Direct Targeting KRAS Mutation in Non-Small Cell Lung Cancer: Focus on Resistance.

KRAS is the most frequently mutated oncogene in non-small cell lung cancers (NSCLC), with a frequency of around 30%, and encoding a GTPAse that cycles between active form (GTP-bound) to inactive form (GDP-bound). The KRAS mutations favor the active form with inhibition of GTPAse activity. KRAS mutations are often with poor response of EGFR targeted therapies. KRAS mutations are good predictive factor for immunotherapy. The lack of success with direct targeting of KRAS proteins, downstream inhibition of KRAS effector pathways, and other strategies contributed to a focus on developing mutation-specific KRAS inhibitors. KRAS p.G12C mutation is one of the most frequent KRAS mutation in NSCLC, especially in current and former smokers (over 40%), which occurs among approximately 12-14% of NSCLC tumors. The mutated cysteine resides next to a pocket (P2) of the switch II region, and P2 is present only in the inactive GDP-bound KRAS. Small molecules such as sotorasib are now the first targeted drugs for KRAS G12C mutation, preventing conversion of the mutant protein to GTP-bound active state. Little is known about primary or acquired resistance. Acquired resistance does occur and may be due to genetic alterations in the nucleotide exchange function or adaptative mechanisms in either downstream pathways or in newly expressed KRAS G12C mutation.

Molecular Mechanism of EGFR-TKI Resistance in EGFR-Mutated Non-Small Cell Lung Cancer: Application to Biological Diagnostic and Monitoring.

Non-small cell lung cancer (NSCLC) is the most common cancer in the world. Activating epidermal growth factor receptor (EGFR) gene mutations are a positive predictive factor for EGFR tyrosine kinase inhibitors (TKIs). For common EGFR mutations (Del19, L858R), the standard first-line treatment is actually third-generation TKI, osimertinib. In the case of first-line treatment by first (erlotinib, gefitinib)- or second-generation (afatinib) TKIs, osimertinib is approved in second-line treatment for patients with T790M EGFR mutation. Despite the excellent disease control results with EGFR TKIs, acquired resistance inevitably occurs and remains a biological challenge. This leads to the discovery of novel biomarkers and possible drug targets, which vary among the generation/line of EGFR TKIs. Besides EGFR second/third mutations, alternative mechanisms could be involved, such as gene amplification or gene fusion, which could be detected by different molecular techniques on different types of biological samples. Histological transformation is another mechanism of resistance with some biological predictive factors that needs tumor biopsy. The place of liquid biopsy also depends on the generation/line of EGFR TKIs and should be a good candidate for molecular monitoring. This article is based on the literature and proposes actual and future directions in clinical and translational research.

KRAS-specific Amino Acid Substitutions are Associated With Different Responses to Chemotherapy in Advanced Non-small-cell Lung Cancer.

BACKGROUND: Emerging data highlight different clinical behaviors according to KRAS amino acid substitutions (AASs) in patients with non-small-cell lung cancer (NSCLC). We aimed to evaluate whether different KRAS AASs were associated with different responses to chemotherapy. PATIENTS AND METHODS: We retrospectively reviewed data from 1190 patients with KRAS mutations who underwent first-line platinum-based chemotherapy for stage IV NSCLC. The response to different chemotherapy regimens was evaluated using the Response Evaluation Criteria In Solid Tumors criteria (v 1.1). Overall survival and time to progression (TTP) were secondary endpoints. RESULTS: Taxane was associated with the best response in the entire cohort (odds ratio, 2.52; 95% confidence interval [CI], 1.82-3.48; P < .001), especially in G12V patients (odds ratio, 2.15; 95% CI, 1.05-4.41; P = .036). Taxane was associated with improved TTP in the entire cohort (hazard ratio [HR], 0.31; 95% CI, 0.26-0.38; P < .001), especially in G13D patients (HR, 0.47; 95% CI, 0.22-1.01; P = .054). Pemetrexed was associated with the worst TTP in the entire cohort, particularly in G12V patients, who had the worst response rates (HR, 0.55; 95% CI, 0.30-0.99; P = .049). No impact on overall survival was observed according to different chemotherapy regimens and AASs. CONCLUSION: KRAS-specific AAS appears to induce different responses to chemotherapy regimens after first-line platinum-based chemotherapy in advanced NSCLC.

