Thierry Lecomte

Analysis of PTEN, BRAF, and EGFR Status in Determining Benefit From Cetuximab Therapy in Wild-Type KRAS Metastatic Colon Cancer

PURPOSE The occurrence of KRAS mutation is predictive of nonresponse and shorter survival in patients treated by anti-epidermal growth factor receptor (anti-EGFR) antibody for metastatic colorectal cancer (mCRC), leading the European Medicine Agency to limit its use to patients with wild-type KRAS tumors. However, only half of these patients will benefit from treatment, suggesting the need to identify additional biomarkers for cetuximab-based treatment efficacy. PATIENTS AND METHODS We retrospectively collected tumors from 173 patients with mCRC. All but one patient received a cetuximab-based regimen as second-line or greater therapy. KRAS and BRAF status were assessed by allelic discrimination. EGFR amplification was assessed by chromogenic in situ hybridization and fluorescent in situ hybridization, and the expression of PTEN was assessed by immunochemistry. RESULTS In patients with KRAS wild-type tumors (n = 116), BRAF mutations (n = 5) were weakly associated with lack of response (P = .063) but were strongly associated with shorter progression-free survival (P < .001) and shorter overall survival (OS; P < .001). A high EGFR polysomy or an EGFR amplification was found in 17.7% of the patients and was associated with response (P = .015). PTEN null expression was found in 19.9% of the patients and was associated with shorter OS (P = .013). In multivariate analysis, BRAF mutation and PTEN expression status were associated with OS. CONCLUSION BRAF status, EGFR amplification, and cytoplasmic expression of PTEN were associated with outcome measures in KRAS wild-type patients treated with a cetuximab-based regimen. Subsequent studies in clinical trial cohorts will be required to confirm the clinical utility of these markers.

Presentation and Long-Term Follow-up of Refractory Celiac Disease: Comparison of Type I With Type II

BACKGROUND & AIMS Refractory celiac disease (RCD) was recently subdivided into 2 subtypes (RCD I and II) based on a normal or abnormal phenotype of intraepithelial lymphocytes (IELs), respectively. It is not clear, however, if these 2 entities differ in their presentation at diagnosis or long-term outcome. We compared the clinical and biological characteristics of RCD I and RCD II at diagnosis, the risk of developing an overt lymphoma, and the predictive factors of survival. METHODS Medical files of 14 patients with RCD I and 43 with RCD II were analyzed retrospectively. Predictive factors of overt lymphoma and survival were studied in univariate and multivariate analyses. RESULTS At diagnosis, malnutrition, ulcerative jejunitis, and lymphocytic gastritis were more common in patients with RCD II than RCD I (P< .05). Overt lymphomas occurred in 2 patients with RCD I and 16 with RCD II. In the univariate analysis, abnormal IEL phenotype and increased age at diagnosis of RCD were predictive factors for overt lymphoma. Abnormal IEL phenotype (P< .01), clonality (P= .01), and overt lymphoma (P= .001) predicted short survival time. Only abnormal IEL phenotype (P= .03) and overt lymphoma (P= .04) were predictive in the multivariate analysis. The 5-year survival rate was 93% in patients with RCD I and 44% with RCD II. CONCLUSIONS RCD II has a much more severe presentation and prognosis than patients with RCD I; <44% of patients with RCD II survive 5 years after diagnosis. Abnormal IEL phenotype is a predictive factor but not a necessary condition for the development of overt lymphoma.

Thymidylate Synthase Gene Polymorphism Predicts Toxicity in Colorectal Cancer Patients Receiving 5-Fluorouracil-based Chemotherapy

Purpose: The target enzyme for 5-fluorouracil (5-FU) is thymidylate synthase (TS). The TYMS gene encoding this enzyme is polymorphic, having either double (2R) or tri-tandem (3R) repeats of a 28-bp sequence in the promoter region and a 6-bp variation in the 3′-untranslated region (3′-UTR). TS expression predicts response to 5-FU-based chemotherapy, and the expression seems to be determined by the TYMS gene promoter. The aim of this study was to investigate the utility of determining these two TYMS gene polymorphisms to predict the toxicity and efficacy of 5-FU treatment in patients with colorectal cancer. Experimental Design: The determination of TYMS genotypes was performed in tumor and normal tissues by PCR amplification from 90 patients with colorectal cancer who were treated with adjuvant or palliative 5-FU-based chemotherapy. Associations between polymorphisms in the TYMS promoter and in the 3′-UTR gene and clinical outcome of these 90 patients treated with 5-FU based chemotherapy were evaluated individually. The linkage between TYMS promoter and TYMS 3′-UTR region polymorphisms was evaluated and a haplotype analysis was performed. Results: Individuals who were homozygous for the double repeat in the TYMS promoter region had more severe side effects to 5-FU. Patients with a 2R/2R, a 2R/3R, or a 3R/3R genotype had a grade 3 or 4 toxicity rate of 43, 18, and 3% respectively (P < 0.01). The TYMS promoter and TYMS 3′-UTR polymorphisms were in linkage disequilibrium, and the haplotype 2R/ins 6-bp was significantly associated with a high risk of severe side effects to 5-FU. The TYMS promoter and TYMS 3′-UTR polymorphisms were not associated with a response to 5-FU and survival of patients who received palliative 5-FU-based chemotherapy. Conclusions: This study demonstrated that TYMS genotyping could be of help in predicting toxicity to 5-FU-based chemotherapy. TYMS genotyping might make it possible to individualize treatment for patients with colorectal cancer.

