Genetic variations in radiation and chemotherapy drug action pathways predict clinical outcomes in esophageal cancer

Neoadjuvant concurrent chemoradiotherapy for locally advanced esophageal cancer in a single high-volume center

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is now considered the standard of care by many centers in the treatment of both squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus. This study evaluates the effectiveness of a neoadjuvant CRT protocol, as regards pathological complete response (pCR) rate and long-term survival.

METHODS

From 2003 to 2011, at Upper G.I. Surgery Division of Verona University, 155 consecutive patients with locally advanced esophageal cancers (90 SCC, 65 adenocarcinoma) were treated with a single protocol of neoadjuvant CRT (docetaxel, cisplatin, and 5-fluorouracil with 50.4 Gy of concurrent radiotherapy). Response to CRT was evaluated through percentage of pathological complete response (pCR or ypT0N0), overall (OS) and disease-related survival (DRS), and pattern of relapse.

RESULTS

One hundred thirty-one patients (84.5 %) underwent surgery. Radical resection (R0) was achieved in 123 patients (79.3 %), and pCR in 65 (41.9 %). Postoperative mortality was 0.7 % (one case). Five-year OS and DRS were respectively 43 and 49 % in the entire cohort, 52 and 59 % in R0 cases, and 72 and 81 % in pCR cases. Survival did not significantly differ between SCC and adenocarcinoma, except for pCR cases. Forty-nine patients suffered from relapse, which was mainly systemic in adenocarcinoma. Only three out of 26 pCR patients with previous adenocarcinoma developed relapse, always systemic.

CONCLUSIONS

This study suggests that patients treated with the present protocol achieve good survival and high pCR rate. Further research is necessary to evaluate whether surgery on demand is feasible in selected patients, such as pCR patients with adenocarcinoma.

Gene polymorphisms predict toxicity to neoadjuvant therapy in patients with rectal cancer

BACKGROUND

Toxicity from neoadjuvant chemoradiation therapy (NT) increases morbidity and limits therapeutic efficacy in patients with rectal cancer. The objective of this study was to determine whether specific polymorphisms in genes associated with rectal cancer response to NT were correlated with NT-related toxicity.

METHODS

One hundred thirty-two patients with locally advanced rectal cancer received NT followed by surgery. All patients received 5-fluorouracil (5-FU) and radiation (RT), and 80 patients also received modified infusional 5-FU, folinic acid, and oxaliplatin chemotherapy (mFOLFOX-6). Grade ≥3 adverse events (AEs) that occurred during 5-FU/RT and during combined 5-FU/RT + mFOLFOX-6 were recorded. Pretreatment biopsy specimens and normal rectal tissues were collected from all patients. DNA was extracted and screened for 22 polymorphisms in 17 genes that have been associated with response to NT. Polymorphisms were correlated with treatment-related grade ≥3 AEs.

RESULTS

Overall, 27 of 132 patients (20%) had grade ≥3 AEs; 18 patients had a complication associated only with 5-FU/RT, 3 patients experienced toxicity only during mFOLFOX-6, and 6 patients had grade ≥3 AEs associated with both treatments before surgery. Polymorphisms in the genes x-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), xeroderma pigmentosum group D (XPD), and tumor protein 53 (TP53) were associated with grade ≥3 AEs during NT (P < .05). Specifically, 2 polymorphisms-an arginine-to-glutamine substitution at codon 399 (Q399R) in XRCC1 and a lysine-to-glutamine substitution at codon 751 (K751Q) in XPD-were associated with increased toxicity to 5-FU/RT (P < .05), and an arginine-to-proline substitution at codon 72 (R72P) in TP53 was associated with increased toxicity to mFOLFOX-6 (P = .008).

CONCLUSIONS

Specific polymorphisms in XRCC1, XPD, and TP53 were associated with increased toxicity to NT in patients with rectal cancer. The current results indicated that polymorphism screening may help tailor treatment for patients by selecting therapies with the lowest risk of toxicity, thus increasing patient compliance.

Association between polymorphisms of XRCC1 and ADPRT genes and ovarian cancer survival with platinum-based chemotherapy in Chinese population

The role of DNA repair gene polymorphisms in cancer development, progression, and response to treatment has received increased attention. We conducted a prospective study to determine whether associations exist between two polymorphisms in XRCC1 and ADPRT and the outcomes of Chinese ovarian cancer patients treated with platinum-based chemotherapy. A total of 335 new cases of ovarian cancer were consecutively collected between May 2005 and May 2007. Follow-up lasted for 4 years, and the outcome measure was survival time. Individuals carrying XRCC1 194Trp/Trp had a longer survival time than did those with the Arg/Arg genotype. Similarly, those carrying XRCC1 399 Gln/Gln genotypes had 0.44-fold the risk of death than those with the Arg/Arg genotype. The combination of XRCC1 194 Trp allele and 399 Gln allele could decrease the death risk of ovarian cancer. In summary, this study is the first to evaluate the associations between polymorphisms in DNA repair gene polymorphism and the risk of ovarian cancer in Chinese population. Our study found a significant association between XRCC1 Arg399Gln and XRCC1 Arg194Trp polymorphism and the clinical outcome of ovarian cancer. Furthermore, studies with larger sample sizes are still needed to confirm these associations in Chinese population.

Tetrandrine enhances cytotoxicity of cisplatin in human drug-resistant esophageal squamous carcinoma cells by inhibition of multidrug resistance-associated protein 1

Multidrug resistance is one of the major causes limiting the efficacy of chemotherapeutic agents to control esophageal cancer. Herein, we investigated that the effect and mechanism of tetrandrine (TET) in the human esophageal squamous carcinoma cisplatin-resistant cell line YES-2/DDP. The human esophageal squamous carcinoma cisplatin-resistant cell line YES-2/DDP was isolated by stepwise selection in increasing concentrations of cisplatin. The CCK-8 method was carried out to measure the cell viability when cells were exposed to TET with or without cisplatin, and the IC50 and resistance index (RI) of cisplatin was then calculated. Real-time RT-PCR and western blotting were used to detect the mRNA and protein expression of multidrug resistance 1 (MDR1), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP), respectively. Flow cytometry was adopted to determine CMFDA efflux and cell apoptosis, respectively. The resulting cell line YES-2/DDP was 16.4-fold resistant to cisplatin, the cytotoxicity of cisplatin to YES-2/DDP cells was enhanced by TET in a dose-dependent manner. Further, it was found that the expression of MDR1 and BCRP was similar in different treated cells. In contrast, the expression of MRP1 was markedly increased in YES-2/DDP cells, which was dose-dependently decreased by TET. In agreement with the results, MRP1 activity was also reversed by TET. In conclusion, TET possesses a reversal effect on drug resistance in YES-2/DDP cells through downregulation of MRP1, and has the potential to be an adjunct to chemotherapy for esophageal cancer.

Clinical issues in oesophageal adenocarcinoma: could DNA copy number hold the key?

While not being considered a common cancer, since 1975 oesophageal adenocarcinoma (OAC) has had the fastest-rising incidence of any malignancy in Caucasian Western populations. In the absence of major improvements in treatment since this rise began, the number of deaths has also increased rapidly. In contrast, there have been significant advances in basic science in this period. One such advance is the discovery of DNA copy number aberrations (CNAs), and their potential role in carcinogenesis. The study of CNAs offers the potential to answer fundamental clinical questions in OAC, which in turn may lead to improved diagnosis, staging and treatment. This review outlines current clinical dilemmas in OAC, discusses the role that CNAs have been shown to play to date and highlights potential future applications.

