KRAS Tumors Research Articles

Abstract LB142: Metabolically defined body size phenotypes in relation to subsequent colorectal cancer risk

Abstract Overweight and obesity have been linked to increased risk of several diseases, including colorectal cancer, but the underlying mechanisms are not fully known. An earlier study analyzed metabolically defined body size phenotypes in relation to colorectal cancer risk, using combinations of C-peptide (a marker of insulin resistance) and body mass index (BMI). Higher serum C-peptide concentrations were associated with higher colorectal cancer risk in both overweight and normal weight individuals compared to individuals with low levels of C-peptide and normal weight. The aim of the present study was to see if these results could be replicated and to further explore the role of metabolism and body size phenotypes in colorectal cancer subtypes. We conducted a nested case-control study of 1010 individuals with colorectal cancer and 1010 individually matched (age, sex, cohort, year of blood sampling and data collection, number of freeze-thaw cycles of plasma samples and fasting status at blood sampling) control participants from the population-based Northern Sweden Health and Disease Study. The blood samples and data used in our analyses were collected at a mean of 9.7 years prior to case diagnosis. Participants were categorized as (1) metabolically healthy/normal weight (BMI < 25 kg/m2), (2) metabolically healthy/overweight (BMI ≥ 25 kg/m2), (3) metabolically unhealthy/normal weight (BMI < 25 kg/m2), or (4) metabolically unhealthy/overweight (BMI ≥ 25 kg/m2), where metabolically healthy was defined as C-peptide in the lowest tertile, as in the previous study. We used multivariable conditional logistic regression to calculate odds ratios and confidence intervals and adjusted for tobacco smoking, recreational physical activity and alcohol consumption as potential confounders. In our preliminary results, metabolically unhealthy/overweight individuals had a significantly higher risk of developing colorectal cancer compared to metabolically healthy/normal weight individuals (adjusted odds ratio =1.44, 95% CI 1.13-1.85). The odds ratio for metabolically unhealthy/normal weight individuals was 1.23 (95% CI 0.92-1.65) and for metabolically healthy/overweight individuals 1.23 (95% CI 0.89-1.70). These results support the potential of a more nuanced analysis of metabolism and body size to better understand their etiological contribution to colorectal cancer development. To gain more knowledge about how the role of metabolism and body size might differ between tumor subtypes, we will also analyze body size phenotypes in relation to subtypes of colorectal cancer based on anatomical tumor site, KRAS and BRAF mutations and microsatellite instability status of the tumor. Citation Format: Linda Vidman, Simon Knekta, Björn Gylling, Carl Zingmark, Anna Löfgren-Burström, Richard Palmqvist, Sophia Harlid, Bethany Van Guelpen. Metabolically defined body size phenotypes in relation to subsequent colorectal cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB142.

Abstract 4255: Concurrent KRAS and TP53 mutations in pancreatic cancer real-world data (RWD) highlight convergent tumor evolutionary patterns

