Clinicopathologic significance of ERCC1, thymidylate synthase and glutathione S-transferase P1 expression for advanced gastric cancer patients receiving adjuvant 5-FU and cisplatin chemotherapy

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

The design, analysis and application of mouse clinical trials in oncology drug development

Background

Mouse clinical trials (MCTs) are becoming wildly used in pre-clinical oncology drug development, but a statistical framework is yet to be developed. In this study, we establish such as framework and provide general guidelines on the design, analysis and application of MCTs.

Methods

We systematically analyzed tumor growth data from a large collection of PDX, CDX and syngeneic mouse tumor models to evaluate multiple efficacy end points, and to introduce statistical methods for modeling MCTs.

Results

We established empirical quantitative relationships between mouse number and measurement accuracy for categorical and continuous efficacy endpoints, and showed that more mice are needed to achieve given accuracy for syngeneic models than for PDXs and CDXs. There is considerable disagreement between methods on calling drug responses as objective response. We then introduced linear mixed models (LMMs) to describe MCTs as clustered longitudinal studies, which explicitly model growth and drug response heterogeneities across mouse models and among mice within a mouse model. Case studies were used to demonstrate the advantages of LMMs in discovering biomarkers and exploring drug’s mechanisms of action. We introduced additive frailty models to perform survival analysis on MCTs, which more accurately estimate hazard ratios by modeling the clustered mouse population. We performed computational simulations for LMMs and frailty models to generate statistical power curves, and showed that power is close for designs with similar total number of mice. Finally, we showed that MCTs can explain discrepant results in clinical trials.

Conclusions

Methods proposed in this study can make the design and analysis of MCTs more rational, flexible and powerful, make MCTs a better tool in oncology research and drug development.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5907-7) contains supplementary material, which is available to authorized users.

Prognostic importance of the albumin to globulin ratio in metastatic gastric cancer patients

AIM

The aim of this study was to evaluate the prognostic importance of the albumin to globulin ratio (AGR) in terms of overall survival (OS) and progression free survival (PFS) in metastatic gastric cancer patients.

METHODS

The patients diagnosed with metastatic gastric cancer between 2009 and April 2016 at the hospital have been studied retrospectively. The clinicopathological characteristics, laboratory, and treatment parameters have been assessed. AGR value has been calculated using the following formula (AGR = serum albumin/total protein - serum albumin).

RESULTS

In total, 251 patients were included in the study population. The median value of AGR was 1.206 (range = 0.460-3.130), and the cut-off value was set as 1.20. Based on the cut-off value, 126 patients were categorized in the low AGR group, while the remaining 125 patients were categorized in the high AGR group. ECOG (Eastern Cooperative Oncology Group) performance scores, CEA levels, CA19-9 levels, hemoglobin levels, lactate dehydrogenase levels, and liver metastasis ratios varied significantly between the low and high AGR groups (p < .05). The Kaplan-Meier curve has shown that, compared to the low AGR group, the high AGR group has better OS (12.2 vs 9.3 months, p = .002) and better PFS (8.0 vs 5.7 months, p < .001) rates. The univariate and multivariate analyses also proved that low AGR is an independent bad risk factor in metastatic gastric cancer patients, both in terms of OS (p = .019, Hazard Ratio (HR) = 1.380, 95% Confidence Interval (CI) = 1.055-1.805) and PFS (p = .002, HR = 1.514, 95% CI = 1.164-1.968).

CONCLUSION

In metastatic gastric cancer patients, AGR is an independent prognostic factor for OS and PFS. Thus, in this patient group, the low cost albumin and globulin which can be measured with routine clinical practice may be used as an appropriate prognostic tool.

Prognostic Value of Excision Repair Cross-Complementing mRNA Expression in Gastric Cancer

Except for excision repair cross-complementing 1 (ERCC1), mRNA expression of the remaining ERCC genes has not been investigated in the prognosis of gastric cancer (GC). The present study aimed to explore the mRNA expression and prognostic values of each member of the ERCC family in GC patients by using the Kaplan–Meier (KM) plotter tool. The details of each ERCC family member were entered into a database and GC patients were separated into high and low expression to draw survival plots using the KM plotter. In the present study, we observed that high expression of ERCC1 mRNA was significantly associated with longer overall survival (OS) for all GC patients (hazard ratio [HR]=0.77, 95% confidence intervals [CI]=0.63–0.95, P=0.016) compared with low expression. High expression of ERCC4 and ERCC6 mRNA indicated a worse OS for all GC patients (HR=1.28, 95% CI=1.02–1.6, P=0.035 and HR=1.25, 95% CI=1.02–1.54, P=0.029, respectively) and especially for patients with intestinal-type GC (HR=1.87, 95% CI=1.26–2.79, P=0.0018 and HR=1.62, 95% CI=1.04–2.54, P=0.033, respectively). High ERCC8 mRNA expression indicated a worse OS for all GC patients (HR=1.34, 95% CI=1.02–1.76, P=0.034) and especially for patients with diffuse-type GC (HR=2.25, 95% CI=1.36–3.75, P=0.0013). In conclusion, our findings indicate that ERCC4, ERCC6, and ERCC8 may be potential biomarkers for GC prognosis and may serve as potential therapeutic targets for GC. However, these findings still need further verification.

Changes of reduced glutathione and glutathione S-transferase levels in colorectal cancer patients undergoing treatment

PURPOSE:

The available data concerning reduced glutathione (GSH) and glutathione S-transferase (GST) levels in colorectal cancer patients during the treatment process are contradictory and insufficient.

METHODS:

Forty patients with metastatic colorectal cancer receiving FOLFOX4 chemotherapy with or without bevacizumab and 40 healthy volunteers were included in the study. Blood samples were taken before treatment, after 2 months and at the end of treatment in the patient group and once in the healthy volunteer group. The levels of GSH and GST in blood serum were evaluated by enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions.