SNAI2 and TWIST1 in lymph node progression in early stages of NSCLC patients.

Lymph node metastasis is an important prognosis factor in non-small cell lung cancer (NSCLC) patients. The aim of this study was to investigate the role of epithelial to mesenchymal transition (EMT) in lymph node progression in the early stages of NSCLC. We studied a retrospective cohort of 160 consecutive surgically treated NSCLC patients with available frozen tumor samples for expression of EMT markers (CDH1, CTNNB1, CDH2, and VIMENTIN), inducers (TGFB1, c-MET, and CAIX), and transcription factors (EMT-TF: SNAI1, SNAI2, ZEB1, TWIST1, and TWIST2). Partial EMT was more frequent in N1-2 (N+) vs N0 patients (P < .01). TGFB1 (P = .02) as well as SNAI2 (P < .01) and TWIST1 (P = .04) were the most differentially expressed genes in N+ tumors. In this group, ZEB1 was correlated with all EMT inducers and other EMT-TFs were overexpressed depending on the inducers. CAIX was an independent prognostic factor for overall survival (IC 95% HR: 1.10-5.14, P = .03). Partial EMT is involved in lymph node progression of NSCLC patients and depends on the TGFß pathway. EMT-TFs are differentially expressed depending on EMT inducers. CAIX might be a relevant prognostic marker in early stage NSCLC.

Prognostic Value of Exon 19 Versus 21 EGFR Mutations Varies According to Disease Stage in Surgically Resected Non-small Cell Lung Cancer Adenocarcinoma.

BACKGROUND: The prognostic value of exon 19 and 21 EGFR mutations in stage IV non-small cell lung cancer (NSCLC) is well established. OBJECTIVE: We aimed to evaluate the prognostic value of the mutations in surgically resected NSCLC. METHODS: We retrospectively reviewed data from 1798 surgically resected NSCLC adenocarcinomas between 2007 and 2017 in three departments of thoracic surgery (Nancy/Strasbourg, France, and Torino, Italy) for whom mutational status was known. Overall survival (OS) was evaluated using log-rank and Cox proportional hazard models. RESULTS: EGFR exon 19 deletion was observed in 108 patients (55.1%) and exon 21 L858R mutations were observed in 88 patients (44.9%). In stage I, the median OS was not significantly different between exons 19 and 21 (p = 0.54), while, in stage II, the median OS reached 65 months [95% confidence interval (CI) 41.67-88.33] for exon 19 mutations and decreased to 48 months for exon 21 mutations (95% CI 44.21-51.79; p = 0.027). In multivariate analysis, exon 19 deletion remained a favorable prognostic factor [hazard ratio (HR) 0.314, 95% CI 0.098-0.997; p = 0.05]. In stage III, the median OS reached 66 months (95% CI 44.67-87.32) for exon 19 mutations and decreased to 32 months for exon 21 mutations (95% CI 29.86-34.14; p = 0.03). In multivariate analysis, exon 19 deletion remained a significantly favorable prognostic factor (HR 0.165, 95% CI 0.027-0.999; p = 0.05). CONCLUSION: The prognostic value of EGFR exon 19 and 21 mutations appears to be different according to disease stage in surgically resected NSCLC.

A compound heterozygote case of isolated sulfite oxidase deficiency.

We report an isolated sulfite oxidase deficiency in the first child boy of a non-consanguineous Caucasian family. He's a compound heterozygote for the sulfite oxidase gene, presenting low cystine, undetectable homocysteine and normal uric acid blood concentrations and undetectable sulfite oxidase activity in his cultured fibroblasts. Both mutations are not reported yet. The clinical presentation was typical and severe, with generalized status epilepticus and premature death.

Epidermal growth factor receptor mutations are linked to skip N2 lymph node metastasis in resected non-small-cell lung cancer adenocarcinomas.

