Prognostic significance of ERCC1 expression in postoperative patients with gastric cancer

Pharmacogenomic Testing to Guide Personalized Cancer Medicine Decisions in Private Oncology Practice: A Case Study

Innovative tumor profiling methodologies are utilized to elucidate the pharmacogenomic landscape of tumor cells in order to support the molecularly guided delivery of therapeutics. Indeed, improved clinical outcomes are achieved in oncology practice by providing the physicians with expert-guided, standardized, and easily interpretable knowledge, translated from molecular profiling analysis to support clinical decision-making. However, there is still limited utilization of the technology especially in small private oncology practices. In this work, we analyzed how molecularly guided interventions in 17 consented cancer patients led to an overall improvement of disease response rates in a private oncology center. The precision medicine strategy was based on the OncoDEEP™ profiling solutions and focused on finding clinically actionable relationships between tumor biomarkers and drug responses. The obtained data support the notion that (a) following the pharmacogenomic-derived recommendations favorably impacted cancer therapy progression, and (b) the earlier profiling followed by the delivery of molecularly targeted therapy led to more durable and improved pharmacological response rates. Moreover, we report the example of a patient with metastatic gastric adenocarcinoma who, based on the molecular profiling data, received an off-label therapy that resulted in a complete response and a current cancer-free maintenance status. Overall, our data provide a paradigm on how molecular tumor profiling can improve decision-making in the routine private oncology practice.

Immunohistochemistry Biomarkers Predict Survival in Stage II/III Gastric Cancer Patients: From a Prospective Clinical Trial

Purpose

Identification of biomarkers to predict recurrence risk is essential to improve adjuvant treatment strategies in stage II/III gastric cancer patients. This study evaluated biomarkers for predicting survival after surgical resection.

Materials and Methods

This post-hoc analysis evaluated patients from the CLASSIC trial who underwent D2 gastrectomywith orwithout adjuvant chemotherapy (capecitabine plus oxaliplatin) at the Yonsei Cancer Center. Tumor expressions of thymidylate synthase (TS), excision repair cross-complementation group 1 (ERCC1), and programmed death-ligand 1 (PD-L1) were evaluated by immunohistochemical (IHC) staining to determine their predictive values.

Results

Among 139 patients, IHC analysis revealed high tumor expression of TS (n=22, 15.8%), ERCC1 (n=23, 16.5%), and PD-L1 (n=42, 30.2%) in the subset of patients. Among all patients, high TS expression tended to predict poor disease-free survival (DFS; hazard ratio [HR], 1.80; p=0.053), whereas PD-L1 positivity was associated with favorable DFS (HR, 0.33; p=0.001) and overall survival (OS; HR, 0.38; p=0.009) in multivariate Cox analysis. In the subgroup analysis, poor DFS was independently predicted by high TS expression (HR, 2.51; p=0.022) in the adjuvant chemotherapy subgroup (n=66). High PD-L1 expression was associated with favorable DFS (HR, 0.25; p=0.011) and OS (HR, 0.22; p=0.015) only in the surgery-alone subgroup (n=73). The prognostic impact of high ERCC1 expression was not significant in the multivariate Cox analysis.

Conclusion

This study shows that high TS expression is a predictive factor for worse outcomes on capecitabine plus oxaliplatin adjuvant chemotherapy, whereas PD-L1 expression is a favorable prognostic factor in locally advanced gastric cancer patients.

Clinical research of individualized therapy in advanced esophageal cancer based on the ERCC1 C8092A genotype

