Association Of KRAS Mutations Research Articles

Kirsten Rat Sarcoma Virus Mutations Effect On Tumor Doubling Time And Prognosis Of Solid Dominant Stage I Lung Adenocarcinoma.

To analyze the impact of Kirsten-Rat-Sarcoma Virus (KRAS) mutations on tumor-growth as estimated by tumor-doubling-time (TDT) among solid-dominant clinical-stage I lung adenocarcinoma. Moreover, to evaluate the prognostic role of KRAS mutations, TDT and their combination in completely-resected pathologic-stage I adenocarcinomas. In this single-center retrospective analysis, completely resected clinical-stage I adenocarcinomas presenting as solid-dominant nodules (consolidation-to-tumor ratio > 0.5) in at least 2 preoperative computed-tomography scans were enrolled. Nodules' growth was scored as fast (TDT < 400 days) or slow (TDT > 400 days). KRAS-mutated adenocarcinomas were identified with next-generation sequencing. Logistic- and Cox-regressions were used to identify predictors of fast-growth and disease-free survival (DFS), respectively. Among 151 patients, 83 (55%) had fast-growing nodules and 64 (42.4%) were KRAS-mutated. Fast-growing nodules outnumbered in the KRAS-mutated group (n = 45; 70.3%), median TDT 95-days (interquartile range, IQR 43.5-151.5) compared to the KRAS wild-type group (38, 43.7%), median TDT 138-days (IQR 70.3-278.5). KRAS-mutations predicted faster-growth at multivariable analysis (P = .009). In a subgroup analysis including 108 pathologic-stage I adenocarcinomas, neither KRAS-mutations (P = .081) nor fast-growing pattern (P = .146) affected DFS. Nevertheless, the association of KRAS-mutations and fast-growing pattern identified a subgroup of patients with worse DFS (P = .02). The combination of fast-growing and KRAS-mutations (hazard-ratio 2.97 [95%CI 1.22-7.25]; P = .017) and average nodule diameter at diagnosis (hazard-ratio 1.08 [95%CI 1.03-1.14]; P = .004) were independent predictors of worse DFS. KRAS mutations are associated to faster growth, in clinical-stage I adenocarcinoma presenting at diagnosis as solid-dominant nodules undergoing complete resection. Moreover, faster-growth identifies a subgroup of pathologic-stage I KRAS-mutated adenocarcinomas with higher recurrences.

Associations of KRAS Mutations and Clinical Characteristics of Colorectal Cancer Patients in Indonesia.

Colorectal cancer (CRC) remains a major burden worldwide, ranking third and second in incidence and mortality respectively. Detection of biomarkers including KRAS mutations can help predict prognosis and response to therapy in CRC, thus this study evaluated the frequency of KRAS mutations among Indonesian patients and their associations with clinicopathologic characteristics. Fifty-three CRC samples were collected from January to September 2022 in the Department of Surgery, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia. KRAS mutations were analyzed using PCR followed by Sanger sequencing. Associations between KRAS mutations were evaluated using binary logistic regression analysis. KRAS mutations were detected in 52.8% of patients (n=28), of which 3.6% were p.Gly12Ser (n=1), 32.1% were p.Gly12Asp (n=9), 7.1% were p.Gly13Asp (n=2), 3.6% were p.Gln61His (n=1), 3.6% were p.Asp126His (n=1), and 3.6% were p.Lys169Glu (n=1). The p.Asp73= polymorphism was detected in 57.1% of the samples (n=16). KRAS mutation status did not differ significantly between the groups based on the age of onset, sex, tumor location, tumor histology, stage, and family history. KRAS mutations are present in high frequency in this cohort of CRC patients in a tertiary hospital in West Java, Indonesia. However, KRAS mutation status is not associated with the age of onset, sex, tumor location, tumor histology, stage, and family history.

The prognostic significance of growth pattern, tumor budding, poorly differentiated clusters, desmoplastic reaction pattern and tumor-stroma ratio in colorectal cancer and an evaluation of their relationship with KRAS, NRAS, BRAF mutations

