DNA repair gene polymorphisms in non-small-cell lung cancer patients treated with first-line platinum-containing chemotherapy. Tumori. 2016;102:367-375. [PMID: 27396427 DOI: 10.5301/tj.5000526]

Variants of ERCC5 and the outcome of platinum-based regimens in non-small cell lung cancer: a prospective cohort study

Excision repair complementary complex 5 (ERCC5) is an important component in the repair pathway of platinum-induced damage. The current study evaluated the effect of ERCC5 variants (rs751402 and rs1047768) on the clinical outcome of platinum-based regimens in non-small cell lung cancer (NSCLC) patients. A prospective, cohort study was conducted on 57 newly diagnosed NSCLC Egyptian patients. Patients received either cisplatin or carboplatin-based chemotherapy. DNA was extracted and the variants were analyzed using real time PCR. This study found no significant difference between the studied variants and patients’ response to chemotherapy, progression-free survival (PFS) or overall survival (OS). However, a statistically significant association was found between the histologic subtypes and the studied variants (p = 0.028 and 0.018 for rs751402 and rs1047768, respectively). A statistically significant association was evident between the type of the allele present in the studied polymorphisms, p value = 0.000040. Moreover, the minor allele frequency (MAF) of the studied variants rs751402 and rs1047768 were similar to those of African and European populations, respectively. Results of this study have concluded that ERCC5 variants did not affect the clinical outcome of platinum-based chemotherapy in NSCLC. A significant coinheritance was found between the two variants of ERCC5. Moreover, the similarity between the MAF of the studied variants and the African or European population can guide future research when extrapolating data from African European populations to their Egyptian counterparts.

The Significant Interaction of Excision Repair Cross-complementing Group 1 Genotypes and Smoking to Lung Cancer Risk

BACKGROUND

The study aims to evaluate the contribution of excision repair cross-complementing group 1 (ERCC1), which plays an important role in genome integrity maintenance, to lung cancer risk.

MATERIALS AND METHODS

ERCC1 rs11615 and rs3212986 genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism analysis and their association with lung cancer risk was examined among 358 lung cancer patients and 716 controls.

RESULTS

The proportions of CC, CT and TT for the rs11615 genotype were 43.6%, 41.6% and 14.8% in the case group and 50.0%, 41.1% and 8.9% in the control group, respectively (p for trend=0.0082). Allelic analysis showed that ERCC1 rs11615 T-allele carriers have a 1.32-fold higher risk of lung cancer than wild-type C-allele carriers [95%confidence interval (CI)=1.09-1.60, p=0.0039]. In addition, a significant interaction between the rs11615 genotype and smoking status was observed.

CONCLUSION

The T allele of ERCC1 rs11615 jointly with smoking habits may contribute to a higher lung cancer risk in Taiwan.

Genetic biomarkers for hepatocellular cancer risk in a caucasian population

AIM

To uncover novel genetic markers that could contribute to predicting hepatocellular carcinoma (HCC) susceptibility in Caucasians.

METHODS

The present retrospective case-control study compared genotype frequencies between a cohort of HCC cases and two, independent, HCC-free, age/sex-matched control groups. The HCC cohort comprised 192 homogeneous patients that had undergone orthotopic liver transplantation. The first control group comprised 167 patients that were matched to the HCC cohort for the percentage of hepatitis B (HBV) and/or hepatitis C (HCV) infections. A second control group included 192 virus-free, healthy individuals that were used to evaluate the generalizability of the identified predictive markers. All cases and controls were Caucasian. The three study populations were characterized with a panel of 31 markers derived from 21 genes that encoded key proteins involved in hepatocarcinogenesis-related pathways. The study end-point was to assess the association between genetic variants and HCC onset.

RESULTS

Five genetic markers were identified as risk factors for HCC in high-risk patients infected with HBV/HCV. According to a dominant model, reduced HCC risk was associated with three polymorphisms: ERCC1 rs3212986 (OR = 0.46, 95%CI: 0.30-0.71, P = 0.0005), GST-P1 rs1138272 (OR = 0.41, 95%CI: 0.21-0.81, P = 0.0097), and CYP17A1 rs743572 (OR = 0.50, 95%CI: 0.31-0.79, P = 0.0032). Conversely, according to a recessive model, increased HCC risk was associated with two polymorphisms: XRCC3 rs1799794 (OR = 3.70, 95%CI: 1.02-13.39, P = 0.0461) and ABCB1 rs1128503 (OR = 2.06, 95%CI: 1.18-3.61, P = 0.0111). These associations remained significant in a subgroup analysis, where patients were stratified according to viral status (HBV- or HCV-positive serology). Two variants exhibited a serology-specific effect: ABCB1 rs1128503 (OR = 4.18, 95%CI: 1.55-11.29, P = 0.0048) showed an effect in the HBV-positive subgroup; and ERCC1 rs3212986 (OR = 0.33, 95%CI: 0.18-0.60, P = 0.0003) showed an effect in the HCV-positive subgroup. Among the five markers identified, ERCC1 rs3212986 (OR = 0.43, P < 0.0001) and CYP17A1 rs743572 (OR = 0.73, P = 0.0310) had a different distribution in patients with HCC compared to healthy individuals. With a recursive partitioning approach, we also demonstrated that significant gene-gene interactions between ERCC1 rs3212986, CYP17A1 rs743572, GST-P1 rs1138272, and the previously described UGT1A7*3 predictive marker, played a role in the complex trait of HCC susceptibility.

CONCLUSION

We identified five polymorphisms and interactions that contributed crucially to predicting HCC risk. These findings represented an important step towards improving HCC diagnosis and management.