Relationship between ERCC1 polymorphisms, disease progression, and survival in the Gynecologic Oncology Group Phase III Trial of intraperitoneal versus intravenous cisplatin and paclitaxel for stage III epithelial ovarian cancer

Genomic instability in ovarian cancer: Through the lens of single nucleotide polymorphisms

Ovarian cancer (OC) is the deadliest gynecological malignancy among all female reproductive cancers. It is characterized by high mortality rate and poor prognosis. Genomic instability caused by mutations, single nucleotide polymorphisms (SNPs), copy number variations (CNVs), microsatellite instability (MSI), and chromosomal instability (CIN) are associated with OC predisposition. SNPs, which are highly prevalent in the general population, show a greater relative risk contribution, particularly in sporadic cancers. Understanding OC etiology in terms of genetic basis can increase the use of molecular diagnostics and provide promising approaches for designing novel treatment modalities. This will help deliver personalized medicine to OC patients, which may soon be within reach. Given the pivotal impact of SNPs in cancers, the primary emphasis of this review is to shed light on their prevalence in key caretaker genes that closely monitor genomic integrity, viz., DNA damage response, repair, cell cycle checkpoints, telomerase maintenance, and apoptosis and their clinical implications in OC. We highlight the current challenges faced in different SNP-based studies. Various computational methods and bioinformatic tools employed to predict the functional impact of SNPs have also been comprehensively reviewed concerning OC research. Overall, this review identifies that variants in the DDR and HRR pathways are the most studied, implying their critical role in the disease. Conversely, variants in other pathways, such as NHEJ, MMR, cell cycle, apoptosis, telomere maintenance, and PARP genes, have been explored the least.

Cancer chemoresistance and its mechanisms: Associated molecular factors and its regulatory role

Cancer therapy has advanced from tradition chemotherapy methods to targeted therapy, novel drug delivery mechanisms, combination therapies etc. Although several novel chemotherapy strategies have been introduced, chemoresistance still remains as one of the major barriers in cancer treatments. Chemoresistance can lead to relapse and hinder the development of improved clinical results for cancer patients, and this continues to be the major hurdle in cancer therapy. Anticancer drugs acquire chemoresistance through different mechanisms. Understanding these mechanisms is crucial to overcome and increase the efficiency of the cancer therapies that are employed. The potential molecular pathways behind chemoresistance include tumor heterogeneity, elevated drug efflux, multidrug resistance, interconnected signaling pathways, and other factors. To surpass this limitation, new clinical tactics are to be introduced. This review aims to compile the most recent information on the molecular pathways that regulate chemoresistance in cancers, which will aid in development of new therapeutic targets and strategies.

New trends in diagnosing and treating ovarian cancer using nanotechnology

Ovarian cancer stands as the fifth most prevalent cancer among women, causing more mortalities than any other disease of the female reproductive system. There are numerous histological subtypes of ovarian cancer, each of which has distinct clinical characteristics, risk factors, cell origins, molecular compositions, and therapeutic options. Typically, it is identified at a late stage, and there is no efficient screening method. Standard therapies for newly diagnosed cancer are cytoreductive surgery and platinum-based chemotherapy. The difficulties of traditional therapeutic procedures encourage researchers to search for other approaches, such as nanotechnology. Due to the unique characteristics of matter at the nanoscale, nanomedicine has emerged as a potent tool for creating novel drug carriers that are more effective and have fewer adverse effects than traditional treatments. Nanocarriers including liposomes, dendrimers, polymer nanoparticles, and polymer micelles have unique properties in surface chemistry, morphology, and mechanism of action that can distinguish between malignant and normal cells, paving the way for targeted drug delivery. In contrast to their non-functionalized counterparts, the development of functionalized nano-formulations with specific ligands permits selective targeting of ovarian cancers and ultimately increases the therapeutic potential. This review focuses on the application of various nanomaterials to the treatment and diagnosis of ovarian cancer, their advantages over conventional treatment methods, and the effective role of controlled drug delivery systems in the therapy of ovarian cancer.

Potentially functional variants in nucleotide excision repair pathway genes predict platinum treatment response of Chinese ovarian cancer patients

Acquired platinum resistance impedes successful treatment of epithelial ovarian cancer (EOC), and this resistance may be associated with inherited DNA damage-repair response. In the present study, we performed a two-phase analysis to assess associations between 8191 single-nucleotide polymorphisms within 127 genes of nucleotide excision repair pathway from a genome-wide association study dataset and platinum treatment response in 803 Han Chinese EOC patients. As a result, we identified that platinum-based chemotherapeutic response was associated with two potentially functional variants MNAT1 rs2284704 T>C [TC + CC versus TT, adjusted odds ratio (OR) = 0.89, 95% confidence interval (CI) = 0.83-0.95 and P = 0.0005] and HUS1B rs61748571 A>G (AG + GG versus AA, OR = 1.10, 95% CI = 1.03-1.18 and P = 0.005). Compared with the prediction model for clinical factors only, models incorporating HUS1B rs61748571 [area under the curve (AUC) 0.652 versus 0.672, P = 0.026] and the number of unfavorable genotypes (AUC 0.652 versus 0.668, P = 0.040) demonstrated a significant increase in the AUC. Further expression quantitative trait loci analysis suggested that MNAT1 rs2284704 T>C significantly influenced mRNA expression levels of MNAT1 (P = 0.003). These results indicated that MNAT1 rs2284704 T>C and HUS1B rs61748571 A>G may serve as potential biomarkers for predicting platinum treatment response of Chinese EOC patients, once validated by further functional studies.

Overcoming Platinum and PARP-Inhibitor Resistance in Ovarian Cancer

Platinum chemotherapy remains the cornerstone of treatment for epithelial ovarian cancer (OC) and Poly (ADP-ribose) polymerase inhibitors (PARPi) now have an established role as maintenance therapy. The mechanisms of action of these agents is, in many ways, complementary, and crucially reliant on the intracellular DNA Damage Repair (DDR) response. Here, we review mechanisms of primary and acquired resistance to treatment with platinum and PARPi, examining the interplay between both classes of agents. A key resistance mechanism appears to be the restoration of the Homologous Recombination (HR) repair pathway, through BRCA reversion mutations and epigenetic upregulation of BRCA1. Alterations in non-homologous end-joint (NHEJ) repair, replication fork protection, upregulation of cellular drug efflux pumps, reduction in PARP1 activity and alterations to the tumour microenvironment have also been described. These resistance mechanisms reveal molecular vulnerabilities, which may be targeted to re-sensitise OC to platinum or PARPi treatment. Promising therapeutic strategies include ATR inhibition, epigenetic re-sensitisation through DNMT inhibition, cell cycle checkpoint inhibition, combination with anti-angiogenic therapy, BET inhibition and G-quadruplex stabilisation. Translational studies to elucidate mechanisms of treatment resistance should be incorporated into future clinical trials, as understanding these biologic mechanisms is crucial to developing new and effective therapeutic approaches in advanced OC.