Multi-loci analysis reveals the importance of genetic variations in sensitivity of platinum-based chemotherapy in non-small-cell lung cancer

Polymorphisms in DNA repair and apoptotic pathways may cause variations in chemosensitivity of non-small-cell lung cancer (NSCLC) through complex gene-gene and gene-environment interactions. A total of 200 advanced NSCLC patients who received platinum-based chemotherapies were recruited. The short-term clinical outcomes were classified as chemosensitive group, including complete remission (CR) and partial remission (PR), and chemoresistant group, namely stable disease (SD) and progression disease (PD) at the end of treatment. We applied multifactor dimensionality reduction (MDR), classification and regression tree (CART) and traditional logistic regression (LR) to explore high-order gene-gene and gene-environment interactions among 11 functional single nucleotide polymorphisms (SNPs), smoking status, cancer stages and treatment regimens in the response to chemotherapy. Multi-loci analyses consistently indicated that interactions among XRCC1 Arg194Trp, XPC PAT, FAS G-1377A, and FASL T-844C were associated with sensitivity to platinum-based chemotherapy. In MDR analysis, the four-factor model yielded the highest test accuracy of 0.72 (permutation P = 0.001). In CART analysis, these four SNPs were the determinant nodes of the growth of regression tree. Patients carrying XRCC1 Arg194Arg, FAS-1377GG, and FASL-844T allele displayed completely no response to platinum, whereas patients with XRCC1 194Trp allele and XPC PAT +/+ had 68.8% response rate to platinum. In LR analysis, a significant gene-dosage effect was detected along with the increasing number of favorable genotypes of these four polymorphisms (P trend = 0.00002). Multi-loci analysis reveals the importance of genetic variations involved in DNA repair and apoptotic pathways in sensitivity of platinum-based chemotherapy in NSCLC.

Influence of DNA repair gene polymorphisms on prognosis in inoperable non-small cell lung cancer patients treated with radiotherapy and platinum-based chemotherapy

Polymorphisms in DNA repair genes may modulate not only an individual DNA repair capacity, DNA damage levels and cancer risk but also clinical outcome after DNA damage-inducing anticancer therapy. In this study, we analyzed the association between the XPA -4G>A, XPD Asp312Asn, hOGG1 Ser326Cys, XRCC1 Arg399Gln, XRCC2 -4234G>C, XRCC3 -4541A>G and Thr241Met polymorphisms and prognosis in 250 inoperable non-small cell lung cancer (NSCLC) patients treated with radiotherapy and platinum-based chemotherapy. In univariate model, the XPA-4A and XRCC1 399Gln alleles alone and in combination influenced survival only in stage III group. In multivariate analysis, the XPA-4 GA/AA was associated with poor survival (HR 1.55, p = 0.011 overall and HR 1.72, p = 0.008 in stage III). In chemoradiotherapy group, the XPA-4A carriers were at increased risk of death and progression (HR 1.73, p = 0.013 and HR 1.65, p = 0.016, respectively), especially in stage III (p = 0.008). Moreover, individuals with ≥ 2 XPA/XRCC1 adverse alleles showed a higher risk of death (HR 1.46, p = 0.036 overall; HR 1.85, p = 0.004 in stage III and HR 1.71, p = 0.022 in chemoradiotherapy group) and progression (HR 1.75, p = 0.011 overall and HR 1.93, p = 0.005 in stage III). The XPA-4 GA/AA genotype individually and together with the XRCC1 399Gln was an independent unfavorable prognostic factor in our study. Thus, our findings indicate a prognostic potential of the XPA-4G>A in unresected NSCLC treated with radiotherapy and chemoradiotherapy. The results require validation in an independent population.

Epidemiologic differences in esophageal cancer between Asian and Western populations

Esophageal cancer is a common cancer worldwide and has a poor prognosis. The incidence of esophageal squamous cell cancer has been decreasing, whereas the incidence of esophageal adenocarcinoma has been increasing rapidly, particularly in Western men. Squamous cell cancer continues to be the major type of esophageal cancer in Asia, and the main risk factors include tobacco smoking, alcohol consumption, hot beverage drinking, and poor nutrition. In contrast, esophageal adenocarcinoma predominately affects the whites, and the risk factors include smoking, obesity, and gastroesophageal reflux disease. In addition, Asians and Caucasians may have different susceptibilities to esophageal cancer due to different heritage backgrounds. However, comparison studies between these two populations are limited and need to be addressed in the near future. Ethnic differences should be taken into account in preventive and clinical practices.

Prognostic and predictive role of JWA and XRCC1 expressions in gastric cancer

PURPOSE

To investigate the expression pattern and significance of DNA repair genes JWA and X-ray repair cross complement group 1 (XRCC1) in gastric cancer.

EXPERIMENTAL DESIGN

Expressions of JWA and XRCC1 were assessed by immunohistochemistry in a training cohort and they went into a second testing cohort and finally to a validating cohort. Prognostic and predictive role of JWA and XRCC1 expression status in cases treated with surgery alone or combined with adjuvant chemotherapy was evaluated, respectively.

RESULTS

JWA and XRCC1 protein levels were significantly downregulated in gastric cancer lesions compared with adjacent noncancerous tissues. Low tumoral JWA or XRCC1 expression significantly correlated with shorter overall survival (OS), as well as with clinicopathologic characteristics in patients without adjuvant treatment. Multivariate regression analysis showed that low JWA and XRCC1 expressions, separately and together, were independent negative markers of OS. Adjuvant fluorouracil-leucovorin-oxaliplatin (FLO) significantly improved OS compared with surgery alone (log-rank test, P = 0.01). However, this effect was evident only in the JWA or XRCC1 low expression group (HR = 0.44; 95% CI: 0.26-0.73; P = 0.002, and HR = 0.44, 95% CI: 0.26-0.75; P = 0.002, respectively); Adjuvant fluorouracil-leucovorin-platinol (FLP) did not improve OS, except in the patients with low JWA and XRCC1 expressions (P = 0.010 for JWA and 0.024 for XRCC1, respectively).

CONCLUSIONS

JWA and XRCC1 protein expressions in tumor are novel candidate prognostic markers and predictive factors for benefit from adjuvant platinum-based chemotherapy (FLO or FLP) in resectable human gastric carcinoma.

Association between polymorphisms in XRCC1 gene and clinical outcomes of patients with lung cancer: a meta-analysis

Background

X-ray repair cross-complementing group 1 (XRCC1) protein plays an important role in the repair of DNA damage and adducts. Single nucleotide polymorphisms (SNPs) of XRCC1 are suspected to have some relationship with response to chemotherapy and overall survival of lung cancer. This meta-analysis aimed to summarize published data on the association between the commonest SNPs of XRCC1 (Arg194Trp, C > T, rs1799782 and Arg399Gln, G > A, rs25487) and clinical outcome of lung cancer patients.

Methods

We retrieved the relevant articles from PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) databases. Studies were selected using specific inclusion and exclusion criteria. Primary outcomes included objective response (i.e., complete response + partial response vs. progressive disease + stable disease) and overall survival (OS). Odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) were estimated. All analyses were performed using the Stata software.

Results

Twenty-two articles were included in the present analysis. XRCC1 Arg194Trp and Arg399Gln polymorphisms were significantly associated with response to treatment in lung cancer patients. Patients with C/T genotype, T/T genotype and minor variant T allele at Arg194Trp were more likely to respond to platinum-based chemotherapy compared with those with C/C genotype (C/T vs. C/C: OR, 2.54; 95%CI, 1.95-3.31; T/T vs. C/C: OR, 2.06; 95%CI, 1.39-3.06; C/T+T/T vs. C/C: OR, 2.42; 95% CI, 1.88-3.10). For XRCC1 Arg399Gln, G/A genotype, A/A genotype and minor variant A allele were associated with objective response in all patients (G/A vs. G/G: OR, 0.67; 95%CI, 0.50-0.90; A/A vs. G/G: OR, 0.43; 95%CI, 0.25-0.73; A/A+G/A vs. G/G: OR, 0.63; 95%CI, 0.49-0.83). Both G/A and A/A genotypes of XRCC1 Arg399Gln could influence overall survival of lung cancer patients (G/A vs. G/G: HR, 1.23; 95%CI, 1.06-1.44; A/A vs. G/G: HR, 2.03; 95%CI, 1.20-3.45). Interaction analysis suggested that compared with the patients carrying C/T+T/T genotype at XRCC1 194 and G/G genotype at XRCC1 399, the patients carrying 194 C/C and 399 G/A+A/A or 194 C/C and 399 G/G genotype showed much worse objective response.

Conclusions

Genetic polymorphisms in XRCC1 gene might be associated with overall survival and response to platinum-based chemotherapy in lung cancer patients.

Prognostic significance of SUV on PET/CT in patients with localised oesophagogastric junction cancer receiving neoadjuvant chemotherapy/chemoradiation:a systematic review and meta-analysis

OBJECTIVE

The objective of this study was to comprehensively review the evidence for use of pre-treatment, post-treatment and changes in tumour glucose uptake that were assessed by 18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) early, during or immediately after neoadjuvant chemotherapy/chemoradiation to predict prognosis of localised oesophagogastric junction (AEG) cancer.