Abstract Pancreatic cancer is one of the most fatal of all cancers. Pancreatic adenocarcinomas have been historically difficult to treat, in part due to lack of early detection, and due to their resistance to conventional chemotherapy. There has recently been an improved understanding of the biologic processes driving pancreatic tumorigenesis, and an increase in clinical trial options available to patients, especially in the context of KRAS mutation positive pancreatic ductal adenocarcinoma (PDAC). KRAS is a known driver of pancreatic cancer initiation, with concurrent loss of TP53 in many cases. Among all mutated genes in pancreatic cancer, KRAS, TP53, CDKN2A, and SMAD4 are most frequently reported, followed by CDKN2B and ARID1A among others. Mutations in TP53 commonly found in pancreatic cancer are either missense or truncating. The specific type of mutation may be important to note since point mutations may produce dysfunctional proteins that acquire gain of functions that are tumor-promoting, although the most well-agreed upon effects of TP53 mutations stem from the absence or decrease of its normal physiologic functions including cell cycle arrest, apoptosis promotion, DNA damage response triggering, maintenance of cell polarity, and maintenance of genomic stability. Here we present an in-depth multi-dimensional analysis of 29 pancreatic adenocarcinoma patients, consisting of 11 patients with KRAS G12D mutations, 5 patients with KRAS G12V mutations, 3 patients with non-canonical KRAS mutations, and 10 patients with no KRAS mutations identified in their tumors. Individual TP53 mutations were highlighted in the context of associated KRAS mutations and tumor genomic landscape at the time of testing. Real-world data was collected with patient consent through community embedded Oncology Clinical Team (ceOCT) facilitated engagement. Tumor evolution prediction rules were constructed based on mutational landscapes of the 29 patients and evidence published in peer-reviewed journals. Pancreatic cancer patient data from the AACR GENIE Cohort v12.0-public database and the cBioportal for Cancer Genomics public site was subsequently used for testing predicted tumor evolutionary trajectories. Here we describe multiple independent combinations of KRAS and TP53 mutations leading to convergent functional outcomes for tumor cells, in the context of patient-specific gene mutation landscapes. Recurrent patterns of paired mutations with common cellular function dysregulation outcomes highlight core underlying mechanisms of pancreatic tumor evolution. Citation Format: Kaumudi Bhawe, Adrienne Nugent, Deb Christensen, Lauren Levine, Emma Shtivelman. Concurrent KRAS and TP53 mutations in pancreatic cancer real-world data (RWD) highlight convergent tumor evolutionary patterns. [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 4255.

Abstract 4045: DCC-3084, a RAF dimer inhibitor, broadly inhibits BRAF class I, II, III, BRAF fusions, and RAS-driven solid tumors leading to tumor regression in preclinical models

Abstract Background: Mutations in the RAS/MAPK pathway are a frequent driver of cancer, with oncogenic RAS or RAF mutations occurring in >30% of all cancers. First generation BRAF inhibitors are approved for use for tumors with Class I BRAF mutations (V600X). However, these drugs are not efficacious in RAF dimer mutant and RAS mutant cancers due to paradoxical activation of RAF dimers. Herein, we describe DCC-3084, a potent and selective investigational Switch Control inhibitor of BRAF and CRAF kinase dimers that targets Class I, II and III BRAF mutations, BRAF fusions, and BRAF/CRAF heterodimers. DCC-3084 combines with inhibitors of additional nodes in the MAPK pathway to potentially target a large unmet medical need in RAS and RAF mutant cancers. Methods: Inhibition of RAF kinases, including off-rate analysis, was measured using recombinant enzymes. X-ray crystallography was used for structure-based drug design. Cellular proliferation was measured using resazurin to monitor cell viability. Synergy in cells was measured using BLISS scores and curve shift analysis. Inhibition of ERK or RSK phosphorylation was measured by AlphaLISA or ELISA. Pharmacokinetics (PK) in the plasma, brain and CSF compartments were measured following oral dosing in Wistar rats. RAF and RAS mutant mouse xenograft models were used to assess PK, pharmacodynamics (PD), and efficacy. Results: DCC-3084 is a potent and selective Switch Control inhibitor of RAF dimers that was designed to target Class I, II, III BRAF mutants, BRAF fusions, and BRAF/CRAF heterodimers. DCC-3084 inhibits BRAF and CRAF, exhibiting slow off-rates (t1/2 >20 hr). Potent single-agent inhibition of MAPK pathway signaling and cellular proliferation was observed in a wide range of Class I, II, III BRAF and BRAF fusion altered cell lines. Synergy was observed in combination with inhibitors of other nodes in the RAS/MAPK pathway in RAS mutant cell lines. DCC-3084 was demonstrated to be CNS penetrable and exhibited dose dependent oral exposure with robust inhibition of the RAS/MAPK pathway in PK/PD models. DCC-3084 accumulated in tumor tissue relative to plasma, further demonstrating a favorable pharmaceutical profile. Oral treatment of DCC-3084 as a single agent resulted in tumor regression in BRAF mutant and KRAS Q61K mutant mouse xenograft models and tumor growth inhibition in KRAS G12C/D mutant models. Additionally, DCC-3084 in combination with a MEKi resulted in tumor regression in KRAS mutant models. Conclusions: The Switch Control inhibitor DCC-3084 broadly inhibits Class I, II and III BRAF mutations, BRAF fusions, and BRAF/CRAF heterodimers leading to tumor regression in preclinical models. The overall preclinical profile of DCC-3084 supports IND-enabling activities towards clinical development in a key area of unmet medical need in RAS and RAF mutant cancers. Citation Format: Stacie L. Bulfer, Bertrand Le Bourdonnec, Jeffery D. Zwicker, Yu Mi Ahn, Gada Al-Ani, Hikmat Al-Hashimi, Chase Crawley, Kristin M. Elliott, Saqib Faisal, Andrew M. Harned, Cale L. Heiniger, Molly M. Hood, Salim Javed, Michael Kennedy, Joshua W. Large, Cynthia B. Leary, Wei-Ping Lu, Kylie Luther, Max D. Petty, Hunter R. Picard, Justin T. Proto, Yeni K. Romero, Forrest A. Stanley, Kristen L. Stoltz, Daniel C. Tanner, Hanumaiah Telikepalli, Mary J. Timson, Lakshminarayana Vogeti, Subha Vogeti, Sihyung Yang, Lexy H. Zhong, Bryan D. Smith, Daniel L. Flynn. DCC-3084, a RAF dimer inhibitor, broadly inhibits BRAF class I, II, III, BRAF fusions, and RAS-driven solid tumors leading to tumor regression in preclinical models. [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 4045.