Glutathione S-Transferase P1 Polymorphism (Ile105Val) Predicts Cumulative Neuropathy in Patients Receiving Oxaliplatin-Based Chemotherapy

Purpose: Glutathione S-transferases (GST) are xenobiotic metabolizing enzymes involved in the detoxification of a variety of chemotherapeutic drugs, including platinum derivatives. Genetic polymorphisms of GSTs have been associated with enzyme activity variations. Thus, a study was done to investigate the relationship between GST polymorphisms and oxaliplatin-related cumulative neuropathy in gastrointestinal cancer patients treated with oxaliplatin-based chemotherapy. Experimental Design: Ninety patients were included. Clinical neurologic evaluation was done at baseline and before each cycle of treatment. We determined genetic variants for GSTP1 exon 5 (Ile105Val), GSTP1 exon 6 (Ala114Val), GSTM1 (homozygous deletion), and GSTT1 (homozygous deletion). We conducted analyses in a subgroup of 64 patients receiving a minimal cumulative dose of 500 mg/m2 of oxaliplatin to examine whether the GST polymorphisms are associated with oxaliplatin-related cumulative neuropathy. Results: Among patients receiving a minimal cumulative dose of 500 mg/m2 of oxaliplatin, 15 patients showed clinically evident oxaliplatin-related cumulative neuropathy scored grade 3 according to an oxaliplatin-specific scale. The oxaliplatin-related cumulative neuropathy scored grade 3 was significantly more frequent in patients homozygous for the GSTP1 105Ile allele than in patients homozygous or heterozygous for the GSTP1 105Val allele (odds ratio, 5.75; 95% confidence interval, 1.08-30.74; P = 0.02). No association was found with respect to any of the GSTM1, GSTT1, or GSTP1 exon 6 genotypes. Conclusions: The results of the current study suggest that the 105Val allele variant of the GSTP1 gene at exon 5 confers a significantly decreased risk of developing severe oxaliplatin-related cumulative neuropathy.

Geriatric Factors Predict Chemotherapy Feasibility: Ancillary Results of FFCD 2001-02 Phase III Study in First-Line Chemotherapy for Metastatic Colorectal Cancer in Elderly Patients

PURPOSE Elderly patients form a heterogeneous population. Evaluation of geriatric factors may help evaluate a patients health status to better adapt treatment. PATIENTS AND METHODS Elderly patients with previously untreated metastatic colorectal cancer (mCRC) were randomly assigned to receive fluorouracil (FU) -based chemotherapy either alone or in combination with irinotecan (IRI) in the Fédération Francophone de Cancérologie Digestive (FFCD) 2001-02 study. Sites participating in the geriatric substudy completed geriatric screening tools to perform prognostic factor analyses for treatment safety during the first 4 months after treatment initiation. RESULTS The geriatric score was calculated in 123 patients (44%). Median age was 80 years (range, 75 to 91 years). The Charlson comorbidity index was ≤ 1 in 75%, Mini-Mental State Examination (MMSE) score was ≤ 27/30 in 31%, and Instrumental Activities of Daily Living (IADL) showed impairment in 34% of the patients. Seventy-one patients (58%) had grade 3 to 4 toxicity, 41 (33%) had a dose-intensity reduction of more than 33%, and 54 (44%) had at least one unexpected hospitalization during the first 4 months after starting treatment. In multivariate analysis, significant predictive factors for grade 3-4 toxicity were IRI arm (odds ratio [OR], 5.03), MMSE ≤ 27/30 (OR, 3.84), and impaired IADL (OR, 4.67); for dose-intensity reduction of > 33%, the significant predictive factors were alkaline phosphates > 2 × upper limit of normal (OR, 4.16) and IRI arm (OR, 6.85); and for unexpected hospitalization, significant predictive factors were MMSE ≤ 27/30 (OR, 4.56) and Geriatric Depression Scale ≤ 2 (OR, 5.52). CONCLUSION Geriatric factors (MMSE and IADL) are predictive of severe toxicity or unexpected hospitalization (MMSE) in a randomized prospective phase III study in mCRC. These results suggest that cognitive function and autonomy impairment should be taken into account when choosing a regimen for chemotherapy.

