Performance of Next-Generation Sequencing for the Detection of Microsatellite Instability in Colorectal Cancer With Deficient DNA Mismatch Repair.

BACKGROUND & AIMS: Next-generation sequencing (NGS) was recently approved by the United States Food and Drug Administration to detect microsatellite instability (MSI) arising from defective mismatch repair (dMMR) in patients with metastatic colorectal cancer (mCRC) before treatment with immune checkpoint inhibitors (ICI). In this study, we aimed to evaluate and improve the performance of NGS to identify MSI in CRC, especially dMMR mCRC treated with ICI. METHODS: CRC samples used in this post hoc study were reassessed centrally for MSI and dMMR status using the reference methods of pentaplex polymerase chain reaction and immunohistochemistry. Whole-exome sequencing (WES) was used to evaluate MSISensor, the Food and Drug Administration-approved and NGS-based method for assessment of MSI. This was performed in (1) a prospective, multicenter cohort of 102 patients with mCRC (C1; 25 dMMR/MSI, 24 treated with ICI) from clinical trials NCT02840604 and NCT033501260, (2) an independent retrospective, multicenter cohort of 113 patients (C2; 25 mCRC, 88 non-mCRC, all dMMR/MSI untreated with ICI), and (3) a publicly available series of 118 patients with CRC from The Cancer Genome Atlas (C3; 51 dMMR/MSI). A new NGS-based algorithm, namely MSICare, was developed. Its performance for assessment of MSI was compared with MSISensor in C1, C2, and C3 at the exome level or after downsampling sequencing data to the MSK-IMPACT gene panel. MSICare was validated in an additional retrospective, multicenter cohort (C4) of 152 patients with new CRC (137 dMMR/MSI) enriched in tumors deficient in MSH6 (n = 35) and PMS2 (n = 9) after targeted sequencing of samples with an optimized set of microsatellite markers (MSIDIAG). RESULTS: At the exome level, MSISensor was highly specific but failed to diagnose MSI in 16% of MSI/dMMR mCRC from C1 (4 of 25; sensitivity, 84%; 95% confidence interval [CI], 63.9%-95.5%), 32% of mCRC (8 of 25; sensitivity, 68%; 95% CI, 46.5%-85.1%), and 9.1% of non-mCRC from C2 (8 of 88; sensitivity, 90.9%; 95% CI, 82.9%-96%), and 9.8% of CRC from C3 (5 of 51; sensitivity, 90.2%; 95% CI, 78.6%-96.7%). Misdiagnosis included 4 mCRCs treated with ICI, of which 3 showed an overall response rate without progression at this date. At the exome level, reevaluation of the MSI genomic signal using MSICare detected 100% of cases with true MSI status among C1 and C2. Further validation of MSICare was obtained in CRC tumors from C3, with 96.1% concordance for MSI status. Whereas misdiagnosis with MSISensor even increased when analyzing downsampled WES data from C1 and C2 with microsatellite markers restricted to the MSK-IMPACT gene panel (sensitivity, 72.5%; 95% CI, 64.2%-79.7%), particularly in the MSH6-deficient setting, MSICare sensitivity and specificity remained optimal (100%). Similar results were obtained with MSICare after targeted NGS of tumors from C4 with the optimized microsatellite panel MSIDIAG (sensitivity, 99.3%; 95% CI, 96%-100%; specificity, 100%). CONCLUSIONS: In contrast to MSISensor, the new MSICare test we propose performs at least as efficiently as the reference method, MSI polymerase chain reaction, to detect MSI in CRC regardless of the defective MMR protein under both WES and targeted NGS conditions. We suggest MSICare may rapidly become a reference method for NGS-based testing of MSI in CRC, especially in mCRC, where accurate MSI status is required before the prescription of ICI.

Overexpression of IgG2 in patients resembling IgG4-related disease with normal IgG4.