Objectives: The impact of skip N2 metastases (i.e. N2 lymph node metastases without N1) on survival in surgically resected non-small lung cancer remains an intriguing and rarely investigated topic. The goal of our study was to elucidate (i) skip N2 influence on overall survival (OS) and time to recurrence (TTR) in patients with resected lung adenocarcinoma and (ii) its link with epidermal growth factor receptor ( EGFR ) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog ( KRAS ) mutations. Methods: A retrospective analysis of 279 consecutive patients with lung pN2 adenocarcinoma, operated in two institutions between 2003 and 2013, was conducted. OS and TTR were calculated using the Kaplan-Meier method. Crude and multivariable-adjusted comparisons by skip N2 for OS and TTR were performed using the Cox method with shared frailty (accounting for the within-centre correlation). Associations between skip N2 metastasis, clinicopathological characteristics and EGFR and KRAS mutations were investigated using the Fisher exact test and Cramér's V -test. Results: The mean age at the time of surgery was 63 years (±12), and the median follow-up time was 36 months (min 3; max 101). Skip N2 was observed in 54 patients (19%). EGFR mutations were observed in 38 patients (14%); KRAS mutations were seen in 86 patients (31%). Patients with skip N2 metastasis were predominantly non-smokers ( P = 0.001), underwent segmentectomy or limited resections ( P = 0.004) and were not submitted to adjuvant therapy ( P = 0.022). Moreover, there was a correlation between EGFR mutations and skip N2 (Cramér's V : 0.25, P < 0.001). Indeed, EGFR mutations were significantly more frequent in skip N2 tumours (33%) compared with non-skip tumours (10%), P < 0.001. No correlation between skip N2 and KRAS mutations was observed (Cramér's V : 0.05, P = 0.46). The multivariable-adjusted model showed a significant skip N2 protective effect on OS (hazard ratio, HR 0.503; P = 0.014; 95% confidence interval, CI: 0.291-0.8704) but not on TTR (HR 0.788; P = 0.446; 95% CI: 0.427-1.454). Conclusions: In our series, lung adenocarcinoma skip N2 metastasis demonstrated a favourable prognosis. The presence of EGFR mutations could have significance in the better survival and in the specific anatomic pathway of lymphatic metastases exhibited by skip N2 tumours.

Perioperative bevacizumab improves survival following lung metastasectomy for colorectal cancer in patients harbouring v-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue exon 2 codon 12 mutations†.

OBJECTIVES: The role of perioperative chemotherapy (POC) and targeted therapies in lung metastasectomy for colorectal cancer (CRC) is still subject to debate. We aimed to evaluate whether POC and targeted therapies were associated with different outcomes according to the mutational status. METHODS: We reviewed data from 223 patients who underwent pulmonary metastasectomy for CRC from 1998 to 2015 and for whom the V-Ki-ras2 Kirsten sarcoma viral oncogene homologue (KRAS) and V-raf Murine sarcoma viral oncogene homologue B1 (BRAF) mutational statuses were known. RESULTS: A total of 167 patients (74%) underwent POC: 62 (37%) received neoadjuvant therapy, 59 (35%) were in the adjuvant setting and 46 (28%) were in both the neoadjuvant and adjuvant settings. POC did not significantly influence either the loco-regional recurrence free survival (LRRFS) (P = 0.21) or the overall survival (OS) (P = 0.29). Furthermore, in cases of adjuvant chemotherapy, outcomes were not significantly different in cases of neoadjuvant chemotherapy or both neoadjuvant and adjuvant treatment (P = 0.26 for OS, P = 0.14 for LRRFS). For patients with KRAS mutation, perioperative bevacizumab was associated with a significant improvement in both LRRFS [70 months (41.58­98.42) vs 24 months (1.15­46.86), P = 0.001] and OS [101 vs 55 months (49.77­60.23), P = 0.004]. However, this benefit was only significant in cases of KRAS exon 2 codon 12 mutations [median OS: 101 months (83.97­118.02) vs 60 months (53­66.99), P < 0.001; median LRRFS: 76 months (64.62­87.38) vs 44 months (35.27­52.73), P < 0.001]. CONCLUSION: Perioperative bevacizumab appears to be beneficial in patients with exon 2 codon 12 KRAS mutations who have undergone lung metastasectomy for CRC.

Epidermal growth factor receptor and v-Ki-ras2 Kirsten rat sarcoma viral oncogen homologue-specific amino acid substitutions are associated with different histopathological prognostic factors in resected non-small-cell lung cancer.

