Potential role of PIN1 genotypes in predicting benefit from oxaliplatin-based and irinotecan-based treatment in patients with metastatic colorectal cancer.

PIN1-mediated substrate isomerization plays a role in the repair of DNA double-strand breaks. We hypothesized that genetic polymorphisms in PIN1-related pathways may affect tumor sensitivity to oxaliplatin or irinotecan in metastatic colorectal cancer (mCRC) patients. We analyzed genomic DNA from five cohorts of mCRC patients (total 950) treated with different first-line treatments: oxaliplatin cohorts 1 (n = 146) and 2 (n = 70); irinotecan cohorts 1 (n = 228), and 2 (n = 276); and combination cohort (n = 230). Single nucleotide polymorphisms of candidate genes were analyzed by PCR-based direct sequencing. In the oxaliplatin cohort 1, patients carrying any PIN1 rs2233678 C allele had shorter progression-free survival (PFS) and overall survival (OS) than the G/G variant (PFS, 7.4 vs. 15.0 months, hazard ratio [HR] 3.24, P < 0.001; OS, 16.9 vs. 31.5 months, HR: 2.38, P = 0.003). In contrast, patients with C allele had longer median PFS than patients with G/G (11.9 vs. 9.4 months, HR: 0.64, 95%CI: 0.45-0.91, P = 0.009) in the irinotecan cohort 1. No significant differences were observed in the combination cohort. In comparison between the irinotecan cohort 1 and combination cohort, the patients carrying the G/G variant benefit greatly from the combination compared with irinotecan-based regimen (PFS, 11.6 vs. 9.4 months, HR 0.61, 95%CI: 0.47-0.78, P < 0.001; OS, 30.6 vs. 24.0 months, HR 0.79, 95%CI: 0.62-1.02, P = 0.060), while no significant difference was shown in any C allele. Germline PIN1 polymorphisms may predict clinical outcomes in mCRC patients receiving oxaliplatin-based or irinotecan-based therapy, and identify specific populations favorable to oxaliplatin plus irinotecan combination therapy.

Gene Polymorphisms in the CCL5/CCR5 Pathway as a Genetic Biomarker for Outcome and Hand-Foot Skin Reaction in Metastatic Colorectal Cancer Patients Treated With Regorafenib.

BACKGROUND: The C-C motif chemokine ligand 5/C-C motif chemokine receptor 5 (CCL5/CCR5) pathway has been shown to induce endothelial progenitor cell migration, resulting in increased vascular endothelial growth factor A expression. We hypothesized that genetic polymorphisms in the CCL5/CCR5 pathway predict efficacy and toxicity in patients with metastatic colorectal cancer (mCRC) treated with regorafenib. PATIENTS AND METHODS: We analyzed genomic DNA extracted from 229 tumor samples from 2 different cohorts of patients who received regorafenib: an evaluation cohort of 79 Japanese patients and a validation cohort of 150 Italian patients. Single nucleotide polymorphisms of CCL5/CCR5 pathway-related genes were analyzed by PCR-based direct sequencing. RESULTS: CCL4 rs1634517 and CCL3 rs1130371 were associated with progression-free survival in the evaluation cohort (hazard ratio [HR] 1.54, P = .043; HR 1.48, P = .064), and progression-free survival (HR 1.74, P < .001; HR 1.66, P = .002) and overall survival (HR 1.65, P = .004; HR 1.65, P = .004) in the validation cohort. The allelic frequencies of CCL5 single nucleotide polymorphisms varied between the evaluation and validation cohorts (G/G variant in rs2280789, 21.5% vs. 1.3%, P < .001; T/T variant in rs3817655, 22.8% vs. 2.7%, P < .001). In the evaluation cohort, patients with the G/G variant in rs2280789 had a higher incidence of grade 3+ hand-foot skin reaction compared to any A allele (53% vs. 27%, P = .078), and similarly to the T/T variant in rs3817655 compared to any A allele (56% vs. 26%, P = .026). CONCLUSION: Genetic variants in the CCL5/CCR5 pathway may serve as prognostic markers and may predict severe hand-foot skin reaction in mCRC patients receiving regorafenib therapy.

Potential role of polymorphisms in the transporter genes ENT1 and MATE1/OCT2 in predicting TAS-102 efficacy and toxicity in patients with refractory metastatic colorectal cancer.