IgG4-Related Disease (IgG4-RD) results from tissue infiltration by IgG4-expressing plasma cells and lymphocytes, leading to fibrosis and organomegaly. Clinical presentation is remarkably variable according to organ involvement, and high IgG4 serum concentration, initially considered a diagnostic hallmark of IgG4-RD, tends to be forgone as an indispensable criterion for its diagnosis; it can indeed be absent in some patients, highlighting the diversity of presentation of this dysimmune condition. Nevertheless, elevation of IgG4 serum concentration in suggestive settings remains an argument in favour of IgG4-RD, and while other IgG subclasses can be elevated, this biological feature lacks any diagnostic value. We retrospectively studied 9 patients (5 females, 4 males, 31-81 years old) for whom a diagnosis of IgG4-RD had been considered, based on clinical, imaging or histological criteria, but appeared to display abnormally high serum IgG2 while IgG4 levels were normal. Increased serum IgG1 in one case and increased IgG3 in another one were also noticed. Immunohistochemical analyses of intracellular immunoglobulins could be performed on tissue lymph node biopsies from 2 patients, which demonstrated strong infiltration with IgG2-expressing plasma cells. Thus, overexpression of IgG2 subclass may highlight cases of dysimmune disorders resembling IgG4-RD, although the disease trigger might be different, notably infectious. We suggest measuring all serum IgG subclass levels in patients with features consistent with IgG4-RD.

Combination of brentuximab-vedotin and ifosfamide, carboplatin, etoposide in relapsed/refractory peripheral T-cell lymphoma.

OBJECTIVES: Relapsed/refractory peripheral T-cell lymphomas (PTCL) have a poor prognosis. We aimed at assessing efficacy of ifosfamide, carboplatin, etoposide (ICE) regimen, a known therapeutic option, to which we added brentuximab-vedotin (BV). METHODS: In this study, we retrospectively analyzed patients with PTCL treated with BV-ICE in our center between July 2014 and March 2018. RESULTS: Fourteen patients received BV-ICE. Median age was 62 years (range, 31-73). Main histological subtypes were PTCL-not otherwise specified (29%), angioimmunoblastic T-cell lymphoma (21%), follicular-T helper (21%), or anaplastic large-cell (15%) lymphomas, all were CD30 positive. Overall response was seen in four (29%) patients, and complete response (CR) in two (14%). Most frequent adverse events were infections, and cytopenia. 2-year progression-free and overall survival were 14% and 17.5%, respectively. CONCLUSION: Patients with relapsed/refractory PTCL treated with BV-ICE can achieve CR, but few had a sustained response. This association should preferably be used as a bridge to stem cell transplant or be followed by maintenance therapy.

Prevalence of Microsatellite Instability in Intraductal Papillary Mucinous Neoplasms of the Pancreas.

Microsatellite instability (MSI) caused by mismatch repair deficiency (dMMR) is detected in a small proportion of pancreatic ductal adenocarcinomas (PDACs). dMMR and MSI have been associated with responses of metastatic tumors, including PDACs, to immune checkpoint inhibitor therapy. We performed immunohistochemical analyses of a 445 PDAC specimens, collected from consecutive patients at multiple centers, to identify those with dMMR, based on loss of mismatch repair proteins MLH1, MSH2, MSH6, and/or PMS2. We detected dMMR in 1.6% of tumor samples; we found dMMR in a larger proportion of intraductal papillary mucinous neoplasms-related tumors (4/58, 6.9%) than non- intraductal papillary mucinous neoplasms PDAC (5/385, 1.3%) (P = .02). PDACs with dMMR contained potentially immunogenic mutations because of MSI in coding repeat sequences. PDACs with dMMR or MSI had a higher density of CD8+ T cells at the invasive front than PDACs without dMMR or MSI (P = .08; Fisher exact test). A higher proportion of PDACs with dMMR or MSI expressed the CD274 molecule (PD-L1, 8/9) than PDACs without dMMR or MSI (4/10) (P = .05). Times of disease-free survival and overall survival did not differ significantly between patients with PDACs with dMMR or MSI vs without dMMR or MSI. Studies are needed to determine whether these features of PDACs with dMMR or MSI might serve as prognostic factors.

BRAF-Mutated Colorectal Cancer: What Is the Optimal Strategy for Treatment?

