NRAS Status Research Articles

Assessment of KRAS and NRAS status in metastatic colorectal cancer: Experience of the National Institute of Oncology in Rabat Morocco

Introduction: RAS status is a predictive biomarker for anti-EGFR response in metastatic colorectal cancer (mCRC). The Idylla technology (IT) is a fully automated molecular testing system based on real-time PCR and provides rapid results in a very short preparation time. In this study, we aimed to evaluate the full RAS mutation status in Moroccan patients with mCRC.

Real-world data of EGFR mutation testing in Chinese non-small cell carcinoma: Low tumor cell number and tumor cellularity can be accepted

IntroductionMolecular testing on advanced non–small cell lung cancer (NSCLC) often confront of limited specimen.The aim of the study is to compare the mutation frequency in adenocarcinoma samples with poor tumor cell content and the optimal samples, making the optimal strategy of mutation analysis. MethodsIn this retrospective study, mutation status of EGFR, ALK, ROS1, BRAF, KRAS, RET, HER2, CMET, NRAS and PIK3CA in 1594 NSCLCs were tested by ARMS-PCR and qRT-PCR, consists of 790 cases of surgical specimens, 741 cases of small biopsies, 63 cases of cytology cell blocks. We analyzed the discrepancies in mutation frequency with optimal specimens and the suboptimal ones. ResultsComparing the gene mutation frequency in optimal and suboptimal samples, only the EGFR mutation rates of surgical samples (12.5 %, 1 out of 8) with < 10 % tumor cellularity was lower than in those with ≥ 10 % (57.1 %, 385 out of 674， p = 0.015). However, surgical specimens with low tumor cellularity (<20 %) were comparable to the qualified samples. The mutation frequency of EGFR in biopsy specimens with poor specimen adequacy( <20 %, <10 %, <5 %, <200, <100, <50) were comparable to the qualified samples. Low tumor cellularity (<20 %, <10 %, <5 %) and low tumor cell number (<200, <100, <50) was not associated with mutational rate for ALK, ROS1, BRAF, KRAS, RET, HER2, CMET, NRAS and PIK3CA mutations in small biopsy samples. ConclusionsIn clinical practice, specimen with low adequacy could attempt in gene mutation testing, including biopsy and surgical specimen. However, the amount of tumor for molecular testing should be reported and suboptimal samples with a negative EGFR mutation result should be considered for combination using of other mutation test method or repeat testing of an alternate tumor sample, especially for the surgical samples.

Investigating the prognostic value of TP53 and PIK3CA mutations in metastatic colorectal cancer (mCRC): Applying Structured Query Language (SQL) algorithms to real-world data from a high-volume U.K. tertiary cancer center.

57 Background: Real world data is a valuable research resource but manual data collection is time consuming and labour intensive. As there is no consensus on the prognostic role of TP53 and PIK3CA mutations in mCRC, we assessed the feasibility of using SQL, a programming language, to derive data from routine electronic clinical notes to investigate the prognostic impact of TP53 and PIK3CA mutations in mCRC. Methods: A cohort of patients (pts) diagnosed with metastatic or recurrent colorectal cancer as per ICD-10 classification from January 2015 to December 2017 and managed at the Royal Marsden Hospital were identified using SQL algorithms developed in-house. Baseline demographics, histopathological and molecular characteristics and death dates were derived from the Electronic Patient Record and extracted in a structured format for statistical analysis. Mutational analysis of TP53 and PIK3CA were performed with standard of care KRAS, NRAS and BRAF testing using next generation sequencing. Overall survival (OS) according to TP53 or PIK3CA mutational status was estimated using the Kaplan-Meier method. Uni- and multivariate Cox regression included KRAS, NRAS, BRAF, sidedness and mismatch repair (MMR) status. Association between TP53 or PIK3CA and MMR status was tested by the Chi squared test. Results: A total of 367 mCRC pts were identified; 10 were excluded due to ineligibility or inadequate data availability. Based on a final dataset of 357 pts, 342 and 354 pts had TP53 and PIK3CA results available. The incidence of TP53 mutations was 75% (n = 257/342) and PIK3CA 16% (n = 55/354). Co-mutations with KRAS, NRAS and BRAF were seen (Table). The overall median follow-up was 42.3 and 42.7 months for TP53 and PIK3CA respectively. There was no difference in OS between TP53 mutant (MT) and wild type (WT) pts (22.0 vs. 22.8 months, p = 0.96) and between PIK3CA MT and WT pts (21.7 vs. 22.4 months, p = 0.49). Right sided and BRAF MT tumours were associated with poorer survival than left sided and BRAF WT tumours when all other factors were constant for TP53 (p&lt;0.001 &amp; p=0.033 respectively) and PIK3CA (both p&lt;0.001) OS on multivariate analysis. MMR deficient tumours were significantly more frequent in TP53 WT compared to TP53 MT tumours (15% vs. 4%, p=0.001) while they were significantly more frequent in PIK3CA MT compared to PIK3CA WT tumours (20% vs. 5%, p &lt; 0.001). Conclusions: Bespoke SQL algorithms enables large-scale data extraction to facilitate research. Based on this dataset, we have shown that TP53 and PIK3CA mutations have no prognostic impact in mCRC. [Table: see text]