Growth pattern (GP), tumor budding (TB), poorly differentiated clusters (PDC), desmoplastic reaction pattern (DRP) and tumor-stroma ratio (TSR) are prognostic histomorphological parameters in colorectal cancer (CRC). Correlations between these parameters, their individual prognostic values, and their relationship with KRAS/NRAS/BRAF mutations have not been comprehensively examined. We aimed to investigate these associations, which have not been previously explored in this combination. 126 CRC cases were included. GP, TB, PDC, DRP and TSR were evaluated by two experienced pathologists. KRAS/NRAS/BRAF mutation profile were determined using qPCR. Demographic, clinicopathological and survival data were recorded. Interrelations were investigated by statistical analysis. Infiltrative GP was more frequent in high-score TB, PDC-G3, and stroma-high tumors (p < 0.05). High-score TB was more common in PDC-G3 and stroma-high tumors (p < 0.05). Immature DRP was more frequent in stroma-high tumors (p = 0.014). Among histomorphological parameters, a significant relationship was found only between infiltrative GP and the presence of KRAS mutation (p = 0.023). Moreover, GP was significantly associated with pT, lymphatic invasion, perineural invasion (p < 0.05). Effects on survival were assessed using Kaplan-Meier method and Cox proportional hazards model. TB and PDC were identified as independent predictors of overall survival. Higher TB score (p = 0.008) and higher PDC grade (p = 0.013) lead to worse survival. Interestingly, GP, DRP, TSR or KRAS/NRAS/BRAF mutations were not associated with overall survival. Our results highlight the prognostic significance of TB and PDC. We suggest incorporating TB and PDC into routine CRC reports. The association of KRAS mutation with infiltrative GP supports its role in the acquisition of invasive behavior.

Associations between KRAS status and clinical features in non-polyp colon cancer patients

Background Mutations of the KRAS gene are common in cancers; they are detected at a very high rate in colon cancer (CC) and are considered a negative disease factor. CC is among the deadliest cancers in Vietnam, and KRAS status for non-polyp colon cancer (NPCC) was rarely reported from the country. In this study, we aim to determine KRAS mutations and the associations of mutation status with clinicopathological features in Vietnamese NPCC patients. Methods Patients with NPCC (stages II or III) and without historical or current polyp appearance were included. Genomic DNA samples were prepared from dissected tumors, and specific sequences of the KRAS gene were amplified by PCR. The mutations at codons 12, 13, 59, 60, 61, 117, and 146 of the gene were determined by using a commercial kit. Possible associations of the KRAS mutation with clinicopathological properties were analyzed using SPSS and GraphPad Prism. Results The KRAS mutation rate was 47.9% in NPCC patients; mutations in exon 2 accounted for 91.4% of all detected mutations. Moreover, the KRAS mutation rate was higher in females (57.1%) than in males (39.8%). The association of KRAS mutation with female NPCC patients was further confirmed by multivariate regression data with OR=2.144 and p = 0.012. Conclusion The KRAS mutation rate was also higher in patients with right colon cancers. The mutated-KRAS-carrying patients potentially experienced anemia. The data provide important scientific background for the treatment and management of the disease.

Abstract 4258: Racial and ethnic differences in the mutational landscape of low-grade serous ovarian cancer

Abstract Objective To characterize the mutational landscape of low grade serous ovarian cancer (LGSOC) with racial/ethnic stratification. Methods The AACR Project GENIE database version 12.0 was queried via cBioPortal (http://genie.cbioportal.org) for low-grade serous ovarian cancer (LGSOC) samples. This is a publicly available, de-identified, multi-institutional database of next-generation sequencing genomic profiling results for tumor samples. Mutation frequencies for 9 homologous recombination deficiency (HRD) genes, 4 MAP-Kinase (MAP-K) pathway genes and 6 mismatch-repair (MMR) deficiency genes were reported and compared between racial/ethnic groups using chi-squared or Fischer’s exact tests. The threshold used for statistical significance was a two-sided alpha of 0.05. Results Among 317 tumor samples of LGSOC, there were high rates of MAP-K pathway gene mutations but low rates of HRD, MMR and TP53 gene mutations (Table 1). Non-Hispanic Black patients had significantly higher rates of KRAS mutations compared to non-Hispanic White patients (6/7, 86% vs 48/178, 27%, p&amp;lt;0.01). There was no difference in KRAS mutation frequency among Asian (6/17, 35%), Hispanic (7/24, 29%) and Native American (2/2, 100%) patients when compared to non-Hispanic White patients. BRAF mutations were less common compared to KRAS mutations (32/317, 10%), with no racial/ethnic differences in mutation frequency. Conclusion High rates of MAP-K pathway mutations in LGSOC support development and trials of drugs targeting this pathway, such as MEK protein inhibitors. Furthermore, prior literature has demonstrated the prognostic advantage of KRAS and BRAF mutations in LGSOC as well as the association of KRAS mutations with progression of serous borderline tumors to LGSOC. These racial/ethnic differences in frequencies of these mutations are thus hypothesis generating for clinical research to evaluate the impact of race/ethnicity on the development and prognosis of this rare ovarian cancer. Mutation frequencies of HR, MAP-kinase, MMR and TP53 genes in low-grade serous ovarian cancer Gene No. of samples with ≥1 mutation No. of samples profiled for mutation Mutation frequency BRCA1 3 287 1.05 BRCA2 7 287 2.44 BRIP1 5 271 1.85 CHEK2 2 278 0.72 BARD1 2 239 0.84 RAD51B - - - RAD51C - - - RAD51D 2 246 0.81 PALB2 2 279 0.72 KRAS 93 317 29.34 NRAS 29 317 9.15 BRAF 32 317 10.09 EIF1AX 14 144 9.72 MSH2 3 275 1.09 MSH3 1 113 0.88 MSH6 6 286 2.10 MLH1 1 317 0.32 MLH3 3 96 3.13 PMS2 1 270 0.37 TP53 12 317 3.79 Citation Format: Muhammad Danyal Ahsan, Emily M. Webster, Sarah R. Levi, Natalie T. Nguyen, Juan R. Cubillos-Ruiz, Evelyn Cantillo, Eloise Chapman-Davis, Melissa K. Frey, Kevin Holcomb. Racial and ethnic differences in the mutational landscape of low-grade serous ovarian cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4258.