OBJECTIVES: Epidermal growth factor receptor (mEGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogen homologue (mKRAS) mutations are the two main oncogenic drivers in resected non-small-cell lung cancer (NSCLC). We aimed to evaluate the correlation between histopathological prognostic factors and these mutations in resected NSCLC. METHODS: We retrospectively reviewed data from 841 patients who underwent a surgical resection with a curative intent for NSCLC between 2007 and 2012. RESULTS: KRAS mutations were observed in 255 patients (32%) and mEGFR in 103 patients (12%). A correlation was observed between mKRAS patients and lymph node involvement [Cramer's V: 0.451, P < 0.001, OR: 7.5 (95% CI: 5.3-10.7), P < 0.001]. Otherwise, a correlation was observed between mKRAS and the risk of harbouring 2 N2 stations [Cramer's V: 0.235, P = 0.02, OR: 3.04 (95% CI: 1.5-6.3), P = 0.004]. High lymph node ratio and angioinvasion were also significantly more frequent in mKRAS [Cramer's V: 0.373, P < 0.001, OR: 6.37 (95% CI: 3.9-10.5), P < 0.001; and Cramer's V: 0.269, P < 0.001, OR: 3.25 (95% CI: 2.4-4.4), P < 0.001, respectively]. Skip N2 and microscopic N2 were significantly more frequent in mEGFR [Cramer's V: 0.459, P < 0.001, OR: 18 (95% CI: 5.6-57.8), P < 0.001; and (Cramer's V: 0.45, P < 0.001 OR: 21.14 (95% CI: 9.2-48.3), P < 0.001, respectively]. CONCLUSIONS: We observed a correlation between mKRAS and negative histopathological prognostic factors and between mEGFR and positive prognostic factors. One can wonder whether histopathological prognostic factors are only clinical reflections of molecular alterations.

Specific KRAS amino acid substitutions and EGFR mutations predict site-specific recurrence and metastasis following non-small-cell lung cancer surgery.

BACKGROUND: We aimed to evaluate whether EGFR mutations (mEGFR) and KRAS amino acid substitutions can predict first site of recurrence or metastasis after non-small-cell lung cancer (NSCLC) surgery. METHODS: Data were reviewed from 481 patients who underwent thoracic surgery for NSCLC between 2007 and 2012. RESULTS: Patients with KRAS G12C developed significantly more bone metastases compared with the remainder of the cohort (59% vs 16%, P<0.0001). This was confirmed in multivariate analysis (MA) (odds ratio (OR): 0.113 (95% confidence interval (CI): 0.055-0.231), P<0.0001). Significantly, more patients with mEGFR developed liver and brain metastases compared with the remainder of the cohort (30% vs 10%, P=0.006; 59% vs 1%, P<0.0001, respectively). These were confirmed in MA (OR: 0.333 (95% CI: 0.095-0.998), P=0.05; OR: 0.032 (95% CI: 0.008-0.135), P<0.0001, respectively). Patients with KRAS G12V developed significantly more pleuro-pericardial metastases compared with the remainder of the cohort (94% vs 12%, P<0.0001). This was confirmed in MA (OR: 0.007 (95% CI: 0.001-0.031), P<0.0001). Wild-type patients developed significantly more lung metastases (35% vs 10%, P<0.0001). This was confirmed in MA (OR: 0.383 (95% CI: 0.193-0.762), P=0.006). CONCLUSION: Epidermal growth factor receptor mutation and KRAS amino acid substitutions seem to predict site-specific recurrence and metastasis after NSCLC surgery.

Clinical effect of molecular methods in sarcoma diagnosis (GENSARC): a prospective, multicentre, observational study.

