcinoma (P < 0.05). MID1 expression had a significantly negative correlation with lymph node metastasis (r = -0.204, P = 0.034) and depth of invasion (r = -0.223, P = 0.020), but was significantly positively correlated with differentiation degree (r = 0.236, P = 0.014). MID1 expression had no relationship with sex, age or tumor pathologic type. Kaplan-Meier analysis indicated that the 7-year cumulative survival rates for patients with high, medium and low MID1 expression were 69.2%, 45.0% and 30.0%, respectively, and their mean survival time was 91.101 mo ± 6.127 mo, 69.389 mo ± 7.512 mo, 50.358 mo ± 8.091 mo.

CONCLUSION: MID1 expression can be used as a parameter for the judgment of colorectal carcinoma differentiation, invasion and lymph node metastasis, and as a useful prognostic marker in patient with colorectal carcinoma.

Expression of circadian clock gene human Period2 (hPer2) in human colorectal carcinoma

Background

Recent studies have shown that disruption of circadian rhythms is one of the tumor promoting factors which contribute to mammalian cancer development and progression, but very little is known about the molecular changes of circadian genes in colorectal carcinoma (CRC). Thus, in this study, changes in the expression of human Period2 (hPer2), one of the key circadian clock regulators, in CRC and its correlation with prognosis were investigated.

Methods

Immunohistochemical (IHC) staining and real-time PCR for hPer2 were performed for 38 CRC cases.

Results

IHC analysis detected positive staining for hPer2 in 81.6% (31/38) of CRC tissues and 97.4% (37/38) of surrounding non-cancerous tissues (P < 0.05). Most colorectal cells in non-cancerous tissues were homogeneously stained. In contrast, in the paired cancerous tissues, a heterogeneous pattern was found with a significant portion of cancer cells displaying negative or weak hPer2 staining. In over 60% cases (24/38), the staining for hPer2 was much stronger in non-cancerous cells than in the paired cancerous cells. Well-differentiated cancer cells are more likely to maintain hPer2 expression than poorly-differentiated ones. Furthermore, associations of decreased hPer2 levels with patients' age, histological grade, TNM stage and expression of nucleus proliferation related antigen: Ki67 were also detected (P < 0.05). Expression of hPer2 did not correlate with that of either p53 or C-erB-2. Similar to hPer2 protein expression, quantitative RT-PCR for hPer2 also showed decreased mRNA expression in CRC.

Conclusion

These results suggest a role for hPer2 in normal colorectal cell function and the potential deregulation of hPer2 expression in the development, invasion, and metastasis of CRC.

Lymph node distribution and pattern of metastases in the mesorectum following total mesorectal excision using the modified fat clearing technique

AIM

To define the distribution, size, location and metastasis of lymph nodes (LNs) within the mesorectum from rectal cancer specimens following total mesorectal excision (TME) surgery without neoadjuvant therapy.

METHODS

Specimens from 60 patients who underwent TME were treated with modified fat clearing solution to retrieve LNs. The mesorectum was divided into right lateral, anterior, posterior and left lateral sides, which were further subdivided into three levels (upper, middle and lower).

RESULTS

1436 LNs were harvested, including 985 small LNs (<5 mm in size). The number of LNs from the anterior, posterior and bilateral mesorectum was 125 (8.7%), 696 (48.5%) and 615 (42.8%), respectively. In the longitudinal axis, the difference in distribution at the three levels was not significant. 200 LN metastases (mLNs) were detected in 33 patients. 48% (96/200) of these were small LNs. More mLNs, especially small LNs, were shown in the more advanced T stage patients. The mLN metastasis rate was not influenced by tumour level.

CONCLUSION

Small LN detection increased the accuracy of N staging by 20% in this study. The incidence of metastasis was the same among the anterior, bilateral and posterior areas of the mesorectum. An increased incidence of mLN metastasis in small LNs was associated with more advanced T staging. mLN metastasis rates in both middle and low rectal cancer were higher in the distal mesorectum than that in the proximal mesorectum. LN number and density were not consistent with spread of the primary tumour. Distal mLNs were found in 35% of cases of both middle and distal rectal cancer, implying a need for TME in both.

Circulating miR-221 directly amplified from plasma is a potential diagnostic and prognostic marker of colorectal cancer and is correlated with p53 expression

BACKGROUND AND AIM

Circulating miRNAs exist in serum and plasma and they can be used as a potential noninvasive molecular marker for colorectal cancer (CRC) diagnosis. The present study was to test the availability of direct amplification of miRNAs from plasma without RNA extraction, and to evaluate its clinical application value in CRC.