Role of common ERCC1 polymorphisms in cisplatin-resistant epithelial ovarian cancer patients: A study in Chinese cohort

Epithelial ovarian cancer (EOC) contributes the majority of death cases among various ovarian malignancies. Although a standard method of treatment is the surgical removal of malignant tissue followed by platinum-based chemotherapy, a group of patients does not respond appropriately to cisplatin. An appropriate response to cisplatin has been linked with the nucleotide excision repair mechanism. The present study aims to investigate the role of polymorphisms in DNA repair genes, excision repair cross-complementation group 1 (ERCC1) with susceptibility to EOC development and tumour response to platinum-based chemotherapy in Chinese EOC patients. Patients (n = 559) reporting to the Department of Oncology and general surgery, the First Affiliated Hospital of Kunming Medical University, were enrolled in the study. Three hundred twenty-three healthy controls hailing from similar geographical areas without a history of cancer enrolled as healthy controls. Excision repair cross-complementation group 1 polymorphisms (rs11615, rs3212986, rs735482, rs2336219, rs3212980, rs3212964, rs3212961 and rs2298881) were genotyped by appropriate methods. Distribution of genotypes and allele for ERCC1 polymorphisms (rs11615, rs3212986, rs735482, rs2336219, rs3212980, rs3212964, rs3212961 and rs2298881) were comparable among healthy controls and EOC patients. Interestingly, homozygous mutant and the minor allele for rs11615 and rs3212986 polymorphisms were significantly higher in nonresponder EOC patients when compared to those with a proper response to cisplatin treatment. The prevalence of other SNPs was comparable among the two treated clinical categories. Furthermore, combined genotype revealed significant association of rs11615: TT/ rs3212986: AA genotype combination with cisplatin nonresponder. Variants of rs11615, rs3212986 polymorphisms are associated with cisplatin resistance in Chinese EOC patients. Combined rs11615 and rs3212986 genotypes can be used as a predictive biomarker for platinum-based chemotherapy outcomes.

FBP1 promotes ovarian cancer development through the acceleration of cell cycle transition and metastasis

Epithelial ovarian cancer (EOC) is the fifth most common malignancy in women, with a 5-year mortality of >70% in North America. As the symptoms are often not observed until the cancer has spread extensively, few women are diagnosed at an early stage of disease. Large-scale gene expression analyses have identified molecular subtypes within high-grade ovarian cancer with variable survival rates and drug resistance. The understanding of gene expression, the mechanisms underlying cancer processes and drug resistances have facilitated the development of targeted therapies. The far-upstream element (Fuse)-binding protein 1 (FBP1) is overexpressed in a number of malignancies such as hepatocellular carcinoma, and has been identified as an oncoprotein. In our early studies, FBP1 was demonstrated to physically interact with p53 and suppresses p53 transcription activity. In the present study, FBP1 expression increased as ovarian cancer developed. Among ovarian normal, adenoma and carcinoma tissues, the highest FBP1 expression was identified in carcinoma tissues. Furthermore FBP1 did not influence the apoptosis of ovarian carcinoma cells, yet enhanced cell cycle transition and metastasis. Therefore, it was hypothesized that FBP1 promotes ovarian cancer development through the acceleration of cell cycle transition and metastasis, and FBP1 is a novel potential biological marker for epithelial ovarian cancer diagnosis.

Pharmacogenetic Analysis of the UK MRC (Medical Research Council) MAGIC Trial: Association of Polymorphisms with Toxicity and Survival in Patients Treated with Perioperative Epirubicin, Cisplatin, and 5-fluorouracil (ECF) Chemotherapy

Purpose: Germline polymorphisms may affect chemotherapy efficacy and toxicity. We examined the effect of polymorphisms in drug metabolism and DNA repair genes on pathologic response rates, survival, and toxicity for patients randomized to surgery alone or perioperative ECF chemotherapy in the MRC MAGIC trial.Experimental Design: DNA was extracted from nontumor resection formalin-fixed paraffin-embedded (FFPE) blocks. ERCC1, ERCC2, XRCC1, DYPD, and OPRT SNPs were evaluated using Sequenom, GSTP1, GSTT1 deletion, and TYMS (TS) 5' 2R/3R using multiplex PCR. Post PCR amplification, TS 2R/3R and GSTT1 samples underwent gel electrophoresis.Results: Polymorphism data were available for 289 of 456 (63.4%) operated patients. No polymorphism was statistically significantly associated with pathologic response to chemotherapy. Median overall survival (OS) for patients treated with surgery alone with any TS genotype was not different (1.76 years 2R/2R, 1.68 years 2R/3R, 2.09 years 3R/3R). Median OS for patients with a TS 2R/2R genotype treated with chemotherapy was not reached, whereas median OS for 2R/3R and 3R/3R patients were 1.44 and 1.60 years, respectively (log rank P value = 0.0053). The P value for the interaction between treatment arm and genotype (3R/3R and 3R/2R vs. 2R/2R) was 0.029. No polymorphism was statistically significantly associated with chemotherapy toxicity.Conclusions: In MAGIC, patients with a TS 2R/2R genotype appeared to derive a larger benefit from perioperative ECF chemotherapy than patients with 3R containing genotypes. Further exploration of this potential predictive biomarker in this patient population is warranted. Clin Cancer Res; 23(24); 7543-9. ©2017 AACR.

Impact of molecular profiling on overall survival of patients with advanced ovarian cancer

OBJECTIVE

Patients with recurrent epithelial ovarian cancer (EOC) have limited treatment options. Studies have reported that biomarker profiling may help predict patient response to available treatments. This study sought to determine the value of biomarker profiling in recurrent EOC.

RESULTS

Patients in the Matched cohort had a median OS of 36 months compared to 27 months for patients in the Unmatched cohort (HR 0.62, 95% CI 0.41-0.96; p < 0.03). Individual biomarkers were analyzed, with TUBB3, and PGP prognostic for survival. Biomarker analysis also identified a molecular subtype (positive for at least two of the following markers: ERCC1, RRM1, TUBB3, PGP) with particularly poor overall survival.

METHODS

224 patients from a commercial registry (NCT02678754) with stage IIIC/IV EOC at diagnosis, or restaged to IIIC/IV EOC at the time of molecular profiling, were retrospectively divided into two cohorts based on whether or not the drugs they received matched their profile recommendations. The Matched cohort received no drugs predicted to be lack-of-benefit while the Unmatched cohort received at least one drug predicted to be lack-of-benefit. Profile biomarker/drug associations were based on multiple test platforms including immunohistochemistry, fluorescent in situ hybridization and DNA sequencing.

CONCLUSIONS

This report demonstrates the ability of multi-platform molecular profiling to identify EOC patients at risk of inferior survival. It also suggests a potential beneficial role of avoidance of lack-of-benefit therapies which, when administered, resulted in decreased survival relative to patients who received only therapies predicted to be of benefit.

Genetic variants as ovarian cancer first-line treatment hallmarks: A systematic review and meta-analysis

BACKGROUND

The potential predictive value of genetic polymorphisms in ovarian cancer first-line treatment is inconsistently reported. We aimed to review ovarian cancer pharmacogenetic studies to update and summarize the available data and to provide directions for further research.

METHODS

A systematic review followed by a meta-analysis was conducted on cohort studies assessing the involvement of genetic polymorphisms in ovarian cancer first-line treatment response retrieved through a MEDLINE database search by November 2016. Studies were pooled and summary estimates and 95% confidence intervals (CI) were calculated using random or fixed-effects models as appropriate.

RESULTS

One hundred and forty-two studies gathering 106871 patients were included. Combined data suggested that GSTM1-null genotype patients have a lower risk of death compared to GSTM1-wt carriers, specifically in advanced stages (hazard ratio (HR), 0.68; 95% CI, 0.48-0.97) and when submitted to platinum-based chemotherapy (aHR, 0.61; 95% CI, 0.39-0.94). ERCC1 rs11615 and rs3212886 might have also a significant impact in treatment outcome (aHR, 0.67; 95% CI, 0.51-0.89; aHR, 1.28; 95% CI, 1.01-1.63, respectively). Moreover, ERCC2 rs13181 and rs1799793 showed a distinct ethnic behavior (Asians: aHR, 1.41; 95% CI, 0.80-2.49; aHR, 1.07; 95% CI, 0.62-1.86; Caucasians: aHR, 0.10; 95% CI, 0.01-0.96; aHR, 0.18; 95% CI, 0.05-0.68, respectively).