BACKGROUND: Advances in molecular genetics of sarcoma have enabled the identification of type-specific aberrations. We aimed to assess the clinical effect of systematic implementation of molecular assays to improve sarcoma misdiagnosis. METHODS: In this multicentre, observational study, we recruited patients from 32 centres of the French Sarcoma Group/Reference Network in Pathology of Sarcomas. Eligibility criteria included: biopsy or surgical resection; suspicion of: dermatofibrosarcoma protuberans (cohort 1), dedifferentiated liposarcoma (cohort 2), Ewing's sarcoma family of tumours (cohort 3), synovial sarcoma (cohort 4), alveolar rhabdomyosarcoma (cohort 5), and myxoid or round cell liposarcoma (cohort 6); review by one sarcoma-expert pathologist; availability of frozen material (except for cohort 1 of patients with dermatofibrosarcoma protuberans because anti-CD34 immunohistochemistry is performed on paraffin-embedded tissue); and patient information. For each case, the pathologist made one primary diagnosis followed by up to two differential diagnoses, based on histological characteristics only. Each diagnosis was classified as certain, probable, or possible. For each case to determine the molecular classification, we did fluorescence in-situ hybridisation on paraffin-embedded samples. We also did comparative genomic hybridisation and quantitative PCR (cohort 2) or reverse transcriptase PCR (cohorts 3-6) on frozen and paraffin-embedded samples. We made a final diagnosis based on the molecular results. The clinical effect of diagnosis correction was assessed by a board of experts. FINDING: Between June 22, 2009, and Oct 30, 2012, 395 patients were enrolled in the study, of which 384 were eligible for inclusion. The diagnosis was eventually modified by molecular genetics for 53 patients: eight (16%) of 50 patients with dermatofibrosarcoma (cohort 1), seven (23%) of 30 patients with dedifferentiated liposarcoma (cohort 2), 13 (12%) of 112 with Ewing's sarcoma family of tumours (cohort 3), 16 (16%) of 97 patients with synovial sarcoma (cohort 4), seven (15%) of 46 patients with alveolar rhabdomyosarcoma (cohort 5), and two (4%) of 49 patients with myxoid or round cell liposarcoma (cohort 6), with an effect on primary management or prognosis assessment in 45 cases. INTERPRETATION: Molecular genetic testing should be mandatory for diagnostic accuracy of sarcoma and appropriate clinical management, even when histological diagnosis is made by pathologist experts in this field. FUNDING: French National Cancer Institute and Nice University Hospital.

Impact of EGFR mutations and KRAS amino acid substitution on the response to radiotherapy for brain metastasis of non-small-cell lung cancer.

BACKGROUND: Our study aimed to evaluate response rate (RR) to brain metastasis radiotherapy (RT), depending on the genomic status of non-small-cell lung cancer. MATERIAL & METHODS: We retrospectively reviewed 1971 non-small-cell lung cancer files of patients with EGFR and KRAS testing and focused on 157 patients who had undergone RT for brain metastasis. RESULTS: A total of 16 patients (10.2%) harbored EGFR mutations (mEGFR) and 45 patients (28.7%) KRAS (mKRAS). In univariate analysis, RR was significantly higher for mEGFR compared with wild-type EGFR/KRAS (odds ratio [OR]: 4.96; p = 0.05) or mKRAS (OR: 1.81; p = 0.03). In multivariate analysis, KRAS G12V or G12C status was associated with both poor RR (OR: 0.1; p < 0.0001) and overall survival (OR: 3.41; p < 0.0001). CONCLUSION: mEGFR are associated with higher RR to brain RT than wild-type EGFR/RAS or mKRAS.

Prognostic value of the KRAS G12V mutation in 841 surgically resected Caucasian lung adenocarcinoma cases.

BACKGROUND: Identifying patients who will experience lung cancer recurrence after surgery remains a challenge. We aimed to evaluate whether mutant forms of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) (mEGFR and mKRAS) are useful biomarkers in resected non-small cell lung cancer (NSCLC). METHODS: We retrospectively reviewed data from 841 patients who underwent surgery and molecular testing for NSCLC between 2007 and 2012. RESULTS: mEGFR was observed in 103 patients (12.2%), and mKRAS in 265 (31.5%). The median overall survival (OS) and time to recurrence (TTR) were significantly lower for mKRAS (OS: 43 months; TTR: 19 months) compared with mEGFR (OS: 67 months; TTR: 24 months) and wild-type patients (OS: 55 months; disease-free survival (DFS): 24 months). Patients with KRAS G12V exhibited worse OS and TTR compared with the entire cohort (OS: KRAS G12V: 26 months vs COHORT: 60 months; DFS: KRAS G12V: 15 months vs COHORT: 24 months). These results were confirmed using multivariate analyses (non-G12V status, hazard ratio (HR): 0.43 (confidence interval: 0.28-0.65), P<0.0001 for OS; HR: 0.67 (0.48-0.92), P=0.01 for TTR). Risk of recurrence was significantly lower for non-KRAS G12V (HR: 0.01, (0.001-0.08), P<0.0001). CONCLUSIONS: mKRAS and mEGFR may predict survival and recurrence in early stages of NSCLC. Patients with KRAS G12V exhibited worse OS and higher recurrence incidences.