RESULTS:

The serum level of GSH was significantly lower in colorectal cancer patients before treatment than in healthy volunteers (37.84 ± 19.39 μg/mL and 52.78 ± 19.39 μg/mL, respectively; p<0.001). After treatment, the level of GSH increased significantly, while the level of GST decreased significantly. These changes were observed only in the groups of patients with partial or complete response, having metastases only in the liver, receiving FOLFOX4 chemotherapy with bevacizumab, or undergoing resection or radiofrequency ablation of liver metastases.

CONCLUSIONS:

GSH and GST levels change significantly during the treatment process and these changes depend on the response to treatment, treatment type, and site of metastases. Further analysis of the changes in GSH and GST levels during treatment would allow the assessment of the predictive potential of this molecular marker.

Asparaginyl endopeptidase promotes the invasion and metastasis of gastric cancer through modulating epithelial-to-mesenchymal transition and analysis of their phosphorylation signaling pathways

Asparaginyl endopeptidase (AEP) is a lysosomal protease often overexpressed in gastric cancer. AEP was expressed higher in peritoneal metastatic loci than in primary gastric cancer. Then we overexpressed AEP or knocked it down with a lentiviral vector in gastric cancer cell lines and detected the cell cycle arrest and the changes of the invasive and metastatic ability in vitro and in vivo. When AEP was knocked-down, the proliferative, invasive and metastatic capacity of gastric cancer cells were inhibited, and the population of sub-G1 cells increased. AEP knockdown led to significant decrease of expression of transcription factor Twist and the mesenchymal markers N-cadherin, ß-catenin and Vimentin and to increased expression of epithelial marker E-cadherin. These results showed that AEP could promote invasion and metastasis by modulating EMT. We used phosphorylation-specific antibody microarrays to investigate the mechanism how AEP promotes gastric cancer invasion and metastasis, and found that the phosphorylation level of AKT and MAPK signaling pathways was decreased significantly if AEP was knocked-down. Therefore, AKT and MAPK signaling pathways took part in the modulation.

Systemic immune-inflammation index as a useful prognostic indicator predicts survival in patients with advanced gastric cancer treated with neoadjuvant chemotherapy

BACKGROUND AND OBJECTIVE

A novel systemic immune-inflammation index named SII (SII=N×P/L), which is based on neutrophil (N), platelet (P) and lymphocyte (L) counts, has emerged and reflects comprehensively the balance of host inflammatory and immune status. We aimed to evaluate the potential prognostic significance of SII in patients with advanced gastric cancer who received neoadjuvant chemotherapy.

SUBJECTS AND METHODS

The retrospective analysis included data from 107 patients with advanced gastric cancer undergoing neoadjuvant chemotherapy and 185 patients with pathology-proven gastric cancer. The optimal cutoff value of SII by receiver operating characteristic curve stratified patients into low SII (<600×109/L) and high SII (SII ≥600×109/L) groups. The clinical outcomes of disease-free survival (DFS) and overall survival (OS) were calculated by Kaplan-Meier survival curves and compared using log-rank test. Univariate and multivariate Cox proportional hazards regression models were used to analyze the prognostic value of SII.

RESULTS

The results indicated that SII had prognostic significance using the cutoff value of 600×109/L on DFS and OS in univariate and multivariate Cox regression survival analyses. Low SII was associated with prolonged DFS and OS, and the mean DFS and OS for patients with low SII were longer than for those with high SII (57.22 vs 41.56 months and 62.25 vs 45.60 months, respectively). Furthermore, we found that patients with low SII had better 1-, 3- and 5-year rates of DFS and OS than those with high SII. In addition, patients with low SII were likely to receive DFS and OS benefits from neoadjuvant chemotherapy and postoperative chemotherapy.

CONCLUSION

SII may qualify as a noninvasive, cost-effective, convenient and reproducible prognostic indicator for patients with advanced gastric cancer undergoing neoadjuvant chemotherapy. It may help clinicians to identify those patients who will benefit from treatment strategy decisions.

Peripheral venous blood neutrophil-to-lymphocyte ratio predicts survival in patients with advanced gastric cancer treated with neoadjuvant chemotherapy

Background

Accurate and useful predictors of gastric carcinoma treated with neoadjuvant chemotherapy are lacking at present. We aim to explore the potential prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) in advanced gastric cancer receiving S-1 plus oxaliplatin (SOX) or oxaliplatin and capecitabine (XELOX) regimen.

Methods

We enrolled 91 patients with advanced gastric cancer treated with neoadjuvant chemotherapy from August 2008 to September 2015. The peripheral venous blood samples were collected before neoadjuvant chemotherapy. The NLR was divided into two groups: low NLR <2.17 group and high NLR ≥2.17 group. Univariate analysis on disease-free survival (DFS) and overall survival (OS) were generated using the Kaplan–Meier method and compared using the log-rank test. Prognostic factors were assessed by univariate analyses, and the independent prognostic factors were evaluated using multivariate analysis (Cox’s proportional-hazards regression model).

Results

The univariate analysis showed that median DFS and median OS were worse for high NLR values than low NLR values before neoadjuvant chemotherapy (median DFS: 19.97 and 26.87 months, respectively, P=0.299; median OS: 25.83 and 29.73 months, respectively, P=0.405). Multivariate analysis showed that the NLR before neoadjuvant chemotherapy was not an independent prognostic factor for DFS and OS. However, median DFS and median OS were worse for high neutrophil values than for low neutrophil values (median DFS: 21.03 and 26.87 months, respectively, P=0.396; median OS: 24.43 and 29.37 months, respectively, P=0.534); for low lymphocyte values than for high lymphocyte values before neoadjuvant chemotherapy (median DFS: 22.33 and 26.87 months, respectively, P=0.624; median OS: 26.37 and 27.93 months, respectively, P=0.584). Nevertheless, patients with low NLR had better 1-year, 3-year, and 5-year DFS and OS rates.

