Publications by authors named "Krens L"

Background: Reproductive-aged women are, according to American and European guidelines, recommended to avoid pregnancy for 12-24 months after bariatric surgery. Oral contraceptives may have suboptimal efficacy after malabsorptive bariatric procedures.

Aim: The aim of this study was to assess contraceptive use pre- and postoperatively in women who underwent bariatric surgery in two obesity clinics in The Netherlands.

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EGFR-antibodies are associated with significant skin toxicity, including acneiform rash and folliculitis. It remains impossible to predict the occurrence of severe skin toxicity due to the lack of predictive markers. Here, we present the first genome-wide association study (GWAS) to find single nucleotide polymorphisms (SNPs) associated with EGFR inhibitor-induced skin toxicity using data of the multicentre randomized phase III CAIRO2 trial (clinicaltrials.

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Purpose: Data on panitumumab dosing in cancer patients with renal insufficiency are lacking. Here, we report a 63-year-old metastatic colorectal cancer patient with chronic kidney injury with a glomerular filtration rate of approximately 11 mL/min.

Methods: Pharmacokinetic parameters, including dose-normalized area under the curve, clearance and elimination half-life (T ) after the 11th and 12th infusions were estimated using trapezoidal non-compartmental methods.

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Introduction: Cetuximab is registered for use in colorectal cancer (CRC) patients with RAS wild-type tumours only. Simvastatin blocks the mevalonate pathway and thereby interferes with the post-translational modification (prenylation) of KRAS. We hypothesize that the activated KRAS pathway in KRAS mutant tumors can be inhibited by simvastatin rendering these tumors sensitive to the EGFR inhibitor cetuximab.

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Panitumumab has proven efficacy in patients with metastatic or locally advanced colorectal cancer patients, provided that they have no activating KRAS mutation in their tumour. Simvastatin blocks the mevalonate pathway and thereby interferes with the post-translational modification of KRAS. We hypothesize that the activity of the RAS-induced pathway in patients with a KRAS mutation might be inhibited by simvastatin.

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Statins may inhibit the expression of the mutant KRAS phenotype by preventing the prenylation and thus the activation of the KRAS protein. This study was aimed at retrospectively evaluating the effect of statin use on outcome in KRAS mutant metastatic colorectal cancer patients (mCRC) treated with cetuximab. Treatment data were obtained from patients who were treated with capecitabine, oxaliplatin bevacizumab ± cetuximab in the phase III CAIRO2 study.

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Introduction: In the literature, data on the effect of renal impairment on the pharmacokinetics of anticancer drugs are scarce. Here, we report a 68-year-old metastatic osteosarcoma patient with impaired renal function due to prior chemotherapy, who was treated on compassionate use basis with 400 mg/m(2) cetuximab.

Material And Methods: Pharmacokinetic parameters after the first dose, including dose-normalised AUC from time zero to day 7, clearance, elimination half-life (t(1/2)), were estimated using trapezoidal non-compartmental methods and compared to pharmacokinetic data from a study population with normal kidney function.

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Purpose: Panitumumab is used for the treatment for metastatic RAS wild-type colorectal cancer (mCRC). It is likely that many of these patients will present with liver metastases and some with liver dysfunction. The pharmacokinetics in patients with hepatic impairment has not been investigated, and dosage adjustments are undetermined.

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Epidermal growth factor receptor (EGFR) inhibitors, such as the monoclonal antibodies cetuximab and panitumumab, have proven efficacy in various types of cancer. However, these agents frequently result in skin toxicity, due to the expression of the EGFR in the skin. A correlation between the occurrence of skin toxicity and anti-tumor activity has been suggested in several phase III studies.

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Background: Currently, only Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutational status is used as a decisional marker for epidermal growth factor receptor (EGFR) inhibitor therapy in colorectal cancer (CRC) patients. Concordance of KRAS status between primary tumors and metastases has always been considered to be close to perfect; however, cases of discordance have been reported. The actual rate of concordance of KRAS status remains unclear, as is the same for v-raf murine sarcoma viral oncogene homolog B1 (BRAF), phosphatidylinositol 3-kinase CA subunit (PIK3CA), and loss of phosphatase and tensin homologue deleted on chromosome ten (PTEN).

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KRAS has an important role in colorectal carcinogenesis and mutant KRAS leads to a permanently activated k-ras protein. To exert its biological activity, k-ras requires post-translational modification by prenylation. K-ras modulation has become a promising concept for new therapies, mostly by interference with the mevalonate pathway and subsequently by the prenylation of k-ras.

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