KRAS G12C mutated advanced non-small cell lung cancer (NSCLC): Characteristics, treatment patterns and overall survival from a Danish nationwide observational register study

ObjectivesWe aimed to characterize the advanced NSCLC population in terms of KRAS G12C prevalence, patient characteristics, and survival outcomes after the introduction of immunotherapies. Materials and MethodsWe identified adult patients diagnosed with advanced NSCLC between January 1, 2018 and June 30, 2021 using the Danish health registries. Patients were grouped by mutational status (any KRAS mutation, KRAS G12C, and KRAS/EGFR/ALK wildtype [Triple WT]). We analyzed KRAS G12C prevalence, patient and tumor characteristics, treatment history, time-to-next-treatment (TTNT), and overall survival (OS). ResultsWe identified 7,440 patients of whom 40% (n = 2,969) were KRAS tested prior to the first line of therapy (LOT1). Among the KRAS tested, 11% (n = 328) harbored KRAS G12C. More KRAS G12C patients were women (67%), smokers (86%), had a high (≥50%) level of PD-L1 expression (54%), and more frequently received anti-PD-L1 treatment than any other group. From the date of the mutational test result, OS (7.1–7.3 months) was similar between the groups. OS from LOT1 (14.0 months) and LOT2 (10.8 months), and TTNT from LOT1 (6.9 months) and LOT2 (6.3 months) was numerically longer for the KRAS G12C mutated group compared to any other group. However, from LOT1 and LOT2, the OS and TTNT were comparable when stratifying the groups by PD-L1 expression level. Regardless of the mutational group, OS was markedly longer for patients with high PD-L1 expression. ConclusionIn patients diagnosed with advanced NSCLC after the implementation of anti-PD-1/L1 therapies, the survival in KRAS G12C mutated patients is comparable to patients with any KRAS mutation, Triple WT, and all NSCLC patients.

143D, a novel selective KRASG12C inhibitor exhibits potent antitumor activity in preclinical models.

The KRASG12C mutant has emerged as an important therapeutic target in recent years. Covalent inhibitors have shown promising antitumor activity against KRASG12C-mutant cancers in the clinic. In this study, a structure-based and focused chemical library analysis was performed, which led to the identification of 143D as a novel, highly potent and selective KRASG12C inhibitor. The antitumor efficacy of 143D in vitro and in vivo was comparable with that of AMG510 and of MRTX849, two well-characterized KRASG12C inhibitors. At low nanomolar concentrations, 143D showed biochemical and cellular potency for inhibiting the effects of the KRASG12C mutation. 143D selectively inhibited cell proliferation and induced G1-phase cell cycle arrest and apoptosis by downregulating KRASG12C-dependent signal transduction. Compared with MRTX849, 143D exhibited a longer half-life and higher maximum concentration (Cmax) and area under the curve (AUC) values in mouse models, as determined by tissue distribution assays. Additionally, 143D crossed the blood‒brain barrier. Treatment with 143D led to the sustained inhibition of KRAS signaling and tumor regression in KRASG12C-mutant tumors. Moreover, 143D combined with EGFR/MEK/ERK signaling inhibitors showed enhanced antitumor activity both in vitro and in vivo. Taken together, our findings indicate that 143D may be a promising drug candidate with favorable pharmaceutical properties for the treatment of cancers harboring the KRASG12C mutation.

