María Jesús Lamas

Purpose Genetic variants in genes involved in the distribution, metabolism, accumulation or repair of lesions are likely to influence the response of drugs used in the treatment of Head and Neck Cancer (HNC). We examine the effect of 36 SNPs on clinical outcomes in patients with locally advanced HNC who were receiving platinum-based chemoradiotherapy (CRT). Methods These SNPs were genotyped in 110 patients using the iPLEX Gold assay on the MassARRAY method in blood DNA samples and used Kaplan–Meier and Cox regression analyses to compare genotype groups with the survival. Results Two SNPs, rs717620 (ABCC2) and rs12934241 (MMP2) were strongly associated with overall survival (OS) and disease-free survival (DFS). At a median follow-up of 64.4 months, the allele A of rs717620 (ABCC2) had an increased risk of disease progression {hazard ratio [HR] = 1.79, p = 0.0018} and death (HR = 2.0, p = 0.00027). ABCC2 was associated with OS after a Bonferroni adjustment for multiple testing. The MMP2 rs12934241‐T allele was associated with an increased risk of worse OS and DFS (p = 0.0098 and p = 0.0015, respectively). One SNP of ABCB1 and three SNPs located in the ERCC2 gene showed an association with response in the subgroup of HNC patients treated with definitive CRT. Conclusions Our findings highlight the potential usefulness of SNPs in different genes involved in drug metabolism and repair DNA to predict the response and survival to CRT. ABCC2 is a potential predictor of OS in patients with HNC.

We studied the predictive value for response and toxicity of functional polymorphisms in genes involved in the oxaliplatin/fluorouracil pathway in colorectal cancer patients. One hundred and twenty-seven (127) patients were treated with curative intended surgery followed by adjuvant chemotherapy with FOLFOX (fluorouracil, leucovorin and oxaliplatin) regimen. The median age was 65.53 (27–80) years (66.9% male, 59.1% rectum). The median follow-up was 8.5 years (IQR, 4.1–9.4). At the end of follow-up, 59 patients (46.5%) had relapsed or died in the whole study population. We did find that XRCC1GG genotype is associated with a higher risk of developing haematologic toxicity. Furthermore, we report a significant association of the TS 3′UTR 6 bp/6 bp polymorphism and the XRCC1 rs25487 with a higher risk of developing anaemia and diarrhoea, respectively. On the other hand, none of the studied polymorphisms showed clinically relevant association with disease-free survival and overall survival or early failure to adjuvant FOLFOX therapy.

Objective Voriconazole is an antifungal agent used in the treatment of aspergillosis and fluconazole-resistant Candida infections. Therapeutic drug monitoring (TDM) of voriconazole is recommended to optimise clinical results. The aim of this study was the development and validation of a high performance liquid chromatography (HPLC) method for measuring voriconazole in human serum, and comparison with an ARK immunoassay method. Methods Linearity, precision, accuracy and stability of the HPLC method were validated according to the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The method was applied to the analysis of 58 trough serum samples from patients treated with voriconazole, and the HPLC-UV (ultraviolet) method was compared with an ARK immunoassay. The correlation of both methods was studied by the Pearson regression coefficient and the concordance of the values was evaluated by the Bland-Altman and Passing-Bablok methods. Results All validation parameters met the criteria set out in the FDA and EMA guidelines. The standard curve was linear over a concentration range of 0.25–16 µg/mL with a limit of quantification of 0.125 µg/mL. No interactions between voriconazole and other drugs was observed and voriconazole was stable after 1 month at −80°C. Comparison of the HPLC method and the enzyme immunoassay method showed a linear correlation with a systematic error of −0.61 µg/mL between both methods. Conclusion The method developed is simple and fast and can be easily applied for routine therapeutic drug monitoring of voriconazole. The HPLC-UV method was more sensitive than the immunoassay method and there was concordance with the immunoassay. Consequently both methods could be used, considering the correlation between them.

: The current review is focussing different factors that contribute and directly correlate to the onset and progression of Age-related Macular Degeneration (AMD). In particular, the susceptibility to AMD due to genetic and non-genetic factors and the establishment of risk scores, based on the analysis of different genes to measure the risk of developing the disease. A correlation with the actual therapeutic landscape to treat AMD patients from the point of view of pharmacokinetics and pharmacogenetics is also exposed. Treatments commonly used, as well as different regimes of administration, will be especially important in trying to classify individuals as “responders” and “non-responders”. Analysis of different genes correlated with drug response and also the emerging field of microRNAs (miRNAs) as possible biomarkers for early AMD detection and response will be also reviewed. : This article aims to provide the reader a review of different publications correlated with AMD from the molecular and kinetic point of view as well as its commonly used treatments, major pitfalls and future directions that, to our knowledge, could be interesting to assess and follow in order to develop a personalized medicine model for AMD.