The association of KRAS mutation with primary tumor location and survival in patients undergoing resection of colorectal cancers and synchronous liver metastases.

Recent evidence suggests that a mutation in the KRAS gene has a significant impact on the clinical behavior and prognosis of patients with metastatic colorectal cancer. The KRAS mutation (m-KRAS) has been associated with decreased survival among patient undergoing treatment with a curative and palliative intent. This is believed to be secondary to a reduced response to anti-EGFR chemotherapy agents and a more intrinsically aggressive biology. The aims of this study were to identify risk factors for m-KRAS in patients with curatively resected colorectal cancer and synchronous liver metastases and to assess its association with disease-specific survival (DSS). The Surveillance, Epidemiology and End Results (SEER) Database was surveyed for patients undergoing resection of colorectal cancer and synchronous liver metastases from 2010 to 2015. A total of 806 patients were included, of which 40% hadm-KRAS. Right-sided primary lesions (OR 2.56, 95% CI: 1.90-3.44, P<0.001) and African-American ethnicity (OR 1.58, 95% CI: 1.05-2.40, P=0.03) were independently associated with m-KRAS on multivariable analysis. Compared to wild-type KRAS (wt-KRAS), m-KRAS was associated with decreased 3- and 5-year DSS (59% vs. 50% and 29% vs. 21%, respectively, P=0.024). After adjusting for confounders, a decreased DSS was observed in patients with right-sided lesions (HR 1.68, 95% CI: 1.32-2.12, P<0.001), while m-KRAS was associated with a trend toward decreased DSS (HR 1.15, 95% CI: 0.91-1.46, P=0.24). In patients undergoing surgical resection of colorectal cancer and synchronous liver metastases, m-KRAS was associated with right-sided lesions and African-American ethnicity. Compared to wt-KRAS, m-KRAS was associated with a reduced DSS. Additionally, right-sided lesions were an independent negative prognostic factor for DSS.

KRAS MUTATIONS DRIVE ADENOMATOID ODONTOGENIC TUMOR

Objective KRAS is the most frequently mutated oncogene in human neoplasms and we have previously reported KRAS p.G12V mutations in adenomatoid odontogenic tumors (AOT). We aimed to expand this cohort of samples and to test the association of KRAS mutations with clinical and histopathological parameters. A convenience sample of 30 AOT cases was included in the study. The hotpot KRAS p.G12V mutation was assessed by TaqMan allele-specific qPCR and codon 12 was direct sequenced. Clinical information obtained included patients age, tumor site, association of the lesion with impacted teeth and clinical tumor size. In addition, tumor capsule thickness was evaluated by morphometric analysis. Statistical analysis was carried out to test the association of KRAS codon 12 mutations with clinico-pathological parameters. Findings Molecular results confirmed KRAS p.G12V mutation in 14/23 cases, and p.G12R in 1/23. Eight cases were wild-type and samples from 7 cases failed amplification. Codon 12 mutations were not associated with any of the clinicopathological parameters tested (p>0.05). Conclusion AOT show high frequency of KRAS codon 12 mutations (15/23, 65%), which occur irrespectively of patients’ age, tumor location, association with impacted teeth, tumor clinical size or histopathological capsule thickness. Supported by FAPEMIG, CAPES and CNPq/Brazil.

