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.

Aims To verify whether fluorouracil (FU) clearance (CL) and volume of distribution (V ss ) are better correlated with specific body compartments, such as body cell mass (BCM), total body water (TBW) or fat free mass (FFM), rather than with body surface area (BSA) or total body weight (BW). Methods Thirty-four patients (13 females and 21 males) affected by colorectal cancer and receiving FU as adjuvant therapy entered the study. CL and V ss were determined after a 2 min i.v. injection of FU (425 mg m x2 ) and leucovorin (20 mg m x2 ). Body composition, in terms of BCM, TBW and FFM, was evaluated non-invasively by bioelectrical impedance analysis (BIA). Results Significant but poor correlations were found between CL or V ss and most anthropometric parameters, including BIA-derived measures (r 2 range=0.10-0.21). However, when multiple regression analysis was performed with sex, TBW and FFM as independent variables, the correlations improved greatly. The best correlation was obtained between CL and sex (r 2 =0.44) and between V ss and sex (r 2 =0.36). FFMnormalized CL was significantly higher in women than in men (0.030t0.008 vs 0.022t0.005 l min x1 kg x1 ; 95% CI of difference 0.012, 0.003; P=0.003),suggesting that FU metabolism is more rapid in females. Surprisingly, V ss was highly correlated with CL (r 2 =0.67; CL=0.52+V ss r0.040). This finding may either be explained by extensive drug metabolism in extra-hepatic organs or by variable inactivation on first-pass through the lung. Both these hypotheses need experimental validation. Conclusions The pharmacokinetics of FU are better predicted by FFM and TBW than by standard anthropometric parameters and predictions are sex-dependent. The use of BIA may lead to improved dosing with FU.

Twenty-two advanced consecutive thyroid cancer patients with varying histologies were treated with the so called BAP regime which consisted of bleomycin (B) 30 mg a day for three days, adriamycin (A) 60 mg/m2 iv in day 5, and cisplatinum (P) 60 to mg/m2 iv in day 5. Patients with progressive, symptomatic recurrent or disseminated disease unresponsive to hormonal and/or isotopic treatment were eligible. Nine patients had an objective response: two long-lasting complete and seven partial responses were observed out of 21 evaluable patients. Stable disease was observed in four additional patients. The median duration of response was 12 months (range, 6-29). The total series experienced a median survival of 11 months (range, 1 to 57), with 2 patients actually disease free. Several histologic types of thyroid carcinoma responded, but the best responses were observed in medullary and anaplastic giant-cell carcinomas. Toxicity was reversible in all but one patient. Of the patients failing on BAP chemotherapy three responded to a four drug second line combination containing vincristine, fluorouracil, BCNU and methotrexate. BAP regime can achieve reasonable palliation, and probably increases survival, in poor-prognosis thyroid cancers.

A method for calculating the initial 5-FU dose is proposed which takes into account patient BW, gender and a target AUC of 596 mg x min/l. Nevertheless, it appears that a substantial part of 5-FU toxicity is not linked to pharmacokinetic factors and dose adjustments must still be on the basis of careful clinical surveillance.

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