The retrospective molecular analysis of large or giant congenital melanocytic nevi in a group of Polish children.

BackgroundLarge and giant congenital melanocytic nevi (CMN), benign naevomelanocytic proliferations derived from neural crests, with a projected adult size (PAS) ≥ 20 cm, are connected to a high risk of melanoma and neurocutaneous melanosis. Among several factors, genetic alterations seem to be involved in tumorigenesis. The aim of the present study was to analyse the mutation status of NRAS and BRAF genes in resection specimens from large or giant CMN in a group of Polish patients.Material and methodsThe formalin-fixed, paraffin-embedded resection specimens from 18 patients, fixed in the years of 2006 to 2017, were included in the study. The regions containing the highest load of melanocytes were macrodissected prior to DNA isolation. The NRAS and BRAF mutation status was evaluated using qPCR.ResultsWe detected activating mutations in NRAS gene (codons: 12 and 61) in 7 out of the 18 (38.9%) patients. No BRAF mutations were found.ConclusionOur study, the first molecular analysis of large/giant CMN in Polish patients, supports the hypothesis that NRAS mutation in codon 61 are frequent, recurrent mutations in large/giant CMN. Moreover, we show, for the first time, that NRAS mutations in codon 12 (p.Gly12Asp) can be also detected in giant CMN. The exact role of these genetic alterations in CMN formation remains to be elucidated.

Abstract CT033: Inducible T cell costimulatory (ICOS) receptor agonist, feladilimab (FE), alone and in combination (combo) with pembrolizumab (PE): Results from INDUCE-1 relapsed/refractory (R/R) melanoma expansion cohorts (EC)