OPINION STATEMENT: The BRAF activating mutation, harbored by approximately 10% of colorectal cancers (CRC), confers dramatic prognosis to advanced diseases. In early-stage setting, the identification of the BRAF mutation does not impact the therapeutic decision. Yet, the BRAF mutation could be considered as a stratification factor in adjuvant trials, because of its prognostic impact after relapse. Moreover, both BRAF mutation and mismatch repair (MMR) statuses should be determined in all CRC to help identify sporadic tumors versus Lynch syndrome-related tumors. Indeed, in patients with MMR-deficient (dMMR) tumors and MLH1 loss of expression, the BRAFV600E mutation indicates a sporadic origin. In advanced BRAF-mutated CRC, the standard of care remains fluoropyrimidine-based cytotoxic regimen in combination with bevacizumab. Although a recent meta-analysis showed that there was insufficient data to justify the exclusion of anti-EGFR monoclonal antibodies, antiangiogenic agents should be preferred in the first-line setting. Despite the lack of a randomized phase 3 study dedicated to BRAF-mutated CRC, chemotherapy intensification combining a quadruple association of 5-fluorouracil, oxaliplatin, irinotecan (FOLFOXIRI), and bevacizumab seems like a valid option. Although first results with BRAF inhibitors as single agents in BRAF-mutated CRC were disappointing, their association with therapies targeting the MAPK pathway seems to overcome the primary resistance to BRAF inhibition. In the field of sporadic CRC, the BRAF mutation is strongly associated with MMR deficiency. Considering breakthrough results of immune checkpoint inhibitors in dMMR repair tumors, determination of the MMR status appears to be mandatory. Given the dramatic prognosis conferred by the BRAF mutation, patients with BRAF-mutated advanced CRC need to be systematically identified and proposed for clinical trial enrolment in order to benefit from innovative therapies.

HSP110 T17 simplifies and improves the microsatellite instability testing in patients with colorectal cancer.

BACKGROUND: Every colorectal cancer (CRC) patient should be tested for microsatellite instability (MSI, a marker for defective DNA mismatch repair) as a first screen for Lynch syndrome (LS). In this study, we investigated whether it may be possible to improve the detection of MSI in CRC. We examined whether the HT17 DNA repeat (critical for correct splicing of the chaperone HSP110) might constitute a superior marker for diagnosis of the MSI phenotype in patients with CRC compared with the standard panel of markers (pentaplex). METHODS: The HT17 polymorphism was analysed in germline DNA from 1037 multi-ethnic individuals. We assessed its sensitivity and specificity for detecting MSI in a multicentre, population-based cohort of 685 patients with CRC and an additional series of 70 patients with CRC considered to be at-risk of LS. All cases were screened earlier for MSI using pentaplex markers. Cases showing discordant HT17/pentaplex results were further examined for the expression of mismatch repair proteins. RESULTS: HT17 status was analysed independently and blinded to previous results from pentaplex genotyping. HT17 showed no germline allelic variation outside a very narrow range. Compared with the pentaplex panel, HT17 showed better sensitivity (0.984 (95% CI 0.968 to 0.995) vs 0.951 (95% CI 0.925 to 0.972)) and similar specificity (0.997 (95% CI 0.989 to 1.000) for both) for the detection of MSI. Furthermore, HT17 alone correctly classified samples judged to be uncertain with the pentaplex panel and showed excellent ability to detect MSI in patients with LS. CONCLUSIONS: HT17 simplifies and improves the current standard molecular methods for detecting MSI in CRC.

Liver biopsy for diagnosis of presumed benign hepatocellular lesions lacking magnetic resonance imaging diagnostic features of focal nodular hyperplasia.