Conclusion

NLR may serve as a cheap and convenient prognostic indicator in gastric carcinoma patients receiving SOX or XELOX neoadjuvant chemotherapy. Low NLR may help the doctors to take efficient treatment measures for gastric cancer.

Prognostic value of diffuse versus intestinal histotype in patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

There are two distinct types of gastric carcinoma (GC), intestinal, more frequently sporadic and linked to environmental factors, and diffuse (undifferentiated) that is highly metastatic and characterized by rapid disease progression and a poor prognosis. However, there are many conflicting data in the literature concerning the association between histology and prognosis in GC. This meta-analysis was performed to provide demonstration if histology according to Lauren classification is associated with different prognosis in patients with GC.

METHODS

We searched PubMed, the Cochrane Library, SCOPUS, Web of Science, CINAHL, and EMBASE for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival (OS) were evaluated.

RESULTS

A total of 73 published studies including 61,468 patients with GC were included in this meta-analysis. Our analysis indicates that GC patients with diffuse-type histology have a worst prognosis than those with intestinal subgroup in all studies (HR 1.23; 95% CI, 1.17-1.29; P<0.0001), in both loco-regional confined (HR 1.21; 95% CI, 1.12-1.30; P<0.0001) and advanced disease (HR 1.25; 95% CI, 1.046-1.50; P=0.014), in Asiatic (HR 1.2; 95% CI, 1.14-1.27; P<0.0001) and Western patients (HR 1.3; 95% CI, 1.19-1.41; P<0.0001), and in those not exposed (HR 1.15; 95% CI, 1.07-1.24; P<0.0001) or exposed (HR 1.27; 95% CI, 1.17-1.37; P<0.0001) to (neo)adjuvant therapy.

CONCLUSIONS

Our results indicated that histology might be a useful prognostic marker for both early and advanced GC patients, with intestinal-type associated with a better outcome. This information could be used for stratification purpose in future clinical trials.

Prognostic Value of Baseline Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratios in Local and Advanced Gastric Cancer Patients

BACKGROUND

We aimed to investigate the prognostic value of baseline neutrophil, lymphocyte, and platelet counts along with the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in local and advanced gastric cancer patients.

MATERIALS AND METHODS

In this retrospective cross-sectional study, a total of 103 patients with gastric cancer were included. For all, patient characteristics and overall survival (OS) times were evaluated. Data from a complete blood count test including neutrophil, lymphocyte, monocyte, white blood cell (WBC) and platelet (Plt) count, hemoglobin level (Hb) were recorded, and the NLR and PLR were obtained for every patient prior to pathological diagnosis before any treatment was applied.

RESULTS

Of the patients, 53 had local disease, underwent surgery and were administered adjuvant chemoradiotherapy where indicated. The remaining 50 had advanced disease and only received chemotherapy. OS time was 71.6±6 months in local gastric cancer patients group and 15±2 months in the advanced gastric cancer group. Univariate analysis demonstrated that only high platelet count (p=0.013) was associated with better OS in the local gastric cancer patients. In contrast, both low NLR (p=0.029) and low PLR (p=0.012) were associated with better OS in advanced gastric cancer patients.

CONCLUSIONS

This study demonstrated that NLR and PLR had no effect on prognosis in patients with local gastric cancer who underwent surgery and received adjuvant chemoradiotherapy. In advanced gastric cancer patients, both NLR and PLR had significant effects on prognosis, so they may find application as easily measured prognostic factors for such patients.

Predictive biomarkers for targeted and cytotoxic agents in gastric cancer for personalized medicine

Gastric cancer (GC) is the fourth most common cancer and the second leading cause of cancer. The treatment of GC remains challenging as the outcomes achieved with surgery alone or adjuvant or neoadjuvant chemotherapy and radiotherapy are relatively poor. New treatment strategies are emerging and are being tested in solid tumors including GC. Over the past few years, the treatment of metastatic colorectal cancer (CRC) has made great advances, but strategies to manage GC have improved little. Multiple drug resistance is common in GC chemotherapy and targeted therapy; some patients appear to receive treatment that is suboptimal or even inefficacious. Unfortunately, there are few validated predictive biomarkers to guide the tailored treatment of GC. ToGA and AVAGAST are two phase III trials that tested the efficacy and safety of targeted agents in advanced gastric cancer (AGC), and results clearly indicated that patients need to be selected and that targeted agents are the best hope for better results. This review aims to provide an overview of potential predictive biomarkers for cytotoxic and targeted agents in GC.

Association of thymidylate synthase expression and clinical outcomes of gastric cancer patients treated with fluoropyrimidine-based chemotherapy: a meta-analysis

PURPOSE

Although several studies have suggested an association between thymidylate synthase (TS) expression and outcomes of gastric cancer (GC) patients treated with fluoropyrimidine-based chemotherapy (FUC), the predictive value of TS for response and survival in this setting is unclear. This meta-analysis aimed to estimate prognostic and predictive significance of TS more precisely.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science databases for literature published up to June 2015. Primary outcomes included hazard ratios (HRs) for overall survival (OS), and event-free survival (EFS) and odds ratio (OR) for chemotherapy response. Fixed- or random-effects models were used to calculate pooled HR and OR according to heterogeneity.