METHODS

We searched for articles published in English; limited to AEG; (18)F-FDG uptake on PET performed on a dedicated device; dealt with the impact of standard uptake value (SUV) on survival. We extracted an estimate of the log hazard ratios (HRs) and their variances and performed meta-analysis.

RESULTS

798 patients with AEG were included. And the scan time for (18)F-FDG-PET was as follows: prior to therapy (PET1, n=646), exactly 2 weeks after initiation of neoadjuvant therapy (PET2, n=245), and pre-operatively (PET3, n=278). In the two meta-analyses for overall survival, including the studies that dealt with reduction of tumour maximum SUV (SUV(max)) (from PET1 to PET2/PET3 and from PET1 to PET2), the results were similar, with the overall HR for non-responders being 1.83 [95% confidence interval (CI), 1.41-2.36] and 2.62 (95% CI, 1.61-4.26), respectively; as for disease-free survival, the combined HR was 2.92 (95% CI, 2.08-4.10) and 2.39 (95% CI, 1.57-3.64), respectively. The meta-analyses did not attribute significant prognostic values to SUV(max) before and during therapy in localised AEG.

CONCLUSION

Relative changes in FDG-uptake of AEG are better prognosticators. Early metabolic changes from PET1 to PET2 may provide the same accuracy for prediction of treatment outcome as late changes from PET1 to PET3.

Neoadjuvant radiochemotherapy in adenocarcinoma of the esophagus: ERCC1 gene polymorphisms for prediction of response and prognosis

INTRODUCTION

Neoadjuvant radiochemotherapy (RT/CTx) regimens were primarily designed for treatment of squamous cell carcinoma of the esophagus. Own preliminary results demonstrate that also patients with locally advanced adenocarcinoma of the esophagus may achieve a major response in 30% with a 3-year survival rate of 80%. To identify these patients, ERCC1 (rs11615) gene polymorphisms were analyzed. ERCC1 is a key enzyme of the nucleotide excision and repair (NER) complex to prevent DNA inter- and intra-strand crosslinks.

PATIENTS AND METHODS

Genomic DNA from 217 patients with cT3/4 adenocarcinoma of the esophagus was extracted from paraffin-embedded tissues. Of these patients, 153 underwent neoadjuvant RT/CTx (CDDP, 5-FU, 36 Gy). For analysis of ERCC1 single nucleotide polymorphisms (SNPs), allelic discrimination was performed by quantitative real-time PCR. Two allele-specific TaqMan probes in competition were used for amplification of ERCC1 (rs11615). Allelic genotyping was correlated with histomorphologic tumor regression after neoadjuvant RT/CTx and survival. Major response (MaHR) was defined as <10% vital residual tumor cells (VRTC).

RESULTS

Analysis of tumor regression revealed a MaHR in 56/153 (36.6%) patients with a 5-year survival rate (5-YSR) of 74% (p < 0.001). ERCC1 gene polymorphisms for all patients showed the following expression pattern: ERCC1 polymorphism (rs11615) CC: n = 27 (12.4%), TT: n = 98 (45.2%), C/T: n = 92 (42.4%). ERCC1 polymorphism CT was identified as a predictor for response to the neoadjuvant RT/CTx (p < 0.001). The 5-YSR for patients with C/T genotype was 51%. Contrary to this, the 5-YSR for the group of patients with a CC/TT polymorphism decreased to 34%.

CONCLUSION

Analysis of ERCC1 (rs11615) gene polymorphisms reveals a significant correlation with response and survival in patients with adenocarcinoma of the esophagus treated with a neoadjuvant radiochemotherapy. Single nucleotide polymorphisms of ERCC1 (rs11615) could therefore be applied to further individualize therapy in esophageal cancer.

Role of interleukin 1 beta in esophageal squamous cell carcinoma

Interleukin (IL)-1 beta has been reported to be a marker of shorter survival in gastric and colorectal adenocarcinoma. In the present study, we examined the potential role and prognostic value of IL-1 beta in esophageal squamous cell carcinoma (SCC). Human esophageal SCC cell line, CE81T, was selected for cellular and animal experiments, in which biological changes after experimental manipulation of IL-1 beta signaling were explored, including tumor growth, invasion capacity, and the sensitivity to treatment. Moreover, 147 esophageal SCC samples were analyzed using immunohistochemical staining to correlate the expression of IL-1 beta with clinical outcome. Our data revealed that IL-1 beta was significantly overexpressed both at mRNA and protein levels in cancer specimens compared to nonmalignant tissues. When IL-1 beta signaling was blocked, tumor growth, invasion ability, and treatment resistance were attenuated. Activation of NF-kappa B, increase of E2-EPF ubiquitin carrier protein and subsequent epithelial-mesenchymal transition might be the underlying mechanisms of the more aggressive tumor growth in IL-1 beta-positive esophageal cancer. The immunochemistry findings indicate that positivity staining of IL-1 beta correlated significantly with higher clinical stage, lower response rate to concurrent chemoradiotherapy (CCRT), and higher recurrence rate after curative treatment. Moreover, IL-1 beta was a significant predictor of survival in patients undergoing surgical intervention or definite CCRT. In conclusion, IL-1 beta is significantly linked to poor prognosis for patients with esophageal cancer and may be a promising molecular target for therapeutic intervention for esophageal SCC.

An expert opinion on esophageal cancer therapy

INTRODUCTION

Worldwide, esophageal cancer (EC) is the seventh leading cause of cancer-related death, with its incidence increasing in the US, where a change in its epidemiology has been noted. Most patients present with regional or distant disease and, therefore, have a very poor prognosis.

AREAS COVERED

Progress made over the last 20 years in the diagnosis, staging and management of EC is focused on in this review, with the emphasis on locally-advanced disease treated with curative intent. Evidence is reviewed from prospective randomized trials and meta-analyses and data are presented regarding new therapy with targeted agents. Although surgery has been the mainstay of treatment for EC, survival with this approach alone remains disappointing. As a result, combined modality treatment (CMT) including chemotherapy and radiation has been incorporated into the treatment paradigm for both operable and inoperable disease. The evidence supporting CMT for EC, the role of surgery at different stages, and how treatment strategies differ based on histology are outlined.

EXPERT OPINION

Trends in 5-year overall survival rates over the last 30 years have increased (from 5 to 17%), suggesting that small, yet significant, improvements in diagnosis, staging, treatment and supportive care are being made. Clearly, the choice of treatment should be guided by disease stage, histology and patient co-morbidities.

The role of glutathione S-transferase P in signaling pathways and S-glutathionylation in cancer

Glutathione S-transferase P is abundantly expressed in some mammalian tissues, particularly those associated with malignancies. While the enzyme can catalyze thioether bond formation between some electrophilic chemicals and GSH, novel nondetoxification functions are now ascribed to it. This review summarizes recent material that implicates GSTP in mediating S-glutathionylation of specific clusters of target proteins and in reactions that define a negative regulatory role in some kinase pathways through ligand or protein:protein interactions. It is becoming apparent that GSTP participates in the maintenance of cellular redox homeostasis through a number of convergent and divergent mechanisms. Moreover, drug platforms that have GSTP as a target have produced some interesting preclinical and clinical candidates.

Impact of ABCB1 C3435T polymorphism on lymph node regression in multimodality treatment of locally advanced esophageal cancer

AIMS

Neoadjuvant treatment strategies have been developed to improve the survival of patients with locally advanced esophageal cancer. Since patients with major histopathological response are the ones who mainly benefit from this therapy, we are looking for causes of nonresponse. The multidrug resistance protein ABCB1 belongs to the ATP-binding cassette superfamily of membrane transporters. By exporting positively charged drugs it plays a role in the acquisition of resistance in anticancer therapy. We examined the ABCB1 gene polymorphism C3435T to predict response and prognosis to neoadjuvant radiochemotherapy (cisplatin, 5-fluorouracil and 36 Gy) in locally advanced esophageal cancer patients.

MATERIALS & METHODS

A total of 262 patients (216 male; 46 female; median age: 62 years) with locally advanced esophageal cancer (squamous cell cancer: n = 116, adenocarcinoma: n = 146) were included in this study. All patients received a neoadjuvant radiochemotherapy (36.0 Gy, 5-fluorouracil, cisplatin) followed by surgery. Histomorphologic regression was classified according to the Cologne Regression Grade with major response being classifed as having less than 10% vital tumor cells (n = 107) and minor response when 10% or more vital tumor cells (n = 155) were detected in the surgical specimen. Genomic DNA was extracted from paraffin-embedded tissues of all study patients. Allelic genotyping was performed for ABCB1 rs1045642 by real-time PCR using two allele-specific TaqMan(®) probes in competition. Allelic genotyping was correlated with therapy response and prognosis.