Correlation between MET protein expression and MET gene copy number in a Caucasian cohort of non-small cell lung cancers according to the new IASLC/ATS/ERS classification.

MET pathway is a promising target in non-small cell lung cancers (NSCLC) requiring companion tests. The aim of this study was to compare MET expression/gene copy number in a Caucasian population of NSCLC patients.We analysed 201 NSCLC, with 141 adenocarcinomas classified according to 2011 IASLC recommendations, for MET expression by immunohistochemistry (IHC) and gene copy number (GCN) by silver in situ hybridisation (SISH) on tissue microarrays. Mutations in EGFR, KRAS, BRAF, HER2, PIK3CA genes and ALK rearrangements were determined.MET overexpression was observed in 44% and a high MET GCN (≥5 copies) in 14%. MET CGN was correlated with MET expression, regardless of IHC scores (p < 0.001) but only 31% of MET overexpressed cases were SISH positive. MET overexpression/GCN number was more frequent in ADC than the other types (p < 0.001), the highest in high grade (74%/34%) and sarcomatoid ADC (86%/43%). Mutations of current genes or ALK rearrangements were identified in overexpressed or amplified MET cases. MET overexpression was an independent prognostic factor for overall survival in non-smoker NSCLC in univariate (p = 0.01) and multivariate (p = 0.01) analyses.MET overexpression is more frequent than MET high GCN, particularly in high grade ADC, regardless of EGFR, KRAS, BRAF, HER2, PIK3CA and ALK status in NSCLC.

A multicenter blinded study evaluating EGFR and KRAS mutation testing methods in the clinical non-small cell lung cancer setting--IFCT/ERMETIC2 Project Part 1: Comparison of testing methods in 20 French molecular genetic National Cancer Institute platforms.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors have limited use as first-line treatment for mutated EGFR metastatic non-small cell lung cancer. The French National Cancer Institute has installed molecular genetics platforms implementing EGFR and KRAS testing. However, there is considerable uncertainty as to which detection methods should be applied for routine diagnosis. This study aimed to compare the EGFR and KRAS genotyping methods developed by the IFCT/ERMETIC2 network platforms in two blind panels: 25 samples of serial dilutions of cell line DNA (20 centers) and 74 FFPE lung tumor samples (10 centers). The best threshold of mutation detection on cell lines was obtained using allele-specific amplification-based technologies. Nonamplifiable tissue samples were significantly less common when using alternative testing versus direct sequencing [15%; 95% confidence interval (CI), 14%-16% versus 40%; 95% CI, 39%-42%; P < 0.001]. Mutated cases increased from 42% (95% CI, 31%-54%) to 53% (95% CI, 41%-64%), with three supplementary EGFR mutations (p.G179A at exon 18 and p.L858R and p.L861Q at exon 21) and five supplementary KRAS mutations, when using alternative testing instead of direct sequencing. False-positive results were observed when using a PCR-based sizing assay, high-resolution melting, or pyrosequencing. Concordance analysis returned good kappa test scores for EGFR exon 19 and KRAS analysis when comparing sequencing with alternative methods and revealed no difference between alternative techniques themselves.

[Comparative cost analysis of molecular biology methods in the diagnosis of sarcomas]. / Analyse comparative des coûts de techniques de biologie moléculaire dans le diagnostic de sarcomes.

Sarcomas represent a complex and heterogeneous group of rare malignant tumors and their correct diagnosis is often difficult. Recent molecular biological techniques have been of great diagnostic use and there is a need to assess the cost of these procedures in routine clinical practice. Using prospective and observational data from eight molecular biology laboratories in France, we used "microcosting" method to assess the cost of molecular biological techniques in the diagnosis of five types of sarcoma. The mean cost of fluorescence in situ hybridization (FISH) was 318 € (273-393) per sample; mean reverse transcription polymerase chain reaction (RT-PCR) cost ranged from 300 € (229-481) per formalin-fixed, paraffin-embedded specimen to 258 € (213-339) per frozen specimen; mean quantitative polymerase chain reaction (Q-PCR) cost was 184 € (112-229) and mean CGH-array cost was 332 € (329-335). The cost of these recently implemented techniques varied according to the type of sarcoma; the method of tissue collection and local organizational factors including the level of local expertise and investment. The cost of molecular diagnostic techniques needs to be balanced against their respective performance.

