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Background: Lymph node metastasis (LNM) is a well-established prognostic factor for colon cancer. Preoperative LNM evaluation is relevant for planning colon cancer treatment. The aim of this study was to construct and evaluate a nomogram for predicting LNM in primary colon cancer according to pathological features. Patients and Methods: Six-hundred patients with clinicopathologically confirmed colon cancer (481 cases in the training set and 119 cases in the validation set) were enrolled in the Affiliated Cancer Hospital of Guangxi Medical University from January 2010 to December 2019. The expression of molecular markers (p53 and β-catenin) was determined by immunohistochemistry. Multivariate logistic regression was used to screen out independent risk factors, and a nomogram was established. The accuracy and discriminability of the nomogram were evaluated by consistency index and calibration curve. Results: Univariate logistic analysis revealed that LNM in colon cancer is significantly correlated (P <0.05) with tumor size, grading, stage, preoperative carcinoembryonic antigen (CEA) level, and peripheral nerve infiltration (PNI). Multivariate logistic regression analysis confirmed that CEA, grading, and PNI were independent prognostic factors of LNM (P <0.05). The nomogram for predicting LNM risk showed acceptable consistency and calibration capability in the training and validation sets. Conclusions: Preoperative CEA level, grading, and PNI were independent risk factor for LNM. Based on the present parameters, the constructed prediction model of LNM has potential application value. [ABSTRACT FROM AUTHOR]

To explore the spectrum of p53 gene mutations of sporadic colorectal carcinoma in Guangxi, a Zhuang autonomous region in southern China, we examined exons 2&nvsim; 11 and exon-intron junctions of p53 gene from 48 patients with sporadic colorectal carcinoma by using single strand conformation polymorphism (SSCP) and DNA direct sequencing. As a result, p53 gene mutations were found in 31.25 percent (15/48) of our patients. A total of 13 types of p53 gene mutations were found, namely, c.370T > G, c.524G > A, c.528C > G, c.529_546del18, c.536A > G, c.736A > G, c.743G > A, c.770_771del2, c.772G > T, c.814G > A, c.949delC, c.782+1G > A, and c.919+1G > C. Only a double heterozygote for c.370T > G and c.529_546del18 was found. All the other mutations were heterozygous. No homozygote was found. 524G > A was the most common mutation, accounting for 18.75 percent (3/16). c.370T > G could not be found in the whole somatic mutation section of IARC TP 53 mutation database (2004 version). c.528C > G, c.949delC, c.782+1G > A, and c.919+1G > C could not be found in colorectal carcinomas reported in the somatic mutation section of IARC TP 53 mutation database (2004 version). The frequency (45.83 percent) of p53 gene mutations in &nvge;60 years old patients was higher than that (16.67 percent) in < 60 year old patients (P < 0.05). The frequency (47.83 percent) of p53 gene mutations in rectal carcinoma was higher than that (16 percent) in colonic carcinoma (P < 0.025). [ABSTRACT FROM AUTHOR]