Gene Promoter Methylation in Endometrial Carcinogenesis

Up to 60% of untreated atypical hyperplastic endometrium will develop into endometrial carcinoma (EC), and for those who underwent a hysterectomy a coexisting EC is found in up to 50%. Gene promoter methylation might be related to the EC development. The aim of this study is to determine changes in gene promoter profiles in normal endometrium, atypical hyperplasia (AH) and EC in relation to K-Ras mutations. A retrospective study was conducted in patients diagnosed with endometrial hyperplasia with and without subsequent EC. Promoter methylation of APC, hMLh1, O6-MGMT, P14, P16, RASSF1, RUNX3 was analysed on pre-operative biopsies, and correlated to the final histological diagnosis, and related to the presence of K-Ras mutations. In the study cohort (n=98), differences in promoter methylation were observed for hMLH1, O6-MGMT, and P16. Promoter methylation of hMLH1 and O6-MGMT gradually increased from histologically normal endometrium to AH to EC; 27.3, 36.4% and 38.0% for hMLH1 and 8.3%, 18.2% and 31.4% for O6-MGMT, respectively. P16 promoter methylation was significantly different in AH (7.7%) compared to EC (38%). K-Ras mutations were observed in 12.1% of AH, and in 19.6% of EC cases. No association of K-Ras mutation with promoter methylation of any of the tested genes was found. In conclusion, hMLH1 and O6-MGMT promoter methylation are frequently present in AH, and thus considered to be early events in the carcinogenesis of EC, whereas P16 promoter methylation was mainly present in EC, and not in precursor lesions supporting a late event in the carcinogenesis.

The association of KRAS mutation in circulating-tumor DNA and survival in patients with pancreatic cancer

Circulating-tumor DNA (ctDNA) has been known to be released from tumor cells and investigated potential biomarkers for therapeutic responses. However, the role of ctDNA in pancreatic cancer has not been well studied. Here we selected KRAS mutation which has been known common over 95% of pancreatic ductal adenocarcinoma (PDA) and evaluated applicability as a prognostic marker through the quantitative analysis of ctDNA and KRAS mutation in the patients with PDA. Total of 147 PDA patients were enrolled in the study. The concentration and fraction of KRAS mutation were measured by KRAS screening multiplex droplet digital PCR kit (Biorad, USA) in plasma. Median of ctDNA concentration, KRAS mutant concentration and fractional abundance were 425 ng/mL, 0.11 copies/uL and 0.35 %, respectively. KRAS mutant concentration and fractional abundance showed the association with poor survival in OS (P =0.007 and P < .001). When we analyzed the receiver operating characteristic (ROC) curve to determine whether KRAS mutation in ctDNA have additive benefits with well-known tumor markers CA19-9, combined with KRAS mutation concentration or KRAS fractional abundance, the value of area under the curve (AUC) was significantly higher than the value calculated as CA19-9 alone. This study represents that KRAS mutant concentration and fractional abundance in ctDNA could be prognostic marker in pancreatic cancer.

Exploring the association between KRAS mutations and depression in non-small cell lung cancer (NSCLC) patients.

114 Background: Previous studies have demonstrated a higher rate of depression in cancer patients harboring KRAS mutations. We evaluated the feasibility of using secondary Electronic Medical Record (EMR) data to examine the association of KRAS mutations with depression in NSCLC patients. Methods: We identified cases with NSCLC from an institutional Cancer Registry. Tumor molecular profiles were obtained as standard of care. Depression was assessed using the Patient Health Questionnaire-2 (PHQ-2), which is part of the institution’s universal Distress Screening tool completed at the time of clinic visit. PHQ-2 score of 2 and above was considered positive for depression. Data was extracted from EMR via Clinical Data Exchange Network bioinformatics tool and confirmed by chart review. Results: Of the 692 NSCLC patients, KRAS status was known in 174 cases: 40 (23%) were KRAS mutated and 134 (77%) were KRAS wild type. 101 (58%) had stage 4 NSCLC. PHQ-2 score was 0 in 146 (83.9%), 1 in 7 (4%), 2 in 19 (10.9%), and &gt; 2 in 2 (1.1%). The rate of positive PHQ-2 for KRAS mutated vs wild type was 15% vs 11% (p = NS). Conclusions: This study in patients with NSCLC did not demonstrate an association between KRAS mutation and depression. Bioinformatics studies harnessing EMR data are a feasible platform to assess the association of genomic data with clinical outcomes and validated algorithms are needed.