RESULTS

A total of 2,442 GC patients in 25 studies met our inclusion criteria. Response rates for FUC were significantly lower in patients with high TS expression than in those with low expression (OR: 0.43, 95% confidence interval [CI]: 0.22-0.84, P=0.013). High TS expression was significantly correlated with unfavorable OS (HR: 1.62, 95% CI: 1.28-2.05, P<0.001) and EFS (HR: 1.54, 95% CI: 1.22-1.93, P<0.001) in advanced disease. However, TS expression was not significantly related to OS (HR: 1.06, 95% CI: 0.74-1.50, P=0.760) or EFS (HR: 1.16, 95% CI: 0.84-1.61, P=0.374) in the adjuvant setting.

CONCLUSION

Higher TS expression might predict drug resistance and adverse prognosis in patients with advanced GC treated with FUC.

Cisplatin resistance and opportunities for precision medicine

Cisplatin is one of the most commonly used chemotherapy drugs, treating a wide range of cancer types. Unfortunately, many cancers initially respond to platinum treatment but when the tumor returns, drug resistance frequently occurs. Resistance to cisplatin is attributed to three molecular mechanisms: increased DNA repair, altered cellular accumulation, and increased drug inactivation. The use of precision medicine to make informed decisions on a patient's cisplatin resistance status and predicting the tumor response would allow the clinician to tailor the chemotherapy program based on the biology of the disease. In this review, key biomarkers of each molecular mechanism will be discussed along with the current clinical research. Additionally, known polymorphisms for each biomarker will be discussed in relation to their influence on cisplatin resistance.

Prognostic value of excision repair cross-complementation group 1 expression in gastric cancer: A meta-analysis

The prognostic impact of excision repair cross-complementation group 1 (ERCC1) expression in gastric cancer (GC) has been investigated for decades, but has yielded controversial results. The aim of the present study was to provide a precise evaluation of whether the expression levels of ERCC1 are associated with overall survival (OS) in patients with GC. A systematic search of Medline and Embase was conducted. Original studies concerning OS and ERCC1 expression were included for critical appraisal. A total of 15 studies comprising 1,425 patients with GC were identified. The results revealed that high/positive ERCC1 expression was an indicator of poor survival in patients with GC [hazard ratio (HR) 1.48; 95% confidence interval (CI) 1.02–2.10; P=0.036; I²=83.8%; random-effects model] compared with low/negative ERCC1 expression. Subgroup analysis indicated that high/positive ERCC1 expression had a significant unfavorable impact on OS in the group of patients evaluated by reverse transcription polymerase chain reaction (RT-PCR; HR 2.57; 95% CI 1.49–4.45). Furthermore, high/positive ERCC1 expression was found to be associated with poor survival in patients receiving platinum-based chemotherapy in the RT-PCR group (HR 2.13; 95% CI 1.06–4.27). These data suggest that ERCC1 may be a useful prognostic factor for GC. In addition, low mRNA levels of ERCC1 appear to be associated with a significant favorable OS benefit from platinum-based chemotherapy.

The relationship between platelet-lymphocyte ratio, neutrophil-lymphocyte ratio, and survival in metastatic gastric cancer on firstline modified docetaxel and cisplatinum plus 5 Fluorourasil Regimen: A single institute experience

BACKGROUND/AIMS

The association between platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), and survival with response rates were evaluated in metastatic gastric cancer (MGC).

PATIENTS AND METHODS

MGC patients on firstline modified docetaxel/cisplatinum/5-fluorourasil [mDCF; docetaxel 60 mg/m2 (days 1-5), cisplatin 60 mg/m2 (day 1), 5FU 600 mg/m2 (days 1-5), q3w] were evaluated retrospectively. The cutoff values were 160 for PLR and 2.5 for NLR. Progression-free survival (PFS) and overall survival (OS) were estimated for group I (PLR >160), group II (PLR ≤ 160), group III (NLR ≥ 2.5), group IV (NLR < 2.5), group V (PLR > 160 and NLR ≥ 2.5), group VI (PLR ≤ 160 and NLR <2.5), and group VII [VIIa (PLR > 160 and NLR < 2.5) and VIIb (PLR ≤160 and NLR ≥ 2.5)].

RESULTS

One hundred and nine MGC patients were evaluated for basal hematological parameters and survival analysis, retrospectively. Most of the patients were male in their fifties with grade III adenocarcinoma (62.9%) and liver metastasis (46.7%). Patients with PLR > 160 and/or NLR ≥ 2.5 had significantly shorter PFS and OS (P = 0.04, 0.01, 0.019, and P = 0.003, 0.002, 0.000, respectively).

CONCLUSION

High PLR (> 160) and/or NLR (≥ 2.5) seem to be poor prognostic factors in MGC.

Blood neutrophil-lymphocyte ratio predicts survival in locally advanced cancer stomach treated with neoadjuvant chemotherapy FOLFOX 4

Accurate predictors of survival for patients with advanced gastric cancer treated with neoadjuvant chemotherapy are currently lacking. In this study, we aimed to evaluate the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with stage III-IV gastric cancer who received neoadjuvant chemotherapy FOLFOX 4 as neoadjuvant chemotherapy. We enrolled 70 patients with stage III-IV cancer stomach in this study. Patients received FOLFOX 4 as neoadjuvant chemotherapy. Blood sample was collected before chemotherapy. The NLR was divided into two groups: high (>3) and low (≤ 3). Univariate analysis on progression-free survival (PFS) and overall survival (OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. The toxicity was evaluated according to National Cancer Institute Common Toxicity Criteria. The univariate analysis showed that PFS and OS were both worse for patients with high NLR than for those with low NLR before chemotherapy (median PFS 28 and 44 months, respectively, P = 0.001; median OS 30 and 48 months, P = 0.001). Multivariate analysis showed that NLRs before chemotherapy were independent prognostic factors of OS but not for progression-free survival. NLR may serve as a potential biomarker for survival prognosis in patients with stage III-IV gastric cancer receiving neoadjuvant chemotherapy. The FOLFOX 4 demonstrated an acceptable toxicity.