BACKGROUND & AIMS: The contribution of liver biopsy for the diagnosis of presumed benign hepatocellular lesions lacking the diagnostic features of focal nodular hyperplasia (FNH) on magnetic resonance imaging (MRI) is unknown. We evaluated liver biopsy and MRI performances in this setting. METHODS: Magnetic resonance imaging and slides of liver biopsies performed for a presumed benign hepatocellular lesion (2006-2013) without the typical features of FNH on MRI were blindly reviewed (n = 45). Eighteen lesions were surgically removed and also analyzed. The final diagnosis was the diagnosis established after surgery or on the biopsy in the absence of surgery. RESULTS: The final diagnosis was FNH (n = 19), hepatocellular adenoma (HCA, n = 15), hepatocellular carcinoma (n = 3) and indefinite (n = 4). Four lesions corresponded to non hepatocellular lesions. FNH, HNF1A mutated and inflammatory HCA were diagnosed accurately on the biopsy in 95%, 67% and 100% of the cases respectively. Diagnostic performance of liver biopsy for HNF1A mutated HCA was lower because of the lack of non-tumoral tissue. Diagnosis based on morphological analysis was certain and correct in 27 cases. Immunostaining allowed a definite diagnosis in 12 additionnal cases. Radiological diagnosis was in agreement with the histological diagnosis in 75.6% of the cases, with a very high sensitivity (97%) and specificity (100%) for the diagnosis of HNF1A mutated HCA. CONCLUSIONS: Liver biopsy has a good diagnostic performance particularly for FNH and inflammatory HCA, and sampling of non-lesional tissue is highly recommended. A biopsy does not seem necessary if H-HCA is diagnosed on MRI.

New Therapeutic Opportunities Based on DNA Mismatch Repair and BRAF Status in Metastatic Colorectal Cancer.

Recently, colorectal cancer (CRC) subtyping consortium identified four consensus molecular subtypes (CMS1-4). CMS1 is enriched for deficient mismatch repair (dMMR) and BRAF (V600E) tumors. Intriguingly, this subtype has better relapse-free survival but worse overall survival after relapse compared with the other subtypes. Growing evidence is accumulating on the benefit of specific therapeutic strategies such as immune checkpoint inhibition therapy in dMMR tumors and mitogen-activated protein kinase (MAPK) pathway targeted therapy in tumors harboring BRAF (V600E) mutation. After reviewing dMMR prognostic value, immune checkpoints as major targets for dMMR carcinomas will be highlighted. Following, BRAF (V600E) prognostic impact will be reviewed and therapeutic strategies with the combination of cytotoxic agents and especially the combinations of BRAF and MAPK inhibitors will be discussed.

Gemcitabine and oxaliplatin with or without cetuximab in advanced biliary-tract cancer (BINGO): a randomised, open-label, non-comparative phase 2 trial.

BACKGROUND: Gemcitabine plus a platinum-based agent (eg, cisplatin or oxaliplatin) is the standard of care for advanced biliary cancers. We investigated the addition of cetuximab to chemotherapy in patients with advanced biliary cancers. METHODS: In this non-comparative, open-label, randomised phase 2 trial, we recruited patients with locally advanced (non-resectable) or metastatic cholangiocarcinoma, gallbladder carcinoma, or ampullary carcinoma and a WHO performance status of 0 or 1 from 18 hospitals across France and Germany. Eligible patients were randomly assigned (1:1) centrally with a minimisation procedure to first-line treatment with gemcitabine (1000 mg/m(2)) and oxaliplatin (100 mg/m(2)) with or without cetuximab (500 mg/m(2)), repeated every 2 weeks until disease progression or unacceptable toxicity. Randomisation was stratified by centre, primary site of disease, disease stage, and previous treatment with curative intent or adjuvant therapy. Investigators who assessed treatment response were not masked to group assignment. The primary endpoint was the proportion of patients who were progression-free at 4 months, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00552149. FINDINGS: Between Oct 10, 2007, and Dec 18, 2009, 76 patients were assigned to chemotherapy plus cetuximab and 74 to chemotherapy alone. 48 (63%; 95% CI 52-74) patients assigned to chemotherapy plus cetuximab and 40 (54%; 43-65) assigned to chemotherapy alone were progression-free at 4 months. Median progression-free survival was 6·1 months (95% CI 5·1-7·6) in the chemotherapy plus cetuximab group and 5·5 months (3·7-6·6) in the chemotherapy alone group. Median overall survival was 11·0 months (9·1-13·7) in the chemotherapy plus cetuximab group and 12·4 months (8·6-16·0) in the chemotherapy alone group. The most common grade 3-4 adverse events were peripheral neuropathy (in 18 [24%] of 76 patients who received chemotherapy plus cetuximab vs ten [15%] of 68 who received chemotherapy alone), neutropenia (17 [22%] vs 11 [16%]), and increased aminotransferase concentrations (17 [22%] vs ten [15%]). 70 serious adverse events were reported in 39 (51%) of 76 patients who received chemotherapy plus cetuximab (34 events in 19 [25%] patients were treatment-related), whereas 41 serious adverse events were reported in 25 (35%) of 71 patients who received chemotherapy alone (20 events in 12 [17%] patients were treatment-related). One patient died of atypical pneumonia related to treatment in the chemotherapy alone group. INTERPRETATION: The addition of cetuximab to gemcitabine and oxaliplatin did not seem to enhance the activity of chemotherapy in patients with advanced biliary cancer, although it was well tolerated. Gemcitabine and platinum-based combination should remain the standard treatment option. FUNDING: Institut National du Cancer, Merck Serono.