Association of KRAS mutations detected via liquid biopsy in metastatic non-small cell lung cancer patients with high levels of FDG-PET SUV.

e20594 Background: We had previously evaluated the relationship between FDG-PET SUV with TP53 and KRAS mutations in formalin fixed paraffin embedded tissue (FFPE) in non-small cell lung cancers (NSCLC) in which genomic profiling had been performed. Considering FDG-PET SUV as a surrogate of glycolysis, we found TP53 and KRAS mutations were associated with increased glycolytic activity. The aim for this study was to evaluate KRAS and TP53 in circulating tumor DNA (ctDNA) in relation to FDG-PET SUV in a different cohort of NSCLCs in which genomic profiling was performed on peripheral blood. Methods: All stage IV NSCLC patients with genomic analysis from ctDNA and baseline FDG-PET scans between December 2014 and November 2016 were included. Associations between KRAS and TP53 mutations and maximal standard uptake value (SUVmax) were assessed using the Mann-Whitney and Kruskal-Wallis test. A subset analysis studying all KRAS positive patients from FFPE and ctDNA was performed based on the specific KRAS mutation. Results:122 patients had FDG-PET scans and genomic analyses of their circulating tumor cells. 62 (51%) patients had a TP53 mutation, 20 (17%) patients had a KRAS mutation, and 13 (11%) patients had both TP53 and KRAS mutations. Patients with a KRAS mutation had a higher SUVmax with a mean of 12.32 (p = 0.019). The presence of TP53 alone or concurrent TP53/KRAS was not significantly related to SUVmax. Analyzing 48 patients with KRAS mutation from FFPE and ctDNA assay, 16 patients had mutations of G12C and 9 patients had G12V. The presence of the G12C mutation was particularly highly correlated with higher SUVmax with a mean of 17.68 (p = 0.0006). Conclusions: In analyzing ctDNA, a larger cohort, mutations in KRAS had the strongest correlation with increased SUVmax. Targeting glycolysis and cellular metabolism could be a potential therapeutic strategy for patients with KRAS mutations. Although individual numbers are small, KRAS subtype analysis showed the presence of the G12C mutation might have the strongest relationship with SUV max and increased glycolysis.

319. Association of KRAS mutation with multi-site metastasis and lung-specific metastasis in advanced colorectal cancers

319. Association of KRAS mutation with multi-site metastasis and lung-specific metastasis in advanced colorectal cancers

Interaction of KRAS somatic mutation and colorectal carcinoma and its association with differential DNA methylation.

577 Background: We examined if KRAS somatic mutation in colorectal carcinoma (CRC) is associated with differential tumor DNA methylation. Methods: We did a genome-wide methylation assay (450K) for a total of 250 paired samples from 125 CRC patients (m = 72, f = 53) at different stages (stage 1: 25, stage II: 33 and stage III: 67). Of them 101 had left-sided CRC (descending colon to rectum); 30 had MSI, and 34 had somatic mutation in KRAS (rs112445441). Results: Frequency of KRAS mutation was not different between right and left-sided CRC (29% vs. 27%). But, like other series, MSI was more frequent in the right-sided tumor (54% vs. 17%, p = 0.003). In patients with wild type KRAS tumor (n = 91), paired comparison between tumor and corresponding normal tissue identified a total of 1244 tumor-specific differential methylation loci (DML) covering 532 genes that were significant at FDR 0.001 and magnitude of difference ≥ 20%; But similar analysis in patients with KRAS mutation (n = 34) revealed 7612 tumor-specific DML covering 2357 genes - suggesting an association of KRAS mutation and DNA methylation. We also found that MSI in tumor tissue was associated with DNA methylation change too. Next, we identified 726 genes that are markedly differentially methylated in tumor compared to corresponding normal tissue only in presence of KRAS mutation, irrespective of MSI status, staging, and location of tumor (KRAS mutation associated tumor-specific genes – list enriched in GO ontology “developmental process”, “biological regulation”). We also identified 241 genes that are differentially methylated in tumor compared to normal tissue irrespective of KRAS mutation, MSI status, staging, and location of tumor. (common tumor-specific genes) Conclusions: KRAS somatic mutation is independently associated with methylation changes in a number of genes related to carcinogenesis in CRC.

Survival outcome according to KRAS mutation status in newly diagnosed patients with stage IV non-small cell lung cancer treated with platinum doublet chemotherapy.

Mutations (MT) of the KRAS gene are the most common mutation in non-small cell lung cancer (NSCLC), seen in about 20-25% of all adenocarcinomas. Effect of KRAS MT on response to cytotoxic chemotherapy is unclear. We undertook a single-institution retrospective analysis of 93 consecutive patients with stage IV NSCLC adenocarcinoma with known KRAS and EGFR MT status to determine the association of KRAS MT with survival. All patients were treated between January 1, 2008 and December 31, 2011 with standard platinum based chemotherapy at the University of Pennsylvania. Overall and progression free survival were analyzed using Kaplan-Meier and Cox proportional hazard methods. All patients in this series received platinum doublet chemotherapy, and 42 (45%) received bevacizumab. Overall survival and progression free survival for patients with KRAS MT was no worse than for patients with wild type KRAS. Median overall survival for patients with KRAS MT was 19 months (mo) vs. 15.6 mo for KRAS WT, p = 0.34, and progression-free survival was 6.2 mo in patients with KRAS MT vs. 7 mo in patients with KRAS WT, p = 0.51. In multivariable analysis including age, race, gender, and ECOG PS, KRAS MT was not associated with overall survival (HR 1.12, 95% CI 0.58-2.16, p = 0.74) or progression free survival (HR 0.80, 95% CI 0.48-1.34, p = 41). Of note, receipt of bevacizumab was associated with improved overall survival only in KRAS WT patients (HR 0.34, p = 0.01). KRAS MT are not associated with inferior progression-free and overall survival in advanced NSCLC patients treated with standard first-line platinum-based chemotherapy.