Correlation between expression of thymidylate synthase and clinical outcome of advanced gastric cancer treated with capecitabine alone chemotherapy

Thymidylate synthase (TS) is a prognostic marker in various tumors. However, the results of previous investigations in gastric cancer (GC) were controversial. The objective of this article is to investigate whether TS expression is associated with clinical outcome in advanced GC receiving capecitabine alone chemotherapy. The study reviewed 58 cases of advanced GC in patients aged ≥65 years between December 2008 and June 2012. All patients were treated with capecitabine alone chemotherapy. Immunohistochemical staining for TS protein expression was performed. The relationships between TS expression and clinicopathological characteristics (included age, gender, number of metastatic sites, Eastern Cooperative Oncology Group (ECOG) score, differentiation, and lymph node metastatic status), chemotherapy response, progression-free survival (PFS), and overall survival (OS) were evaluated. There was no association between TS expression and age, gender, number of metastatic sites, ECOG score, differentiation, and lymph node metastatic status (P > 0.05). The chemotherapy response rates among patients with low- and high-level expression of TS protein were 52.0 % (13/25) and 21.2 % (7/33), respectively (χ (2) = 5.968, P = 0.015). The median PFS and OS in patients with low-level TS expression were significantly longer than those with high-level TS expression (PFS 8.0 vs 2.8 m, P = 0.001; OS 13.3 vs 7.9 m, P = 0.002, respectively). Multivariate Cox regression analysis revealed that TS expression was independent risk factor for OS (hazard ratio (HR) 0.237; 95 % confidence interval (CI) 0.108 to 0.520; P = 0.000). The present study demonstrates that TS expression is associated with chemotherapy response, PFS, and OS in advanced GC patients treated with capecitabine alone chemotherapy.

Prognostic significance of ERCC1 expression in postoperative patients with gastric cancer

AIM

This study explored the correlation between the expression of excision repair cross-complementation group 1 (ERCC1) and the prognosis of gastric cancer patients.

METHODS

From January 2005 to December 2008, 605 patients who underwent radical surgery in The First Affiliated Hospital of Nanjing Medical University were enrolled. We conducted the follow-up every 6 months and its contents included a comprehensive medical history, tumor markers and abdominal ultrasound or CT and other imaging findings. Deadline was April 30, 2013 and follow-up time between 51 to 91 months. Survival time is calculated from the date of diagnosis to death or last follow-up date. Immunohistochemistry (IHC) was used to assess the expression of ERCC1 in resected samples. The relationship between ERCC1 expression and survival of patients was investigated. The comparison of count data were analyzed by Chi-square test. Median survival time (MST) and the 5-year survival rate were calculated by life table analysis. The Kaplan-Meier curves were used for survival analysis.

RESULTS

ERCC1 expression was positive in 412 patients (68.1%). There is no significant difference between ERCC1-positive group and ERCC1-negative group in terms of the MST and 5-year survival rate (P=0.455). The MST and 5-year survival rate have no significant difference (P=0.162) between group with chemotherapy and group with no chemotherapy in patients with ERCC1-positive expression. However, the MST and 5-year survival rate in patients with ERCC1-negative expression benefited more from with chemotherapy (P=0.019). The ERCC1-positive patients survived longer than those ERCC1-negative patients (P=0.183) in subgroup with no adjuvant chemotherapy. In the subgroup analysis, ERCC1 expression had no significant relationship with overall survival in patients with stage II or III gastric cancer (P>0.05).

CONCLUSIONS

ERCC1 might be a good prognostic factor for the patients of gastric cancer after radical resection. Patients with ERCC1-negative expression could benefit more from adjuvant chemotherapy.

The prognostic value of ERCC1 expression in gastric cancer patients treated with platinum-based chemotherapy: a meta-analysis

Numerous studies examined the association between excision repair complementation group 1 (ERCC1) expression and the prognosis of gastric cancer patients receiving platinum-based chemotherapy but yielded controversial results. We thus conducted a meta-analysis to quantitatively evaluate the prognostic value of ERCC1 expression in gastric cancer patients receiving platinum-based chemotherapy. A systematic literature search was performed to identify relevant studies in PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, and WanFang Database up to December 17, 2013. Pooled hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence intervals (CIs) were estimated. Moreover, meta-regression analysis and subgroup analysis were conducted according to ethnicity, HR extraction, detection methods, survival analysis, and quality score. A total of 1,409 patients from 21 studies were subjected to final analysis. Positive/high ERCC1 expression was significantly associated with poorer overall survival (HR, 1.58; 95 % CI, 1.09-2.28), especially in Asians (HR, 1.81; 95 % CI, 1.20-2.73), and lower response rate (OR, 0.26; 95 % CI, 0.18-0.36), but not with clinicopathological features, such as gender (OR, 1.01; 95 % CI, 0.68-1.51), grade (OR, 0.66; 95 % CI, 0.43-1.01), and stage (OR, 1.05; 95 % CI, 0.58-1.90). This meta-analysis suggested that ERCC1 expression might be a useful biomarker to predict response and survival for gastric cancer patients receiving platinum-based chemotherapy, particularly in Asians.

Gastric cancer pharmacogenetics: progress or old tripe?

Gastric cancer remains the second most frequent cause of cancer-related mortality. While surgery is traditionally the initial treatment for early-stage disease, the addition of chemotherapy has been shown to significantly increase overall survival and progression-free survival in advanced and metastatic stages of disease. However, despite the incorporation of newer chemotherapies and regimens into gastric cancer clinical trials, the response rate and median overall survival for treated patients has not significantly improved throughout the years; therefore, newer therapeutic approaches to improve upon the medication selection process are warranted. Treatment and dose selection based on patient factors, such as genetic variation, may provide a more rational and potentially more powerful means of personalizing chemotherapy. This review provides an update on the current status of pharmacogenetic studies regarding germline DNA mutations that may alter response to chemotherapeutic agents used to treat gastric cancer, including perspectives on clinical translation and future work.