Novel mutant KRAS addiction signature predicts response to the combination of ERBB and MEK inhibitors in lung and pancreatic cancers

KRAS mutations are prevalent in pancreatic and lung cancers, but not all mutant (mt) KRAS tumors are addicted to mt KRAS. Here, we discovered a 30-gene transcriptome signature "KDS30" that encodes a novel EGFR/ERBB2-driven signaling network and predicts mt KRAS, but not NRAS or HRAS, oncogene addiction. High KDS30 tumors from mt KRAS lung and pancreatic cancer patients are enriched in genes upregulated by EGFR, ERBB2, mt KRAS or MEK. EGFR/ERBB2 (neratinib) and MEK (cobimetinib) inhibitor combination inhibits tumor growth and prolongs mouse survival in high, but not low, KDS30 mt KRAS lung and pancreatic xenografts, and is synergistic only in high KDS30 mt KRAS patient-derived organoids. Furthermore, mt KRAS high KDS30 lung and pancreatic cancer patients live significantly shorter lives than those with low KDS30. Thus, KDS30 can identify lung and pancreatic cancer patients whose tumors are addicted to mt KRAS, and predicts EGFR/ERBB2 and MEK inhibitor combination response.

Detection of circulating KRAS mutant DNA in extracellular vesicles using droplet digital PCR in patients with colon cancer.

Extracellular vesicles secreted by tumor cells contain double-stranded DNA called extracellular vesicle DNA (evDNA). EvDNA is genomic DNA that reflects cancer driver mutations. However, the significance of evDNA analysis in the diagnosis and surveillance of colon cancer remains unclear. This study aimed to investigate the clinical utility of extracellular vesicles and evDNA isolated from the plasma of colon cancer patients harboring KRAS G12D and G13D mutations. Cell-free DNA (cfDNA) and evDNA were collected from the plasma of 30 patients with colon cancer. KRAS mutation status (G12D and G13D) was detected using a droplet digital polymerase chain reaction assay (ddPCR). Sensitivity and specificity were evaluated in patients with wild-type KRAS tumors. Mutation status was correlated with carcinoembryonic antigen (CEA) levels and overall survival (OS). Thirty cfDNA and evDNA pairs showed a KRAS fractional abundance (FA) ranging from 0 to 45.26% and 0 to 83.81%, respectively. When compared with eight wild-type KRAS samples, cfDNA exhibited 70% sensitivity and 100% specificity, whereas evDNA achieved 76.67% sensitivity and 100% specificity. The concentration of evDNA was significantly lower than that of cfDNA, but it obtained a higher FA than cfDNA, while showing a positive correlation with CEA. Our findings demonstrate the feasibility of evDNA as a complementary tool to aid current methods of patient evaluation in the diagnosis and surveillance of colon cancer.

AN OMNIBUS TEST FOR DETECTION OF SUBGROUP TREATMENT EFFECTS VIA DATA PARTITIONING.

Late-stage clinical trials have been conducted primarily to establish the efficacy of a new treatment in an intended population. A corollary of population heterogeneity in clinical trials is that a treatment might be effective for one or more subgroups, rather than for the whole population of interest. As an example, the phase III clinical trial of panitumumab in metastatic colorectal cancer patients failed to demonstrate its efficacy in the overall population, but a subgroup associated with tumor KRAS status was found to be promising (Peeters et al. (Am. J. Clin. Oncol. 28 (2010) 4706-4713)). As we search for such subgroups via data partitioning based on a large number of biomarkers, we need to guard against inflated type I error rates due to multiple testing. Commonly-used multiplicity adjustments tend to lose power for the detection of subgroup treatment effects. We develop an effective omnibus test to detect the existence of, at least, one subgroup treatment effect, allowing a large number of possible subgroups to be considered and possibly censored outcomes. Applied to the panitumumab trial data, the proposed test would confirm a significant subgroup treatment effect. Empirical studies also show that the proposed test is applicable to a variety of outcome variables and maintains robust statistical power.