A V530I Mutation in c-KIT Exon 10 Is Associated to Imatinib Response in Extraabdominal Aggressive Fibromatosis.

Aggressive fibromatosis (AF) or desmoid tumor is a rare condition, characterized by deep tissue invasion by a monoclonal fibroblastic neoplasm, developed from musculoaponeurotic structures. Surgery is the treatment of choice, but negative margins can hardly been achieved in large tumors, and can lead to major functional disability. AF medical therapy includes nonsteroids anti-inflammatory drugs, tamoxifen, with inconsistent results. Several reports of imatinib efficacy in AF appear in the literature. Here, we describe for the first time a V530I KIT exon 10 mutant that was associated to a dramatic imatinib response in an extraabdominal aggressive fibromatosis. The previously discovered V530I substitution was characterized in the core binding factor AML, but had never been reported in any other condition, so far. In this paper, we discuss the KIT exon 10 mutations or polymorphisms that have been described in a variety of KIT-related conditions, including acute myelogenous leukemia, mastocytosis, and aggressive fibromatosis.

Marked activity of irinotecan and rapamycin combination toward colon cancer cells in vivo and in vitro is mediated through cooperative modulation of the mammalian target of rapamycin/hypoxia-inducible factor-1alpha axis.

PURPOSE: Despite recent progress, colon cancer is often resistant to combination chemotherapy, highlighting the need for development of novel therapeutic approaches. An attractive target is hypoxia-inducible factor-1alpha (HIF-1alpha), a key transcription factor with a pivotal role in tumor cell metabolism. One potential class of therapeutic agents targeting HIF-1alpha are mammalian target of rapamycin inhibitors such as rapamycin. A second class are topoisomerase I inhibitors, such as irinotecan, which are able to inhibit the accumulation of HIF-1alpha. We here investigated whether combination of rapamycin and irinotecan was active in human colon cancer models. EXPERIMENTAL DESIGN: Human metastatic tumors were xenografted in nude mice and treated with low doses of irinotecan alone, rapamycin alone, or combination of both drugs. The cellular effects of irinotecan and rapamycin were further characterized for HT-29 and HCT-116 colon cancer cells in vitro. RESULTS: In contrast to single-agent therapy, xenografted tumors treated with combination of irinotecan and rapamycin showed potent inhibition of the mammalian target of rapamycin/HIF-1alpha axis, which was accompanied by a dramatic reduction in tumor volume. In vitro experiments showed that exposure to low concentrations of the two drugs resulted in massive HT-29 cell death under hypoxic, but not normoxic, conditions, in full agreement with a cytotoxic effect mediated through HIF-1alpha rather than through induction of genotoxic lesions. HCT-116 cells were less sensitive to the combined treatment due to constitutive activation of phosphatidylinositol 3-kinase/Akt and Ras/mitogen-activated protein kinase pathways. CONCLUSION: These results identify HIF-1alpha as a promising target and provide a rationale for clinical trials of low-dose irinotecan and rapamycin combination toward metastatic colon cancer.

Diminution of Circulating CD4+CD25 high T cells in naïve Crohn's disease.

Crohn's disease is considered to be caused either by an excess of T-cell effector functions and/or by a defective regulatory T-cell compartment. The aim of this study was to assess in Crohn's disease the frequency of circulating CD4(+)CD25(high) T cells that possess regulatory T-cell functions and CD4(+)CD25(low) T cells that contain activated T cells. Flow cytometry of peripheral blood was used to assess CD4(+)CD25(high) and CD4(+)CD25(low) T-cell frequencies in a cohort of 66 patients with Crohn's disease in comparison to 19 patients with ulcerative colitis and 31 healthy individuals enrolled as controls. The CD4(+)CD25(high) T-cell frequency was significantly lowered in naïve Crohn's disease (P = 0.013) and in ulcerative colitis (P = 0.001). CD4(+)CD25(low) T-cell frequency was increased in Crohn's disease (P = 0.0001) and in ulcerative colitis (P = 0.0002). Both CD4(+)CD25(high) and CD4(+)CD25(low) T-cell frequencies are altered in naïve Crohn's disease resulting in an imbalance between both populations and a relative contraction of the CD4(+)CD25(high) T-cell population.