[Development and validation of a prognostic prediction model for patients with stage Ⅰ to Ⅲ colon cancer incorporating high-risk pathological features]

Objective: To examine a predictive model that incorporating high risk pathological factors for the prognosis of stage Ⅰ to Ⅲ colon cancer. Methods: This study retrospectively collected clinicopathological information and survival outcomes of stage Ⅰ~Ⅲ colon cancer patients who underwent curative surgery in 7 tertiary hospitals in China from January 1, 2016 to December 31, 2017. A total of 1 650 patients were enrolled, aged (M(IQR)) 62 (18) years (range: 14 to 100). There were 963 males and 687 females. The median follow-up period was 51 months. The Cox proportional hazardous regression model was utilized to select high-risk pathological factors, establish the nomogram and scoring system. The Bootstrap resampling method was utilized for internal validation of the model, the concordance index (C-index) was used to assess discrimination and calibration curves were presented to assess model calibration. The Kaplan-Meier method was used to plot survival curves after risk grouping, and Cox regression was used to compare disease-free survival between subgroups. Results: Age (HR=1.020, 95%CI: 1.008 to 1.033, P=0.001), T stage (T3:HR=1.995,95%CI:1.062 to 3.750,P=0.032;T4:HR=4.196, 95%CI: 2.188 to 8.045, P<0.01), N stage (N1: HR=1.834, 95%CI: 1.307 to 2.574, P<0.01; N2: HR=3.970, 95%CI: 2.724 to 5.787, P<0.01) and number of lymph nodes examined (≥36: HR=0.438, 95%CI: 0.242 to 0.790, P=0.006) were independently associated with disease-free survival. The C-index of the scoring model (model 1) based on age, T stage, N stage, and dichotomous variables of the lymph nodes examined (<12 and ≥12) was 0.723, and the C-index of the scoring model (model 2) based on age, T stage, N stage, and multi-categorical variables of the lymph nodes examined (<12, 12 to <24, 24 to <36, and ≥36) was 0.726. A scoring system was established based on age, T stage, N stage, and multi-categorical variables of lymph nodes examined, the 3-year DFS of the low-risk (≤1), middle-risk (2 to 4) and high-risk (≥5) group were 96.3% (n=711), 89.0% (n=626) and 71.4% (n=313), respectively. Statistically significant difference was observed among groups (P<0.01). Conclusions: The number of lymph nodes examined was an independent prognostic factor for disease-free survival after curative surgery in patients with stage Ⅰ to Ⅲ colon cancer. Incorporating the number of lymph nodes examined as a multi-categorical variable into the T and N staging system could improve prognostic predictive validity.

Clinicopathological characteristics and prognosis of schistosomal colorectal cancer

AIM

The aim of the present study was to investigate the clinicopathological characteristics and prognostic factors of schistosomal colorectal cancer.

METHOD

A total of 74 consecutive schistosomal colorectal cancer patients who underwent curative surgery from July 2009 to July 2012 were included in this study. The clinical and pathological characteristics of all 74 patients were analysed and univariate and multivariate analyses were performed. This study demonstrated positive correlations between the site of deposition of schistosomal eggs and certain essential variables.

RESULTS

Depositional site of schistosome eggs, carcinoembryonic antigen (CEA) level and the pathological N and T stages were statistically significantly correlated with overall survival (OS). The pathological T stage and the CEA level were independent prognostic factors for OS. The site of deposition of schistosome eggs was positively correlated with the T and N stages, tumour size, the CEA level and the resection margins.

CONCLUSIONS

Schistosome eggs might be associated with tumorigenesis. The site of deposition of schistosome eggs was statistically significantly correlated with OS but it was not an independent prognostic factor for OS. It was, however, correlated with the depth of the tumour. The presence of schistosoma eggs at the margin did not affect the patient's prognosis or anastomotic healing. The existing standard surgical approach was equally applicable to schistosomal colorectal cancer. It was not necessary to expand the scope of surgical resection.

Identification of smut-responsive genes in sugarcane using cDNA-SRAP

Sugarcane smut, caused by the fungus Sporisorium scitamineum, is one of the main diseases that affect sugarcane worldwide. In the present study, the cDNA-SRAP technique was used to identify genes that are likely to be involved in the response of sugarcane to S. scitamineum infection. In total, 21 bands with significant differential expression during cDNA-SRAP analysis were cloned and sequenced. Real-time qPCR confirmation demonstrated that expression of 19 of these 21 differential bands was consistent with the expression observed during cDNA-SRAP analysis, with a deduced false positive rate of 9.5%. Sequence alignment indicated that 18 of 19 differentially expressed genes showed homologies from 19% to 100% to certain genes in GenBank, including the following genes: topoisomerase (EU048780), ethylene insensitive (EU048778), and tetraspanin (EU048770). A real-time qPCR assay showed that during 0-72 h after pathogen infection, expression of the topoisomerase and the ethylene insensitive genes was upregulated, whereas expression of the tetraspanin gene was downregulated, identical to the expression patterns observed under salicylic acid treatment. Therefore, all three genes are thought to play a role during S. scitamineum challenge, but with different functions. To our knowledge, this is the first report on the application of cDNA-SRAP in differential gene expression analysis of sugarcane during a sugarcane-S. scitamineum interaction. The results obtained also contribute to a better understanding of the molecular mechanisms associated with sugarcane-S. scitamineum interactions.

Relationship between esophageal cancer and interactions of genes and environmental factors

AIM: To explore the risk factors of esophageal cancer and these factors' interaction from the angle of environment and heredity.

METHODS: Using a case-control study, we performed epidemiologic investigations on all the objects. Immunohistochemical method was adopted to detect P53, P16 and CyclinD1 protein expressions in 47 patients and 50 controls. Multivariate analysis was used to assess the relationship between the environmental factors and gene expression in the progress of esophageal cancer.

RESULTS: At the certain level(α = 0.10)Significant risk factors(P = 0.10) included substantive intake of mildewed potatoes(P = 6.396), smoking(P = 3.054), esophageal cancer with family history (P = 6.120), over-expression of p53 protein (P = 7.028) and absent expression of p16 protein (P = 4.676). Tea drinking (P = 0.241) and frequent intake of bean product (P = 0.160) were the protective factors. Synergism was significantly showed in interactions between over-expression of P53 and smoking, substantive intake of mildewed potatoes, esophageal cancer with family history, as well as between absent expression of p16 protein and those above factors. On the contrary, tea drinking could antagonize the mutation of p53 gene and influence family history of esophageal cancer.

CONCLUSION: Environmental factors together with heredity play important roles in the high incidence of esophageal cancer in Fujian province and the interactions between gene and environment were particularly significant in the development of esophageal cancer.