Abstract Background: INDUCE-1 is a first-in-human trial investigating FE, an IgG4 ICOS agonist non-T-cell depleting mAb, in monotherapy (mono) and combo with PD-1 inhibitor PE. ICOS is highly expressed in melanoma, an immunotherapy responsive tumor, and is a biomarker of response to anti-CTLA-4 treatment; in nonclinical models, ICOS agonism has enhanced activity in combo with immune checkpoint blockade (ICB). Preliminary data from INDUCE-1 R/R melanoma ECs are presented to support FE expansion in ICB experienced (exp) R/R melanoma patients (pts). Methods: Eligible pts had non-uveal R/R melanoma, ≤5 prior lines of systemic therapy, achieved response or stable disease (SD) on prior anti-PD-1/L1 treatment, and no prior immunotherapy-related Grade ≥3 toxicities leading to treatment discontinuation. In FE mono and FE + PE 200 mg combo ECs, pts were randomized to FE 0.3 or 1 mg/kg; treatment was given every 3 wks up to 35 cycles until disease progression or unacceptable toxicity. Safety and efficacy were assessed. Biomarkers in tumor biopsies were analyzed. Results: By 30 Mar 2020, 39 pts in the mono EC were evaluable (21 pts at 0.3; 18 pts at 1 mg/kg FE); all pts were anti-PD-1/L1 exp; 21/39 (54%) were anti-CTLA-4 exp; 7/39 (18%) had ≥4 prior lines of therapy. Of the 39 pts, 29 (74%) discontinued treatment due to progression. Response rate was 10% (4/39; 1 complete response, 3 partial responses); 8/39 (21%) pts had SD and 2/8 (25%) pts with SD had tumor size reductions (RECIST v1.1) at ≥19%; 5 pts (13%) had SD at ≥18 wks. Duration of response (DoR) was 2.0+ to 6.3 mo. BRAF and NRAS status did not impact clinical activity. Anti-CTLA-4 exp pts had a numerically higher response rate than anti-CTLA-4 naïve pts. In the combo EC, 17 anti-PD-1/L1 exp pts were evaluable (6 pts at 0.3; 11 pts at 1 mg/kg FE); 12/17 (71%) were anti-CTLA-4 exp; 15/17 (88%) discontinued treatment, all due to progression. Response rate was 18% (3/17), DoR was 7.9+ to 8.2 mo, and disease control rate (response or SD) was 53% (9/17); 1 pt with SD had tumor size reduction of 10%. Ongoing analyses with mono EC showed a 28.6% (2/7) response rate, DoR of 2.0+ to 6.3 mo, and mOS of ~26 mo in pts with ICOS high tumor-infiltrating T cells. Sample size limits comparison; however, clinical activity was similar between FE doses and between BRAF+ and BRAF− pts. Adverse events (AEs) were consistent with AEs reported for PE. Conclusions: FE is the first ICOS agonist with reported single-agent activity in ICB exp R/R melanoma, supporting ICOS as a target. FE + PE in combo shows promising clinical activity and manageable safety in R/R melanoma. Continued survival follow-up of ECs is warranted. Updated efficacy and PK/PD data to be presented. Funding: Study 204691 (NCT02723955) funded by GSK in collaboration with Merck Sharp &amp; Dohme Corp, a subsidiary of Merck &amp; Co, Inc, Kenilworth, NJ, USA. Citation Format: Michele Maio, Jeffrey S. Weber, Maria Vieito Villar, Frans L. Opdam, Victor Moreno, Omid Hamid, José Trigo, Michael Chisamore, Marco Balas, Sapna Yadavilli, David C. Turner, Courtney Henry, Xiao Ji, Catherine Ellis, Marc Ballas, Axel Hoos, Antoine Italiano. Inducible T cell costimulatory (ICOS) receptor agonist, feladilimab (FE), alone and in combination (combo) with pembrolizumab (PE): Results from INDUCE-1 relapsed/refractory (R/R) melanoma expansion cohorts (EC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT033.

Recurrent KRAS, KIT and SF3B1 mutations in melanoma of the female genital tract

BackgroundMalignant melanoma of the female genital tract is relatively uncommon and accounts for 3–7% of all melanoma localizations. This study aimed to identify driver genes in melanoma of the female genital tract with the purpose of enhancing understanding of disease pathogenesis and identifying potential new therapeutic targets to develop effective therapies.MethodsKIT (CD117) and BRAF expression were detected immunohistochemically. Polymerase Chain Reaction (PCR) and Sanger sequencing techniques were performed to identify the mutational status of BRAF, NRAS, KRAS, NF1, KIT, PDGFRA and SF3B1 on 19 melanomas of the female genital tract, paired with 25 cutaneous melanomas, 18 acral melanomas and 11 melanomas of nasal cavity.ResultsSomatic variant analysis identified KRAS (6/19; 32%) as the most commonly mutated gene, followed by KIT (4/19; 21%), SF3B1 (3/19; 16%) and NRAS (1/19; 5%). None of the cases were found to harbor BRAF, NF1 and PDGFRA mutations in melanomas of the female genital tract. However, none of the cases were found to harbor SF3B1 and KIT mutations in cutaneous melanomas, acral melanomas and melanomas of nasal cavity. Recurrent KIT mutations, as well as mutations in the less frequently mutated genes NRAS and SF3B1, were exclusively detected in vulvovaginal melanomas, but not in tumors arising in the cervix. However, recurrent KRAS mutations were detected in similar frequencies in tumors of the vulva, vagina, and cervix. Additionally, recurrent KRAS and KIT mutations occurred predominantly in polygonal and epithelioid cell types of melanoma in the female genital tract. Immunohistochemistry revealed moderate or strong cytoplasmic CD117 expression in 6 of the 19 cases (31.6%).ConclusionsWe observed that gynecologic melanoma harbored distinct mutation rates in the KIT, BRAF, SF3B1, KRAS, and NRAS genes. Our findings support the notion that gynecologic melanoma is a distinct entity from non-gynecologic melanoma, and these findings offer insights into future therapeutic options for these patients.