ERCC1 and TS expression and prognosis in colon cancer after postoperative adjuvant chemotherapy

AIM: To explore the relationship between excision repair cross-complementing group 1 (ERCC1) expression, thymidylate synthase (TS) expression and the prognosis in colon cancer after postoperative adjuvant chemotherapy.

METHODS: Seventy-six patients who were diagnosed with colon cancer for the first time were enrolled in our study. All the patients received radical operation, were pathologically diagnosed with stage Ⅱ or Ⅲ disease, accepted FOLFOX4 (L-OHP+5-Fu+CF) chemotherapy and were followed at least 3 years. Immunohistochemistry was used to detect ERCC1 and TS expression levels in colon cancer. The relationship between the expression of ERCC1 and TS and postoperative survival was analyzed retrospectively.

RESULTS: The positive expression rates of ERCC1 and TS in colon cancer were 36.8% and 43.4%, respectively. There were a negative correlation between the positive expression of ERCC1 and TS and tumor differentiation (P = 0.019 and 0.024). The median survival time was significantly longer in patients with negative ERCC1 expression than in those with positive expression (P < 0.05), and in patients with negative TS expression than in those with positive expression (P < 0.05). Cox multivariate regression analysis revealed that patients with positive ERCC1 and TS expression did not benefit from chemotherapy (HR = 3.50, 95%CI: 1.59-7.73, P = 0.002; HR = 0.52, 95%CI: 0.35-0.87, P = 0.010).

CONCLUSION: ERCC1 and TS may be biomarkers for predicting the prognosis of colon cancer patients receiving chemotherapy.

Predictive role of Glutathione S-transferases (GSTs) on the prognosis of osteosarcoma patients treated with chemotherapy

OBJECTIVE

We conducted a comprehensive study to investigate the role of GSTM1, GSTTI and GSTP1 genetic variation involved in transport pathways in response to chemotherapy and clinical outcome of osteosarcoma.

METHODS

A total of 146 patients were included in our study between January 2008 and December 2009. All the patients were followed up to death or January 2012. Genotyping of GSTM1, GSTT1 and GSTP1 was conducted in a 384-well plate format on the Sequenom MassARRAY platform.

RESULTS

Sixty seven patients (45.9%) died during the follow-up period. The median age of patients was 14.2 years and ranged from 9.3 to 38.7 years. The median follow-up time was 29.6 months (range 5 to 60 months). Individuals with GSTP1 G/G genotype tended to live shorter than A/A genotype, and we found a significantly higher risk of death from osteosarcoma (adjusted HR=2.73, 95% CI=1.05-7.45). Individuals with the GSTP GG genotype were more likely to have a poor response to chemotherapy, with an OR of 2.73 (95%CI, 1.07-7.81). However, we did not find association of polymorphisms in GSTM1 and GSTT1 with response to chemotherapy and prognosis of osteosarcoma.

CONCLUSION

Our study provides information for prediction of treatment outcome in clinical oncology. Due to the limited number of samples, the results of our study need to be confirmed by large sample size studies.

shRNA-mediated GSTP1 gene silencing enhances androgen-independent cell line DU145 chemosensitivity

PURPOSE

Design short hairpin RNA (shRNA) interference sequence to silence glutathione S-transferase P1 (GSTP1) gene of androgen-independent prostate cancer cell line DU145, and then to explore its effect on sensitivity to chemotherapeutics.

METHODS

Target sequence was picked up to form the shRNA. DU145 cell was divided into five groups according to the shRNA added for transfection: shRNA255, shRNA554, shRNA593, negative-shRNA and blank group. Fluorescence microscope was used to pick up the shRNA with the highest transfection ratio. Western blotting and RT-PCR were taken to pick up the shRNA with the best gene silencing result. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay and terminal de-oxynucleotidyl transferase-mediated dUTP nick end-labeling assay were used to detect survival ratio and apoptosis ratio of DU145 administered of fluorouracil (5-FU) or paclitaxel (PA) at different concentrations before and after shRNA transfection.

RESULTS

Three different shRNA oligonucleotides (shRNA255; shRNA554; shRNA593) targeting the coding sequence of GSTP1 mRNA and one negative control shRNA were constructed. The transfection ratio of shRNA554 (76.2 ± 0.68 %) was higher than that of shRNA255 (63.3 ± 1.04 %) (P < 0.01) or shRNA593 (72.7 ± 0.33 %) (P < 0.01). After transfection of shRNA554, the mRNA and protein of level were the lowest, P < 0.01. The survival ratio of DU145 administered with 5-FU of different concentrations (30, 60, 120, 240 μg/ml) declined after transfection (P < 0.01). Besides, the apoptosis ratio increased after transfection (P < 0.01). Similarly the survival ratio of DU145 administered with PA of different concentrations (0.2, 2, 10, 20 μg/ml) declined (P < 0.01) and the apoptosis ratio increased (P < 0.01) after transfection.

CONCLUSIONS

The gene GSTP1 silence via shRNA transfection to androgen-independent prostate cancer cell line DU145 enhances the sensitivity to chemotherapeutics.

GSTP1, ERCC1 and ERCC2 polymorphisms, expression and clinical outcome of oxaliplatin-based adjuvant chemotherapy in colorectal cancer in Chinese population

AIM

Platinum agents have shown to be effective in the treatment of colorectal cancer. We assessed whether single nucleotide polymorphisms (SNPs) in GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln might predict the overall survival in patients receiving oxaliplatin-based chemotherapy in a Chinese population.

METHODS

SNPs of GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln in 335 colorectal cancer patients were assessed using TaqMan nuclease assays.

