Dramatic efficacy of vemurafenib in both multisystemic and refractory Erdheim-Chester disease and Langerhans cell histiocytosis harboring the BRAF V600E mutation.

Histiocytoses are rare disorders of unknown origin with highly heterogeneous prognosis. BRAFV600E gain-of-function mutations have been observed in 57% of cases of Langerhans cell histiocytosis (LCH) and 54% of cases of Erdheim-Chester disease (ECD), but not in other types of histiocytoses. Targeted therapy with an inhibitor of mutated BRAF (vemurafenib) improves survival of patients with melanoma.

Detection of BRAF p.V600E mutations in melanomas: comparison of four methods argues for sequential use of immunohistochemistry and pyrosequencing.

BRAF p.V600 mutation detection recently became necessary to treat metastatic melanoma patients with vemurafenib. This study compares different methods of detection of BRAF mutations.

Linear quantification of lymphoid infiltration of the tumor margin: a reproducible method, developed with colorectal cancer tissues, for assessing a highly variable prognostic factor.

Background: Lymphoid infiltration is a prognostic marker in solid tumors, such as colorectal, breast and lung carcinomas. However, lymphoid infiltration is heterogeneous and the reproducibility of quantification based on single counts within a tumor is very low. We aimed to develop a reproducible method for evaluating lymphoid infiltration in tumors.

Effects of endoplasmic reticulum stressors on maturation and signaling of hemizygous and heterozygous wild-type and mutant forms of KIT.

Gain of function mutations of KIT are frequent in some human tumors, and are sensible to tyrosine kinase inhibitors. In most tumors, oncogenic mutations are heterozygous, however most in vitro data of KIT activation have been obtained with hemizygous mutation. This study aimed to investigate the maturation and activation of wild-type (WT) and mutant (M) forms of KIT in hemizygous and heterozygous conditions.

Colorectal neuroendocrine carcinomas and adenocarcinomas share oncogenic pathways. A clinico-pathologic study of 12 cases.

Objective: Neuroendocrine carcinomas (NECs) are rare neoplasms with an increasing incidence. Oncogenetic pathways of colorectal NEC are still poorly understood, and no treatment standards are available for these rare tumors.

Methods: We analyzed retrospectively the clinical records and histology of 12 patients with colorectal NEC.

High prevalence of BRAF V600E mutations in Erdheim-Chester disease but not in other non-Langerhans cell histiocytoses.

Histiocytoses are rare disorders of unknown origin with highly heterogeneous prognosis. BRAF mutations have been observed in Langerhans cell histiocytosis (LCH). We investigated the frequency of BRAF mutations in several types of histiocytoses.

Prognostic value of BRAF(V⁶⁰⁰) mutations in melanoma patients after resection of metastatic lymph nodes.

Purpose: BRAF (V600) mutations are frequent in melanomas, and BRAF(V600)-targeted therapy have dramatic, but often transitory, efficacy in stage IV patients. Prognosis of patients with American Joint Committee on Cancer (AJCC) stage III melanoma is heterogeneous. We aimed to determine the overall survival (OS) of stage III patients with a nodal deposit of ≥2 mm according to BRAF (V600) mutations and other previously reported prognostic criteria.

Outcome of patients with platelet-derived growth factor receptor alpha-mutated gastrointestinal stromal tumors in the tyrosine kinase inhibitor era.

Purpose: Platelet-derived growth factor receptor-alpha (PDGFRA) mutations are found in approximately 5% to 7% of advanced gastrointestinal stromal tumors (GIST). We sought to extensively assess the activity of imatinib in this subgroup.

Experimental Design: We conducted an international survey among GIST referral centers to collect clinical data on patients with advanced PDGFRA-mutant GISTs treated with imatinib for advanced disease.

Levels of gemcitabine transport and metabolism proteins predict survival times of patients treated with gemcitabine for pancreatic adenocarcinoma.