CONCLUSION(S)

The definition of integrative predictive models should encompass genetic information, especially regarding GSTM1 homozygous deletion. Justifying additional pharmacogenetic investigation are variants in ERCC1 and ERCC2, which highlight the DNA Repair ability to ovarian cancer prognosis. Further knowledge could aid to understand platinum-treatment failure and to tailor chemotherapy strategies.

Chemosensitizing effect of shRNA-mediated ERCC1 silencing on a Xuanwei lung adenocarcinoma cell line and its clinical significance

Lung cancer is a common fatal malignancy in both men and women. Xuanwei, Yunnan has the highest incidence of lung cancer in China. The area has a specific risk factor in the domestic combustion of bituminous coal, and lung cancer patients from this area tend to be resistant to platinum-based treatments. However, little is known about the mechanism of platinum resistance in patients from Xuanwei. Herein, we used lentiviral infection with shRNA to silence expression of the DNA repair enzyme ERCC1 in XWLC05 both in its RNA and protein expression level, a lung adenoma cell line derived from a patient from Xuanwei. ERCC1 expression in this cell line is high and contributes to its resistance to cisplatin. Suppression of ERCC1 decreased XWLC05 proliferation in vitro (IC50 of cisplatin 1.34 µM for shRNA-infected cells vs. 4.54 µM for control cells) and increased the apoptotic rate after treatment with cisplatin (81.2% shRNA cells vs. 58% control cells, P<0.05). Progression-free survival was longer in ERCC1-negative lung adenoma patients than those with high ERCC1 levels (30 vs. 11 months, P<0.0001). ERCC1 expression was identified as a prognostic marker for overall survival in the patient cohort with operable lesions. Taken together, our data identify ERCC1 as a disease marker in lung adenoma patients from Xuanwei and confirm the significance of resection for the subsequent effect of platinum treatment in these patients. Additional studies are needed to determine the mechanism of ERCC1-induced platinum resistance in lung adenoma patients from Xuanwei.

Role of Pharmacogenomics in Kidney Disease and Injury

There has been considerable excitement in the kidney community surrounding the research findings on the genetic contributions to kidney diseases. However, positive outcomes of personalized therapeutic interventions can be circumvented by unpredictable pharmacokinetics of prescribed drugs. Furthermore, unpredictable drug disposition can result in toxicities such as kidney injury. Patient covariates, disease covariates, and pharmacogenetics all contribute to variability in drug disposition. Further treatment personalization and avoidance of drug- and biologic- induced kidney injury will require extensive knowledge and expertise in renal clinical pharmacology. The current review will focus on the pharmacogenetics of drugs and biologics used in the treatment of glomerular kidney diseases and drugs implicated in inducing kidney injury phenotypes.

Overexpression of S100A14 in human serous ovarian carcinoma

S100 calcium binding protein A14 (S100A14) is a member of the S100 protein family that plays an important role in the progression of several types of cancer. In the present study, the expression and clinical effect of S100A14 was evaluated in serous ovarian carcinoma (SOC). SOC tissue specimens and a panel of normal ovarian and fallopian tubal tissue specimens were obtained between November 2008 and August 2012 from the Affiliated Hospital of Qingdao University. Immunohistochemistry (IHC) was used to detect the expression of S100A14 in the SOC and normal control tissues. In addition, ELISA was performed to assess S100A14 expression in a subset of serum samples. The association between the expression of S100A14 in SOC and the corresponding clinical and pathological data was analyzed. The IHC results revealed that S100A14 was mainly located in the cytoplasm of the majority of SOC cells, and the expression levels of S100A14 in the tumor tissues were significantly increased compared with the levels identified in normal ovarian specimens (P<0.001). Consistently, the serum levels of S100A14 in patients with SOC were also increased compared with the levels in healthy individuals (P<0.001). S100A14 expression was similar in the epithelium of SOC lesions and the fallopian tube, which supported the dualistic model for ovarian serous carcinogenesis. Additional analysis of the expression of S100A14 and corresponding clinical and pathological data revealed the correlation between the elevated expression of S100A14 and resistance to platinum-based chemotherapy. However, the protein level of S100A14 was not associated with the pathological stage, differentiation or metastasis of SOC. Overall, the present results demonstrate that S100A14 is likely to be involved in the resistance of SOC to platinum-based chemotherapy.

Clinical utility of plasma Epstein-Barr virus DNA and ERCC1 single nucleotide polymorphism in nasopharyngeal carcinoma

BACKGROUND

Single nucleotide polymorphism (SNP) of the excision repair cross-complementing group 1 (ERCC1) gene has been linked with sensitivity to platinum and radiation. The authors hypothesized that the ERCC1 genotype for the SNPs cytosine-to-thymine substitution at codon 118 (C118T) and cytosine-to-adenine substitution at codon 8092 (C8092A) is prognostic in patients with nasopharyngeal carcinoma (NPC) who receive either radiotherapy (RT) or cisplatin plus RT.

METHODS

The authors tested their hypothesis using biomarker screening samples from the Hong Kong NPC Study Group 0502 trial, which was a prospective, multicenter clinical trial that used post-RT plasma Epstein-Bar virus (EBV) DNA (pEBV) levels to screen patients with high-risk NPC for adjuvant chemotherapy.

RESULTS

ERCC1 SNPs were analyzed in 576 consecutive patients who were screened by pEBV. In the total biomarker population, there was no significant association of ERCC1 C118T or C8092A genotype with relapse-free survival (RFS) or overall survival (OS). There also was no correlation between ERCC1 genotype and ERCC1 protein or messenger RNA expression in a subset of patients who had available paired biopsies. Post-RT pEBV status was the only independent prognosticator for RFS and OS in multivariate analyses. However, there was a significant interaction between ERCC1 C118T genotype and post-RT pEBV status (RFS, P = .0106; OS, P = .0067). The ERCC1 C118T genotype was significantly associated with both RFS (hazard ratio, 1.67; 95% confidence interval, 1.07-2.61; P = .024) and OS (hazard ratio, 2.31; 95% confidence interval, 1.22-4.40; P = .0106) in the post-RT pEBV-negative population, but not in the pEBV-positive population.

CONCLUSIONS

The current results prospectively validate pEBV as the most significant prognostic biomarker in NPC that can be used to select high-risk patients for adjuvant therapy. The ERCC1 C118T genotype may help to identify a favorable subgroup (approximately 7%) of pEBV-negative patients with NPC who have an excellent prognosis and can be spared the toxicities of further therapy.

Can pharmacogenetics explain efficacy and safety of cisplatin pharmacotherapy?

Several recent pharmacogenetic studies have investigated the variability in both outcome and toxicity in cisplatin-based therapies. These studies have focused on the genetic variability of therapeutic targets that could affect cisplatin response and toxicity in diverse type of cancer including lung, gastric, ovarian, testicular, and esophageal cancer. In this review, we seek to update the reader in this area of investigation, focusing primarily on DNA reparation enzymes and cisplatin metabolism through Glutathione S-Transferases (GSTs). Current evidence indicates a potential application of pharmacogenetics in therapeutic schemes in which cisplatin is the cornerstone of these treatments. Therefore, a collaborative effort is required to study these molecular characteristics in order to generate a genetic panel with clinical utility.

ERCC1 polymorphisms as prognostic markers in T4 breast cancer patients treated with platinum-based chemotherapy

BACKGROUND

Polymorphisms in the excision repair cross-complimentary group 1 (ERCC1) gene have been involved in the prognosis of various cancers. In the present study, we evaluated the prognostic role of the two most common ERCC1 polymorphisms in patients with T4 breast cancer receiving platinum-based chemotherapy.