RESULTS

At the time of final analysis on Nov. 2011, the median follow-up period was 37.7 months (range from 1 to 60 months). A total of 229 patients died during follow-up. Our study showed GSTP1 Val/Val (HR=0.44, 95% CI=0.18-0.98), ERCC1 C/C (HR=0.20, 95% CI=0.10-0.79) and ERCC2 G/G (HR=0.48, 95% CI=0.19-0.97) to be significantly associated with better survival of colorectal cancer. GSTP1 Val/Val, ERCC1 C/C and ERCC2 G/G were also related to longer survival among patients with colon cancer, with HRs (95% CIs) of 0.41 (0.16-0.91), 0.16 (0.09-0.74) and 0.34 (0.16-0.91), respectively.

CONCLUSION

GSTP1, GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln genotyping might facilitate tailored oxaliplatin-based chemotherapy for colorectal cancer patients.

Differential expression and prognostic value of ERCC1 and thymidylate synthase in resected gastric adenocarcinoma

BACKGROUND

Excision repair cross-complementing gene-1 (ERCC1) and thymidylate synthase (TS) are key regulatory enzymes whose expression patterns are associated with overall survival (OS) in several malignancies. Their expression patterns and prognostic value in resected gastric adenocarcinoma (GAC) are not known.

METHODS

In total, 109 patients who underwent resection for GAC between January 2000 and June 2011 had tissue available for analysis. The primary objective was to assess for the differential expression of ERCC1 and TS using immunohistochemistry. The secondary objective was to assess for the association between OS and the expression of ERCC1 and TS.

RESULTS

The median follow-up was 21.2 months, and the median OS was 28.8 months. Resected GAC exhibited differential expression of ERCC1 (high expression, 23%; n = 25) and TS (high expression, 43%; n = 47). ERCC1 and TS expression were not associated with OS. In a subset analysis of patients who received chemotherapy (n = 73), high ERCC1 expression was associated with decreased OS (16.7 months vs 53.8 months; P = 0.03). After controlling for known adverse pathologic features, high ERCC1 expression persisted as a negative prognostic factor in multivariate Cox regression analysis (hazard ratio, 2.5; 95% confidence interval, 1.03-6.0; P = .04). Conversely, in patients who underwent resection only (n = 35), high ERCC1 expression demonstrated a trend toward improved OS (40.4 months vs 12.7 months; P = .10); a positive prognostic influence also was present on multivariate analysis (hazard ratio, 0.20; 95% confidence interval, 0.04-0.86; P = .03).

CONCLUSIONS

Resected GAC exhibited differential expression of TS and ERCC1. Among all patients, ERCC1 and TS expression levels were not associated with OS. High ERCC1 tumor expression was associated with decreased OS in the patients who received chemotherapy but was associated with increased OS in those who underwent surgery alone. ERCC1 expression had prognostic value in resected gastric cancer, and further investigation is warranted.

Clinical significance of TS and BRCA1 protein overexpression in gastric cancer

AIM: To investigate the correlation between thymidylate synthase (TS) and breast cancer susceptibility gene-1 (BRCA1) expression and clinicopathological characteristics of gastric cancer.

METHODS: Two hundred and forty-six surgical specimens of gastric cancer collected from patients with complete clinical data who were treated at Fuzhou General Hospital of Nanjing Military Command between January 2011 and January 2012 were used in this study. The protein expression of TS and BRCA1 in these specimens was examined by immunohistochemistry. The correlation between TS and BRCA1 protein expression and clinicopathological characteristics of gastric cancer was analyzed.

RESULTS: The rates of TS and BRCA1 overexpression in gastric cancer were 39.02% (96/246) and 55.69% (137/246), respectively. There was no relationship between TS overexpression and sex, age, tumor site, histotype, differentiation, distant metastasis, depth of invasion, TNM stage and lymph node metastasis (all P > 0.05). BRCA1 protein overexpression was associated with depth of invasion (P < 0.01) and TNM stage (P < 0.05), but not with sex, age, tumor site, differentiation, lymph node metastasis or distant metastasis (all P > 0.05). The co-expression rate of TS and BRCA1 in gastric cancer was 26.02% (64/246). The overexpression of TS was negatively correlated with that of BRCA1 (P < 0.01, r = 0.2472).

CONCLUSION: There exists TS and BRCA1 overexpression in gastric cancer. The overexpression of BRCA1was associated with TNM stage and depth of invasion, which implies that BRCA1 overexpression may be related to invasion of gastric cancer. Detection of BRCA1 protein overexpression may be used to assess the malignant biological behavior and prognosis of gastric cancer and help choose chemotherapy drugs.

Blood neutrophil-lymphocyte ratio predicts survival for stages III-IV gastric cancer treated with neoadjuvant chemotherapy

Background

Accurate predictors of survival for patients with advanced gastric cancer treated with neoadjuvant chemotherapy are currently lacking. In this study, we aimed to evaluate the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with stage III-IV gastric cancer who received neoadjuvant chemotherapy.

Methods

We enrolled 46 patients in this study. The NLR was divided into two groups: high (>2.5) and low (≤2.5). Univariate analysis on progression-free survival (PFS) and overall survival(OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. We analyzed whether chemotherapy normalized high NLR or not, and evaluated the prognostic significance of normalization on survival.

Results

The univariate analysis showed that PFS and OS were both worse for patients with high NLR than for those with low NLR before chemotherapy (median PFS 16 and 49 months, respectively, P = 0.012; median OS 21 and 52 months, P = 0.113). PFS and OS were also worse for patients with high NLR than for those with low NLR before surgery (median PFS 12 and 35 months, P = 0.019; median OS 21 and 52 months, P = 0.082). Multivariate analysis showed that both NLR before chemotherapy and surgery were independent prognostic factors of PFS. Neoadjuvant chemotherapy normalized high NLR in 11 of 24 patients, and these 11 patients had better median PFS and OS than the 13 patients who had high NLR both before chemotherapy and before surgery (PFS: 35.0 and 10.0 months, P = 0.003; OS: 60 and 16 months, P = 0.042).