Perilipin deficiency and autosomal dominant partial lipodystrophy.

Perilipin is the most abundant adipocyte-specific protein that coats lipid droplets, and it is required for optimal lipid incorporation and release from the droplet. We identified two heterozygous frameshift mutations in the perilipin gene (PLIN1) in three families with partial lipodystrophy, severe dyslipidemia, and insulin-resistant diabetes. Subcutaneous fat from the patients was characterized by smaller-than-normal adipocytes, macrophage infiltration, and fibrosis. In contrast to wild-type perilipin, mutant forms of the protein failed to increase triglyceride accumulation when expressed heterologously in preadipocytes. These findings define a novel dominant form of inherited lipodystrophy and highlight the serious metabolic consequences of a primary defect in the formation of lipid droplets in adipose tissue.

Hepatic molecular effects of rosiglitazone in human non-alcoholic steatohepatitis suggest long-term pro-inflammatory damage.

AIM: Glitazones are agonists of peroxisome proliferator-activated receptor-γ (PPAR-γ) and have been proposed for the treatment of non-alcoholic steatohepatitis (NASH). However, efficacy results are conflicting and hepatic molecular changes induced by glitazones are mostly unknown. The aim of this study was to analyze the hepatic inflammatory and fibrogenic molecular effects of rosiglitazone in NASH patients. METHODS: Hepatic expression of PPAR-γ and several inflammatory/immune and fibrogenic genes were studied before and after a 12-month treatment with rosiglitazone or placebo in 25 patients with NASH from the Fatty Liver Improvement with Rosiglitazone Therapy (FLIRT) trial. RESULTS: Treatment with rosiglitazone induced hepatic PPAR-γ expression but increased the expression of several pro-inflammatory genes such as SOCS3 and TLR4. There was a significant reduction in mRNA and protein levels of α-smooth muscle actin, compatible with previously documented antifibrotic actions of rosiglitazone on stellate cells. However, there was no change in type 1 collagen and transforming growth factor-ß expression thus suggesting an offset of the antifibrogenic actions by long-term pro-inflammatory changes. CONCLUSION: In NASH patients, hepatic PPAR-γ induction by rosiglitazone was associated with increased hepatic expression of pro-inflammatory genes which may explain the lack of long-term histological benefit shown in human studies with this drug. It is unclear whether these results are a class effect of PPAR-γ agonists or a specific effect of rosiglitazone.

Inflammatory/juvenile-like polyps in neurofibromatosis type 1 associated with epithelial dysplasia.

The term "juvenile-like (inflammatory/hyperplastic) mucosal polyps" (JLIHMP) has been recently introduced to describe a spectrum of polypoid lesions in patients with neurofibromatosis type 1 (NF-1). Due to the scarce number of reported cases and histopathological similarities with entities such as sporadic/syndromic juvenile polyps or inflammatory fibroid polyps, this entity remains a subject of debate. We describe herein a case of multiple JLIHMPs in a patient with NF-1, and we document the presence of low-grade dysplasia within one of these polyps.