METHODS

A total of 47 patients with T4 breast cancer undergoing treatment with a platinum-based regimen were collected and followed up (median 159 months; range, 42-239 months). ERCC1 C8092A (rs3212986) and T19007C (rs11615) polymorphisms were genotyped, using an automated sequencing approach. The same series was screened for BRCA1/2 mutations by DHPLC analysis and DNA sequencing.

RESULTS

Among the tested patients, 16 (34%) and 25 (53%) presented the 8092A (homo-zygosity A/A or heterozygosity A/C) and the 19007C (homozygosity C/C or heterozygosity C/T) genotypes, respectively. The 8092A and 19007C genotypes in ERCC1 were significantly associated with overall survival in T4 breast cancer patients treated with chemotherapy containing platinum (p-values = 0.036 and 0.004, respectively). Univariate and multivariate Cox regression analyses showed that combination of 8092A and 19007C genotypes acts as a significant prognostic factor in women with T4 breast cancer receiving platinum-based chemotherapy (p-values = 0.022 and 0.049, respectively). Two (4.3%) out of 47 cases were found to carry BRCA1/2 mutations; they presented the highest overall survival rates into the series.

CONCLUSIONS

The ERCC1 8092A and 19007C genotypes or their combination may predict a favorable prognosis in T4 breast cancer patients undergoing a platinum-based treatment. Further large-scale, prospective studies are needed to validate our findings.

Predicting the outcome of platinum-based chemotherapies in epithelial ovarian cancer using the 8092C/A polymorphism of ERCC1: a meta-analysis

BACKGROUND

In the present study, we performed this meta-analysis to estimate the association between excision repair cross-complementation group 1 (ERCC1) gene polymorphism and clinical resistance to platinum-based chemotherapy in the patients with epithelial ovarian cancer (EOC).

METHODS

A total of 10 studies consist of 1479 EOC patients relating ERCC1 rs11615C/T and rs3212986C/A polymorphisms to the response of platinum-based chemotherapy were included in this meta-analysis.

RESULTS

The analysis showed that the AA genotype of the rs3212986C/A polymorphism in ERCC1 was associated with progression-free survival of EOC patients (HR = 1.39, 95% CI = 1.12-1.73) and that the CA or AA genotypes could influence overall survival (HR = 1.28, 95% CI = 1.05-1.56; and HR = 1.55, 95% CI = 1.17∼2.05, respectively).

CONCLUSIONS

The ERCC1 rs3212986C/A polymorphism may be a useful prognostic marker in platinum-based treatment of EOC.

Genetic variations in radiation and chemotherapy drug action pathways and survival in locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy

Background and Purpose

Treatment outcomes vary greatly in patients with nasopharyngeal carcinoma (NPC). The purpose of this study is to evaluate the influence of radiation and chemotherapy drug action pathway gene polymorphisms on the survival of patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy.

Material and Methods

Four hundred twenty-one consecutive patients with locoregionally advanced NPC were prospectively recruited. We utilized a pathway approach and examined 18 polymorphisms in 13 major genes. Polymorphisms were detected using the LDR-PCR technique. Multifactor dimensionality reduction (MDR) analysis was performed to detect potential gene-gene interaction.

Results

After adjustment for clinicopathological characteristics, overall survival was significantly decreased in patients with the MPO rs2243828 CT/CC genotype (HR=2.453, 95% CI, 1.687-3.566, P<0.001). The ERCC1 rs3212986 CC (HR=1.711, 95% CI, 1.135-2.579, P=0.010), MDM2 rs2279744 GT/GG (HR=1.743, 95% CI, 1.086-2.798, P=0.021), MPO rs2243828 CT/CC (HR=3.184, 95% CI, 2.261-4.483, P<0.001) and ABCB1 rs2032582 AT/AA (HR=1.997, 95% CI, 1.086-3.670, P=0.026) genotypes were associated with poor progression-free survival. Prognostic score models based on independent prognostic factors successfully classified patients into low-, intermediate-, and high-risk groups. Furthermore, MDR analysis showed no significant interaction between polymorphisms.

Conclusions

Four single nucleotide polymorphisms were associated with survival in patients with locoregionally advanced NPC treated with cisplatin- and fluorouracil-based chemoradiotherapy. Combining clinical prognostic factors with genetic information was valuable in identifying patients with different risk.

Sensitivity and resistance to treatment in the primary management of epithelial ovarian cancer

Ovarian carcinoma is the most lethal gynaecologic malignancy. Despite wide initial sensibility to chemotherapy especially to platinum-based regimens, the vast majority of patients with advanced stages of the disease develop recurrences and subsequent resistance to treatments. Ovarian cancer is actually considered as a heterogeneous disease at the clinical, histological and molecular level. In this review, the mechanisms of intrinsic sensitivity or resistance to treatment, especially to platinum-based chemotherapy are considered with particular reference to the significance of tumour heterogeneity. The molecular features involved in acquired resistance are reviewed and the current hypotheses are discussed. In particular, potential disruptions of the DNA reparation pathways are highlighted.

Polymorphisms in ERCC1 C8092A predict progression-free survival in metastatic/recurrent nasopharyngeal carcinoma treated with cisplatin-based chemotherapy

OBJECTIVES

We evaluated whether DNA repair gene polymorphisms had an effect on clinical outcomes in metastatic/recurrent nasopharyngeal carcinoma (NPC) patients treated with cisplatin-based chemotherapy.

MATERIALS AND METHODS

Clinical data of 101 patients with metastatic/recurrent NPC between 2004 and 2011 were reviewed. Five potentially functional polymorphisms (ERCC1 Asn118Asn, ERCC1 C8092A, XPD Lys751Gln, XRCC1 Arg399Gln and XRCC1 Arg280His) were genotyped using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

RESULTS

The ERCC1 C8092A polymorphism was an independent predictor of PFS in Chinese NPC patients treated with cisplatin-based chemotherapy. Compared to the patients carrying the C/C genotype, the patients with the C/A or A/A genotype had an increased risk of disease progression on cisplatin-based chemotherapy (7.9 vs. 9.3 months; HR 1.61; 95 % CI 1.08-2.61; p = 0.047). However, no association between the other polymorphisms, response rate, disease progression and survival was detected in metastatic/recurrent NPC patients.

CONCLUSION

The ERCC1 C8092A polymorphism might be a useful predictive marker in metastatic/recurrent NPC patients treated with cisplatin-based chemotherapy. However, a large-scale prospective study is warranted to validate our findings.

The role of single nucleotide polymorphisms of the ERCC1 and MMS19 genes in predicting platinum-sensitivity, progression-free and overall survival in advanced epithelial ovarian cancer

OBJECTIVE

This study aims to assess the role of polymorphisms in DNA repair genes, excision repair cross-complementation group 1 (ERCC1) and methyl-methanesulfonate sensitivity 19 (MMS19), in tumor response to platinum-based chemotherapy and survival in advanced epithelial ovarian cancer (EOC).

METHODS

Single nucleotide polymorphism (SNP) analysis was performed on the paraffin-embedded tumor tissue of women with advanced EOC, treated with platinum-based chemotherapy at the University of Oklahoma Health Sciences Center. Polymorphisms from two ERCC1 (codon-118 and C8092A) and three MMS19 (rs2211243, rs2236575 and rs872106) gene loci were evaluated by real time PCR Allelic Discrimination Assay.

RESULTS

Genotyping was performed in 107 patients, 45 platinum-sensitive and 62 platinum-resistant. ERCC1, codon-118 and C8092A genotyping was evaluable in 98 and 106 patients respectively and in all 107 patients for MMS19 polymorphisms. No differences were observed in genotype between platinum-sensitive and platinum-resistant patients. Polymorphisms in the ERCC1, codon-118 and MMS19 genes did not correlate with overall survival (OS), although a trend toward improved progression free survival (PFS) was observed in patients expressing the minor (GG) alleles of the rs872106 MMS19 gene. Women homozygous for the ERCC1-C8092A minor (AA) alleles had a significant increase in PFS compared to AC and CC patients and both AA and AC genotypes conferred improved survival over the major (CC) genotype.