Background & Aims: Patients who undergo surgery for pancreatic ductal adenocarcinoma (PDAC) frequently receive adjuvant gemcitabine chemotherapy. Key determinants of gemcitabine cytotoxicity include the activities of the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), and ribonucleotide reductase subunit 1 (RRM1). We investigated whether tumor levels of these proteins were associated with efficacy of gemcitabine therapy following surgery.

B-RAF mutant alleles associated with Langerhans cell histiocytosis, a granulomatous pediatric disease.

Background: Langerhans cell histiocytosis (LCH) features inflammatory granuloma characterised by the presence of CD1a+ dendritic cells or 'LCH cells'. Badalian-Very et al. recently reported the presence of a canonical (V600E)B-RAF mutation in 57% of paraffin-embedded biopsies from LCH granuloma.

Competitive allele specific TaqMan PCR for KRAS, BRAF and EGFR mutation detection in clinical formalin fixed paraffin embedded samples.

Background: The development of targeted therapies has created a need for robust molecular characterization of cancer and it has become a challenge to validate methods to ensure accuracy in tumor mutation testing.

Methods: The current study was designed to evaluate KRAS, BRAF and EGFR genotyping by Competitive Allele Specific hydrolysis probes (TaqMan) PCR technology (CAST), on suboptimal formalin fixed paraffin embedded (FFPE) tumor samples. Assays were calibrated on FFPE samples and a minimal quantification cycle (Cq) cut-off was determined to standardize analyses and avoid over-interpretation of degraded material.

A mild form of SLC29A3 disorder: a frameshift deletion leads to the paradoxical translation of an otherwise noncoding mRNA splice variant.

We investigated two siblings with granulomatous histiocytosis prominent in the nasal area, mimicking rhinoscleroma and Rosai-Dorfman syndrome. Genome-wide linkage analysis and whole-exome sequencing identified a homozygous frameshift deletion in SLC29A3, which encodes human equilibrative nucleoside transporter-3 (hENT3). Germline mutations in SLC29A3 have been reported in rare patients with a wide range of overlapping clinical features and inherited disorders including H syndrome, pigmented hypertrichosis with insulin-dependent diabetes, and Faisalabad histiocytosis.

Defective mismatch repair status as a prognostic biomarker of disease-free survival in stage III colon cancer patients treated with adjuvant FOLFOX chemotherapy.

Purpose: Adding oxaliplatin to adjuvant 5-fluorouracil (5-FU) chemotherapy improves 3-year disease-free survival (DFS) after resection of stage III colon cancer. Several studies suggest that patients with tumors exhibiting defective mismatch repair (MMR) do not benefit from adjuvant 5-FU chemotherapy, but there are few data on 5-FU-oxaliplatin (FOLFOX) adjuvant chemotherapy in this setting. The aim of this study was to evaluate the prognostic value of MMR status for DFS in patients with stage III colon cancer receiving adjuvant FOLFOX chemotherapy.

Management of gastrointestinal stromal tumours of limited size: proposals from a French panel of physicians.

A number of guidelines on the management of gastro-intestinal stromal tumours (GISTs) have been published, mostly based on expert consensus. However, these guidelines have generally failed to address the specific problem of GISTs of limited size (i.e.

[HER2 and gastric cancer. Recommendations for clinical practice in 2011].

Trastuzumab in combination with capecitabine or 5-fluorouracil and cisplatin has been approved by the European Medicines Agency (EMEA) for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive (immunohistochemistry [IHC] 3+ or IHC 2+/ fluorescence in situ hybridization [FISH]-positive or IHC 2+/ silver in situ hybridization [SISH]-positive) metastatic adenocarcinoma of the stomach or gastro-esophageal (GE) junction. HER2 testing in gastric cancer (GC) differs from testing in breast cancer (BC) due to major differences in the tumor biology; as the disease is progressing rapidely, we recommend to test every GC at diagnosis and to offer a rapid testing (less than five days) in the metastatic setting. IHC should be the initial testing methodology and FISH or SISH should be used to retest IHC 2+ samples.

Alternatively spliced NKp30 isoforms affect the prognosis of gastrointestinal stromal tumors.