The present study aimed to explore the role and clinical value of the detection of Excision repair cross-complementing 1(ERCC1) C8092A polymorphisms in individualized therapy of patients with advanced esophageal cancer. A total of 127 patients with advanced esophageal cancer were enrolled between January 2010 and January 2014 in Anhui Provincial Hospital. Patients were randomly assigned in a 1:2 ratio to a standard treatment group or an individualized treatment group, respectively, prior to ERCC1 C8092A assessment. Patients in the standard treatment group were treated with paclitaxel and cisplatin. The DNA was obtained from the peripheral blood of individualized treatment patients, amplified by PCR and sequenced to determine the ERCC1 C8092A polymorphism prior to the administration of chemotherapies. Patients with the ERCC1 C8092A genotype of A/A or A/C received paclitaxel and cisplatin, and those with the genotype of C/C received paclitaxel and fluorouracil. The primary endpoint was response rate (RR). The secondary endpoints included toxicity of chemotherapy, progression-free survival (PFS) and overall survival (OS) times. Differences between the groups were evaluated by χ² test. Differences in survival were analyzed by Kaplan-Meier survival curves. The survival rate was analyzed by log-rank test. Follow-up data was obtained until December 2015. The RR was obtained for 15 patients (34.8%) in the standard treatment group and 45 patients (53.6%) in the individualized treatment group (χ²=3.095; P=0.046). For adverse events, nausea and vomiting and anemia were significantly decreased in the individualized treatment group compared with the standard treatment group (P=0.001 and P=0.004, respectively). The median progression free survival time was 4.4 months [95% confidence interval (CI)3.8-5.0 months] in the standard treatment group and 6.6 months (95% CI, 5.8-7.4 months) in the individualized treatment group (P=0.018). The median overall survival time was 11.4 months (95% CI, 10.1-12.7 months) in the standard treatment group and 14.2 months (95% CI, 13.2-15.2 months) in the individualized treatment group (P=0.008). The RR, toxicity of chemotherapy, PFS and OS were significantly improved in the individualized treatment group compared with the standard treatment group. Detection of ERCC1 gene polymorphisms maybe performed for patients with advanced esophageal cancer to improve individualized therapy, which requires additional study.

High excision repair cross-complementation group 1 expression is associated with favorable prognostic factors in breast cancer

Distortion of DNA can inhibit transcription and replication, resulting in cell death. The nucleotide excision repair (NER) pathway recognizes and repairs DNA adducts. Excision repair cross-complementation group 1 (ERCC1) is a nuclease that serves a vital role in the NER pathway. Few studies have investigated ERCC1 expression in breast cancer. The aim of the present study was to analyze the association between clinicopathological features and ERCC1 expression in breast cancer. ERCC1 expression was studied in 224 invasive ductal carcinomas by immunohistochemical staining. ERCC1 expression was analyzed as an immunoreactive score, and classified into low and high expression groups. The association between immunohistochemical parameters and clinicopathological features was evaluated. High expression of ERCC1 was observed in 33 cases (14.7%) and was statistically associated with lower T stage (P=0.005), lower tumor size (P=0.001), no lymph node metastasis (P=0.044) and no lymphovascular invasion (LVI; P=0.004). Additionally, high ERCC1 expression was associated with a positive estrogen receptor (ER) (P=0.006) and progesterone receptor (PR) (P=0.001) expression status. Non-triple-negative breast carcinoma occurred more frequently in the high expression group (97%) than the low expression group; however, the difference was not statistically significant (P=0.056). Overall and disease-free survival were also not significantly different between the two groups (P=0.989 and P=0.215, respectively). In conclusion, high ERCC1 expression is statistically associated with lower T stage, smaller tumor size, no lymph node metastasis, no LVI, and positive ER and PR expression. This suggests that ERCC1 is associated with favorable prognostic parameters in breast cancer.

Effects of taxol resistance gene 1 expression on the chemosensitivity of SGC-7901 cells to oxaliplatin

The present study aimed to evaluate the role of taxol resistance gene 1 (Txr1) in the development of oxaliplatin (L-OHP) resistance in gastric cancer (GC). Using SGC-7901 cells as a model, Txr1 was exogenously expressed or knocked down using small interfering RNA. Quantitative polymerase chain reaction (qPCR) and western blotting were performed to establish whether the Txr1 gene is involved in chemoresistance, and cell proliferation was assessed using an MTS assay. To this end, the mRNA and protein levels of Txr1, thrombospondin-1 and excision repair cross-complementing 1 protein were measured using qPCR and western blotting, respectively. Txr1-knockdown significantly increased the sensitivity of the SGC-7901 cells to L-OHP, whereas Txr1 overexpression promoted the resistance of the SGC-7901 cells to L-OHP. Exogenous Txr1 expression in the SGC-7901 cells induced L-OHP resistance, and the siRNA knockdown of Txr1 sensitized the human GC cells to L-OHP. Txr1 is, therefore, likely to play a role in L-OHP resistance, acting via TSP1, and should be investigated as a potential therapeutic target in the treatment of GC.