Survival Outcomes in Patients with Monobloc-Resected Stage IIC (pT4bN0) Colon Cancer: A Retrospective Observational Cohort Study.

BACKGROUND: Stage II colon cancer (CC) exhibits considerable prognostic heterogeneous. Our objective was to assess survival but also the prognosis impact of microsatellite instability (MSI) in patients with stage IIC (T4bN0M0) CC. PATIENTS AND METHODS: We conducted a retrospective observational study including all patients who had primary stage IIC CC resection between 2010 and 2020 in 2 expert centers. The primary endpoint was overall survival (OS) and disease-free survival (DFS) and time-to-relapse (TTR) were secondary endpoints. RESULTS: Sixty-six patients, median age of 74 years [30-95], were included, with 37.9% presenting MSI (n = 25). Organ invasion involved the last ileal loop (n = 17), another colonic segment (n = 15), omentum (n = 13), visceral peritoneum (n = 13), and the bladder (n = 4). Surgical quality criteria showed complete monobloc resection in all patients and 93.9% R0 resection. After a median follow-up of 5 years [3.5-6.6], the entire population showed a 5-year OS of 65.2% [53.0-80.3] and 5-year DFS of 53.5% [41.1-69.6], with 18.9% [6.8-29.4] experiencing relapses at 5 years. The MSI phenotype correlated with improved 5-year OS (75.5% [56.5-100] vs. 59.5% [44.9-79.0], HR 0.41 [0.17-0.99]; P = .04), but DFS and TTR did not differ. Adjuvant chemotherapy was administered to 34.9% of patients. Univariate analysis identified age > 65 years, MSI status, and the number of nodes as factors associated with OS. CONCLUSION: These data underline, in relation to a low rate of relapse, the lack of consensus regarding the appropriate indication for adjuvant chemotherapy in this high-risk stage II population.

Adipokine profile in glucocorticoid-treated patients: baseline plasma leptin level predicts occurrence of lipodystrophy.

CONTEXT: Glucocorticoid therapy may result in adipose tissue redistribution of unknown pathophysiology. OBJECTIVES: To evaluate the effects of glucocorticoids on adipokine levels and adipose tissue inflammation. To compare the results in patients with or without glucocorticoid-induced lipodystrophy (GIL) after 3 months of therapy. DESIGN AND SETTING: Prospective monocentric study. PATIENTS: Adult patients initiating systemic, high-dose prednisone therapy for at least 3 months. Blood samples and subcutaneous abdominal adipose tissue biopsies were collected at baseline and month 3. The presence of GIL after 3 months of therapy was assessed using standardized photography. RESULTS: Thirty-two patients were enrolled. Blood samples and subcutaneous abdominal adipose tissue were available at baseline and month 3 for 30 patients [median age: 61 (38-79) years, 77% women]. Among those 30 patients, 15 were classified as GIL+ and 15 were GIL- at month 3. Between baseline and month 3, adiponectin and leptin levels increased in the overall population while the level of resistin remained unchanged. At baseline, leptin level was higher [19.3 (8.3-31.1) vs 4.5 (2.4-11.3) µg/l, P = 0.006] and resistin level lower [7.1 (6.3-12.4) vs 10.4 (8.0-21.7) µg/l, P = 0.05] in GIL+ than in GIL- patients. Baseline leptin level was predictive of GIL occurrence. Receiver operating characteristic curve analysis demonstrated that the best diagnostic accuracy was obtained with a baseline leptin cut-off of 5.9 µg/l (sensitivity: 93%, specificity: 60%). At month 3, leptin and adiponectin levels increased more in the GIL+ than in the GIL- group, as did the number of anti-inflammatory M2 macrophages in subcutaneous abdominal fat. CONCLUSION: Glucocorticoid-induced lipodystrophy is associated with a different adipokine profile both before and after glucocorticoid therapy. Serum leptin level prior to glucocorticoid therapy is highly predictive of GIL occurrence.

[Targeting HER2 in colorectal cancer]. / Cibler HER2 dans le cancer colorectal.