CONCLUSIONS

Polymorphisms in ERCC1, codon-118 and MMS19 genes are not associated with clinical response to platinum or survival. The ERCC1-C8092A genotypes containing an "A" allele were associated with significant improvement in PFS and OS strengthening the value of this specific genotype in survival.

Association of ERCC1 SNPs with outcome in platinum-treated patients with advanced urothelial cancer: a Hellenic Cooperative Oncology Group study

Aim: The association between two polymorphisms of ERCC1 and treatment outcomes after platinum-based chemotherapy in patients with advanced urothelial cancer (UC) was examined. Materials & methods: Genotyping of 19007C>T and 8092C>A polymorphisms was determined by PCR amplification and RFLP in 113 advanced UC patients, treated with platinum-based chemotherapy. Results: Seventy eight patients (69%) were carriers of the 19007T polymorphic allele: 51 (45%) heterozygotes and 27 (24%) homozygotes. Fifty three (47%) patients were carriers of the 8092A polymorphic allele: the frequencies of C/A and A/A genotypes were 37% and 10%, respectively. The T/T genotype was independently associated with prolonged median cancer-specific survival (not-reached vs 14.8 months; p = 0.026). There was no interaction between T/T or any other genotype with the type of platinum derivative (cisplatin/carboplatin). Conclusion: 19007C>T, especially in its homozygotic state, but not 8092C>A polymorphism, could be a useful prognostic marker in advanced UC treated with platinum-based chemotherapy.

Original submitted 17 July 2012; Revision submitted 21 September 2012

Comparison of ERCC1/XPF genetic variation, mRNA and protein levels in women with advanced stage ovarian cancer treated with intraperitoneal platinum

OBJECTIVE

Approximately 20% of patients receiving platinum-based chemotherapy for epithelial ovarian cancer (EOC) are refractory or develop early recurrence. Identifying these patients early could reduce treatment-associated morbidity and allow quicker transfer to more effective therapies. Much attention has focused on ERCC1 as a potential predictor of response to therapy because of its essential role in the repair of platinum-induced DNA damage. The purpose of this study was to accurately measure protein levels of ERCC1 and its essential binding partner XPF from patients with EOC treated with platinum-based therapy and determine if protein levels correlate with mRNA levels, patient genotypes or clinical outcomes.

METHODS

ERCC1 and XPF mRNA and protein levels were measured in frozen EOC specimens from 41 patients receiving intraperitoneal platinum-based chemotherapy using reverse transcription polymerase chain reaction and western blots. Genotypes of common nucleotide polymorphisms were also analyzed. Patient outcomes included progression free (PFS) and overall survival (OS).

RESULTS

Expression of ERCC1 and XPF were tightly correlated with one another at both the mRNA and protein level. However, the mRNA and protein levels of ERCC1 were not positively correlated. Likewise, none of the SNPs analyzed correlated with ERCC1 or XPF protein levels. There was an inverse correlation between mRNA levels and patient outcomes.

CONCLUSION

Neither genotype nor mRNA levels are predictive of protein expression. Despite this, low ERCC1 mRNA significantly correlated with improved PFS and OS.

Gene set analysis of survival following ovarian cancer implicates macrolide binding and intracellular signaling genes

BACKGROUND

Genome-wide association studies (GWAS) for epithelial ovarian cancer (EOC), the most lethal gynecologic malignancy, have identified novel susceptibility loci. GWAS for survival after EOC have had more limited success. The association of each single-nucleotide polymorphism (SNP) individually may not be well suited to detect small effects of multiple SNPs, such as those operating within the same biologic pathway. Gene set analysis (GSA) overcomes this limitation by assessing overall evidence for association of a phenotype with all measured variation in a set of genes.

METHODS

To determine gene sets associated with EOC overall survival, we conducted GSA using data from two large GWAS (N cases = 2,813, N deaths = 1,116), with a novel Principal Component-Gamma GSA method. Analysis was completed for all cases and then separately for high-grade serous histologic subtype.

RESULTS

Analysis of the high-grade serous subjects resulted in 43 gene sets with P < 0.005 (1.7%); of these, 21 gene sets had P < 0.10 in both GWAS, including intracellular signaling pathway (P = 7.3 × 10(-5)) and macrolide binding (P = 6.2 × 10(-4)) gene sets. The top gene sets in analysis of all cases were meiotic mismatch repair (P = 6.3 × 10(-4)) and macrolide binding (P = 1.0 × 10(-3)). Of 18 gene sets with P < 0.005 (0.7%), eight had P < 0.10 in both GWAS.

CONCLUSION

This research detected novel gene sets associated with EOC survival.

IMPACT

Novel gene sets associated with EOC survival might lead to new insights and avenues for development of novel therapies for EOC and pharmacogenomic studies.

Association between polymorphisms of ERCC1 and survival in epithelial ovarian cancer patients with chemotherapy

Aim: We evaluated whether the ERCC1 polymorphisms had an effect on survival in epithelial ovarian cancer (EOC) patients with platinum-based chemotherapy. Materials & methods: Clinical data of 209 EOC patients between 2002 and 2008 were reviewed. The genotypes of 19007T/C and 8092C/A polymorphisms were assessed in all patients using PCR–RFLP. Results: The 19007T/C polymorphism was significantly associated with response to treatment. Compared with the patients carrying C/C genotype, the patients with the T/T genotype have a significantly decreased response to platinum-based chemotherapy (odds ratio: 32.26; 95% CI: 3.66–250.00). Cox’s multivariate analysis suggested that EOC patients with the T/T genotype had an increased risk of disease progression (hazard ratio: 3.34; 95% CI: 1.77–6.29) and death (hazard ratio: 2.87; 95% CI: 1.38–5.96) compared with those carrying the C/C genotype. Conclusion: The 19007T/C polymorphism may be a useful prognostic marker in patients with EOC treated with platinum-based chemotherapy in Chinese women.

Original submitted 26 October 2011; Revision submitted 5 December 2011

Dose-dense therapy is of benefit in primary treatment of ovarian cancer: contra

Several studies in the past have tried to improve the prognosis of ovarian cancer by increasing the dose intensity of platinum. Only 2 out of 12 randomized studies showed survival benefit at the cost of significant long-term toxicity. Dose-dense induction therapy with combined weekly paclitaxel (at a dose of 90 mg/m(2)) and weekly carboplatin [at an area under the curve (AUC) of 4 mg·ml/min] followed by 3-weekly paclitaxel/carboplatin was very effective in platinum-resistant patients (response 58%, progression-free survival 10 months). In first-line, however, no survival benefit was found with the same dose-dense weekly paclitaxel/carboplatin regimen over standard-dosed 3-weekly paclitaxel/carboplatin in a randomized study. Very recently, the Japanese Gynecologic Oncology Group (JGOG) study no. 3016, randomizing patients in first-line between dose-dense weekly paclitaxel 80 mg/m(2) plus 3-weekly carboplatin AUC 6 and 3-weekly paclitaxel/carboplatin, showed a significant increase in progression-free survival (median 28 versus 17.2 months in the control arm; hazard ratio for progression, 0.71; 95% confidence interval, 0.58-0.88; P=0.0015). The 3-year overall survival was 72% versus 65% (P=0.03), respectively. The hematologic toxicity was substantial in both arms and substantially higher than observed with the weekly paclitaxel/carboplatin induction regimen. Many patients had treatment delays, dose reductions and stopped treatment prematurely. The JGOG 3016 study is the only dose-dense study with such a significant survival benefit. It is also the only dose-intensity study performed in Asian patients. Genotypes and phenotypes are thought to represent important determinants of drug efficacy in ovarian cancer. Therefore, confirmatory studies with this JGOG regimen together with translational research are needed in both Caucasian and Asian patients.