Kristen Rat Sarcoma Viral Oncogene Mutations in Colorectal Carcinomas at the University Teaching Hospital in Lusaka, Zambia

Background: The second leading cause of cancer-related deaths worldwide is colorectal cancer. With an incidence rate of 4.8 per 100,000, this is Zambia’s sixth most prevalent cancer;
 
 Methods: This laboratory-based, cross-sectional study examined the frequency of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation and its association with prognostic factors in colorectal carcinoma cases from the University Teaching Hospital-Adult Hospital (UTHs), Lusaka, Zambia;
 
 Results: Thirty (30) formalin-fixed paraffin-embedded (FFPE) samples collected between June 2017 and June 2018 were sent to the Lancet laboratories and analyzed for KRAS mutations (codons 12 and 13). One FFPE block did not meet the inclusion criteria and was excluded. The demographic and clinicopathological data were analyzed using STATA 12. Males outnumber females by 20 to nine. The average age of the patient was 45 ± 16 years. The rectum was the location of 44.8% of the tumors, with the majority being conventional adenocarcinoma (CAC) (65.6 %). All cases (100%) had advanced-stage (stages 3 and 4) disease; however, only 27.6% of patient tumors exhibited lymphovascular invasion. KRAS mutation was detected in 11 (37.9%) cases and mainly in left-sided tumors (62.5%). KRAS mutations were only detected in CAC and serrated adenocarcinoma subtypes. No significant associations were observed between the KRAS mutation status and tumor or patient’s clinical and sociodemographic factors;
 
 Conclusion: We advocate for incorporating KRAS mutation testing into the standard of care for treating colorectal cancer.

Kristen Rat Sarcoma Viral Oncogene Mutations in Colorectal Carcinomas at the University Teaching Hospital in Lusaka, Zambia

Background: The second leading cause of cancer-related deaths worldwide is colorectal cancer. With an incidence rate of 4.8 per 100,000, this is Zambia’s sixth most prevalent cancer;
 Methods: This laboratory-based, cross-sectional study examined the frequency of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation and its association with prognostic factors in colorectal carcinoma cases from the University Teaching Hospital-Adult Hospital (UTHs), Lusaka, Zambia;
 Results: Thirty (30) formalin-fixed paraffin-embedded (FFPE) samples collected between June 2017 and June 2018 were sent to the Lancet laboratories and analyzed for KRAS mutations (codons 12 and 13). One FFPE block did not meet the inclusion criteria and was excluded. The demographic and clinicopathological data were analyzed using STATA 12. Males outnumber females by 20 to nine. The average age of the patient was 45 ± 16 years. The rectum was the location of 44.8% of the tumors, with the majority being conventional adenocarcinoma (CAC) (65.6 %). All cases (100%) had advanced-stage (stages 3 and 4) disease; however, only 27.6% of patient tumors exhibited lymphovascular invasion. KRAS mutation was detected in 11 (37.9%) cases and mainly in left-sided tumors (62.5%). KRAS mutations were only detected in CAC and serrated adenocarcinoma subtypes. No significant associations were observed between the KRAS mutation status and tumor or patient’s clinical and sociodemographic factors; 
 Conclusion: We advocate for incorporating KRAS mutation testing into the standard of care for treating colorectal cancer.

A Sampling of Highlights from the Literature.