Among the molecular subgroups of interest in metastatic colorectal cancer (mCRC), innovations are underway for tumors with overexpression of HER2 (Human Epidermal Growth Factor Receptor 2). Overexpression of the HER2 protein concerns 2 to 5% of CRC at any stage mainly located in the distal colon and rectum. Diagnosis is based on immunohistochemistry, in situ hybridization with appropriate criteria for colorectal localization, and molecular biology (NGS: next-generation sequencing). Overexpression of HER2 is a predictive factor for resistance to treatments targeting EGFR which are indicated in the case where the tumor is wild-type RAS. It seems to be associated with a poor prognosis of mCRC with a higher risk of brain metastasis. Regarding treatments targeting HER2, no randomized controlled phase III has been published to date. However, several combinations have been evaluated in phase II with clinically meaningful objective response rates: trastuzumab-deruxtecan (45%), trastuzumab-tucatinib (46%), trastuzumab-pyrotinib (45%), trastuzumab-pertuzumab (30%) ou trastuzumab-lapatinib (30%). In this literature review, we present here the current state of knowledge on the diagnostic methods of HER2 overexpression in CRC, the main clinical, molecular and prognostic characteristics, and the efficacy results of the different therapeutic combinations for the patients with HER2 overexpressed mCRC. This justifies, despite the lack of marketing authorization in France and in Europe for agents targeting HER2 in CRC, the systematic evaluation of the HER2 status, as recommended in particular by the NCCN (National Comprehensive Cancer Network).

LMNA mutations induce a non-inflammatory fibrosis and a brown fat-like dystrophy of enlarged cervical adipose tissue.

Some LMNA mutations responsible for insulin-resistant lipodystrophic syndromes are associated with peripheral subcutaneous lipoatrophy and faciocervical fat accumulation. Their pathophysiologic characteristics are unknown. We compared histologic, immunohistologic, ultrastructural, and protein expression features of enlarged cervical subcutaneous adipose tissue (scAT) obtained during plastic surgery from four patients with LMNA p.R482W, p.R439C, or p.H506D mutations versus cervical fat from eight control subjects, buffalo humps from five patients with HIV infection treated or not with protease inhibitors, and dorsocervical lipomas from two patients with mitochondrial DNA mutations. LMNA-mutated cervical scAT and HIV-related buffalo humps were dystrophic, with an increased percentage of small adipocytes, increased fibrosis without inflammatory features, and decreased number of blood vessels, as compared with control samples. Samples from patients with LMNA mutations or protease inhibitor-based therapy demonstrated accumulation of prelamin A, altered expression of adipogenic proteins and brown fat-like features, with an increased number of mitochondria and overexpression of uncoupling protein 1 (UCP1). These features were absent in samples from control subjects and from patients with HIV not treated with protease inhibitors. Mitochondrial DNA-mutated cervical lipomas demonstrated inflammatory fibrosis with distinct mitochondrial abnormalities but neither UCP1 expression nor prelamin A accumulation. In conclusion, Enlarged cervical scAT from patients with lipodystrophy demonstrated small adipocytes, fibrosis, and decreased vessel numbers. However, only cervical fat from patients with LMNA mutations or who had received protease inhibitor therapy accumulated prelamin A and exhibited similar remodeling toward a brown-like phenotype with UCP1 overexpression and mitochondrial alterations.

Brain IGF-1 receptors control mammalian growth and lifespan through a neuroendocrine mechanism.

Mutations that decrease insulin-like growth factor (IGF) and growth hormone signaling limit body size and prolong lifespan in mice. In vertebrates, these somatotropic hormones are controlled by the neuroendocrine brain. Hormone-like regulations discovered in nematodes and flies suggest that IGF signals in the nervous system can determine lifespan, but it is unknown whether this applies to higher organisms. Using conditional mutagenesis in the mouse, we show that brain IGF receptors (IGF-1R) efficiently regulate somatotropic development. Partial inactivation of IGF-1R in the embryonic brain selectively inhibited GH and IGF-I pathways after birth. This caused growth retardation, smaller adult size, and metabolic alterations, and led to delayed mortality and longer mean lifespan. Thus, early changes in neuroendocrine development can durably modify the life trajectory in mammals. The underlying mechanism appears to be an adaptive plasticity of somatotropic functions allowing individuals to decelerate growth and preserve resources, and thereby improve fitness in challenging environments. Our results also suggest that tonic somatotropic signaling entails the risk of shortened lifespan.

