The present study aimed at investigating whether the simultaneous evaluation of pharmacokinetic, pharmacogenetic and demographic factors could improve prediction on toxicity and survival in colorectal cancer patients treated with adjuvant 5-fluorouracil (5FU)/leucovorin therapy. One hundred and thirty consecutive, B2 and C Duke's stage colorectal cancer patients were prospectively enrolled. 5FU pharmacokinetics was evaluated at the first cycle. Thymidylate synthase (TYMS) 5 0 UTR and 3 0 UTR polymorphisms and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms were assessed in peripheral leukocytes. Univariate and multivariate analyses were applied to evaluate which variables could predict chemotherapy-induced toxicity, disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that: (a) low 5FU clearance was an independent predictive factor for severe toxicity (OR ¼ 7.32; Po0.0001); (b) high-5FU clearance predicted poorer DFS (HR ¼ 1.96; P ¼ 0.041) and OS (HR ¼ 3.37; P ¼ 0.011); (c) advanced age was associated with shorter DFS (HR ¼ 3.34; P ¼ 0.0008) and OS (HR ¼ 2.66; P ¼ 0.024); (d) the C/C genotype of the MTHFR C677T polymorphism was protective against grade 3 -4 toxicity (P ¼ 0.040); (e) none of the TYMS polymorphisms could explain 5FU toxicity or clinical outcome.

Thymidylate synthase (TYMS) is the main molecular target for fluoropyrimidine anticancer drugs, and its expression has been correlated with the number of repeats of a 28-bp sequence in the 5'-untranslated region of the TYMS gene and with the presence of a G --> C single-nucleotide polymorphism in the second repeat of 3R alleles. Based on this double polymorphism, three main TYMS alleles have so far been identified: TYMS 2R, TYMS 3RC and TYMS 3RG. During genetic analysis of TYMS polymorphisms in 100 colorectal cancer patients, three patients revealed an unexpected 113-bp band after electrophoresis of the restriction fragment length polymorphism analysis. Subsequent sequencing revealed two 28-bp repeats in the 5'-untranslated region and the presence in both repeats of cytosine instead of guanine at the 12th nucleotide. This allele variant (TYMS 2RC) has not been previously described in man. All three patients were heterozygotes for TYMS 2RC and experienced grade 2-3 chemotherapy-related toxicity.

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WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Gemcitacine is taken up by the cell through various nucleoside transporters of either the concentrative (CNT) or equilibrative type (ENT) and is then transformed into the inactive metabolite, dFdU, by cytidine deaminase (CDA) and into the active metabolite, dFdCMP, by deoxycytidine kinase (dCK).• While the major contribution of CDA to gemcitabine elimination is well recognized no data about the role of CNT and ENT activities have yet been reported. Both nucleoside transporters exhibit genetic polymorphisms characterized by different expression levels or nucleoside affinity. WHAT THIS STUDY ADDS• The plasma clearance (CL) of gemcitabine has been determined following the standard 30 min infusion of 1000-1250 mg m -2 . The in vivo CDA activity was measured as end of infusion metabolic ratio (MR = dFdU : gembitabine) and the variant hCNT-1 and hENT-1 alleles were genotyped.• Our results confirmed that gemcitabine CL is directly correlated with CDA activity and inversely correlated with age and, for the first time, show that patients heterozygous for the -706 G > C hENT-1 mutation have a lower CL as compared with wild type patients. AIMGemcitabine (GEM) enters normal and tumour cells via concentrative (CNT) and equilibrative nucleoside transporters (ENT) and is subsequently deaminated to the inactive difluorodeoxyurine (dFdU) by cytidine deaminase (CDA). The aim of our study was to ascertain whether the nucleoside transporter genotype and the CDA activity phenotype can predict total GEM plasma clearance. METHODSForty-seven patients received GEM 1000-1250 mg m -2 i.v. over 30 min. Plasma concentrations of GEM and dFdU were measured and individual pharmacokinetic profiles were determined. CDA activity was measured ex vivo in plasma samples. The two most common hENT1 and hCNT1 polymorphisms were determined from genomic DNA. RESULTSMultivariate analysis revealed that GEM plasma clearance (CL) was positively correlated with the end of infusion dFdU : GEM ratio (P < 0.0001), which is a marker of in vivo CDA activity. The ENT1 genotype characterized by high transport capacity (G/G) and age were inversely correlated with CL (P = 0.027 and 0.048, respectively). A strong correlation was found between end of infusion GEM concentration and area under the concentration-time curve from time 0 to infinity (AUC(0,•)) (r 2 = 0.77). CONCLUSIONSOur results confirm the role of CDA and age on the interindividual variability of GEM CL and show the contribution of the hENT1 genotype for the first time.

Plant protection is essential for providing high-quality food in adequate quantities. However, the use of insecticides often induces adverse effects on environment and human health. The Agency for the Environmental Protection of Tuscany (Italy) arranges pesticide ingredients in five classes basing on their impact on human health. We classified the pesticide treatments carried out by 48 winegrowers of the Veneto Region (Italy) in relation to the active ingredients contained into the used pesticides over a three-year period (2015 e2017). It was found that the cost of insecticides and their class of impact were related, and that the cost's pressure led farmers to favor insecticides with active ingredients having a high negative impact on human health. The same active ingredients are used worldwide. We propose to implement taxation measures and subsidies to deter the use of the most harmful insecticides.