RESULTS

Allelic discrimination revealed a TT genotype in 27%, a CC in 19% and a CT genotype in 54% of the study patients. This SNP was not predictive for response of the primary tumor to neoadjuvant radiochemotherapy. The ABCB1 genotype CC was associated with lymph node formation (p = 0.012) and distant metastases (p = 0.019). Patients with a TT genotype exhibited a significantly less positive lymph node status (ypN1 35%) after chemoradiation compared with patients with a CC (ypN1 = 60%) or CT (ypN1 = 46%) genotype. Moreover, patients bearing the TT genotype exhibited no distant metastasis, while five patients with a CC and two patients with CT genotype had distant metastases. In Kaplan-Meier curves, adenocarcinoma patients with a CC genotype showed a worse survival rate than patients with TT or CT (p = 0.048).

CONCLUSION

Our data supports the impact of ABCB1 on effectiveness of esophageal cancer treatment. SNPs of ABCB1 could be helpful in predicting lymph node regression in the multimodality treatment of locally advanced esophageal cancer.

Genetic variation in DNA-repair pathways and response to radiochemotherapy in esophageal adenocarcinoma: a retrospective cohort study of the Eastern Cooperative Oncology Group

Background

Recent data in esophageal cancer suggests the variant allele of a single-nucleotide polymorphism (SNP) in XRCC1 may be associated with resistance to radiochemotherapy. However, this SNP has not been assessed in a histologically homogeneous clinical trial cohort that has been treated with a uniform approach. In addition, whether germline DNA may serve as a surrogate for tumor genotype at this locus is unknown in this disease. Our objective was to assess this SNP in relation to the pathologic complete response (pCR) rate in subjects with esophageal adenocarcinoma who received cisplatin-based preoperative radiochemotherapy in a multicenter clinical trial (Eastern Cooperative Oncology Group 1201). As a secondary aim, we investigated the rate of allelic imbalance between germline and tumor DNA.

Methods

Eighty-one eligible treatment-naïve subjects with newly diagnosed resectable esophageal adenocarcinoma received radiotherapy (45 Gy) concurrent with cisplatin-based chemotherapy, with planned subsequent surgical resection. The primary endpoint was pCR, defined as complete absence of tumor in the surgical specimen after radiochemotherapy. Using germline DNA from 60 subjects, we examined the base-excision repair SNP, XRCC1 Arg399Gln, and 4 other SNPs in nucleotide excision (XPD Lys751Gln and Asp312Asn, ERCC1 3' flank) and double-stranded break (XRCC2 5' flank) repair pathways, and correlated genotype with pCR rate. Paired tumor tissue was used to estimate the frequency of allelic imbalance at the XRCC1 SNP.

Results

The variant allele of the XRCC1 SNP (399Gln) was detected in 52% of subjects. Only 6% of subjects with the variant allele experienced a pCR, compared to 28% of subjects without the variant allele (odds ratio 5.37 for failing to achieve pCR, p = 0.062). Allelic imbalance at this locus was found in only 10% of informative subjects, suggesting that germline genotype may reflect tumor genotype at this locus. No significant association with pCR was noted for other SNPs.

Conclusions

Assessed for the first time in a prospective, interventional trial cohort of esophageal adenocarcinoma, XRCC1 399Gln was associated with resistance to radiochemotherapy. Further investigation of this genetic variation is warranted in larger cohorts. In addition, these data indicate that germline genotype may serve as a surrogate for tumor genotype at this locus.

Comparison of nedaplatin and irinotecan for patients with squamous and nonsquamous cell carcinoma of the lung: meta-analysis of four trials

BACKGROUND

Non-small cell lung cancer has several types of pathology and is moderately responsive to anticancer drugs, but specific chemotherapy regimens for each have not been established.

METHODS

We compared the outcomes of patients with squamous and nonsquamous cell carcinoma of the lung, which were compiled from four of our own studies of nedaplatin (NP) with irinotecan (CPT).

RESULTS

One hundred twenty-one patients with stage IIIB/IV non-small cell lung cancer received 50 to 100 mg/m NP and 50 to 60 mg/m CPT per cycle. Eighty-six patients were men and 35 were women, with a median age of 70 years (range, 29-84 years). Seventeen, 88, 8, and 8 patients had a performance status of 0, 1, 2, and 3, respectively. Twenty seven of the 121 patients had squamous cell carcinoma. Responses to the NP and CPT regimen were complete in two cases and partial in 45. The response rate was 51.9 and 35.1% in patients with squamous and nonsquamous cell carcinoma, respectively. Comparisons of survival revealed that the median survival time, 1-year survival rate, and 2-year survival rate were 14.5 and 9.1 months, 63.0 and 39.4%, and 29.6 and 19.1% for patients with squamous and nonsquamous cell carcinoma, respectively.

CONCLUSIONS

The NP and CPT regimen is suggested to be more active against squamous cell carcinoma of the lung, and a comparative study to confirm this is recommended.

Prognostic significance of baseline positron emission tomography and importance of clinical complete response in patients with esophageal or gastroesophageal junction cancer treated with definitive chemoradiotherapy

BACKGROUND

Metabolic imaging is of interest in esophageal cancer; however, the usefulness of initial standardized uptake value (SUV) in positron emission tomography (PET) is unknown in patients with esophageal or gastroesophageal carcinoma treated with definitive chemoradiotherapy. The authors hypothesized that initial SUV would correlate with patient outcome.

METHODS

The authors retrospectively analyzed esophageal or gastroesophageal carcinoma patients who had baseline PET and endoscopic ultrasonography in addition to other routine staging. All patients received definitive chemoradiotherapy. Multiple statistical methods were used.

RESULTS

The authors analyzed 209 consecutive esophageal or gastroesophageal carcinoma patients treated with definitive chemoradiation for outcome; of these, 180 had baseline PET for additional analyses. The median overall survival (OS) for all patients was 20.7 months (95% confidence interval, 18.8-26.3). Patients with clinical complete response (CR) lived longer than those with less than clinical CR (P < .0001). The median initial SUV was 12.7 (range, 0-51). Higher initial SUV was associated with longer tumors (P = .0001), higher T-stage status (P < .0001), positive N-stage status (P = .0001), higher overall stage (P < .0001), lack of clinical CR (P = .0002), and squamous cell histology (P < .0001). In the univariate analysis, initial SUV was associated with OS (Cox model, P = .016; log-rank test, P = .002). In the multivariate analysis, initial SUV dichotomized by the median value (P = .024) and tumor grade (P = .016) proved to be independent OS prognosticators. Median initial SUV for clinical CR patients was 10.2, compared with 15.3 for less than clinical CR patients (P = .0058).

CONCLUSIONS

The data indicate that a higher initial SUV is associated with poorer OS in patients with esophageal or gastroesophageal carcinoma receiving definitive chemoradiation. Upon validation, baseline PET may become a useful stratification factor in randomized trials and for individualizing therapy.

Overcoming tumor multidrug resistance using drugs able to evade P-glycoprotein or to exploit its expression

Multidrug resistance (MDR) is a major obstacle to the effective treatment of cancer. Cellular overproduction of P-glycoprotein (P-gp), which acts as an efflux pump for various anticancer drugs (e.g. anthracyclines, Vinca alkaloids, taxanes, epipodophyllotoxins, and some of the newer antitumor drugs) is one of the more relevant mechanisms underlying MDR. P-gp belongs to the superfamily of ATP-binding cassette transporters and is encoded by the ABCB1 gene. Its overexpression in cancer cells has become a therapeutic target for circumventing MDR. As an alternative to the classical pharmacological strategy of the coadministration of pump inhibitors and cytotoxic substrates of P-gp and to other approaches applied in experimental tumor models (e.g. P-gp-targeting antibodies, ABCB1 gene silencing strategies, and transcriptional modulators) and in the clinical setting (e.g. incapsulation of P-gp substrate anticancer drugs into liposomes or nanoparticles), a more intriguing strategy for circumventing MDR is represented by the development of new anticancer drugs which are not substrates of P-gp (e.g. epothilones, second- and third-generation taxanes and other microtubule modulators, topoisomerase inhibitors). Some of these drugs have already been tested in clinical trials and, in most of cases, show relevant activity in patients previously treated with anticancer agents which are substrates of P-gp. Of these drugs, ixabepilone, an epothilone, was approved in the United States for the treatment of breast cancer patients pretreated with an anthracycline and a taxane. Another innovative approach is the use of molecules whose activity takes advantage of the overexpression of P-gp. The possibility of overcoming MDR using the latter two approaches is reviewed herein. 