An enzyme-linked immunosorbent assay for therapeutic drug monitoring of cetuximab.

An enzyme-linked immunosorbent assay (ELISA) measuring serum infliximab concentrations in treated patients was developed. Microtiter plates were sensitized with tumor necrosis factor α (TNF-α) and saturated with phosphate-buffered saline (PBS) containing 1% bovine serum albumin (BSA). Samples diluted 1:100 in PBS-1% BSA were added and bound infliximab was detected using peroxidase-conjugated goat anti-human immunoglobulin G specific for Fc fragment (HRP-anti hIgG). Reading was performed using an ELISA plate reader. The limit of detection, calculated by assaying 10 replicates of a drug-free serum sample or blank sample and defined as the lowest concentration distinguishable from zero at 2 standard deviations, was 0.014 μg/mL. Each quality control sample was tested on 7 occasions on 1 day and on 5 separate days. The intraday precision indices of the method were (percent coefficients of variation, CV%) 11.7%, 6.2%, and 6.9% for 0.04 μg/mL, 2 μg/mL, and 4.5 μg/mL, respectively. The corresponding bias measures (percent deviation) were −5.5%, −1.9%, and −7.9%, respectively. The between-days precision was 9.8%, 5.3%, and 5.3% for 0.04 μg/mL, 2 μg/mL, and 4.5 μg/mL, respectively. The corresponding bias were +0.3%, −0.3%, and −7.8%, respectively. Lower limit of quantitation and upper limit of quantitation were 0.04 μg/mL and 4.5 μg/mL, respectively. Trough serum concentrations of infliximab were measured in 6 adult patients with various diseases and in 5 pediatric patients with Crohns disease. For the latter group, samples drawn 1 hour after the end of the infusion and repeated measurements also were available. Data were described using a 1-compartment population pharmacokinetic model. Terminal elimination half-life was 10.9 days. This method is rapid, accurate, and reproducible, and may be useful in therapeutic drug monitoring of infliximab.

Chromoendoscopic Colonoscopy for Detecting Preneoplastic Lesions in Hereditary Nonpolyposis Colorectal Cancer Syndrome

BACKGROUND & AIMS In hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, flat and small adenomas are particularly prone to malignant transformation but might be missed by standard colonoscopy. We prospectively studied the diagnostic yield of high-resolution colonoscopy coupled with chromoendoscopy for preneoplastic and neoplastic colorectal lesions in patients with HNPCC syndrome. METHODS Thirty-six consecutive asymptomatic patients (mean age, 42 years) belonging to HNPCC families and receiving genetic counseling were enrolled in this prospective study. Colonoscopy was performed in 2 steps. Conventional colonoscopy was performed first, followed by a second colonoscopy with chromoendoscopy with indigo carmine (.4%) dye sprayed onto the entire proximal colon. RESULTS Conventional colonoscopy identified 25 lesions (mean size, 4 +/- 3 mm) in 13 patients. Seven lesions, detected in 5 patients, were adenomas, 3 of which were located in the proximal colon. Chromoendoscopy identified additional 45 lesions (mean size, 3 +/- 1 mm) in 20 patients; most of these lesions were flat and hyperplastic. Eleven additional adenomas were detected in the proximal colon of 8 patients, and 8 of these 11 lesions were flat. The use of chromoendoscopy significantly increased the detection rate of adenomas in the proximal colon, from 3 of 33 patients to 10 of 33 patients (P = .045). CONCLUSION Relative to conventional colonoscopy, high-resolution colonoscopy with chromoendoscopy markedly improves the detection of adenomas in patients with HNPCC syndrome and might help to prevent colorectal carcinoma in these patients with a very high risk of colorectal cancer.