Changing pathology with changing drugs: tumors of the gastrointestinal tract.

Gastrointestinal cancer treatment is being based more and more on pathology that yields integrated information leading to targeted therapy, i.e. morphological identification of the histological type of the tumor and its context, staging of the tumor, and identification of various targets. This provides a realistic appraisal of the tumor and allows surgeons and oncologists to choose the best treatment from an increased range of drug options. An accurate diagnosis remains the major determinant of treatment, but new drugs and new insights into molecular pathways acting in carcinogenesis enhance molecular diagnosis in cancer. In most adenocarcinomas, therapy is only organ orientated and staging dependent, and not patient targeted. Currently, the identification and validation of new targets as well as molecular classification of the tumors are inducing the incorporation of new tests into the daily practice of surgical pathology. These new tests require appropriate tissue preservation and selection of the tissue to be analyzed and harmonized to morphological criteria. In colorectal adenocarcinoma, which is the second most common malignant tumor in both genders, the biomarkers that are relevant at the present time are the genetic instability status of the tumor, the KRAS mutation status as a negative predictive marker for the overall rate of response to anti-EGFR treatment in patients with metastatic cancer, and BRAF mutation as an unfavorable prognostic marker. In gastric adenocarcinoma, HER2 overexpression is correlated with poor outcomes and more aggressive disease in a subset of cases with clinical response to trastuzumab. Met mutations have also been evidenced. Hepatocellular carcinoma is a highly chemoresistant tumor with several genetic alterations. Pancreatic adenocarcinoma is a leading cause of cancer death with frequent KRAS mutations. No biomarker has been clearly identified in either of these tumors. Gastrointestinal stromal tumors that constitute less than 3% of all gastrointestinal malignancies have been individualized since 1988. They express the KIT protein, a membrane receptor, and respond to imatinib which is a tyrosine kinase receptor inhibitor, depending on the mutational status of the tumor.

Testing for ROS1, ALK, MET, and HER2 rearrangements and amplifications in a large series of biliary tract adenocarcinomas.

Biliary tract carcinomas are divided into intrahepatic, perihilar, distal extrahepatic cholangiocarcinomas, and gallbladder adenocarcinomas. Therapies targeting ROS1, ALK, MET, and HER2 alterations are currently evaluated in clinical trials. We assessed ROS1 and ALK translocations/amplifications as well as MET and HER2 amplifications for each tumor subtype by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) in 73 intrahepatic, 40 perihilar bile duct, 36 distal extrahepatic cholangiocarcinomas, and 45 gallbladder adenocarcinomas (n = 194). By FISH, we detected targetable alterations in 5.2% of cases (n = 10): HER2 and MET amplifications were found in 4.1% (n = 8) and 1.0% (n = 2), respectively. The HER2-amplified cases were mostly gallbladder adenocarcinomas (n = 5). The MET- and HER2-amplified cases were all positive by IHC. Fourteen cases without MET amplification were positive by IHC, whereas HER2 over-expression was detected by IHC only in HER2-amplified cases. We detected no ALK or ROS1 translocation or amplification. Several alterations were consistent with aneuploidy: 24 cases showed only one copy of ROS1 gene, 4 cases displayed a profile of chromosomal instability, and an over-representation of centromeric alpha-satellite sequences was found in five cases. We confirm a relatively high rate of HER2 amplifications in gallbladder adenocarcinomas and the efficacy of IHC to screen these cases. Our results also suggest the value of IHC to screen MET amplification. Contrary to initial publications, ROS1 rearrangements seem to be very rare in biliary tract adenocarcinomas. We confirm a relatively high frequency of aneuploidy and chromosomal instability and reveal the over-representation of centromeric alpha-satellite sequences in intrahepatic cholangiocarcinomas.