Voriconazole is an antifungal metabolised by CYP2C19 enzyme, which can be inhibited by proton‐pump inhibitors (PPIs). A prospective observational study was carried out to determine the influence of PPIs on voriconazole pharmacokinetic. The 78 patients included were divided into 4 groups: omeprazole (n = 32), pantoprazole (n = 25), esomeprazole (n = 3) and no PPI (n = 18). Patients with no PPI had no significant difference in plasma voriconazole concentration when compared with those with PPI (2.63 ± 2.13 μg/mL [95% confidence interval {CI} 1.57–3.69] vs 2.11 ± 1.73 μg/mL [95%CI 1.67–2.55], P > .05). However, voriconazole plasma concentration was significantly lower in patients treated with pantoprazole vs those treated with omeprazole (1.44 ± 1.22 μg/mL [95%CI 0.94–1.94) vs 2.67 ± 1.88 μg/mL [95%CI 2.02–3.32], P = .013) suggesting a greater CYP2C19 enzyme inhibitory effect of omeprazole. This study demonstrates the greater CYP inhibition capacity of omeprazole and should be helpful for the choice of PPIs for patients treated with voriconazole.

Background: Voriconazole, a first‐line agent for the treatment of invasive fungal infections, is mainly metabolized by cytochrome P450 (CYP) 2C19. A significant portion of patients fail to achieve therapeutic voriconazole trough concentrations, with a consequently increased risk of therapeutic failure.Objective: To show the association between subtherapeutic voriconazole concentrations and factors affecting voriconazole pharmacokinetics: CYP2C19 genotype and drug–drug interactions.Methods: Adults receiving voriconazole for antifungal treatment or prophylaxis were included in a multicenter prospective study conducted in Spain. The prevalence of subtherapeutic voriconazole troughs was analyzed in the rapid metabolizer and ultra‐rapid metabolizer patients (RMs and UMs, respectively), and compared with the rest of the patients. The relationship between voriconazole concentration, CYP2C19 phenotype, adverse events (AEs), and drug–drug interactions was also assessed.Results: In this study 78 patients were included with a wide variability in voriconazole plasma levels with only 44.8% of patients attaining trough concentrations within the therapeutic range of 1 and 5.5 µg/ml. The allele frequency of *17 variant was found to be 29.5%. Compared with patients with other phenotypes, RMs and UMs had a lower voriconazole plasma concentration (RM/UM: 1.85 ± 0.24 µg/ml vs other phenotypes: 2.36 ± 0.26 µg/ml). Adverse events were more common in patients with higher voriconazole concentrations (pCYP2C19 genotype‐guided voriconazole dosing to achieve concentrations in the therapeutic range in the early course of therapy. Larger studies are needed to confirm the impact of pharmacogenetics on voriconazole pharmacokinetics.

Background: Platinum‐based chemoradiotherapy (CRT) is the standard treatment for locally advanced head and neck squamous‐cell carcinomas (HNSCC), and most patients experience serious toxicities. The aim of this study was to investigate the association between candidate genes involved in radiation/platinum pathways and acute toxicity of CRT to determine the predictive value of these polymorphisms for toxicity.Methods: Thirty‐six selected single nucleotide polymorphisms (SNPs) in 29 genes were genotyped in 110 patients treated with cisplatin‐based CRT. DNA was obtained from blood samples, and SNP analysis was performed using a MassARRAY iPLEX Gold (Sequenom) method.Results: Patients with ERCC1 rs11615‐C allele (P = .0066), ERCC1 rs735482‐C allele (P = .0204), and ERCC4 rs1799801‐C allele (P = .0286) had lower risk of grade 2‐3 hematologic toxicity. In addition, the presence of G allele of GSTP1 was associated with a significantly lower risk of severe dysphagia (P = .0004).Conclusion: Polymorphisms in ERCC1 and GSTP1 may act as prognostic factors of acute toxicity during treatment with CRT in HNSCC patients.