Prognostic value of ERCC1 and ERCC2 gene polymorphisms in patients with gastric cancer receiving platinum-based chemotherapy

We conducted a prospective study to analyze whether ERCC1 rs11615 and rs3212986 and ERCC2 rs13181 and rs1799793 gene polymorphisms could serve as potential biomarkers for the prognosis of gastric cancer. A total of 228 patients with pathologically proven gastric cancer and receiving platinum-based chemotherapy were recruited from our hospital between October 2009 and October 2011. The ERCC1 rs11615 and rs3212986 and ERCC2 rs13181 and rs1799793 polymorphisms were genotyped using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. Conditional logistic regression analysis revealed that patients carrying the CA and AA genotypes of ERCC1 rs3212986 polymorphism showed a poorer response to chemotherapy compared to the CC genotype (CA vs. CC: OR = 0.28, 95% CI = 0.06-0.98, P = 0.04; AA vs. CC: OR = 0.49, 95% CI = 0.06-0.98, P = 0.01). Moreover, the CA+AA genotype of ERCC1 rs3212986 polymorphism showed a significantly poorer response to chemotherapy (CA+AA vs. CC: OR = 0.49, 95% CI = 0.27-0.90). Patients with the AA genotype of ERCC1 rs3212986 polymorphism had a longer overall survival time when compared with the CC genotype (34.91 months vs. 51.19 months, log-rank P = 0.003). The AA genotype of ERCC1 rs3212986 polymorphism in gastric cancer patients was correlated with a higher risk of death from varying causes by the Cox proportional hazards model, compared to the CC genotype (HR = 6.19, 95% CI = 1.42-30.60). In conclusion, the ERCC1 rs3212986 polymorphism was found to influence the response to chemotherapy and overall survival of gastric cancer patients.

Epigenetic screening of salivary gland mucoepidermoid carcinoma identifies hypomethylation of CLIC3 as a common alteration

OBJECTIVES

The role of promoter methylation in the development of mucoepidermoid carcinoma (MEC) has not been fully explored. In this study, we investigated the epigenetic landscape of MEC.

METHODS

The Illumina HumanMethylation27 BeadChip array and differential methylation analysis were utilized to screen for epigenetic alterations in 14 primary MEC tumors and 14 matched normal samples. Bisulfite sequencing was used to validate these results, with subsequent quantitative Methylation-Specific PCR (qMSP) to validate chloride intracellular channel protein 3 (CLIC3) in a separate cohort. Furthermore, CLIC3 immunohistochemical (IHC) staining was performed in another separate cohort of MEC. Finally, clinical and pathological characteristics were statistically analyzed for correlation with methylation status of CLIC3 and CLIC3 IHC H-scores by Wilcoxon rank sum, Kruskall-Wallis, and X(2) test tests.

RESULTS

We obtained 6 significantly differentially methylated gene candidates demonstrating significant promoter hyper- or hypo-methylation from the array data. Using bisulfite sequencing, we found one gene, CLIC3, which showed differential methylation between MEC tumor and normal samples in a small validation cohort. qMSP analysis of the CLIC3 promoter in a separate validation set showed significantly lower methylation level in tumor than in normal. The level of CLIC3 methylation in MECs was not statistically correlated with clinical or pathological characteristics. However, IHC staining intensity and distribution of CLIC3 were significantly increased in MECs, compared with those of normal salivary gland tissues.

CONCLUSIONS

Hypomethylation of CLIC3 promoter and its overexpression are significant events in MEC. Its functional role and potential therapeutic utility in MEC are worthy of further exploration.