KRAS, NRAS and BRAF mutational status and first line treatment patterns in Slovenian population with metastatic colorectal carcinoma: Five year results.

e15546 Background: A phase IV non-interventional study was performed from 2013 till 2018 including 650 patients with primary aim to assess KRAS, NRAS and BRAF mutational status in Slovenian population with metastatic colorectal carcinoma (mCRC) suitable for first-line treatment. The evaluation of decisions for first-line treatment regarding the biomarkers status and assessing the possible impact of the time period of the biomarker status analysis report on the treatment decision were also incorporated in the analysis. The molecular analyses for KRAS and NRAS gene mutations were performed on exons 2, 3 and 4, and for BRAF gene mutations on exon 15. The first line systemic treatment options for RAS (KRAS/NRAS) wild type (wt) and mutated type (mt) mCRC subjects were as follows: chemotherapy - Fluoropyrimidine based systemic therapy combined with oxaliplatin and/or irinotecan with/without VEGF inhibitor bevacizumab and for RAS wt subjects, with/without EGFR inhibitors, cetuximab or panitumumab. Methods: To indicate the degree of certainty of KRAS, NRAS and BRAF status frequency as being wild type or mutant type 95% confidence interval was calculated. Results: The KRAS/NRAS/BRAF mutation rates were as follows - The distribution of subjects with KRAS mutated and wild-type tumors, was almost equal, 48.8% and 47.9% respectively. Eighty nine percent of the subjects had NRAS wild type tumours and 86.1% had BRAF wild type tumours. The most frequently used treatment regardless the biomarkers status and in accordance with the treatment guidelines was bevacizumab based combination therapy (53.1%). The EGFR inhibitor (cetuximab or panitumumab) based combination therapy was used in one third of mCRC subjects (30.9%), all with mCRC RAS wt. The time period from the initial presentation of the patient until the biomarker status analysis report was two weeks. Conclusions: With this study, we have proven that the distribution of the mutations in exons 2-4 of KRAS and NRAS genes and exon 15 in the BRAF gene in the Slovenian population with metastatic colorectal cancer matches historical data. Based on this, we conclude that the treatment decision in Slovenian population with metastatic colorectal carcinoma should be in the accordance with international treatment guidelines and on evidence based medicine. The molecular analysis performed at the Institute of Oncology Ljubljana was providing necessary biomarkers status report in an acceptable time that didn’t affect the treatment decision or delay the needed cancer treatment.

PD-L1 Expression in 65 Conjunctival Melanomas and Its Association with Clinical Outcome.

Conjunctival melanoma (CM) iss a rare and aggressive tumour that is increasing in frequency. The prognostic value of PD-L1 expression, alone or in combination with CD8 and PD-1 expression and the BRAF and NRAS status, has not been determined in CM to date. We evaluated the expression of PD-L1, CD8, PD-1 in CM and investigated whether there was an association between the expression of these markers and the BRAF and NRAS molecular profile as well as some clinico-pathological criteria. A total of sixty-five CM were assessed for PD-L1, PD-1, and CD8 expression by immunohistochemistry (IHC) and for BRAF and NRAS genomic alterations using molecular biology techniques and anti-BRAF and anti-NRAS antibodies. PD-L1 expression in tumour cells (TC) was very low or absent but detected in tumour-infiltrating immune cells (IC). A correlation was observed between the expression of PD-L1, CD8, and PD-1 in IC. No correlation between PD-L1 expression (in tumour and/or immune cells) and BRAF or NRAS mutations was observed. PD-L1 expression in IC correlated with a higher pTNM stage and PD-L1 expression in TC with worse disease-specific survival. PD-L1 expression is a potential prognostic biomarker that correlates with poor prognosis in CM patients.

Effect of K-RAS, N-RAS, B-RAF mutations and micro-satellite status on survival in colorectal peritoneal metastases treated with CRS and HIPEC

Effect of K-RAS, N-RAS, B-RAF mutations and micro-satellite status on survival in colorectal peritoneal metastases treated with CRS and HIPEC

KRAS and NRAS mutation detection in circulating DNA from patients with metastatic colorectal cancer using BEAMing assay: Concordance with standard biopsy and clinical evaluation.