Abstract LB-253: A comprehensive evaluation of immune checkpoints ligands (ICPLs) in more than 1,000 cancer cell lines (CCLs) identifies specific expression patterns

Abstract Background: Targeting ICPs pathways is a promising approach for cancer therapy. Many interactions may exist between ICPLs expressed by antigen-presenting cells (e.g. tumor cells) and receptors on T cells. ICPLs expression in tumor cells can be upregulated by constitutive oncogenic signaling, independently of signals from the microenvironment. Our goal was to identify specific patterns of ICPLs expression across tumor types. Material and methods: Transcript expression levels of IPCLs (PDL1, PDL2, CD80, CD86, B7RP1, B7H3, B7H4, HVEM, CD137L, OX40L, CD70, CD40, and GAL9) and MHC I &amp; II were analyzed in 1,036 human CCLs from the Cancer Cell Line Encyclopedia. An unsupervised hierarchical clustering analysis was performed and the association of KRAS mutation with ICPLs expression was tested. Results: B7H3 was the most widely and highly expressed. A total of 9 clusters with clear patterns were observed (A &amp; B1-8) including 15% (A), 15% (B1), 17% (B2), 3% (B3), 6% (B4), 16% (B5), 9% (B6), 10% (B7) and 9% (B8) of the CCLs. Some malignancies were mostly represented in one cluster (breast, kidney), others in 2 clusters [neuroblastoma, small-cell lung cancer (SCLC)], but the majority were widely distributed among ≥ 3 clusters [non-small cell lung cancer (NSCLC), head&amp;neck (H&amp;N), melanoma, endometrium, colorectal (CRC), sarcomas]. Cluster A included hematological malignancies (HM) (71%) and melanoma (14%) CCLs expressing high levels of MHCII , B7RP1, CD137L, CD70, CD80, CD86, GAL9, HVEM, and/or OX40L. B3 included SCLC (42%) and neuroblastoma (26%) CCLs with low MHCI and ICPLs expression levels. Other clusters were composed of CCLs from various origins. B1 was characterized by high CD137L and CD70 and was mainly represented by kidney (18%), NSCLC (11%), and HM (11%) CCLs. B2 included glioma (15%), NSCLC (14%) and sarcomas (8%) CCLs with high PDL1&amp;2 and OX40L. B4 was enriched in NSCLC (22%) and CRC (18%) lines and was characterized by high expression of MHCII and PDL1 in some CCLs. B5 included NSCLC (18%) and SCLC (15%) among others and was poorly defined in terms of ICPLs expression. B6 included HM (32%), melanoma (16%), endometrium (15%) and gastric (9%) CCLs with high expression of GAL9 and HVEM. B7 included NSCLC (18%), pancreatic (12%), melanoma (10%), glioma (10%) and H&amp;N (5%) CCLs expressing MHCII and high levels of PDL1&amp;2, HVEM, CD137L, CD70 and/or B7H4. B8 included mostly breast (31%), ovarian (13%), H&amp;N (9%) and esophageal (8%) CCLs with high B7-H4 expression levels. KRAS mutation was observed in 143/897 CCLs, mostly in pancreas, NSCLC and CRC CCLs. PDL1 expression was higher in KRAS mutant vs. wild-type NSCLC lines (t-test P=0.0017), while no difference was observed in pancreas and CRC. Conclusion: Patterns of expression of ICPLs ligands are not mainly associated with the tissue of origin. Various ICPLs may be co-expressed by the same tumor cell. The effect of oncogenic drivers on ICPLs expression levels maybe context-dependent. Citation Format: Aurélie Swalduz, Jean-Philippe Foy, Xiaojun Jiang, Roberto Incitti, Sylvie Chabaud, David Pérol, Jean-Yves Blay, Olivier Trédan, Isabelle Treilleux, Aurélien Marabelle, Maurice Pérol, Christophe Caux, Pierre Saintigny. A comprehensive evaluation of immune checkpoints ligands (ICPLs) in more than 1,000 cancer cell lines (CCLs) identifies specific expression patterns. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-253. doi:10.1158/1538-7445.AM2014-LB-253

Association of KRAS mutations in cell-free circulating tumor DNA with occurrence of resistance to TKIs in NSCLC.