METHODS

Plasma miR-21, miR-221 and miR-222 levels were determined in 103 CRC patients and 37 healthy normal controls by quantitative reverse transcription-polymerase chain reaction. Immunohistochemical staining for p53, carcinoembryonic antigen (CEA), estrogen receptor (ER) and progesterone receptor (PR) was carried out in the same CRC patient cohort. The correlation between miR-221 levels and protein levels of p53, CEA, ER and PR, clinicopathological features or overall survival was analyzed.

RESULTS

A standard curve shows a good linearity between the log of sample input and C(T) values over three orders of magnitude of plasma miR-21, miR-221 and miR-222. ROC curve analysis reveals that the plasma levels of miR-221 is a potential biomarker for differentiating CRC patients from controls. Kaplan-Meier curve assessment shows that the elevated plasma miR-221 level is a significant prognostic factor for poor overall survival in CRC patients. The immunohistochemistry analysis demonstrates a significant correlation between plasma miR-221 level and p53 expression.

CONCLUSIONS

The direct amplification of plasma miR-221 can be used as a potential noninvasive molecular marker for diagnosis and prognosis of CRC and is correlated with p53 expression.

Development of a multiplex MethyLight assay for the detection of multigene methylation in human colorectal cancer

In peripheral blood, cell-free methylated DNA has been reported to be a useful biomarker of noninvasive blood screening for the detection of colorectal cancer (CRC), including the genes ALX homeobox 4 (ALX4), septin 9 (SEPT9), or transmembrane protein with EGF-like, and two follistatin-like domains 2 (TMEFF2). Here we report a multiplex MethyLight polymerase chain reaction (PCR) assay that simultaneously detected the methylation status of ALX4, SEPT9, and TMEFF2, as well as quantifying methylation level of these genes in a total of 127 fresh tissue samples and 182 peripheral blood samples from CRC patients. Using the multiplex MethyLight assay, methylated ALX4, SEPT9, and TMEFF2 occurred in 56, 78, and 75% of CRC tissue samples and in 48, 75, and 71% of peripheral blood samples from CRC patients. The sensitivities of the combined study using the three genes as biomarkers for the detection of CRC in primary tissues and peripheral blood samples were 84 and 81%, with specificities of 87 and 90%, respectively. Combining the specificity of real-time PCR, the high throughput of multiplex PCR, and the high sensitivity of multigene detection, this multiplex MethyLight PCR assay may allow for future screening programs with large-scale noninvasive blood testing for early-stage CRC.

Recurrence and surveillance of colorectal adenoma after polypectomy in a southern Chinese population

BACKGROUND AND AIM

Repeat colonoscopy is often performed within a short time after polypectomy due to the fear that colorectal adenomas were missed during the initial colonoscopy or that new adenomas have developed. The aim of this study was to estimate the actual recurrence rate of adenoma and its association with the length of the surveillance interval after polypectomy in a southern Chinese population.

METHODS

A total of 1,356 patients undergoing endoscopic polypectomy and completing three or more surveillence colonoscopies between 1976 and 2007 were retrospectively analyzed. The recurrence rates of adenoma and advanced adenoma and surveillance intervals after polypectomy were identified based on the features of adenomas detected on initial colonoscopy.

RESULTS

The recurrence rates of advanced adenoma in patients with non-advanced adenoma on the initial colonoscopy were 0.9, 3.9, 5.8, and 29.2% during surveillance intervals of 1-3, 3-5, 5-10, and 10-20 years post-initial colonoscopy; for patients with advanced adenoma on the initial colonoscopy, the recurrence rates were 3.8, 13.1, 34.7, and 52.0% during the same surveillance intervals, respectively. Older age (p < 0.05 for trend) and male sex [hazard ratio (HR) 2.11, 95% confidence interval (CI) 1.27-3.53] were significantly associated with recurrence for advanced adenoma, as were the size and number of baseline adenoma (p < 0.05 for trend), tubulovillous, villous adenoma (HR 2.57, 95% CI 1.24-5.32), and high-grade dysplasia (HR 1.61, 95% CI 1.07-2.42). When 5% of patients had recurring advanced adenoma, the surveillance interval was estimated to be 6.9 (95% CI 6.3-12.2) years in the low-risk group and 3.0 (95% CI 2.7-3.2) years in the high-risk group.