Pre-treatment tumor expression of ERCC1 in women with advanced stage epithelial ovarian cancer is not predictive of clinical outcomes: a Gynecologic Oncology Group study

OBJECTIVE

Excision repair cross-complementation group 1 (ERCC1) is required for the repair of platinum-induced DNA damage. This study sought to assess the prognostic value of ERCC1 expression, measured by immunohistochemistry (IHC) using a highly specific antibody, in advanced epithelial ovarian cancer (EOC) patients treated with platinum-based chemotherapy.

METHODS

Formalin-fixed, paraffin-embedded tumors were collected from two GOG phase III trials (GOG-172 and GOG-182) of patients with stage III/IV EOC treated with platinum-based chemotherapy. ERCC1 was detected by (IHC) using FL297 polyclonal antibody and tumors were categorized as negative or positive, based on nuclear staining of tumor cells. ERCC1 genotyping was performed as previously reported. Associations between ERCC1 expression and clinical characteristics, platinum responsiveness, progression-free survival (PFS) or overall survival (OS) were evaluated.

RESULTS

Of 408 eligible patients, 27% had tumors that were ERCC1 positive. ERCC1 expression was not associated with clinical characteristics or platinum-responsiveness. Women with ERCC1-positive versus -negative tumors had similar median PFS (17.9 months versus 17.5 months, respectively, p=0.59), median OS (52.0 months versus 47.0 months, respectively, p=0.30), risk of disease progression (adjusted hazard ratio [HR]=0.90, 95% confidence interval (CI): 0.71-1.15, p=0.41), and risk of death (adjusted HR=0.81, 95% CI: 0.61-1.07, p=0.14). ERCC1 expression, as measured by IHC, was not associated with single nucleotide polymorphisms (SNPs), in codon 118 and C8092A, of the ERCC1 gene.

CONCLUSIONS

ERCC1 expression, measured by IHC in pre-treatment tumor specimens, using a highly specific antibody, has limited clinical value in patients with advanced EOC treated with platinum and taxane based chemotherapy.

Pre-treatment tumor expression of ERCC1 in women with advanced stage epithelial ovarian cancer is not predictive of clinical outcomes: a Gynecologic Oncology Group study

OBJECTIVE

Excision repair cross-complementation group 1 (ERCC1) is required for the repair of platinum-induced DNA damage. This study sought to assess the prognostic value of ERCC1 expression, measured by immunohistochemistry (IHC) using a highly specific antibody, in advanced epithelial ovarian cancer (EOC) patients treated with platinum-based chemotherapy.

METHODS

Formalin-fixed, paraffin-embedded tumors were collected from two GOG phase III trials (GOG-172 and GOG-182) of patients with stage III/IV EOC treated with platinum-based chemotherapy. ERCC1 was detected by (IHC) using FL297 polyclonal antibody and tumors were categorized as negative or positive, based on nuclear staining of tumor cells. ERCC1 genotyping was performed as previously reported. Associations between ERCC1 expression and clinical characteristics, platinum responsiveness, progression-free survival (PFS) or overall survival (OS) were evaluated.

RESULTS

Of 408 eligible patients, 27% had tumors that were ERCC1 positive. ERCC1 expression was not associated with clinical characteristics or platinum-responsiveness. Women with ERCC1-positive versus -negative tumors had similar median PFS (17.9 months versus 17.5 months, respectively, p=0.59), median OS (52.0 months versus 47.0 months, respectively, p=0.30), risk of disease progression (adjusted hazard ratio [HR]=0.90, 95% confidence interval (CI): 0.71-1.15, p=0.41), and risk of death (adjusted HR=0.81, 95% CI: 0.61-1.07, p=0.14). ERCC1 expression, as measured by IHC, was not associated with single nucleotide polymorphisms (SNPs), in codon 118 and C8092A, of the ERCC1 gene.

CONCLUSIONS

ERCC1 expression, measured by IHC in pre-treatment tumor specimens, using a highly specific antibody, has limited clinical value in patients with advanced EOC treated with platinum and taxane based chemotherapy.

Genetic polymorphisms as predictive and prognostic biomarkers in gynecological cancers: a systematic review

PURPOSE

Numerous studies have explored the potential role of genetic polymorphisms as predictive or prognostic biomarkers in gynecologic malignancies. A systematic review for all eligible polymorphisms has not yet been reported. The aim of this study was to summarize the current status of the field and provide direction for future research.

DESIGN

We searched literature databases (MEDLINE, EMBASE, Cochrane) from 2006 to April 2011 to identify studies evaluating the association between gene polymorphisms and clinical outcome in ovarian, endometrial, cervical, or vulvar cancer. The main outcome measures were overall survival (OS) and progression-free survival (PFS). Studies reporting relationships between polymorphisms and toxicity were also included.

RESULTS

Sixty two studies met the inclusion criteria. The median sample size was 140. Most of the included studies (n=50, 81%) were conducted in ovarian cancer patients. Almost a third assessed potential predictive associations between gene polymorphism and outcome in ovarian cancer. The most commonly evaluated genes were ERCC1, VEGF, ABCB1 (MDR), and GSTP1. Most studies (n=44, 71%) were observational case-series. Only four studies (6%) included a validation arm and patient population ethnicity was explicitly stated only in 27% of included studies.

CONCLUSION

No consistent association between any gene polymorphism and clinical outcome in gynecological cancers has been found across studies. There is incomplete adherence to the REMARK guidelines and inadequate methodology reporting in most studies. Moving forward, analysis of large trial-based clinical samples; adherence to the highest methodological standards, and focus on validation analyses are necessary to identify clinically useful pharmacogenomic biomarkers of outcome.

Association of keap1 and nrf2 genetic mutations and polymorphisms with endometrioid endometrial adenocarcinoma survival

OBJECTIVE

Dysregulation of Kelch-like erythroid cell-derived protein with CNC homology-associating protein (Keap)-nuclear factor E2-related factor 2 (Nrf2) homeostasis owing to oncogenic mutations or to endogenous alteration of protein expression levels is implicated in tumor resistance to adjuvant treatment. To understand the role of Keap1 and Nrf2 in endometrial cancer, we performed DNA sequencing of tumors and noted the relation of the DNA sequence with annotated clinicopathologic data.

METHODS

We sequenced the Keap1 and Nrf2 genes in 105 tumor specimens. Associations of genetic mutations and polymorphisms with the patients' clinicopathologic characteristics were evaluated.

RESULTS

We detected 9 patients with Keap1 mutations and 3 patients with Nrf2 mutations. No patient had both Keap1 and Nrf2 mutations. We found 2 single nucleotide polymorphisms within the coding region of Keap1 - rs1048290 (c. 1413C>G) and rs11545829 (c. 1611C>T) that displayed high heterogeneity in our cohort. The c. 1413C>G polymorphism is significantly associated with progression-free survival by multivariate analysis (hazard ratio, 0.16; 95% confidence interval, 0.036-0.69; P = 0.014). The presence of Keap1 or Nrf2 mutations and c. 1611C>T are not associated with the clinical outcome of the patients.

CONCLUSIONS

Mutations impairing Keap1-Nrf2 interaction are relatively common in endometrial cancer (12 [11.4%] of 105). Keap1 single nucleotide polymorphism rs1048290 may be a novel independent prognostic marker for patients with endometrial cancer receiving adjuvant treatment. Therefore, genotyping patients for this Keap1 polymorphism will help identify patient subgroups more likely to benefit from standard adjuvant therapy.