DNA repair gene and MTHFR gene polymorphisms as prognostic markers in locally advanced adenocarcinoma of the esophagus or stomach treated with cisplatin and 5-fluorouracil-based neoadjuvant chemotherapy

BACKGROUND

DNA repair plays an important role in chemoresistance to platinum-based therapy, and therefore polymorphisms in the genes may modulate therapeutic response. We assessed 12 polymorphisms in 7 DNA repair genes and 2 polymorphisms in the MTHFR gene for association with disease response and prognosis.

METHODS

A total of 258 patients included in the study had adenocarcinoma of the esophagus (n = 114) or gastric cancer (n = 144), at stage cT3/4 and cM0, and had been treated with platinum-based neoadjuvant polychemotherapy. The patients were genotyped for polymorphisms in the XPC, XPD, XPG, APEX, XRCC1, NBS1, XRCC3, and MTHFR genes by the allelic discrimination method and the data correlated with various clinical parameters.

RESULTS

None of the investigated polymorphisms was associated with histopathological response. XRCC3 polymorphisms rs861539 (P = 0.02) and rs861530 (P = 0.05) showed association with clinical response in gastric cancer. The variants in XRCC3 (rs861539, P = 0.05; rs1799794, P = 0.03) and MTHFR (rs1801131, P = 0.02) were associated with survival in esophageal and gastric cancer, respectively. In R0 resected patients, XRCC3 variants (rs861539, P = 0.04; rs861530, P = 0.02) in esophageal cancer, and XRCC3 (rs1799794, P = 0.02) and MTHFR (rs1801131, P = 0.005) in gastric cancer predicted survival. Cox regression revealed ypT category (P = 0.001) and lymphatic vessel invasion (P = 0.03) to be independent prognostic factors for esophageal cancer, and histopathological response (P = 0.01), MTHFR variant (rs1801131, P = 0.002), and ypN category (P = 0.02) to be prognostic factors for gastric cancer.

CONCLUSION

In gastric cancer patients, MTHFR variant (rs1801131) could serve as a potential prognostic marker. In esophageal cancer patients, none of the polymorphisms studied had conclusive results in multivariate analysis, although XRCC3 variant (rs861539) showed an effect on survival in Kaplan-Meier univariate analysis.

Genetic variation in radiation and platinum pathways predicts severe acute radiation toxicity in patients with esophageal adenocarcinoma treated with cisplatin-based preoperative radiochemotherapy: results from the Eastern Cooperative Oncology Group

PURPOSE

Germline genetic variations may partly explain the clinical observation that normal tissue tolerance to radiochemotherapy varies by individual. Our objective was to evaluate the association between single-nucleotide polymorphisms (SNPs) in radiation/platinum pathways and serious treatment-related toxicity in subjects with esophageal adenocarcinoma who received cisplatin-based preoperative radiochemotherapy.

METHODS

In a multicenter clinical trial (E1201), 81 eligible treatment-naïve subjects with resectable esophageal adenocarcinoma received cisplatin-based chemotherapy concurrent with radiotherapy, with planned subsequent surgical resection. Toxicity endpoints were defined as grade ≥3 radiation-related or myelosuppressive events probably or definitely related to therapy, occurring during or up to 6 weeks following the completion of radiochemotherapy. SNPs were analyzed in 60 subjects in pathways related to nucleotide/base excision- or double stranded break repair, or platinum influx, efflux, or detoxification.

RESULTS

Grade ≥3 radiation-related toxicity (mostly dysphagia) and myelosuppression occurred in 18 and 33% of subjects, respectively. The variant alleles of the XRCC2 5' flanking SNP (detected in 28% of subjects) and of GST-Pi Ile-105-Val (detected in 65% of subjects) were each associated with higher odds of serious radiation-related toxicity compared to the major allele homozygote (47% vs. 9%, and 31% vs. 0%, respectively; P = 0.005). No SNP was associated with myelosuppression.

CONCLUSIONS

This novel finding in a well-characterized cohort with robust endpoint data supports further investigation of XRCC2 and GST-Pi as potential predictors of radiation toxicity.

Interleukin-2 -330T>G genetic polymorphism associates with prognosis following surgery for thoracic esophageal squamous cell cancer

BACKGROUND

Key molecules in the T helper (Th)1 and Th2 pathways underlie differential responses to the progression and surgical treatment of cancer. We investigated the relationship between Th1/Th2 cytokine polymorphism and prognosis in patients with thoracic esophageal squamous cell cancer.

MATERIALS AND METHODS

The study participants were 159 Japanese patients treated for thoracic esophageal squamous cell cancer with curative esophagectomy at Akita University Hospital. We determined the associations between prognosis following esophagectomy and genetic polymorphisms in Th1 cytokines (interleukin [IL]-2, Interferon-γ, IL-12β), and Th2 cytokines (IL-4, IL-10).

RESULTS

IL-2 -330T>G genetic polymorphism was significantly associated with prognosis after esophagectomy. Univariate and multivariate analyses using a Cox proportional hazards model revealed that patients carrying the IL-2 -330G/G genotype had a significantly poorer prognosis than those carrying the T/G or T/T genotype. However, IL-2 -330T>G polymorphism was not associated with preoperative serum IL-2 levels. Moreover, interferon-γ, IL-12β, IL-4, and IL-10 genetic polymorphisms were not associated with prognosis after esophagectomy for thoracic esophageal squamous cell cancer.

CONCLUSIONS

It is suggested that IL-2 -330T>G genetic polymorphism may be a predictive factor for prognosis in patients receiving esophagectomy for thoracic esophageal squamous cell cancer.

Single nucleotide polymorphisms of DNA repair genes as predictors of radioresponse

Radiation therapy is a key modality in the treatment of cancer. Substantial progress has been made in unraveling the molecular events which underpin the responses of malignant and surrounding normal tissues to ionizing radiation. An understanding of the genes involved in processes such as DNA double-strand break repair, DNA damage response, cell-cycle control, apoptosis, cellular antioxidant defenses, and cytokine production, has evolved toward examination of how genetic variants, most often, single nucleotide polymorphisms (SNPs), may influence interindividual radioresponse. Experimental approaches, such as candidate SNP-association studies, genome-wide association studies, and massively parallel sequencing are being proposed to address these questions. We present a focused review of the evidence supporting an association between SNPs in DNA repair genes and radioresponse in normal tissues and tumors. Although preliminary results indicate possible associations, there are methodological weaknesses in many of the studies, and independent validation of SNPs as biomarkers of radioresponse in much larger cohorts will likely require research cooperation through international consortia.

Translational medicine and reliability of single-nucleotide polymorphism studies: can we believe in SNP reports or not?

BACKGROUND

The number of genetic association studies is increasing exponentially. Nonetheless, genetic association reports are prone to potential biases which may influence the reported outcome.

AIM

We hypothesized that positive outcome for a determined polymorphism might be over-reported across genetic association studies analysing a small number of polymorphisms, when compared to studies analysing the same polymorphism together with a high number of other polymorphisms.

METHODS

We systematically reviewed published reports on the association of glutathione s-transferase (GST) single-nucleotide polymorphisms (SNPs) and cancer outcome.

RESULT

We identified 79 eligible trials. Most of the studies examined the GSTM1, theGSTP1 Ile105Val mutation, and GSTT1polymorphisms (n = 54, 57 and 46, respectively). Studies analysing one to three polymorphisms (n = 39) were significantly more likely to present positive outcomes, compared to studies examining more than 3 polymorphisms (n=40) p = 0.004; this was particularly evident for studies analysing the GSTM1polymorphism (p =0.001). We found no significant associations between journal impact factor, number of citations, and probability of publishing positive studies or studies with 1-3 polymorphisms examined.

CONCLUSIONS

We propose a new subtype of publication bias in genetic association studies. Positive results for genetic association studies analysing a small number of polymorphisms (n = 1-3) should be evaluated extremely cautiously, because a very large number of such studies are inconclusive and statistically under-powered. Indeed, publication of misleading reports may affect harmfully medical decision-making and use of resources, both in clinical and pharmacological development setting.