BACKGROUND: Trifluridine (FTD) is an active cytotoxic component of the metastatic colorectal cancer (mCRC) drug TAS-102, and thymidine phosphorylase inhibitor (TPI) inhibits the rapid degradation of FTD. We tested whether single nucleotide polymorphisms (SNPs) in genes involved in FTD metabolism and TPI excretion could predict outcome in patients with mCRC treated with TAS-102. PATIENTS AND METHODS: We investigated three different cohorts: a training cohort (n = 52) and a testing cohort (n = 129) both receiving TAS-102 and a control cohort (n = 52) receiving regorafenib. SNPs of TK1, ENT1, CNT1, MATE1, MATE2 and OCT2 were analysed by polymerase chain reaction-based direct DNA sequencing. RESULTS: In the training cohort, patients with any ENT1 rs760370 G allele had a significantly longer progression-free survival (PFS; 3.5 versus 2.1 months, respectively, hazard ratio [HR] 0.44, P = 0.004) and overall survival (OS; 8.7 versus 5.3 months, respectively, HR 0.27, P = 0.003) than the A/A genotype. These findings were validated in the testing cohort (P = 0.021 and 0.009 for PFS and OS, respectively). In addition, the combination of ENT1 rs760370, MATE1 rs2289669 and OCT2 rs316019 SNPs significantly stratified patients with the risk of PFS and OS in both cohorts (P < 0.001 for PFS and OS in the training cohort; P = 0.053 and 0.025 for PFS and OS, respectively, in the testing cohort). No significant differences were observed in the control group. CONCLUSIONS: The combination of ENT1, MATE1 and OCT2 SNPs may serve as a predictive and prognostic marker in mCRC patients treated with TAS-102.

Predictive value of TLR7 polymorphism for cetuximab-based chemotherapy in patients with metastatic colorectal cancer.

The TLR7 and TLR9 signalings are implicated in the regulation of the immune system through type-I interferon induction. Preclinical studies have demonstrated the immunomodulatory and antitumor effects of TLR7 and TLR9 agonists in combination with cetuximab. We tested the hypothesis that genetic variations in TLR7 and TLR9 and their downstream molecules IRF5 and IRF7 were associated with outcomes in metastatic colorectal cancer (mCRC) patients receiving cetuximab-based chemotherapy. Six single nucleotide polymorphisms (SNPs) in TLR7, TLR9, IRF5 and IRF7 were tested for the association with RR, PFS, and OS in KRAS-wild type mCRC patients. Patients treated with FOLFIRI + cetuximab or FOLFIRI + bevacizumab in the FIRE-3 trial served as a discovery set (FIRE3-Cet, n = 244) or a control set (FIRE3-Bev, n = 246), respectively. Patients treated with FOLFOX or SOX + cetuximab in the JACCRO-CC05/06 trial served as a validation set (JACCRO, n = 76). Genomic DNA isolated from tumor tissue samples was analyzed by PCR-based direct sequencing. In the discovery cohort, patients with the TLR7 rs3853839 G/G variant showed a trend toward longer PFS than those with any C variants (median 10.0 vs. 11.8 months, HR 1.39, p = 0.092). This preliminary association was confirmed in the validation cohort, and those with the G/G genotype showed a PFS benefit compared with others (univariate: 9.1 vs. 11.6 months, HR 2.04, p = 0.005, multivariate: HR 2.02, 95% CI: 1.14-3.55, p = 0.015). This association was not observed in the control cohort. Our findings suggest that TLR7 rs3853839 predicts the outcome of cetuximab-based chemotherapy in mCRC patients.

Single nucleotide polymorphisms in the IGF-IRS pathway are associated with outcome in mCRC patients enrolled in the FIRE-3 trial.

The Insulin-like growth factor (IGF)/IGF-receptor pathway with its scaffolding proteins Insulin Receptor Substrate (IRS)1 and IRS2 are crucial regulators of metabolism and progression in metastatic colorectal cancer (mCRC). The goal of the study was the identification of predictive and prognostic markers among IRS1, IRS2, IGF1 and IGF-1R SNPs in mCRC patients enrolled in the FIRE-3 trial. Four SNPs of IRS (IRS1 rs1801278, rs1801123; IRS2 rs1805097, rs2289046) and four SNPs of IGF1-IGFR1 (rs6214, rs6220, rs2946834, rs2016347) were analyzed by PCR/direct-sequencing in the FIRE-3 trial. The relation of SNPs with PFS and OS was evaluated through Kaplan-Meier method and log-rank test in the overall population and in subgroup according to RAS status and treatment arm. In the overall population IRS1 rs1801123 C/- carriers (N= 105) achieved significantly worse OS compared to T/T (N = 464) in univariate (HR = 1.32 [95%CI 1.03-1.70], p = 0.029) and in multivariable. Similar results were observed among RAS wild type. Patients with IGF1 rs2946834 T/- variant (N= 280) achieved improved PFS compared to C/C (N = 257) in univariate (HR = 0.77 [95%CI 0.64-0.92], p = 0.004) and in multivariable. In the RAS wild-type subgroup IGF1 rs2946834 T/- carriers showed better PFS and OS compared to C/C (univariate HR for PFS = 0.65 [95%CI 0.51-0.81], p < 0.001; multivariable HR for PFS = 0.63 [95%CI 0.50-0.81], p < 0.001). IRS1 rs1801123 SNP was identified as a new prognostic marker for mCRC. IGF1 rs2946834 was confirmed as prognostic factor in the overall population and in RAS wild type patients. Our findings underline the importance of IGF downstream signaling pathway in RAS wild-type mCRC patient.