CONCLUSIONS

Among our patient group, the recurrence of advanced adenoma after polypectomy increased with the length of the surveillance interval. Based on our results, a 3-year follow-up of patients after polypectomy could be effective in preventing the recurrence of advanced adenoma in high-risk patients.

Impact of p27mt gene on transplantation model of human colorectal cancer in nude mice

AIM: To investigate the inhibitory and anti-metastatic effect of mutant p27 gene (p27mt) on the growth of colorectal cancer xenografts in nude mice and its underlying mechanism.

METHODS: Inhibitory effect of p27mt gene on the growth of colorectal cancer xenografts was determined by measurement of tumor size before and after direct intra-tumoral injection of Ad-p27mt in a pre-established transplantation model of human colorectal cancer in nude mice. Cell cycle and apoptosis were detected by flow cytometry performed on single-cell suspension from an isolated tumor. Expression of MMP-9 in tumor tissue was detected by immunohistochemistry.

RESULTS: The average sizes of transplantation tumors were 1.94 ± 0.67 cm³, 2.75 ± 0.83 cm³ and 3.01 ± 0.76 cm³ in the Ad-p27mt, Ad-LacZ and control groups, respectively (P < 0.05). The average proliferation rates were 37.34% ± 1.45%, 53.16% ± 3.27% and 54.48% ± 2.43%, in the Ad-p27mt, Ad-LacZ and control groups, respectively (P < 0.05). The average apoptosis rates were 19.79% ± 3.32%, 6.38% ± 4.91% and 7.25% ± 5.20% in the Ad-p27mt, Ad-LacZ and control groups, respectively (P < 0.01). The average MMP-9 expression rates were 20%, 75% and 66.7% in the Ad-p27mt, Ad-LacZ and control groups, respectively (P < 0.01).

CONCLUSION: p27mt inhibits the growth of transplanted tumor by blocking the proliferation of cancer xenografts and by promoting apoptosis of transplantated tumor cells, as well as decrease transpl-anted tumor metastasis.

Establishment and management of hereditary colorectal cancer tissue bank in Yunnan province

AIM: To establish a tissue bank of hereditary colorectal cancer to rescue and preserve the national resources of hereditary colorectal cancer family in Yunnan province.

METHODS: Specimens of whole blood, serum, plasma and stool of patients and their lineal consanguinity in hereditary colorectal cancer family were collected and then DNA was extracted from these specimens for preservation. Tissue specimens in vitro (including tumor tissues, peri-tumor tissues and normal tissues) were collected and paraffin-embedded sections were prepared of operative patients. At the same time, DNA specimens of whole blood and tumor tissue of sporadic colorectal cancers were taken as controls. Simultaneously we developed an information management system for tissue bank with the operating system platform for Window XP, database ACCESS2003.

RESULTS: From September 2007 to June 2008, we collected 14 hereditary colorectal families (10 FAP families and 4 HNPCC families) including 9 Han families, 2 Bai families, 2 Yi families and 1 Zang family. There were 356 blood specimens and 157 tissue specimens. DNA of all family members was extracted in reserve. And 354 blood specimens of sporadic colorectal cancer including 127 ones of non-Han nationalities were collected.

CONCLUSION: We established a standard tissue bank of hereditary colorectal cancer in Yunnan province.

Effects of resistant starch on colonic preneoplastic aberrant crypt foci in rats

This study was designed to determine the effects of resistant starch (RS) at different levels on the azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) at the pre-initiation (PI) and promotion (P) stages in Wistar rats. According to the consuming assigned diets, all animals received AOM at a dosage of 15 mg/kg once a week for two consecutive weeks. In experiment 1, four groups of rats (n=12) were given AOM after 3 weeks of consuming the AIN-76 (control group) and RS diets. In experiment 2, four groups of rats (n=12) were given AOM before 3 weeks of consuming the AIN-76 and RS diets. Rats were killed after 13 weeks of initial injecting AOM. Colons were fixed in formalin and ACF were quantified after staining. In experiment 1, rats fed RS had more ACF than that of the control fed rats. In experiment 2, rats fed RS had fewer ACF than that of the control fed rats. The results indicate that dietary RS suppresses AOM-induced ACF formation, only at the P stage. A significant dose-response effect was observed between suppression of ACF formation and dietary RS amount. However, RS promote the formation of ACF at the PI stage.