Patients with metastatic colorectal cancer (mCRC) are routinely screened for either K- and N-RAS to select the appropriate treatment. The present study aimed to evaluate the concordance between K- and NRAS status in the tissue (either primary tumor or metastasis) and the plasma of patients with mCRC and to identify the associations between K- and NRAS mutations in ctDNA and the clinicopathological parameters. Samples from a total of 31 patients with mCRC with measurable disease according to the Response Evaluation Criteria in Solid Tumors were analyzed. For all patients, K- and NRAS status was determined in the tissue by matrix-assisted laser desorption/ionization time of flight mass spectrometry. For the detection of RAS mutations in cell-free tumor DNA also defined as circulating tumor DNA (ctDNA), the OncoBEAM® RAS CRC kit (Sysmex Inostics) was used. A total of 6/31 tissue samples expressed wild-type KRAS, whereas 25/31 presented mutations. In addition, 7/31 plasma samples expressed wild-type KRAS, mutations were detected in 22/31 patients, and for 2/31 patients, the test did not provide a conclusive result. A total of 24/31 patients expressed wild-type NRAS, 6/31 had mutations and 1/21 was not informative. For the KRAS mutational status, a moderate concordance (agreement, 85.18%; Cohen's k, 0.513) between the tissue and plasma analysis was observed; for NRAS, a fair agreement (agreement, 83.33%; Cohen's k, 0.242) was obtained. In conclusion, both tissue and plasma analyses should be performed for the management of patients with mCRC. To better exploit the beads, emulsions, amplification, magnetics (BEAMing) technique in the clinical setting, studies aimed at determining the RAS status to monitor therapy and during follow-up are warranted.

INFLUENCE OF SOMATIC MUTATIONS OF KRAS, NRAS, BRAF AND MICROSATELLITE INSTABILITY STATUS ON SURVIVAL OF COLORECTAL CANCER PATIENTS WITH PERITONAL CARCINO

Purpose: to evaluate the effect of somatic mutations of the KRAS, NRAS, BRAF genes and the status of microsatellite instability on the overall and disease-free survival of patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.Material and Methods. From 2012 to 2018, the study included 45 patients who underwent surgery for synchronous peritoneal carcinomatosis with colorectal cancer. In all patients, mutations of the KRAS, NRAS, BRAF genes and MSI status of the tumor and peritoneum metastases were determined using Sanger sequencing, fragment analysis and digital droplet polymerase chain reaction. The effect of mutations on patient survival was evaluated.Results. The prevalence of somatic mutations was 69 % of patients. The discordance between the tumor and peritoneum metastases was 9 %. All tumors and peritoneum metastases were microsatellite stable. KRAS, NRAS, BRAF mutations did not affect the overall and disease-free survival (p=0.87 and p=0.85, respectively).Conclusion. Somatic mutations in the KRAS, NRAS, or BRAF genes are not a prognostic factor affecting the overall and relapse-free survival of colorectal cancer patients with peritoneal carcinomatosis. The molecular status of primary tumor may differ from the status of peritoneal metastasis. It should be taken into account when prescribing targeted drugs.

Abstract 1433: Role of the E3 ubiquitin ligase NEDD4 in the regulation of PTEN and MDM2 in colorectal cancer

Abstract Introduction: NEDD4 (neural precursor cell-expressed developmentally down-regulated 4), a member of the HECT (homologous to E6AP C-terminus) family of E3 ubiquitin ligases, has been shown to be an important regulator of multiple proteins involved in cancer development, including the tumor suppressor PTEN and the proto-oncogene MDM2. Furthermore, NEDD4 has been shown to be overexpressed and act as an oncogene in multiple cancer types. We have previously shown that NEDD4 is overexpressed in colorectal cancer (CRC) and that it can promote growth of colon cancer cells independently of PTEN and PI3K/AKT signaling. In the present study, we investigated the role of NEDD4 in regulating the PTEN/PI3K pathway and the MDM2/p53 axis in CRC. Materials and Methods: The CRISPR/Cas9 system was applied to generate a Caco2 NEDD4 knockout cell line, and NEDD4 knockdown was performed in LS174T and SW480 cells. Gene expression profiles of 412 primary CRCs, 51 normal mucosa samples, 38 CRC cell lines, as well as the Caco2 parental and NEDD4 knockout cell lines, were generated using exon-resolution Affymetrix Human Exon Arrays or Human Transcriptome Arrays. The NEDD4 expression level was correlated with the mutation status of KRAS, PTEN, TP53, PIK3CA, BRAF and NRAS. Western blotting was used to detect and quantify NEDD4, PTEN and MDM2 protein levels. Results and Discussions: Gene expression analysis of the patient material confirmed our previous study that NEDD4 is significantly upregulated in CRC as compared to normal colonic mucosa. There was no correlation between NEDD4 expression and mutations in KRAS, BRAF, NRAS, PTEN, PIK3CA and TP53. CRISPR/Cas9-mediated NEDD4 knockout in Caco2 cells resulted in a reduction (P &amp;lt;0.01) in both the PTEN and MDM2 protein levels as compared to control cells. Gene set analysis showed that PI3K/AKT/MTOR signaling was upregulated in the NEDD4 knockout cells as compared to control cells. siRNA-mediated depletion of NEDD4 in LS174T cells was associated with reduced levels of MDM2, but did not affect the PTEN protein level. In SW480 cells, depletion of NEDD4 affected neither the MDM2 nor the PTEN protein level. By analyzing the expression of NEDD4, PTEN and MDM2 in 38 CRC cell lines by Western blotting, a positive correlation (P&amp;lt;0.01) was observed between NEDD4 and PTEN protein, while there was no significant correlation between NEDD4 and MDM2. Conclusion: The data show that NEDD4 is significantly upregulated in CRC, and that NEDD4 expression correlates with PTEN expression. The data further suggest that NEDD4 has the ability to regulate the PTEN and MDM2 protein levels in colon cancer cells in a cell line-specific manner. Citation Format: Lars M. Knudsen, Anita Sveen, Christer A. Andreassen, Christian H. Bergsland, Ina A. Eilertsen, Nikoline L. Rasmussen, Max Z. Totland, Peter W. Eide, Jarle Bruun, Ragnhild A. Lothe, Edward Leithe. Role of the E3 ubiquitin ligase NEDD4 in the regulation of PTEN and MDM2 in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1433.