Pharmacogenetic analyses of cisplatin-induced nephrotoxicity indicate a renoprotective effect of ERCC1 polymorphisms

AIM

We investigated whether genetic polymorphisms may contribute to the interpatient variability of cisplatin-induced nephrotoxicity.

PATIENTS & METHODS

Polymorphisms in the candidate genes GSTM1, GSTT1, OCT1, OCT2, LARP2, ERCC1, XRCC1 and EPO were analyzed for associations with nephrotoxicity in 79 cancer patients receiving cisplatin-containing chemotherapy.

RESULTS

Higher cisplatin dose was associated with strongly decreased estimated glomerular filtration rates (eGFR) (r(2) = 0.205). Two highly genetically linked polymorphisms in the ERCC1 gene, 8092C>A and Asn118Asn, were significantly associated with change in eGFR, accounting for an additional 13% of interindividual variability. Homozygous carriers of the 8092A allele in ERCC1 showed no reduction in eGFR, compared with the 11.5% mean eGFR decrease in C allele carriers (p = 0.004). Homozygous carriers of the C allele of Asn118Asn showed no reduction in eGFR, compared with the 12.8% mean eGFR decrease seen in T allele carriers (p = 0.047). Polymorphisms in the other candidate genes were not associated with cisplatin-induced nephrotoxicity.

CONCLUSION

Genetic polymorphisms in ERCC1 may be valuable predictors of cisplatin-induced nephrotoxicity.

Nucleotide excision repair gene variants and association with survival in osteosarcoma patients treated with neoadjuvant chemotherapy

The aim of this study was to investigate the role of common polymorphisms in the nucleotide excision repair pathway genes in the tumorigenesis of osteosarcoma and in the response to DNA damaging therapies, such as cisplatin-based neoadjuvant therapy. Excision repair cross-complementing (ERCC) group 2 (XPD; rs13181 and rs1799793), group 5 (XPG; rs17655) and group 1 (XPA; rs3212986 and rs11615) polymorphisms were analyzed in a group of 130 homogenously treated patients with high-grade osteosarcoma, for association with event-free survival (EFS), using the Kaplan-Meier plots and log-rank test. A positive association was observed between both XPD single-nucleotide polymorphisms and an increased EFS (hazards ratio (HR) = 0.34, 95% confidence interval (CI) 0.12-0.98 and HR = 0.19, 95% CI 0.05-0.77, respectively). We had also performed a case-control study for relative risk to develop osteosarcoma. Patients carrying at least one variant allele of XPD rs1799793 had a reduced risk of developing osteosarcoma, compared with wild-type patients (odds ratio = 0.55, 95% CI 0.36-0.84). This study suggests that XPD rs1799793 could be a marker of osteosarcoma associated with features conferring either a better prognosis or a better outcome after platinum therapy, or both.

Xeroderma pigmentosum complementation group C single-nucleotide polymorphisms in the nucleotide excision repair pathway correlate with prolonged progression-free survival in advanced ovarian cancer

BACKGROUND

The nucleotide excision repair (NER) pathway is the principal DNA repair pathway for removing bulky platinum DNA adducts. Suboptimal DNA repair may lead to improved response to platinum agents. The objective of this study was to determine whether single-nucleotide polymorphisms (SNPs) in NER pathway genes could be markers of platinum response in ovarian cancer.

METHODS

The authors identified patients with advanced-stage, papillary serous ovarian cancer who underwent primary cytoreductive surgery followed by platinum-based chemotherapy. DNA was isolated from peripheral blood specimens. Twenty-two SNPs within NER genes (xeroderma pigmentosum [XP] complementation group A [XPA], XPB/excision repair cross-complementing rodent repair deficiency, complementation group 3 [ERCC3], XPC, XPD/ERCC2, XPF/ERCC4, XPG/ERCC5, Cockayne syndrome group B protein [CSB]/ERCC8, ERCC1) were genotyped using polymerase chain reaction analysis.

RESULTS

In total, 139 patients with stage III and IV papillary serous ovarian cancer were genotyped. The XPC (reference SNP 3731108 [rs3731108]) adenosine-guanine (AG)/AA genotype versus the GG genotype was associated with prolonged a progression-free survival (PFS) of 21.3 months versus 13.4 months (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.42-0.95; P = .03). The XPC (rs1124303) guanosine-thymidine (GT)/GG genotype versus the TT genotype was associated with a prolonged PFS of 22.8 months versus 14.9 months (HR, 0.47; 95% CI, 0.24-0.94; P = .03). The XPC poly(AT) (PAT) (-/+)/(-/-) genotype versus the (+/+) genotype was associated with a prolonged PFS of 17 months versus 11.6 months (HR, 0.56; 95% CI, 0.36-0.89; P = .01). The XPF/ERCC4 (rs12926685) cytidine-thymidine (CT)/CC genotype versus the TT genotype was associated with a prolonged PFS of 16.7 months versus 12.4 months (HR, 0.63; 95% CI, 0.41-0.95; P = .03). On multivariate analysis adjusting for breast cancer (BRCA) gene and cytoreductive surgery status, the XPC SNPs remained significantly associated with prolonged PFS.

CONCLUSIONS

The current results indicated that XPC is a key component of the NER pathway that participates in DNA damage repair. SNPs in the XPC gene may represent novel markers of ovarian cancer response to platinum-based chemotherapy.

Part 4: pharmacogenetic variability in anticancer pharmacodynamic drug effects

Response to treatment with anticancer drugs is subject to wide interindividual variability. This variability is expressed not only as differences in severity and type of toxicity, but also as differences in effectiveness. Variability in the constitution of genes involved in the pharmacokinetic and pharmacodynamic pathways of anticancer drugs has been shown to possibly translate into differences in treatment outcome. The overall knowledge in the field of pharmacogenetics has tremendously increased over the last couple of years, and has thereby provided opportunities for patient-tailored anticancer therapy. In previous parts of this series, we described pharmacogenetic variability in anticancer phase I and phase II drug metabolism and drug transport. This fourth part of a four-part series of reviews is focused on pharmacodynamic variability and encompasses genetic variation in drug target genes such as those encoding thymidylate synthase, methylene tetrahydrofolate reductase, and ribonucleotide reductase. Furthermore, genetic variability in other pharmacodynamic candidate genes involved in response to anticancer drugs is discussed, including genes involved in DNA repair such as those encoding excision repair crosscomplementing group 1 and group 2, x-ray crosscomplementing group 1 and group 3, and breast cancer genes 1 and 2. Finally, somatic mutations in KRAS and the gene encoding epidermal growth factor receptor (EGFR) and implications for EGFR-targeted drugs are discussed. Potential implications and opportunities for patient and drug selection for genotype-driven anticancer therapy are outlined.

Polymorphisms in ABCB1 and ERCC2 associated with ovarian cancer outcome

Using the most comprehensive approach to selecting polymorphisms to date, we sought to examine whether time to recurrence in ovarian cancer was associated with common inherited variation in eight genes involved in drug metabolism, multi-drug resistance, or DNA repair, namely ABCB1, CYP2C8, CYP3A4, ERCC1, ERCC2, GSTM1, XPC, and XRCC1. Invasive epithelial ovarian cancer patients (N=445) seen at the Mayo Clinic from 1999 to 2009 with 275 observed recurrences or deaths were analyzed at 94 SNPs in these candidate genes. Cox regression was used to estimate hazard ratios and 95% confidence intervals for each single nucleotide polymorphism (SNP) and outcome (defined as time to recurrence or death). Analyses were conducted at the gene level and on case subsets defined by histopathology and chemotherapeutic agent. At ABCB1, minor alleles at several SNPs were associated with outcome, with the most significant being the intronic SNP rs12334183 (HR=0.65, 95% Cl 0.51-0.83; p=0.0005). Overall variation in ABCB1 was predictive of outcome as well (p=0.003). At ERCC2, minor alleles at several SNPs were associated with outcome among women with high-grade serous disease (e.g., rs238417, HR 0.74, 95% Cl 0.59-0.92; p=0.006). No associations with outcome were observed in GSTM1, CYP2C8, CYP3A4, ERCC1, XPC, or XRCC1. In summary, inherited variation in ABCB1 and ERCC2 was associated with outcome in patients with ovarian cancer seen at the Mayo Clinic. As the associated SNPs have not been studied previously in ovarian cancer, these findings suggest novel sites of variation which may, in part, explain the range of treatment responses seen in this disease.