Alpha-methylacyl-CoA racemase/P504S overexpression in colorectal carcinoma is correlated with tumor differentiation

Alpha-methylacyl-CoA racemase (AMACR)/P504S is an enzyme involved in the metabolism of branched-chain fatty acids. Little is known about correlation of AMACR expression with colorectal carcinoma (CRC) differentiation and prognosis. We investigated the expression of AMACR in 106 cases of primary CRC, and in 47 lymph nodes with metastatic CRC by immunohistochemical analysis. These cases were divided into 3 groups according to the histologic differentiation of the primary tumors. group A included 50 cases of histologically well and moderately differentiated CRCs, 20 of these with lymph node metastasis; group B included 23 cases of well and moderately differentiated CRCs, histologically similar to group A, except these tumors had small foci (less than 20%) of high-grade carcinoma, and 10 of these had lymph node metastasis; group C included 33 cases of poorly differentiated adenocarcinoma and undifferentiated carcinoma, 17 with lymph node metastasis. The results showed the overall positive rates of expression in primary and metastatic CRCs were 59.4% and 46.8%, respectively. Expression in groups A (76.0%) and B (69.6%) was much higher than that in group C (27.3%). In group B, although overexpression of AMACR in primary tumors was similar to that of group A, it was only seen in 30.0% of group B metastatic tumors, which was similar to the rate of expression in group C (23.5%). In contrast, rates of expression in group A primary and metastatic tumors were similar (80.0% and 75.0%). Positive staining for AMACR in benign epithelium adjacent to tumor was rare (<2%). No relation was found between AMACR expression and overall survival. Our findings support the view that the expression of AMACR in CRC is correlated with tumor differentiation.

Preoperatively molecular staging with CM10 ProteinChip and SELDI-TOF-MS for colorectal cancer patients

OBJECTIVES

To detect the serum proteomic patterns by using SELDI-TOF-MS (surface enhanced laser desorption/ ionization-time of flight-mass spectrometry) technology and CM10 ProteinChip in colorectal cancer (CRC) patients, and to evaluate the significance of the proteomic patterns in the tumour staging of colorectal cancer.

METHODS

SELDI-TOF-MS and CM10 ProteinChip were used to detect the serum proteomic patterns of 76 patients with colorectal cancer, among them, 10 Stage I, 19 Stage II, 16 Stage III and 31 Stage IV samples. Different stage models were developed and validated by support vector machines, discriminant analysis and time-sequence analysis.

RESULTS

The Model I formed by 6 protein peaks (m/z: 2759.58, 2964.66, 2048.01, 4795.90, 4139.77 and 37761.60) could be used to distinguish local CRC patients (Stage I and Stage II) from regional CRC patients (Stage III) with an accuracy of 86.67% (39/45). The Model II formed by 3 protein peaks (m/z: 6885.30, 2058.32 and 8567.75) could be used to distinguish locoregional CRC patients (Stage I, Stage II and Stage III) from systematic CRC patients (Stage IV) with an accuracy of 75.00% (57/76). The Model III could distinguish Stage I from Stage II with an accuracy of 86.21% (25/29). The Model IV could distinguish Stage I from Stage III with accuracy of 84.62% (22/26). The Model V could distinguish Stage II from Stage III with accuracy of 85.71% (30/35). The Model VI could distinguish Stage II from Stage IV with accuracy of 80.00% (40/50). The Model VII could distinguish Stage III from Stage IV with accuracy of 78.72% (37/47). Different stage groups could be distinguished by the two-dimensional scattered spots figure obviously.

CONCLUSION

This method showed great success in preoperatively determining the colorectal cancer stage of patients.

Trend of morbidity and mortality of colorectal carcinoma in Nangang District of Harbin from 1992 to 2001

AIM: To determine the epidemiological characteristics of colorectal carcinoma (CRC) morbidity and mortality in Nangang District, Harbin, and to indicate the harmful effect of CRC on the people in that community.

METHODS: The data on morbidity and mortality of CRC in Nangang District (1992-2001) were sorted and coded according to ICD-9 criteria. The crude morbidity and mortality, age-standardized morbidity and mortality (adjusted by the world population), truncated morbidity and mortality (35-64 years old) as well as cumulative rates (0-65 years old) were calculated respectively. Trend u-test and u-test were adopted to analyze the preceding data. The morbidity and mortality in the near future were predicted based on Gray Modeling (GM1, 1).