Macrophages can be reprogrammed to promote antitumor responses (by Noah Smith via Wikimedia Commons).Multiple factors contribute to the suppression that occurs in the tumor microenvironment (TME) and this could potentially be alleviated through various mechanisms. Chen et al. find that high potassium in the TME inhibits antitumor responses from tumor-associated macrophages (TAM) via alteration of their metabolism. Blocking this metabolic switch enables TAMs to mount effective antitumor responses. Chryplewicz et al. find that TAMs in glioma are reprogrammed to a proinflammatory phenotype, along with other antitumor remodeling of the TME and tumor vasculature, after treatment with VEGF inhibitors and imipramine (tricyclic anti-depressant). These studies provide insight into multiple mechanisms of TAM suppression and potential targets that can be used to boost antitumor responses.Chen S, …, Wang D. Cell Metab 2022 September 13. DOI:10.1016/j.cmet.2022.08.016.Chryplewicz A, …, Hanahan D. Cancer Cell 2022 September 15;40:1111–27.E9.Dietary intake can affect microbiota and immunity (by the NCI via Wikimedia Commons).Dietary intake can affect antitumor immunity and response to immunotherapy. In a prospective study, Simpson et al. evaluated dietary patterns and microbial signatures of different patient populations and how these factors related to response to neoadjuvant immune checkpoint inhibition. Distinct differences between response groups were observed not only in microbial composition but also in immune-related adverse events. Specific diets, as well as certain microbial compositions, were associated with better treatment outcomes. The data highlight the crossroads of cancer-intrinsic and -extrinsic factors with patient lifestyle, and how these factors together can shape responses to treatment.Simpson RC, …, Long GV. Nat Med 2022 September 12. DOI:10.1038/s41591-022-01965-2.Immunotherapy can overcome resistance to HER2-targeted therapy (from IrinaPav via Wikimedia Commons).HER2-specific antibodies such as trastuzumab are used to treat HER2+ breast cancer, but not all patients respond and some that do ultimately relapse. Using orthogonal approaches, including analysis of tumor tissue and transcriptomic data from trastuzumab-treated patients with HER2+ breast cancer and a fully humanized immunocompetent model of HER2+ breast cancer, Rivas et al. find that a population of TGFβ-activated cancer-associated fibroblasts (CAF) and low IL2 activity associate with trastuzumab resistance. Targeting IL2 to fibroblast activation protein-α (FAP)–expressing cells restores tumor responsiveness to trastuzumab by enhancing NK cell–mediated antibody-dependent cytotoxicity, highlighting the therapeutic potential of targeting stromal components in the tumor microenvironment.Rivas EI, …, Calon A. Nat Commun 2022 September 9;13:5310.A Treg subpopulation of CAR T cells drives therapeutic resistance (from NIH via Flickr).Using single-cell profiling methods, two groups have identified subpopulations of CD19-targeting CAR T cells with T regulatory (Treg)–cell phenotypes associated with poor response in patients with B-cell lymphoma. Good et al. find a higher proportion of circulating CD4+Helios– Treg CAR T cells in patients with progressive disease who received axicabtagene ciloleucel (axi-cel), highlighting their potential as a biomarker prognostic for progression at day 7 post infusion. Haradhvala et al. similarly identify CAR+ Treg cells in blood and infusion products for patients nonresponsive to either axi-cel or tisagenlecleucel, and validate their role in mouse models of CAR T-cell treatment. The studies provide new insight into therapeutic resistance to CAR T-cell therapy.Good Z, …, Mackall CL. Nat Med 2022 September 12;28:1860–71.Haradhvala NJ, …, Maus MV. Nat Med 2022 September 12;28:1848–59.Covalent K-Ras(G12C) inhibitor provides a new target for immunotherapy (from Rawpixel).MHC class I presentation of tumor-specific peptides derived from intracellular proteins provides a target for anticancer therapy. Zhang et al. have identified a new class of therapeutically targetable MHC class I epitopes: covalently modified intracellular proteins. K-Ras(G12C) covalently conjugated to the K-Ras(G12C)-specific inhibitor ARS1620 can undergo antigen processing and presentation on MHC class I. ARS1620-specific antibodies can recognize MHC class I–restricted ARS1620-peptides. Incorporating such an antibody into a bispecific T-cell engager (BiTE) induces T-cell responses against K-Ras(G12C) tumor cells, suggesting a new strategy for cancer immunotherapy.Zhang Z, …, Craik CS. Cancer Cell 2022 September 12;40:1060–69.e7.NK cells are key component of the antitumor immune response (from NIAID via Wikimedia Commons).Understanding the factors that regulate the maturation and function of natural killer (NK) cells is important for understanding the antitumor immune response. Imianowski et al. show that the transcriptional regulator BACH2 is expressed in developing and mature NK cells and is a negative regulator of NK-cell maturation and function, keeping NK cells quiescent under conditions of IL15 stimulation. In mice lacking BACH2 in NK cells, the NK cells show increased cytotoxicity and enhanced ability to limit metastasis to the lungs in two preclinical models. The data provide new avenues for potential therapeutic modulation of NK cell–mediated antitumor immunity.Imianowski CJ, …, Roychoudhuri R. J Exp Med 2022 September 30;219:e20211476.