Conclusions

NLR may serve as a potential biomarker for survival prognosis in patients with stage III-IV gastric cancer receiving neoadjuvant chemotherapy.

ERCC1 predicts outcome in patients with gastric cancer treated with adjuvant cisplatin-based chemotherapy

BACKGROUND

Adjuvant chemotherapy is gaining an increasing role in resectable gastric cancer. Customizing chemotherapy on the basis of chemosensitivity may improve outcome, and putative predictive molecular markers have been mostly evaluated in Asian patients. We profiled key DNA and damage signaling factors and correlated them with outcome, in a European cohort.

METHODS

Formalin-fixed tumor samples obtained from surgical specimens of patients treated with adjuvant cisplatin-based chemotherapy for gastric cancer were analyzed. Immunohistochemistry (IHC) was performed to analyze excision repair cross-complementing gene 1 (ERCC1) and thymidylate synthase (TS) expression, and p53 mutations were detected with direct sequencing.

RESULTS

Among the 68 patient recruited, the median age was 69 (range 30-74), and UICC stage was III in 44 patients (65 %). With a median follow-up of 40.5 months, disease-free and overall survival were 18.0 (95 % CI 13.4-22.76) and 56 months (95 % CI 44.87-67.13), respectively. ERCC1 score was 0 in 14 out 67 (21 %) cases, 1 in 19 (28 %), 2 in 20 (30 %) and 3 in 14 cases (21 %). Longer overall survival (p = 0.04) was found in patients categorized as ERCC1 negative by IHC according to median score. TS score was 0 in 16 out 67 (24 %) cases, 1 in 27 (40 %), 2 in 16 (24 %) and 3 in 8 cases (12 %). Mutations of p53 were found in 21 out 66 (32 %) cases. Neither TS nor p53 were found to correlate with outcome.

CONCLUSION

Excision repair cross-complementing gene 1 by IHC might predict patients more likely to benefit from adjuvant cisplatin-based chemotherapy in curatively resected gastric cancer. In patients exhibiting ERCC1 positive tumors, alternative regimens should be evaluated.

Excision repair of BPDE-adducts in human lymphocytes: diminished capacity associated with ERCC1 C8092A (rs3212986) polymorphism

Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), a metabolite of Benzo[a]pyrene (B[a]P), is a high-risk factor for development of a number of cancers. DNA damage caused by BPDE is normally repaired by Nucleotide Excision Repair system of which ERCC1 exerts an important role. We investigated whether two single nucleotide polymorphisms in ERCC1 (C19007T; rs11615 and C8092A; rs3213986) affected the repair efficacy of BPDE-DNA adducts. We collected peripheral blood of 780 healthy individuals from the northeast of China and detected the genotypes of rs11615 and rs3213986. The amount of induced BPDE-DNA adducts in lymphocytes from 117 randomly selected participants was assessed by HPLC. Presence of BPDE-DNA adducts in nucleus of lymphocytes was visualized using the modified comet assay. ERCC1 and CAST (3' adjacent gene of ERCC1) mRNA expression levels were quantified after in vitro exposure to BPDE. We found that the minor A allele in rs3212986 was related to higher levels of BPDE-DNA adducts and holistic marking DNA damage (P < 0.01). Haplotype CA (rs11615 and rs3213986) was also associated with an elevated risk of high BPDE-DNA adduct levels (OR = 1.801, 95 % CI of OR 1.191-2.724). Interestingly, in participants with AA genotype for rs3213986, CAST mRNA level was decreased compared to individuals with the homozygous CC genotype. Our findings suggests that ERCC1 C8092A (rs3213986) is associated with a diminished capacity of repairing BPDE-DNA adducts and may be used as a valid biomarker to predict an individual's risk to develop cancer upon exposure to environmental carcinogens.

Predictive value of thymidylate synthase expression in gastric cancer: a systematic review with meta-analysis

PURPOSE

The relationship between thymidylate synthase (TS) expression and outcomes in gastric cancer (GC) patients remains controversial, although most studies reported poor survival and reduced response to fluoropyrimidine were related to high TS in tumors. We carried out a systematic review of the literature with meta-analysis to estimate the predictive value of TS expression from published studies.

METHODS

We identified 24 studies analysing the outcome data in gastric cancer stratified by TS expression. Effect measures of outcome were hazard ratios (HRs) for overall survival (OS) and event-free survival (EFS), or the odds ratio (OR) for overall response rate (ORR). HRs and ORs from these eligible studies were pooled using random-effects meta- analysis.

RESULTS

Fifteen studies investigated outcomes in a total of 844 patients with advanced GC, and nine studies investigated outcomes in a total of 1,235 patients with localized GC undergoing adjuvant therapy. Meta- analysis of estimates showed high TS expression was significantly associated with poor OS in the advanced setting (HR: 1.43, 95%CI: 1.08 - 1.90), and poor EFS in the adjuvant setting (HR: 1.53, 95%CI: 1.01 - 2.32). Subgroup analysis demonstrated TS expression to have even greater value in predicting OS, EFS and ORR in advanced GC patients treated with fluoropyrimidine monotherapy (HR for OS: 2.32, 95%CI: 1.53 - 3.50; HR for EFS: 1.76, 95%CI: 1.19 - 2.60; OR for ORR: 0.32, 95%CI: 0.11 - 0.95).

CONCLUSION

High levels of TS expression were associated with a poorer OS for advanced GC patients compared with low levels. In the adjuvant setting, high TS expression was also associated with a worse EFS. Additional studies with consistent methodology are needed to define the precise predictive value of TS.