CYP2A6 and ERCC1 polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Background:

We evaluated the association between polymorphisms of cytochrome P450 2A6 (CYP2A6)/excision repair cross-complementation group 1 (ERCC1)/X-ray repair cross-complementing group 1(XRCC1) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.

Methods:

Among MGC patients (n=108), who received S-1 (40 mg m⁻² b.i.d., days 1–14) and cisplatin (60 mg m⁻², day 1) every 3 weeks, we analysed the wild-type allele (W) and variants (V) of CYP2A6 (*4, *7, *9, *10), and the polymorphisms of ERCC1 (rs11615, rs3212986) and XRCC1 (rs25487).

Results:

Patients having fewer CYP2A6 variants had better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4=66.7 vs 58.3 vs 32.3% P=0.008), time to progression (TTP) (7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A (rs3212986) was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (4.4 vs 7.6 vs 7.9 months) (P=0.012). Patients carrying both risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C) vs those carrying none showed an adjusted odds ratio of 0.113 (P=0.004) for response, and adjusted hazard ratios of 3.748 (P=0.0001) for TTP and 2.961 (P=0.006) for death.

Conclusion:

Polymorphisms of CYP2A6 and ERCC1 19442C>A correlated with the efficacy of S-1/cisplatin.

Regulation of excision repair cross-complementation group 1 by Snail contributes to cisplatin resistance in head and neck cancer

PURPOSE

We investigated the mechanism and clinical significance of the epithelial-mesenchymal transition (EMT)-induced chemoresistance in head and neck squamous cell carcinoma (HNSCC).

EXPERIMENTAL DESIGN

The correlation between the expression of different EMT regulators and chemoresistance genes, such as excision repair cross complementation group 1 (ERCC1), was evaluated in cancer cell lines from the NCI-60 database and four human HNSCC cell lines. Ectopic expression of Snail or short-interference RNA-mediated repression of Snail or ERCC1 was done in HNSCC cell lines. Cell viability was examined for cells after cisplatin treatment. A luciferase reporter assay and chromatin immunoprecipitation were used to identify the transcriptional regulation of ERCC1 by Snail. Immunohistochemical analysis of Snail, Twist1, ERCC1, hypoxia inducible factor-1 α (HIF-1α), and NBS1 were done in samples from 72 HNSCC patients receiving cisplatin-based chemotherapy.

RESULTS

The correlation between the expression of Snail and ERCC1 was confirmed in different cell lines, including HNSCC cells. In HNSCC cell lines, overexpression of Snail in the low endogenous Snail/ERCC1 cell lines FaDu or CAL-27 increased ERCC1 expression, and hypoxia or overexpression of NBS1 also upregulated ERCC1. Knockdown of Snail in the high endogenous Snail/ERCC1 cell line OECM-1 downregulated ERCC1 expression and attenuated cisplatin resistance. Furthermore, suppression of ERCC1 in Snail- or NBS1-overexpressing HNSCC cells enhanced sensitivity to cisplatin. Snail directly regulated ERCC1 transcription. In patients with HNSCC, coexpression of Snail and ERCC1 correlated with cisplatin resistance and a poor prognosis.

CONCLUSIONS

Activation of ERCC1 by Snail is critical in the generation of cisplatin resistance of HNSCC cells.

Translational research in the Gynecologic Oncology Group: evaluation of ovarian cancer markers, profiles, and novel therapies

OBJECTIVES

To review the translational research (TR) performed in the Gynecologic Oncology Group (GOG) to evaluate ovarian cancer markers, profiles and novel therapies.

METHODS

Prospective trials with stand alone or embedded TR objectives involving patient and specimen accrual as well as retrospective studies using banked specimens and resources were and continue to be performed in the GOG. Appropriate statistical methods are employed to evaluate associations with clinical characteristics and outcomes including tumor response, adverse events, progression free survival and overall survival.

RESULTS

Highlights are presented for some of the collaborative and multidisciplinary TR conducted with the GOG to evaluate markers, pathway and novel therapeutics in epithelial ovarian, primary peritoneal and/or fallopian tube cancer. For example, in GOG 111, high immunohistochemical (IHC) expression of cyclin E was associated with a shorter median survival (29 versus 35 months) and an increased risk of death (hazard ratio [HR]=1.4, 95% confidence interval [CI]=1.0-2.1, p=0.05). In GOG 114/132, non-detectable immunoblot expression of maspin was associated with debulking status (p=0.034) and an increased risk of disease progression (HR=1.89, 95% CI=1.04-3.45, p=0.038) and death (HR=1.99, 95% CI=1.07-3.69, p=0.030) while high CD105-microvessel density (MVD), but not CD31-MVD in tumor was associated with increased risk of disease progression (HR=1.873, 95% CI=1.102-3.184, p=0.020) but not death. In GOG 172, low IHC expression of BRCA1 was associated with advanced stage (p<0.001), serous histology (p<0.001) and a reduced risk of disease progression (HR=0.64, 95% CI=0.42-0.96) and death (HR=0.51, 95% CI=0.32-0.83) while the CA/AA versus CC genotypes in C8092A in ERCC1 were associated with an increased risk of disease progression (HR=1.44, 95% CI=1.06-1.94, p=0.018) and death (HR=1.50, 95% CI=1.07-2.09, p=0.018).

CONCLUSIONS

The GOG has an extensive TR program that provides clues regarding the molecular and biochemical mechanisms of disease, treatments and outcomes in women with or at risk for a gynecologic malignancy.

Epidermal growth factor receptor intron 1 CA dinucleotide repeat polymorphism and survival of advanced gastric cancer patients treated with cetuximab plus modified FOLFOX6

Cetuximab is a monoclonal antibody targeting epidermal growth factor receptor (EGFR). The present study investigated the association between germline genetic polymorphisms and the treatment outcome of cetuximab plus modified leucovovin, fluorouracil, and oxaliplatin (FOLFOX)6 chemotherapy in advanced gastric cancer (AGC). DNA from peripheral blood mononuclear cells of 38 patients enrolled in a phase II study of cetuximab plus modified FOLFOX6 were analyzed for 16 polymorphisms in eight genes (EGFR, epidermal growth factor, transforming growth factor-alpha (TGFA), thymidylate synthase, excision repair cross-complementation group 1, Xeroderma pigmentosum group D, and fragment c gamma receptors (FCGR)2A and 3A). The EGFR intron 1 CA repeat polymorphism was associated with survival. Twenty-one patients had low repeats (sum of both alleles or=38). Patients with low CA repeats had longer progression-free survival (adjusted hazard ratio [HR] 0.42 [95% confidence interval [CI] 0.19-0.96], P = 0.040) and overall survival (adjusted HR 0.40 [95% CI 0.16-0.99], P = 0.048) compared with patients with high CA repeats. In addition, the tumor EGFR expression was higher in patients with a lower number of CA repeats. The association between the CA repeat status and survival was not found in a separate cohort of AGC patients (n = 68) treated only with modified FOLFOX6. These results suggest that the EGFR intron 1 CA repeat polymorphism could be a useful, predictive biomarker of cetuximab efficacy in AGC and merits further investigation in randomized studies.