Clinical, environmental and histological distribution ofBRAF,NRASandTERTpromoter mutations among patients with cutaneous melanoma: a retrospective study of 563 patients*

The distinct somatic mutations that define clinical and histopathological heterogeneity in cutaneous melanoma could be dependent on host susceptibility to exogenous factors like ultraviolet radiation. Firstly, to characterize patients with cutaneous melanoma clinically and pathologically based on the mutational status of BRAF, NRAS and TERT promoter. Secondly, to elucidate the modified features due to the presence of TERT promoter mutations over the background of either BRAF or NRAS mutations. We performed a retrospective study on 563 patients with melanoma by investigating somatic mutations in BRAF, NRAS and TERT promoter. We observed co-occurrence of TERT promoter mutations with BRAF and NRAS mutations in 26.3% and 6.9% of melanomas, respectively. Multivariate analysis showed an independent association between BRAF mutations and a decreased presence of cutaneous lentigines at the melanoma site, and an increased association with the presence of any MC1R polymorphism. We also observed an independent association between TERT promoter mutations and increased tumour mitotic rate. Co-occurrence of BRAF and TERT promoter mutations was independently associated with occurrence of primary tumours at usually sun-exposed sites, lack of histological chronic sun damage in surrounding unaffected skin at the melanoma site, and increased tumour mitotic rate. Co-occurrence of NRAS and TERT promoter mutations was independently associated with increased tumour mitotic rate. The presence of TERT promoter together with BRAF or NRAS mutations was associated with statistically significantly worse survival. The presence of TERT promoter mutations discriminates BRAF- and NRAS-mutated tumours and indicates a higher involvement of ultraviolet-induced damage and tumours with worse melanoma-specific survival than those without any mutation. These observations refine classification of patients with melanoma based on mutational status.

Mutation analysis and genomic imbalances of cells found in effusion fluids from patients with ovarian cancer.

Ovarian carcinomas and carcinosarcomas often cause malignant effusions, an accumulation within serous cavities of fluid containing cancer cells. Few studies have focused on the molecular alterations and genetic mechanisms behind effusion formation. The present study investigated the mutation status of TP53, PIK3CA, KRAS, HRAS, NRAS and BRAF in effusion fluids from 103 patients with ovarian cancer. In addition, array Comparative Genomic Hybridization (aCGH) analysis was performed on 20 effusions from patients with high-grade serous carcinoma (10 cases positive for TP53 mutation and 10 with TP53 wild-type). TP53 mutations, two of which were novel: c.826_830delCCTGT and c.475_476GC>TT, were identified in 44% of the cases. Mutations in KRAS, HRAS, and PIK3CA were identified in two, two and four cases, respectively. None of the effusions analysed showed NRAS or BRAF mutations. The aCGH analysis revealed highly imbalanced genomes similar to those described in primary ovarian carcinomas. No specific profile was indicated to distinguish tumors with TP53 mutations from those without. The molecular profiling of cells found in effusion fluids from patients with ovarian cancer thus showed considerable molecular heterogeneity. TP53 seems to be the most frequently mutated gene in these cells and may serve a leading role in the metastatic process.