11056 Background: EGFR activating mutations predict sensitivity to tyrosine kinase inhibitors (TKIs) in NSCLC. Although initial responses are commonly observed, patients inevitably progress as a co...

KRAS mutations are associated with solid growth pattern and tumor-infiltrating leukocytes in lung adenocarcinoma

KRAS mutations define a clinically distinct subgroup of lung adenocarcinoma patients, characterized by smoking history, resistance to EGFR-targeted therapies, and adverse prognosis. Whether KRAS-mutated lung adenocarcinomas also have distinct histopathological features is not well established. We tested 180 resected lung adenocarcinomas for KRAS and EGFR mutations by high-sensitivity mass spectrometry-based genotyping (Sequenom) and PCR-based sizing assays. All tumors were assessed for the proportion of standard histological patterns (lepidic, acinar, papillary, micropapillary, solid, and mucinous), several other histological and clinical parameters, and TTF-1 expression by immunohistochemistry. Among 180 carcinomas, 63 (35%) had KRAS mutations (KRAS+), 35 (19%) had EGFR mutations (EGFR+), and 82 (46%) had neither mutation (KRAS−/EGFR−). Solid growth pattern was significantly over-represented in KRAS+ carcinomas: the mean±s.d. for the amount of solid pattern in KRAS+ carcinomas was 27±34% compared with 3±10% in EGFR+ (P<0.001) and 15±27% in KRAS−/EGFR− (P=0.033) tumors. Furthermore, at least focal (≥20%) solid component was more common in KRAS+ (28/63; 44%) compared with EGFR+ (2/35; 6%; P<0.001) and KRAS−/EGFR− (21/82; 26%; P=0.022) carcinomas. KRAS mutations were also over-represented in mucinous carcinomas and were significantly associated with the presence of tumor-infiltrating leukocytes and heavier smoking history. EGFR mutations were associated with non-mucinous non-solid patterns, particularly lepidic and papillary, lack of necrosis, lack of cytological atypia, hobnail cytology, TTF-1 expression, and never/light smoking history. In conclusion, extended molecular and clinicopathological analysis of lung adenocarcinomas reveals a novel association of KRAS mutations with solid histology and tumor-infiltrating inflammatory cells and expands on several previously recognized morphological and clinical associations of KRAS and EGFR mutations. Solid growth pattern was recently shown to be a strong predictor of aggressive behavior in lung adenocarcinomas, which may underlie the unfavorable prognosis associated with KRAS mutations in these tumors.

Association of KRAS mutation with worse recurrence-free survival and site of metastatic progression after resection of hepatic colorectal metastases.

3609 Background: There are conflicting results regarding the influence of KRAS mutation status and outcome in patients (pts) with colorectal cancer. A recent report suggested worse outcome in KRAS mutated (MUT) pts who underwent resection of hepatic metastases (Karagkounis et al, ASCO 2012). Methods: Recurrence patterns and survival were evaluated in 169 patients who had undergone resection of liver metastases, then received adjuvant hepatic arterial infusion and systemic chemotherapy, and for whom KRAS data were available. Kaplan-Meier methods were used to estimate recurrence free survival (RFS) and overall survival (OS). Log-rank test was used to determine whether survival functions differed by KRAS mutation status. Cumulative incidence function was used to estimate the probability of time from adjuvant therapy to bone, brain, lung and liver metastases separately. Mutations in KRAS (codons 12, 13) were detected using the iPLEX assay (Sequenom, Inc). Results: Median follow-up for the entire cohort was 38.8 months. 118 were KRAS wildtype (WT), and 51 were KRAS MUT (45 G12, 5 G13, 1 K117N). The 3 year RFS was 48% [95%CI: 37-58%] for KRAS WT pts and 30% [15-44%] for MUT pts (p&lt;0.01). OS at 3 years was 96% [88-98%] for KRAS WT and 80% [61-90%] for MUT pts (p=0.08). Cumulative incidence of developing bone, brain, lung, and liver metastases by 2 years is presented in Table 1. The cumulative incidence of metastases to bone at 2 years was 0% and 13.7% in KRAS WT versus MUT pts (p&lt;0.01), to brain 0% versus 4.6% for KRAS WT versus MUT (p=0.05), and to lung 27% versus 47.5% in KRAS WT versus MUT pts (p&lt;0.01). Conclusions: In pts who have had liver resection followed by adjuvant therapy, those with KRAS MUT have a worse RFS and seemingly worse OS than those who are KRAS WT. Also, patients with KRAS MUT appear more likely to develop bone, brain, and lung metastases. Further investigation of a larger number of patients is warranted. [Table: see text]