Effect of low-frequency KRAS mutations on the response to anti-EGFR therapy in metastatic colorectal cancer

BACKGROUND Only patients with wild-type (WT) KRAS tumors benefit from anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (Mabs) in metastatic colorectal cancer (mCRC). Pyrosequencing is now widely used for the determination of KRAS mutation burden and a conservative cut-off point of 10% has been defined. Up until now, the impact of low-frequency KRAS mutations (<10%) on the response to anti-EGFR Mabs has yet to be evaluated. PATIENTS AND METHODS Tumors from patients receiving anti-EGFR Mabs based on a WT genotype for KRAS, as determined using direct sequencing, have been retrospectively analyzed by pyrosequencing. Patients were categorized as WT (no KRAS mutation) or low-frequency mutation when KRAS mutation was <10% (KRAS low MT). RESULTS A total of 168 patients treated by anti-EGFR Mabs for mCRC were analyzed. According to pyrosequencing, 138 tumors remained KRAS WT, while 30 tumors were KRAS low MT. In the KRAS low MT and KRAS WT groups, the response rates were 6.7% and 37.0%, respectively, while stabilization amounted to 23.3% versus 32.6% and progression to 70% versus 29% (P < 0.01). Progression-free survival (PFS) was 2.7 ± 0.5 months for KRAS low MT and was 6.0 ± 0.3 months for KRAS WT (P < 0.01). CONCLUSIONS These results appear to validate consideration of low-frequency KRAS mutation tumors as positive, and justify a large-scale prospective study.

Effets vasculaires et rénaux des médicaments anti-angiogéniques : recommandations françaises pour la pratique (SN, SFHTA, APNET, FFCD)

Angiogenesis inhibitor drugs (bevacizumab, sunitinib, sorafénib...) are now widely used for treatment of cancers, including colorectal, advanced renal cell and hepatocellular carcinomas, breast cancer). Vascular and renal side-effects of these drugs are not well known. Hypertension is one of the most common side effects. Incidence of hypertension may be different among angiogenis inhibitors and seems dose-depend. Arterial pressure can usually be controlled with anti-hypertensive medications, and treatment with angiogenesis inhibitors can be continued in most cases; however, serious hypertension-induced side effects were reported included malignant hypertension, stroke and reversible posterior leucoencephalopathy. Renal damage is infrequently reported: usually reversible mild or moderate proteinuria and in some rare cases nephritic syndrome, acute renal dysfunction, proliferative or collapsing glomerulonephritis, interstitial nephritis and thrombotic microangiopathy. Prolongation of the QT interval, congestive heart failure and left ventricular dysfunction have been reported in patients using tinibs. In the present guidelines, we recommend: (1) before the first administration of angiogenesis inhibitors: acute IV or oral antihypertensive medications should not be administered in a patient regardless of arterial pressure levels with postponing the administration because of hypertension is not recommended; (2) initial work-up should include ambulatory measurement of arterial pressure (by the general practitioner or by the patient using home blood pressure (three times in the morning and in the evening during three consecutive days) with a validated (cf: http://afssaps.sante.fr/) upper arm device: ideally, this device should be financed and provided by the pharmaceutical companies marketing the angiogenesis inhibitor drugs. Using 24-hour ambulatory blood pressure measurement is optional; (3) urine dipstick (and quantification if positive) and estimated glomerular filtration rate (using abbreviated MDRD rather than Cockcroft-Gault formula) must be performed before treatment and regularly during follow-up; (4) therapeutic management must be done in accordance with national or international guidelines (in France: http://www.has-sante.fr/); (5) optimal care is best achieved within a network of professionals including general practitioners, oncologists, cardiologists and nephrologists.

Circulating free tumor DNA and colorectal cancer.

Cancer is characterized by multiple somatic genetic and epigenetic alterations that could be useful as molecular markers for detecting tumor DNA in different bodily fluids. In patients with various diseases as well as in healthy subjects, circulating plasma and serum carry small amounts of non-cell-bound DNA. In this free circulating DNA, tumor-associated molecular alterations can be detected in patients who have cancer. In many instances, the alterations identified are the same as those found in the primary tumor tissue, thereby suggesting tumor origin from a fraction of the circulating free DNA. In fact, various types of DNA alterations described in colorectal cancer have been detected in the circulating free DNA of patients with colorectal cancer. These alterations include KRAS2, APC and TP53 mutations, DNA hypermethylation, microsatellite instability (MSI) and loss of heterozygosity (LOH). Also, advances in polymerase chain reaction (PCR)-based technology now allow the detection and quantification of extremely small amounts of tumor-derived circulating free DNA in colorectal cancer patients. The present report summarizes the literature available so far on the mechanisms of circulating free DNA, and on the studies aimed at assessing the clinical and biological significance of tumor-derived circulating free DNA in colorectal cancer patients. Thus, tumor-derived circulating free DNA could serve as a marker for the diagnosis, prognosis and early detection of recurrence, thereby significantly improving the monitoring of colorectal cancer patients.