An association between DNA repair gene polymorphisms and survival in patients with resected non-small cell lung cancer

DNA repair genetic polymorphisms have been studied extensively in relation to lung cancer susceptibility, but much less is known about their role in clinical outcome modulation. In this report, we examined effect of the XPA -4G>A, XPD Asp312Asn, Leu751Gln, hHR23B Ala249Val, XPG Asp1104His, XRCC1 Arg399Gln, XRCC2 -4234G>C and XRCC3 Thr241Met polymorphisms on overall survival in 162 patients with resected non-small cell lung cancer (NSCLC). The XRCC3 Met/Met genotype was significantly associated with increased risk of death among all patients and men in uni- and multivariate analyses. The risk was higher for adenocarcinoma patients possessing the XRCC3 Met/Met or XRCC1 Gln/Gln genotypes, although their frequency was small. The XRCC1 399Gln allele was also associated with poor prognosis in stage II-IIIA and among older individuals. Men homozygous for the XPD 312 Asn/Asn had significantly better survival with the risk of death being at borderline significance in uni- and multivariate models. Younger cases and ever smokers smoking less than median pack-years showed significantly increased risk of death associated with the XPA -4A allele. A presence of one or two XRCC2 -4234C alleles had a protective effect in males and ever smokers with lower cumulative smoking dose, although the CC genotype was rarely observed. When number of combined risk alleles was considered, we found that carriers of >4 adverse alleles were at significantly increased risk of death in uni- and multivariate models. Therefore, our results indicate that selected genetic polymorphisms in DNA repair genes may influence overall survival in resected NSCLC.

Biomarkers in Barrett’s esophagus and esophageal adenocarcinoma: Predictors of progression and prognosis

Barrett’s esophagus is a well-known premalignant lesion of the lower esophagus that is characterized by intestinal metaplasia of the squamous epithelium. It is clinically important due to the increased risk (0.5% per annum) of progression to esophageal adenocarcinoma (EA), which has a poor outcome unless diagnosed early. The current clinical management of Barrett’s esophagus is hampered by the lack of accurate predictors of progression. In addition, when patients develop EA, the current staging modalities are limited in stratifying patients into different prognostic groups in order to guide the optimal therapy for an individual patient. Biomarkers have the potential to improve radically the clinical management of patients with Barrett’s esophagus and EA but have not yet entered mainstream clinical practice. This is in contrast to other cancers like breast and prostate for which biomarkers are utilized routinely to inform clinical decisions. This review aims to highlight the most promising predictive and prognostic biomarkers in Barrett’s esophagus and EA and to discuss what is required to move the field forward towards clinical application.

A phase I/II and pharmacogenomic study of pemetrexed and cisplatin in patients with unresectable, advanced gastric carcinoma

This phase I/II study was conducted to determine the maximum recommended dose of pemetrexed when given in combination with a fixed dose of cisplatin, and the efficacy, toxicity and association of 5,10-methylenetetrahydrofolate reductase (MTHFR) variants with this pemetrexed--cisplatin combination, in patients with unresectable, advanced gastric carcinoma. Patients 18-70 years of age, with stage IV disease or post-surgery recurrence, no earlier palliative chemotherapy, 0 or 1 Eastern Cooperative Oncology Group performance status, were included. The cisplatin dose was 75 mg/m. In phase I, the initial dose of pemetrexed was 600 mg/m, escalated in 100 mg/m increments. In phase II, efficacy, including overall response rate, overall survival, as well as toxicity and MTHFR pharmacogenetics were investigated. Phase I enrolled 16 patients; 700 mg/m was defined as pemetrexed recommended dose. Thirteen serious adverse events were reported; the most common grade 3/4 toxicities were haematologic (10 of 13, 76.9%). Phase II enrolled 73 patients, 69 qualified for safety and 68 for efficacy analysis; 65 for pharmacogenomic analysis. Overall response rate was 23.5% (14.1%, 35.4%), disease control rate 55.9%, median overall survival 11.8 months (95% confidence interval, 7.2-18.5 months), progression-free survival 4.9 months (95% confidence interval, 2.8-7.1 months), and median response duration 5.4 months. Patients with MTHFR A1298C variants had median overall survival of 6.6 months, significantly shorter than patients with the wild type (median 18.5 months, P=0.001). The pemetrexed--cisplatin combination in patients with advanced gastric cancer generates modest efficacy and a manageable toxicity profile. The reduced overall survival in patients with MTHFR A1298C polymorphism variants deserves further investigation.

Evaluation of MTHFR677C>T polymorphism in prediction and prognosis of esophageal squamous cell carcinoma: a case-control study in a northern Indian population

Early diagnosis and better prognosis of esophageal squamous cell carcinoma (ESCC) is still a challenge. Besides environmental risk factors, nutritional deficiencies have an established role in pathogenesis of ESCC. Folate deficiency and functional polymorphisms in folate metabolizing genes such as methylene tetrahydrofolate reductase (MTHFR) 677C>T may have oncogenic role through disruption of normal DNA methylation pattern, synthesis, and impaired DNA repair. MTHFR677C>T or A222V (rs1801133) polymorphism has conflicting role in susceptibility to ESCC among different populations. Thus, we aimed to study the role of MTHFR677C>T polymorphism in susceptibility, survival, and interaction with environmental risk factors in ESCC patients from a northern Indian population. A case control study was performed in 208 ESCC incident cases (including 114 follow-up cases) and 223 healthy controls, and genotyping was done by PCR-RFLP. Our results show no significant association of MTHFR677C>T polymorphism with ESCC, tumor locations, or gender of subjects. However, we found a trend of decreased risk of ESCC due to interaction of MTHFR677CT genotype with smoking and alcohol intake. Kaplan Meier, and Cox regression survival analysis showed no prognostic impact of MTHFR677C>T polymorphism in ESCC patients. In conclusion, MTHFR677C>T polymorphism does not seem to have significant role either in susceptibility or survival of ESCC in a northern Indian population.

Critical role of surgery in patients with gastroesophageal carcinoma with a poor prognosis after chemoradiation as defined by positron emission tomography

BACKGROUND

The prognosis of patients with localized gastroesophageal carcinoma (LGC) can be defined after chemoradiation by the standardized uptake value (SUV) of positron emission tomography (PET). High SUV (HSUV) after chemoradiation portends a poor prognosis. The authors retrospectively examined the role of surgery in patients with HSUV after chemoradiation.

METHODS

The authors analyzed the postchemoradiation PET scans of 204 LGC patients. One hundred twenty-nine patients had HSUV. Two postchemoradiation variables were evaluated: SUV and surgery and their association with overall survival (OS) and event-free survival (EFS). The log-rank test, multivariate Cox proportional hazards model, and Kaplan-Meier survival plots were used to assess the association between OS or EFS and the dichotomized SUV (using the median SUV as the cutoff) and surgery.

RESULTS

The median SUV was 4.6. The OS of the 52 patients who had an SUV above the median and did not undergo surgery (HSUV-NS) (median OS, 1.22 years; 95% confidence interval [95% CI], 1.02-2.16 years) was much shorter than that of the 77 patients with an SUV above the median who underwent surgery (HSUV-S) (median OS, 2.7 years; 95% CI, 2.43 years to not reached [P<.0001]). Similarly, the EFS for patients with HSUV-NS was significantly shorter than that for patients with HSUV-S (P=.001). In the multivariate analyses, patients who underwent surgery (irrespective of SUV) had a lower risk of death (P=.0001) and disease progression (P=.002).

CONCLUSIONS

The data from the current study suggest that surgery may prolong OS and EFS in patients with a poor prognosis after chemoradiation as defined by PET. However, these data need confirmation.

A large-scale candidate gene approach identifies SNPs in SOD2 and IL13 as predictive markers of response to preoperative chemoradiation in rectal cancer

Neoadjuvant radiochemotherapy followed by total mesorectal excision is now the standard treatment for locally advanced rectal cancer. However, tumor response to chemoradiation varies widely among individuals and cannot be determined before the final pathologic evaluation. The aim of this study was to identify germline genetic markers that could predict sensitivity or resistance to preoperative radiochemotherapy (RT-CT) in rectal cancer. We evaluated the predictive value of 128 single-nucleotide polymorphisms (SNPs) in 71 patients preoperatively treated by RT-CT. The selected SNPs were distributed over 76 genes that are involved in various cellular processes such as DNA repair, apoptosis, proliferation or immune response. The SNPs superoxide dismutase 2 (SOD2) rs4880 (P=0.005) and interleukin-13 (IL13) rs1800925 (P=0.0008) were significantly associated with tumor response to chemoradiation. These results reinforce the idea of using germline polymorphisms for personalized treatment.