Incidence of venous thromboembolism in patients with colorectal cancer according to oncogenic status.

There are conflicting data regarding the role of KRAS mutation on the risk of venous thromboembolism (VTE) in colorectal cancer (CRC) patients. Moreover, the role of other biomarkers such as NRAS or BRAF has not been studied. To analyze the incidence of VTE in a cohort of patients with CRC based on KRAS, NRAS, and BRAF status. We performed a retrospective review of patients with unresectable locally advanced and metastatic CRC (mCRC) and known KRAS/NRAS/BRAF status, attended in the Medical Oncology Department of the Hospital General Universitario Gregorio Marañón (Madrid, Spain). The primary outcome was VTE defined as any venous thromboembolic event that occurred either 6months before or at any time after the diagnosis of CRC. The biomarker status (KRAS, NRAS, and BRAF) and other predictors of thrombosis were collected. One hundred and ninety-four patients were identified and included in the analysis. Forty-one patients (21.1%) experienced VTE. The incidence was 19.1% in RAS-mutated patients, 28.6% in BRAF-mutated patients and 21% in triple wild-type patients (p = NS). In multivariate analysis, ECOG ≥ 2 was the only independent predictor of VTE (OR 8.73; CI 95% 1.32-57.82; p = 0.025). In our study, biomarkers have not been associated with an increased risk of VTE in CRC patients. A high incidence of VTE in BRAF-mutated patients has been observed and should be explored in further studies.

SALVO: Single-arm phase II study of ipilimumab and nivolumab as adjuvant therapy for resected mucosal melanoma.

TPS65 Background: Mucosal melanoma is a rare and, therefore, poorly studied malignancy. Patients with resected primary tumors have a median time to recurrence of 5.5 months. While no one adjuvant therapy is of proven benefit for patients, immunotherapy has shown activity in metastatic mucosal melanoma. Methods: We are performing a single arm, phase II clinical trial through the Midwest Melanoma Partnership/Hoosier Cancer Research Network (6 sites) for resected mucosal melanoma. The primary endpoint is recurrence free survival (RFS), and it will include 36 subjects. Patients must have had an R0 or R1 resection of a mucosal melanoma (sinonasal, anorectal, vulvar, or other), and register within 90 days of surgery. Adjuvant radiation is allowed prior to registration but not required. Therapy consists of ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) IV q3w x 4, then 480 mg nivolumab x 1 year. Statistical power is calculated to be 85% to detect a change in RFS from 5.5 months to 9.5 months, with a one sided alpha of 0.05. Enrollment began Sept 2017, with current participation from 6 large volume centers in the United States, with 17 patients enrolled as of Sept 2019. Full accrual is anticipated to complete by year end 2020. Patients will be followed for RFS and OS. Translational studies will include mutational burden, c-kit, BRAF, NRAS status, and serum markers of immunity -- including soluble PD-L1 and Bim. Clinical trial information: NCT03241186.

Dual-specificity protein phosphatase DUSP4 regulates response to MEK inhibition in BRAF wild-type melanoma

BackgroundAiming to improve treatment options for BRAF wild-type melanoma, we previously conducted the DOC-MEK study of docetaxel with MEK inhibitor (MEKi) selumetinib or placebo, revealing trends to prolongation of progression-free survival (hazard ratio 0.75, P = 0.130), and improved response rates (32% vs 14%, P = 0.059) with docetaxel plus selumetinib. NRAS status did not associate with outcome. Here, the aim was to identify novel biomarkers of response to MEKi.MethodsA MEK 6 gene signature was quantified using NanoString and correlated with clinical outcomes. Two components of the gene signature were investigated by gene silencing in BRAF/NRAS wild-type melanoma cells.ResultsIn melanomas of patients on the selumetinib but not the placebo arm, two gene signature components, dual-specificity protein phosphatase 4 (DUSP4) and ETS translocation variant 4 (ETV4), were expressed more highly in responders than non-responders. In vitro, ETV4 depletion inhibited cell survival but did not influence sensitivity to MEKi selumetinib or trametinib. In contrast, DUSP4-depleted cells showed enhanced cell survival and increased resistance to both selumetinib and trametinib.ConclusionsETV4 and DUSP4 associated with clinical response to docetaxel plus selumetinib. DUSP4 depletion induced MEKi resistance, suggesting that DUSP4 is not only a biomarker but also a mediator of MEKi sensitivity.Clinical Trial RegistrationDOC-MEK (EudraCT no: 2009-018153-23).