Evaluation of the prognostic/predictive role of tumor EGFR and KRAS mutations in Greek metastatic non-small cell lung cancer patients treated with first-line chemotherapy.

e19048 Background: KRAS mutations are reported in 20-25% of non-small cell lung cancer (NSCLC). Little is known about the prognostic/predictive role of KRAS in advanced NSCLC, with conflicting results among small studies. Recent evidence showed that KRAS mutations could predict for worse outcome in patients treated with platinum-based adjuvant chemotherapy. Methods: KRAS and EGFR genotypes were evaluated in 414 NSCLC patients with available clinical data, diagnosed from March 2000 to December 2012 (tissue blocks from the HeCOG tumor repository). KRAS and EGFR mutations were associated with clinicopathological parameters (mutated vs. wild-type). Outcome comparisons were performed in 214 metastatic patients with treatment data available, following 1st-line chemotherapy without tyrosine kinase inhibitors. Results: The majority of the patients were male (80%), current smokers (53%), with adenocarcinoma (AC) histology (65%). EGFR mutations were found in 10% and KRAS mutations in 17% of all histological types, while in AC they were 14% and 21%, respectively. Most EGFR mutations were classical (79%), while most common KRAS mutations were p.G12C (39%), p.G12D (30%) and p.G12V (15%). Two tumors had concurrent EGFR and KRAS mutations. EGFR mutations were significantly associated with female gender, AC histology and non-smoking status, as previously described. KRAS mutations were associated with AC histology and younger age (&lt;60). At a median follow-up of 31 months, EGFR status did not show any significant associations with OS or PFS, while KRAS mutations were prognostic for worse OS compared to KRAS and EGFR wild-type tumors (HR=1.67, CI=1.08-2.59, p=0.021). This effect was also significant (p=0.022) in the presence of treatment type, with platinum-based therapy being a positive prognostic factor for OS (HR=0.62, CI=0.4-0.92, p=0.019). The association of KRAS mutations with PFS was not significant. Conclusions: EGFR and KRAS genotype incidences are presented for the first time for Greek metastatic NSCLC patients. In this setting, the presence of KRAS mutations significantly increases and platinum 1st-line treatment decreases the risk of death.

Characteristics of Advanced- and Non Advanced Sporadic Polypoid Colorectal Adenomas: Correlation to KRAS Mutations

The malignant potential of colorectal adenomas highly correlates with their pathological characteristics, such as size, histology and grade of dysplasia. Currently, based on these parameters, adenomas are characterized as "non-advanced or advanced" and patient surveillance is adjusted accordingly. The aim of this study was to investigate the correlation between the KRAS mutations and characteristics of non-advanced and advanced colorectal adenomas for predicting the risk of increased malignant potential of adenomas that may influence the decision to offer follow-up endoscopic surveillance. We used a mutagenic polymerase chain reaction - restriction fragment length polymorphism method to determine KRAS mutations in 164 colorectal sporadic polypoid adenomas (51 non-advanced-, 113 advanced adenomas) and in 40 early colorectal carcinomas. The method of mutation detection was validated according to recommendation for KRAS mutation testing in colorectal carcinoma of the European Quality Assurance Program. The limit of detection of the assay was 3 % mutated DNA with a good reproducibility. Evaluation of pathological characteristics was performed according to European Guidelines for Quality Assurance in Colorectal Cancer Screening and Diagnosis. The morphological parameters of the adenoma such as size, histology, grade of dysplasia are highly correlated with one another: an increasing adenoma size raised the proportion of villous histology and degree of dysplasia (all p < 0.0001). KRAS mutations were detected in 31 % of the non-advanced adenomas, in 57.5 % of the advanced adenomas and in 62.5 % of the early carcinomas. Most mutations occurred at codon 12 rather than at codon 13 (72 %, 82 %, 76 % versus 22 %, 17 %, 24 %, respectively). There was no significant difference in association of KRAS mutation with age, gender, location among non-advanced-, and advanced adenomas and early carcinomas. KRAS mutation was found more often in tubulovillous and villous adenomas, whereas wild-type KRAS was observed more frequently in tubular adenomas (P < 0.0001) and there was an increased prevalence of KRAS mutations in larger adenomas (P < 0.0001). In this study KRAS mutation occurred with the same frequency in adenomas with low-grade (48 %) and high-grade (50 %) dysplasia. KRAS mutation is very strongly associated with a villous architecture and through villous component expansion, KRAS mutations may increase risk of tumor progression in sporadic colorectal polypoid adenomas.