Biomarkers in Barrett's oesophagus

Biomarkers are needed to screen multiple stages in the clinical pathway of Barrett's oesophagus patients; from disease diagnosis to risk stratification and predicting response to therapy. Routes to the identification of biomarkers have been recognized by known molecular features of the disease and more recently through transcriptomic, methylation and proteomic screening approaches. The majority of Barrett's oesophagus patients remain undiagnosed in the general population. In order to develop a tool to screen for Barrett's oesophagus in the primary care setting, minimally invasive sampling methods coupled with immunocytology-based biomarkers are currently being assessed. Biomarkers may also have utility in surveillance programmes by allowing endoscopic interval to be adjusted according to individual neoplastic risk. Many individual biomarkers have been proposed in this regard, but have frequently been assessed in studies of limited power, or have lacked sufficient sensitivity or specificity when assessed in wider population-based studies. Biomarker panels may provide a route forward. In this regard, a panel of methylation markers has shown promise in a multicentre, double-blind, validation study. Biomarkers are also being developed to improve detection of high-grade dysplasia and oesophageal adenocarcinoma, utilizing brush cytology combined with FISH (fluorescence in situ hybridization), and to assess therapeutic success and risk of complication during photodynamic therapy. Finally, we outline progress in identifying alternative sources of biomarkers for this condition.

Nucleotide excision repair polymorphisms and survival outcome for patients with metastatic breast cancer

PURPOSE

Inter-individual variations in treatment efficacy may be influenced by polymorphisms in DNA repair genes. We investigated the association of 3 functional polymorphisms in the nucleotide excision repair (NER) pathway with survival outcome of 95 patients with metastatic breast cancer (MBC) treated with DNA-damaging chemotherapy.

METHODS

ERCC1 8092 C/A, ERCC2 Asp312Asn and ERCC2 Lys751Gln were determined using Taqman-based genotyping assays. Genotype associations with breast cancer-specific survival (BCSS) and progression-free survival (PFS) were evaluated using Kaplan-Meier estimates and hazard ratios calculated using Cox regression analysis. Tests for trend were conducted by calculating P-values for the HR coefficient in proportional hazards regression models.

RESULTS

ERCC2 Lys751Gln was significantly associated with BCSS (median: 24.8 months for AA/AC combined and 14.2 months for CC, HR: 1.9 (95% CI 1.06-3.26)). Median BCSS decreased with increasing number of designated adverse genotypes for the 3 polymorphisms (P (trend) = 0.003). Risk estimates for PFS were nonsignificantly elevated and were significantly elevated for BCSS for patients with 2 (HR = 2.21, 95% CI: 1.04-4.72) or 3 (HR = 6.67, 95% CI: 2.19-20.29) adverse genotypes. In treatment subgroup analysis, risk estimates for BCSS were significantly elevated for patients with 3 adverse genotypes treated with cyclophosphamide, mitoxantrone and vinblastine (HR: 11.9, 95% CI 1.77-79.51) and P (trend) = 0.02 for increasing number of adverse genotypes. Risk of progression was significantly increased for patients with 1 adverse genotype treated with cyclophosphamide, mitoxantrone and carboplatin (HR: 3.5, 95% CI 1.19-10.6) and P (trend) = 0.02 for increasing number of adverse genotypes.

CONCLUSION

Polymorphisms in NER pathway may impact survival outcome for patients with MBC following treatment with DNA-damaging chemotherapy. These results provide support for a polygenic pathway approach for assessing the prognostic and predictive potential of polymorphisms in treatment outcome.

Tumor response is predicted by patient genetic profile in rectal cancer patients treated with neo-adjuvant chemo-radiotherapy

The aim of the study was the identification of a pharmacogenetic profile predictive of the tumor regression grade (TRG), considered as tumor response parameter, after neo-adjuvant treatment in rectal cancer patients. A total of 238 rectal cancer patients treated in a neo-adjuvant setting by a fluoropyrimidines-based chemo-radiotherapy (RT) were genotyped for 25 genetic polymorphisms in 16 genes relevant for treatment-associated pathways. Two polymorphisms were associated with TRG in a multivariate analysis: hOGG1-1245C > G, which can affect radiosensitivity and MTHFR-677C > T, which is involved in fluoropyrimidines action. Patients bearing at least one variant allele had a lower chance to get TRG ≤ 2 (OR = 0.46 95% CI 0.23-0.90, P = 0.024; and OR = 0.48 95% CI 0.24-0.96, P = 0.034; respectively). An association trend was observed for ABCB1-3435C > T, which is responsible for the multi-drug resistance (odds ratio (OR) = 1.96, 95% confidence interval (CI) 0.98-3.95, P = 0.057). Exploratory classification and regression tree (CART) analysis highlighted high-order gene-gene and gene-environment interactions and a genetic signature associated with differential response, with hOGG1-1245C > G as the most predictive factor. Other significant variables were: ABCB1-3435C > T, MTHFR-677C > T, ERCC1-8092C > A, ABCC2-1249G > A, XRCC1-28152G > A, XRCC3-4541A > G and patients gender. On the basis of CART results, patients were categorized into three groups according to tumor response probability: intermediate and high profiles had a higher probability to get TRG ≤ 2 as compared with low profiles (OR = 4.12 95% CI 1.46-11.65, P < 0.001 and OR = 12.44, 95% CI 5.52-28.04, P < 0.0001, respectively). This study evidences a major role of hOGG1-1245C > G and MTHFR-677C > T polymorphisms in the tumor response of rectal cancer patients treated with chemo-RT in neo-adjuvant setting, and shows the relevance of gene-gene and gene-environment interactions for complex phenotypes as tumor response.

Pharmacogenomics of platinum-based chemotherapy in NSCLC

NSCLC is the leading cause of cancer-related death in the US. Patients with NSCLC are mostly treated with platinum-based chemotherapy, often in combination with radiation therapy. However, the development of chemo-resistance is a major hurdle limiting treatment success. In this review, we summarize the current understanding of the genetic factors modulating chemoresistance to platinum chemotherapeutics and their association with clinical outcomes for NSCLC patients. We focus on candidate pathways responsible for drug influx and efflux, metabolism and detoxification, DNA damage repair, and other downstream cellular processes that modulate the effect of platinum-based therapy. We also discuss the application of pathway-based polygenic and genome-wide approaches in identifying genetic factors involved in NSCLC clinical outcomes. Overall, current studies have shown that the effects of each individual polymorphism on clinical outcomes are modest suggesting that a more comprehensive approach that incorporates polygenetic, phenotypic, epidemiologic and clinical variables will be necessary to predict prognosis for NSCLC patients receiving platinum-based chemotherapeutics.

The higher the decrease in the standardized uptake value of positron emission tomography after chemoradiation, the better the survival of patients with gastroesophageal adenocarcinoma

BACKGROUND

Postchemoradiation percentage decrease in standardized uptake value (SUV) of positron emission tomography (PET) from baseline correlates with overall survival (OS) and pathologic response. Analyses of dichotomized data are commonly reported. The authors analyzed percentage SUV decrease as both dichotomized and continuous variables.

METHODS

The authors assessed 151 consecutive patients with gastroesophageal adenocarcinoma who had chemoradiation and surgery. Baseline and postchemoradiation PET/computed tomography imaging was performed. The log-rank test and Cox proportional hazards models were used to associate percentage SUV changes and OS, and logistic regression models were used to detect the association between percentage SUV changes and pathologic response.

RESULTS

A >52% SUV decrease (dichotomized analysis) was associated with a longer OS (log-rank test, P = .023). The univariate Cox proportional hazards model indicated that greater percentage SUV decrease (as a continuous variable) was associated with a lower risk of death (hazard ratio [HR], 0.99; P = .01). Pathologic response (< or =50% residual cancer) was associated with longer OS (P = .003). Patients with chemoradiation resistance (>50% residual cancer) tended to have a higher risk of death than those with chemoradiation sensitivity (0-50% residual cancer; HR, 2.12; P = .099). In the multivariate model, the percentage SUV decrease (as a continuous variable) was the only prognosticator of OS (P = .01). The percentage SUV decrease was nonsignificantly associated with pathologic complete response (univariate odds ratio [OR], 1.01; P = .06 and multivariate OR, 1.03; P = .07).