The natural killer (NK) cell receptor NKp30 is involved in the recognition of tumor and dendritic cells (DCs). Here we describe the influence of three NKp30 splice variants on the prognosis of gastrointestinal sarcoma (GIST), a malignancy that expresses NKp30 ligands and that is treated with NK-stimulatory KIT tyrosine kinase inhibitors. Healthy individuals and those with GIST show distinct patterns of transcription of functionally different NKp30 isoforms.

Langerhans' cell histiocytosis of the liver in adults.

Among adults, liver involvement is relatively frequent in Langerhans' cell histiocytosis (LCH), even though it is often overlooked. In fact, the liver involvement may be missed in apparently localized LCH or when it is the sole site of involvement. We present 23 cases of liver involvement in LCH out of a cohort study of 85 adult patients included in the French Histiocytosis Study Group Registry.

Evaluation of predictive models in daily practice for the identification of patients with Lynch syndrome.

The optimal strategy for identifying patients with Lynch syndrome among patients with newly diagnosed colorectal cancer (CRC) is still debated. Several predictive models (e.g.

Attenuated immunochemotherapy regimen (R-miniCHOP) in elderly patients older than 80 years with diffuse large B-cell lymphoma: a multicentre, single-arm, phase 2 trial.

Background: Diffuse large B-cell lymphoma is a common cancer in elderly patients. Although treatment has been standardised in younger patients, no prospective study has been done in patients over 80 years old. We aimed to investigate the efficacy and safety of a decreased dose of CHOP (doxorubicin, cyclophosphamide, vincristine, and prednisone) chemotherapy with a conventional dose of rituximab in elderly patients with diffuse large B-cell lymphoma.

A quality control program for mutation detection in KIT and PDGFRA in gastrointestinal stromal tumours.

Background: Although most gastrointestinal stromal tumours (GIST) carry oncogenic mutations in KIT exons 9, 11, 13 and 17, or in platelet-derived growth factor receptor alpha (PDGFRA) exons 12, 14 and 18, around 10% of GIST are free of these mutations. Genotyping and accurate detection of KIT/PDGFRA mutations in GIST are becoming increasingly useful for clinicians in the management of the disease.

Method: To evaluate and improve laboratory practice in GIST mutation detection, we developed a mutational screening quality control program.

Germline CYBB mutations that selectively affect macrophages in kindreds with X-linked predisposition to tuberculous mycobacterial disease.

Germline mutations in CYBB, the human gene encoding the gp91(phox) subunit of the phagocyte NADPH oxidase, impair the respiratory burst of all types of phagocytes and result in X-linked chronic granulomatous disease (CGD). We report here two kindreds in which otherwise healthy male adults developed X-linked recessive Mendelian susceptibility to mycobacterial disease (MSMD) syndromes. These patients had previously unknown mutations in CYBB that resulted in an impaired respiratory burst in monocyte-derived macrophages but not in monocytes or granulocytes.

Discontinuation of imatinib in patients with advanced gastrointestinal stromal tumours after 3 years of treatment: an open-label multicentre randomised phase 3 trial.

Background: The effect of imatinib discontinuation on progression-free survival and overall survival in long-lasting responders with advanced gastrointestinal stromal tumours (GIST) is unknown. We assessed treatment interruption in patients with non-progressive disease according to the Response Evaluation Criteria In Solid Tumors criteria after 3 years of imatinib in a randomised trial.

Methods: In this open-label national multicentre phase 3 study in France, patients with GIST free of progression after 3 years of imatinib 400 mg/day were randomly assigned to continue or interrupt imatinib.

Juvenile xanthogranuloma with hematological dysfunction treated with 2CDA-AraC.

Juvenile xanthogranuloma was diagnosed in two infants aged 8 and 2 months with skin lesions, hepatosplenomegaly, and pancytopenia. Disease control was not achieved with first-line vinblastine-steroid-VP16 combination therapy. Two courses of 2-chlorodeoxyadenosine (2CDA) (0.