RESULTS: The CRC morbidity and mortality had been significantly increasing year by year (u = 2.45, P <0.05; u = 1.97, P <0.05 respectively). The morbidity increased from 13.06/100 000 (1992-1993) to 19.37/100 000 (2000-2001) with an average of 4.83% for each year. The mortality for males and females increased from 2.83/100 000, 3.61/100 000 (1992-1993) to 9.60/100 000, 7.90/100 000 (2000-2001) with an anverage of 23.92% (u = 1.47, P >0.05) and 11.88% (u = 1.97, P <0.05) respectively. The age-standardized morbidity (adjusted by the world population) for males and females increased with a rate of 3.24% and 1.19% respectively. And the corresponding rates for mortality were 17.31% and 7.69% respectively. The cumulative and truncated morbidities were also increasing. The cumulative and truncated mortalities increased at an annual rate of 26.00%, 24.95% for males and 11.67%, 10.87 for females. The predicted morbidity and mortality were 28.15/100 000, 13.43/100 000 for males and 24.16/100 000, 20.45/100 000 for females respectively in 2006.

CONCLUSION: The morbidity and mortality of CRC have increased in 1992-2001, and will keep on increasing in the future, which are expected to reach 26.12/100 000 and 17.43/100 000 in 2006, respectively.

Clinical pathology and hereditary predisposition in patients with primary colorectal cancer: An analysis of 594 cases

AIM: To analyze the features of clinical pathology and hereditary predisposition of primary colorectal cancer (CRC) patients.

METHODS: A total of 594 primary CRC inpatients were continuously investigated in our hospital and cooperation hospitals. They were proved to be primary colorectal cancer by histopathological examination. The following data of all patients should be registered: sex, family history of colorectal cancer, site, number and histological type of primary cancer. Tumor sites were classified as proximal colon to the splenic flexure, distal colon to the splenic flexure and whole colorectum. Hereditary predisposition of CRC is that CRC patients have two or more first- or second-degree relatives (or both) with CRC. And hereditary predisposition of malignant tumor is that CRC patients have two or more first- or second-degree relatives (or both) with malignant tumor. Hereditary nonpolyposis colorectal cancer (HNPCC) was diagnosed by any of Amsterdam criteria, Amsterdam criteria II and Japanese criteria of HNPCC. CRC patients were divided into seven groups by the age being diagnosed.

RESULTS: The distribution of the age diagnosed as colorectal cancer was not normal distribution. The median diagnosed age of CRC patients was 65.1 years. There were more patients in -70 years group than other groups. In age of 70 years before, the proportion of patients was increasing with the increasing of age and more elder patients were found. But in more than 70 years old group, the proportion of patients was decreased by the increasing of patients age. Most of colorectal caner were located distal to the splenic flexure, and rectal cancer was in 45.3% patients. There was no correlation between tumor site and the age in CRC (P > 0.05). The most frequent histological type was adenocarcinoma (87.5%). In addition, the proportion of mucoid adenocarcinoma and signet-ring cell carcinoma were 8.2% and 5.2%, respectively. The proportion of signet-ring cell carcinoma was higher in older groups (P < 0.05). As to the proportion of multiple primary cancers, multiple primary CRCs, hereditary predisposition of cancer and hereditary predisposition of colorectal cancer were 13.1%, 10.1%, 17.2% and 5.2%, respectively. The incidence of HNPCC diagnosed by Amsterdam criteria, Amsterdam criteria Ⅱ and Japanese criteria of HNPCC were 0.5%, 2.9% and 2.4%, respectively. The correlation had been found between the occurrences of multiple primary cancers and multiple primary CRCs with familial history of malignant tumors (P < 0.05), and there were more multiple primary cancers and multiple primary CRCs in CRC patients with familial history of malignant tumors. But obvious correlation was not found between the occurrence of multiple primary cancers and multiple primary CRCs with familial history of CRCs (P > 0.05).

CONCLUSION: Age of patients with colorectal cancer is not normal distribution, and the proportion of elder patients with colorectal cancer becomes higher in all CRC patients. Most of tumors locate distal to the splenic flexure and adenocarcinoma is the most common histological type. There are 17.2% colorectal cancer patients with hereditary cancer predisposition. The occurrences of multiple primary cancers and multiple primary CRCs are correlated with familial history of malignant tumors.