CONCLUSIONS

The greater the decline in SUV after chemoradiation, the longer is the OS of gastroesophageal adenocarcinoma patients. The percentage SUV decrease as a continuous variable is a better prognosticator of OS than its dichotomized assessments.

Genetic variations as cancer prognostic markers: review and update

Cancer molecular epidemiology traditionally studies the relationship between genetic variations and cancer risk. However, recent studies have also focused on disease outcomes. The application and design of disease outcome studies have been an extension of disease risk assessment. Yet there are a number of unique considerations important in outcome assessments. We review how genetic approaches used for disease susceptibility, such as candidate gene and genome-wide association study (GWAS) approaches, can be adapted carefully to systematically identify cancer prognostic and predictive alleles. We discuss the interrelatedness among the disease susceptibility, treatment response, and prognosis at the genetic level and focus on how the emerging technologies and approaches can uniquely benefit the genetic prognosis studies.

Association between polymorphisms in DNA repair genes and survival of non-smoking female patients with lung adenocarcinoma

Background

Excision repair cross-complementing group 1 (ERCC1) and group 2 (ERCC2), and X-ray repair cross-complementing group 1 (XRCC1) proteins play important roles in the repair of DNA damage and adducts. Single nucleotide polymorphisms (SNPs) of DNA repair genes are suspected to influence treatment effect and survival of cancer patients. This study aimed to investigate the relationship between polymorphisms in ERCC2, ERCC1 and XRCC1 genes and survival of non-smoking female patients with lung adenocarcinoma.

Methods

We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to evaluate SNPs in ERCC2, ERCC1 and XRCC1 genes among 257 patients.

Results

The overall median survival time (MST) was 13.07 months. Increasing numbers of either ERCC1 118 or XRCC1 399 variant alleles were associated with shorter survival of non-smoking female lung adenocarcinoma patients (Log-rank P < 0.001). The adjusted hazard ratios (HRs) for individuals with CT or TT genotype at ERCC1 Asn118Asn were 1.48 and 2.67 compared with those with CC genotype. For polymorphism of XRCC1 399, the HRs were 1.28 and 2.68 for GA and AA genotype. When variant alleles across both polymorphisms were combined to analysis, the increasing number of variant alleles was associated with decreasing overall survival. Using the stepwise Cox regression analysis, we found that the polymorphisms in ERCC1 and XRCC1, tumor stage and chemotherapy or radiotherapy status independently predicted overall survival of non-smoking female patients with lung adenocarcinoma.

Conclusions

Genetic polymorphisms in ERCC1 and XRCC1 genes might be prognostic factors in non-smoking female patients with lung adenocarcinoma.

Myeloperoxidase genotypes and enhanced efficacy of chemotherapy for early-stage breast cancer in SWOG-8897

PURPOSE

Myeloperoxidase (MPO) generates reactive oxygen species and also activates xenobiotics. In a rigorous clinical trial (Southwest Oncology Group SWOG-8897), we examined relationships between genotypes and disease-free survival (DFS) among women treated for breast cancer, as well as those who did not receive adjuvant chemotherapy.

PATIENTS AND METHODS

Patients were assigned to risk groups according to standard prognostic features; the low-risk group (n = 753 genotyped) received follow-up only, and the high-risk group (n = 401 genotyped) was randomly assigned to adjuvant cyclophosphamide, methotrexate, and fluorouracil (CMF) or cyclophosphamide, doxorubicin, and fluorouracil (CAF), with or without tamoxifen. DNA from archived normal lymph node tissue was genotyped, and Cox proportional hazard models were used to calculate DFS associated with MPO genotypes.

RESULTS

Among women in the treatment arm, those with MPO G alleles had more than a two-fold reduction in hazard of recurrence (adjusted hazard ratio [HR] for GA genotypes, 0.51; 95% CI, 0.21 to 0.99; HR for GG genotypes, 0.41; 95% CI, 0.21 to 0.77). Effects were greatest among women who were further randomly assigned to tamoxifen (HR for GA genotypes, 0.28; 95% CI, 0.12 to 0.69; HR for GG genotypes, 0.19; 95% CI, 0.08 to 0.45). There were no significant associations between genotypes and DFS among women in the untreated arm, and relationships between genotypes and DFS did not differ by CAF or CMF.

CONCLUSION

These results, observed in two independent study populations, indicate that high-activity MPO genotypes are associated with better survival among women receiving cyclophosphamide-containing therapy, particularly when followed by tamoxifen therapy. MPO can be inhibited and/or upregulated by commonly used drugs; thus, our findings merit further investigation for optimization of therapeutics for breast cancer.

Cisplatin pharmacogenetics, DNA repair polymorphisms, and esophageal cancer outcomes

OBJECTIVES

Genetic variations or polymorphisms within genes of the nucleotide excision repair (NER) pathway alter DNA repair capacity. Reduced DNA repair (NER) capacity may result in tumors that are more susceptible to cisplatin chemotherapy, which functions by causing DNA damage. We investigated the potential predictive significance of functional NER single nucleotide polymorphisms in esophageal cancer patients treated with (n = 262) or without (n = 108) cisplatin.

METHODS

Four NER polymorphisms XPD Asp312Asn; XPD Lys751Gln, ERCC1 8092C/A, and ERCC1 codon 118C/T were each assessed in polymorphism-cisplatin treatment interactions for overall survival (OS), with progression-free survival (PFS) as a secondary endpoint.

RESULTS

No associations with ERCC1 118 were found. Polymorphism-cisplatin interactions were highly significant in both OS (P = 0.002, P = 0.0001, and P < 0.0001) and PFS (P = 0.006, P = 0.008, and P = 0.0007) for XPD 312, XPD 751, and ERCC1 8092, respectively. In cisplatin-treated patients, variant alleles of XPD 312, XPD 751, and ERCC1 8092 were each associated with significantly improved OS (and PFS): adjusted hazard ratios of homozygous variants versus wild-type ranged from 0.22 [95% confidence interval (CI): 0.1-0.5] to 0.31 (95% CI: 0.1-0.7). In contrast, in patients who did not receive cisplatin, variant alleles of XPD 751 and ERCC1 8092 had significantly worse survival, with adjusted hazard ratios of homozygous variants ranging from 2.47 (95% CI: 1.1-5.5) to 3.73 (95% CI: 1.6-8.7). Haplotype analyses affirmed these results.

CONCLUSION

DNA repair polymorphisms are associated with OS and PFS, and if validated may predict for benefit from cisplatin therapy in patients with esophageal cancer.

Overexpression of AIB1 predicts resistance to chemoradiotherapy and poor prognosis in patients with primary esophageal squamous cell carcinoma

AIB1 (amplified in breast cancer 1) is frequently overexpressed in esophageal squamous cell carcinoma (ESCC), but the significance of AIB1 expression in chemoradiotherapy (CRT) sensitivity and its effect on prognosis are still unclear. In this study, the expression of AIB1 was examined by immunohistochemistry in 98 biopsy specimens of primary ESCC patients treated with definitive CRT. AIB1 overexpression was found in 63/98 (64.3%) of the ESCCs. There was a significant association between AIB1 overexpression and distant lymph node metastases (P = 0.011), but not regional lymph node metastases. In the M0 subgroup, overexpression of AIB1 was observed more frequently in stage T4 than in stage T2-3 (66.7%vs 38.5%, P = 0.031). In addition, AIB1 expression was the only factor that showed a significant correlation with CRT response, in which overexpression of AIB1 was observed more frequently in the CRT resistant group than in the CRT effective group (86.5%vs 50.8%, P < 0.001). Univariate analysis revealed that AIB1 overexpression was associated with poor progression-free survival (PFS) (P < 0.001) and poor disease-specific survival (DSS) (P <0.001). Furthermore, AIB1 expression could stratify patient survival in stages T2-3, T4, N1, and M0 (P < 0.05), as well as in the CRT effective group (P < 0.05), and AIB1 overexpression and CRT resistance were evaluated as significant independent prognostic factors for both PFS and DSS in multivariate analysis. These findings suggest that overexpression of AIB1 is a useful predictor of CRT resistance and an independent molecular marker of poor prognosis for ESCC patients.