Expression of plasma methylated Septin9 gene and its clinical significance in patients with gastric cancer

Background and purpose: Gastric cancer is one of the most common malignant tumors in our country. The diagnosis and treatment process of gastric cancer lacks of sensitive and specific biomarker. This study aimed to explore the expression of plasma methylated Septin9 gene (mSEPT9) and its clinical significance in patients with gastric cancer. Methods: From April 2020 to November 2020, 221 patients with gastric cancer and 34 patients with no evidence of disease who visited Zhongshan Hospital Fudan University were enrolled. The status of mSEPT9 was detected by polymerase chain reaction (PCR) fluorescence probe method, and relative mSEPT9 value was determined by the ΔΔCt method. Detailed clinical data including pathological characteristics (patients characteristics and pathology characteristics) and serum biomarkers [carcinoembryonic antigen (CEA), carbohydrate antigen (CA)12-5, CA19-9 and CA72-4] were collected and analyzed. Paired t test, χ2 test and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis. Results: The positive rate, sensitivity and specificity of plasma mSEPT9 were 35%, 35% and 100%, respectively in untreated patients with gastric cancer. The positive rate of mSEPT9 was higher in patients with blood vessel invasion, serosa invasion and lymphatic metastasis, which was 46.87% vs 12.50%, 45.16% vs 14.29%, 75.00% vs 40.00%, respectively (P<0.05). The positive rate of mSEPT9 was higher in progressive disease (PD) patients than in partial response (PR) and stable disease (SD) patients, which were 68.75% and 17.74%, the differences were statistically significant (P<0.05). mSEPT9 level before PD and at the time of PD showed statistically significance. Conclusion: Plasma mSEPT9 detection demonstrates a more satisfactory diagnostic performance in gastric cancer than traditional serum biomarkers. The biomarker can provide information regarding severity with high positive rate among PD patients. The status and level of mSEPT9 were of clinical significance in evaluating tumor burden and predicting treatment response

Role of Plasma methylated SEPT9 for Predicting Microvascular Invasion and Tumor Proliferation in Hepatocellular Carcinoma

Background: Methylated SEPT9 (mSEPT9) has a role in the occurrence and development of hepatocellular carcinoma (HCC). Here, we studied the significance of plasma mSEPT9 for predicting prognosis-associated pathological parameters in patients with HCC. Methods: We retrospectively analyzed data from 205 subjects, including 111 HCC patients, 53 patients with at-risk liver disease (ARD) and 41 healthy donors (HDs). Analysis of plasma mSEPT9 was performed using methylation-specific polymerase chain reaction. Levels of mSEPT9 among different groups were compared using a nonparametric Mann-Whitney U test or a one-way ANOVA test. Correlations between pretreatment plasma mSEPT9 and clinicopathological characteristics were analyzed using the Chi-square. Univariate and multivariate analyses were used to identify factors related to microvascular invasion (MVI). Performance of variables for MVI prediction was evaluated by receiver operating characteristics curve. Results: A specific increase of plasma mSEPT9 in HCC was found when compared with ARD and HDs (HCC vs ARD, P   =  1.1  ×  10 −5 and HCC vs HDs, P    =   3.7  ×  10 −10 ). Pretreatment plasma mSEPT9 was significantly correlated tumor number ( P   =  .004), tumor size ( P   =  4.6  ×  10 −5 ), MVI ( P   =  .002) and Barcelona Clinic Liver Cancer stage ( P   =  .012). Levels of plasma mSEPT9 correlated significantly with Ki67 expression in tumor ( r   =  0.356, P   =  1.3  ×  10 −4 ). Univariate and multivariate analyses showed that plasma mSEPT9 and serum protein induced by vitamin K absence or antagonist-II (PIVKA-II) were independent predictors for MVI. A combination of these 2 markers exhibited a larger areas under the curve (areas under the curve [AUC]  =  0.72) than mSEPT9 or PIVKA alone (AUC  =  0.67 and 0.65), especially in early-stage HCC. Conclusions: Plasma mSEPT9 is a promising noninvasive biomarker for predicting MVI and tumor proliferation in HCC. Integration plasma mSEPT9 detection into clinical settings might facilitate the patient management