Tumour response and safety of cetuximab in a window pre-operative study in patients with squamous cell carcinoma of the head and neck.

BACKGROUND: To investigate the safety and activity of cetuximab in the pre-operative treatment of squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Cetuximab was administered for 2 weeks before surgery to 33 treatment-naïve patients selected for primary surgical treatment. Tumour biopsies, 2-[fluorine-18]-fluoro-2-deoxy-d-glucose positron emission tomography ((18)FDG-PET) and imaging were carried out at baseline and before surgery. The primary aim of the study was safety and the secondary aims included metabolical, radiological and pathological tumour response. Five untreated patients were included as controls. RESULTS: Cetuximab given 24 h before surgery was safe. Ninety percent of patients had (18)FDG-PET partial response (EORTC guideline) in the cetuximab group versus 0% in the control group. Delta maximal standardized uptake values (ΔSUVmax) were correlated with tumour cellularity on the surgical specimens (P < 0.0001). For patients with ΔSUVmax less than -25% or less than -50%, Ki67 was significantly decreased by cetuximab (P = 0.01 and 0.003). Cetuximab induced down-regulation of pEGFR (P = 0.0004) and pERK (P = 0.003). CONCLUSIONS: Short-course pre-operative administration of cetuximab is safe and shows a high rate of (18)FDG-PET response. (18)FDG-PET response was correlated with residual tumour cellularity suggesting that (18)FDG-PET deserves further investigation as a potential early marker of cetuximab activity in SCCHN.

Mutations in the glucokinase regulatory protein gene in 2p23 in obese French caucasians.

AIMS/HYPOTHESIS: Glucokinase regulatory protein (GKRP) controls the activity of glucokinase in liver but possibly also in some areas of the central nervous system, suggesting that it could play a role in body mass control. Its gene is located in a region (2p21-23) linked to serum leptin levels. Our goal was to investigate whether mutations in the GKRP gene were associated with obesity. METHODS: Mutations were sought in the GKRP gene of 57 patients from the families of the French genome-wide scan for obesity that contributed most to the positive LOD score with 2p21-23. The identified mutations were further sought in 720 unrelated obese individuals and 384 individuals of normal weight and their effect on the properties of recombinant GKRP were investigated. RESULTS: The most frequent mutation (Pro446Leu) had a similar allele frequency in the obese (0.63) and normal weight (0.64) subjects and did not affect the properties of GKRP. Similarly, no effect on the properties of GKRP was observed with Arg590Tyr, found in 10 out of 720 obese subjects and in 2 out of 384 control subjects (p=0.18). Mutation Arg227Stop was found in one obese family and in 1 out of 384 control subjects and led to an insoluble protein. Mutation Arg518Gln, replacing a conserved residue, led to a marked decrease in the affinity of GKRP for both fructose 6-phosphate and fructose 1-phosphate and to a destabilization of GKRP. However, this mutation did not co-segregate with obesity in the single family in which it was found. CONCLUSIONS/INTERPRETATION: Mutations that affect the properties of GKRP are found in the French population, but they do not seem to account for the linkage between the 2p23 locus and quantitative markers of obesity.