Mutational Profile of Driver Genes in Brazilian Melanomas.

PURPOSEMutation testing of the key genes involved in melanoma oncogenesis is now mandatory for the application of targeted therapeutics. However, knowledge of the mutational profile of melanoma remains largely unknown in Brazil.PATIENTS AND METHODSIn this study, we assessed the mutation status of melanoma driver genes BRAF, NRAS, TERT, KIT, and PDGFRA in a cohort of 459 patients attended at Barretos Cancer Hospital between 2001 and 2012. We used polymerase chain reaction followed by Sanger sequencing to analyze the hot spot mutations of BRAF exon 15 (V600E), NRAS (codons 12/13 and 61), TERT (promoter region), KIT (exons 9, 11, 13, and 17), and PDGFRA (exons 12, 14, and 18) in tumors. The mutational profile was investigated for associations with demographic, histopathologic, and clinical features of the disease.RESULTSThe nodular subtype was most frequent (38.9%) followed by the superficial spreading subtype (34.4%). The most frequent tumor location was in the limbs (50.0%). The mutation rates were 34.3% for TERT and 34.1% for BRAF followed by NRAS (7.9%), KIT (6.2%), and PDGFRA (2.9%). The BRAF (P = .014) and TERT (P = .006) mutations were associated with younger patients and with different anatomic locations, particularly in the trunk, for the superficial spreading and nodular subtypes, respectively (P = .0001 for both). PDGFRA mutations were associated with black skin color (P = .023) and TERT promoter mutations with an absence of ulceration (P = .037) and lower levels of lactate dehydrogenase. There was no association between patient survival rates and mutational status.CONCLUSIONThe similar mutational profile we observe in melanomas in Brazil compared with other populations will help to guide precision medicine in this country.

Clinical Application of Next-Generation Sequencing as A Liquid Biopsy Technique in Advanced Colorectal Cancer: A Trick or A Treat?

Owing to its advantages over prior relevant technologies, massive parallel or next-generation sequencing (NGS) is rapidly evolving, with growing applications in a wide range of human diseases. The burst in actionable molecular alterations in many cancer types advocates for the practicality of using NGS in the clinical setting, as it permits the parallel characterization of multiple genes in a cost- and time-effective way, starting from low-input DNA. In advanced clinical practice, the oncological management of colorectal cancer requires prior knowledge of KRAS, NRAS, and BRAF status, for the design of appropriate therapeutic strategies, with more gene mutations still surfacing as potential biomarkers. Tumor heterogeneity, as well as the need for serial gene profiling due to tumor evolution and the emergence of novel genetic alterations, have promoted the use of liquid biopsies—especially in the form of circulating tumor DNA (ctDNA)—as a promising alternative to tissue molecular analysis. This review discusses recent studies that have used plasma NGS in advanced colorectal cancer and summarizes the clinical applications, as well as the technical challenges involved in adopting this technique in a clinically beneficial oncological practice.

LAG3 in Solid Tumors as a Potential Novel Immunotherapy Target.

We performed a prospective immunohistochemical analysis of lymphocyte activation gene 3 (LAG3) for 430 consecutive patients with advanced gastrointestinal, genitourinary, or rare cancers between June 2012 and March 2016. Most patients (428/430, 99.5%) were evaluable for LAG3 expression by immunohistochemistry. In total, 18.5% (79/428) of the evaluated cancers expressed LAG3, including pancreatic cancer (33.3%, 2/6), gastric cancer (24.7%, 21/85), colorectal cancer (23.6%, 48/203), melanoma (12.5%, 1/8), genitourinary cancer (9.5%, 4/46), biliary tract cancer (6.3%, 1/16), and sarcoma (5.4%, 2/37), but not miscellaneous (0.0%, 0/14) or hepatocellular (0.0%, 0/15) cancer. Among 149 metastatic colorectal cancer patients, there was no statistically significant difference in sex, age, primary tumor site, pathologic differentiation, KRAS and NRAS status, BRAF status, and microsatellite instability according to LAG3 status (expressed vs. nonexpressed). Among 53 metastatic gastric cancer patients, LAG3 was only significantly associated with Epstein Barr virus status (P=0.042). Our results add to the emerging literature on LAG3 expression in various cancer types and support the need for extended clinical exploration of this target for immunotherapy.