Practical Implications of KRAS Mutation Status and Sidedness of Primary Tumour in Patients with Colorectal Cancer and Synchronous Liver Metastases: A Subset Analysis of the CoSMIC Study.

Simple SummaryPatients presenting with liver metastases at the time of diagnosis of their colorectal cancer (termed ‘synchronous disease’) have a worse outcome than those whose disease is limited to the primary bowel tumour. There is evidence to show that patients with tumours on the right side of the colon have worse survival. Furthermore, mutations in the KRAS gene have also been shown to adversely affect outcome. This study explores the association between the side of the primary colorectal tumour in patients with synchronous disease and mutations in the KRAS gene on survival. We analyse a specific cohort of patients from the previously published CoSMIC study who presented with colorectal cancer and synchronous liver metastases and who had their colorectal tumour analysed for KRAS mutations. We find that for this cohort, neither mutations in the KRAS gene nor the side of the colon tumour influenced survival.Patients with colorectal cancer presenting with synchronous liver metastases have less favourable outcomes than those with primary-only disease. There is evidence of different genetic mutational signatures according to the sidedness of the primary tumour. KRAS mutations are key driver mutations in colorectal cancer progression. This post hoc analysis of the previously reported CoSMIC inception cohort explores the association between primary tumour sidedness and KRAS mutational status on the outcome of patients with colorectal cancer and synchronous liver metastases. Patients diagnosed with synchronous disease were recruited between April 2014 and March 2017 and, after exclusions, 83 patients undergoing colorectal primary KRAS mutation testing constituted the final study population. Data were collected prospectively on demographic profiles, treatment, and outcomes. Twenty-one patients (25%) had right-sided tumours and 62 (75%) had left-sided tumours, with 46 (55%) and 37 (45%) exhibiting wildtype and mutated KRAS, respectively. There was no difference in distribution of liver metastases by KRAS status (unilobar vs. bi-lobar; p = 0.58; Fisher’s Exact test) and no difference in 5-year survival according to KRAS mutation status (Log-rank test, p = 0.82) or tumour sidedness (p = 0.16). In summary, in this cohort of patients with colorectal cancer and synchronous liver metastases, neither KRAS mutation status nor tumour sidedness influenced survival.

A STING operation to expose KRAS and STK11 co-mutated lung cancers.

KRAS and STK11 (LKB1) co-mutated (KL) tumors define an immunologically cold and anti-PD-(L)1-refractory non-small-cell lung cancer (NSCLC) subset. In this issue of Cancer Cell, Kitajima etal. outline a strategy to unleash innate immunity in KL tumors by utilizing epigenetic de-repression of STING and pulsed inhibition of spindle assembly checkpoint kinase MPS1.

The Role of Neighborhood Air Pollution Exposure on Somatic Non-Small Cell Lung Cancer Mutations in the Los Angeles Basin (2013-2018).

Limited previous work has identified a relationship between exposure to ambient air pollution and aggressive somatic lung tumor mutations. More work is needed to confirm this relationship, especially using spatially resolved air pollution. We aimed to quantify the association between different air pollution metrics and aggressive tumor biology. Among patients treated at City of Hope Comprehensive Cancer Center in Duarte, CA (2013–2018), three non-small cell lung cancer somatic tumor mutations, TP53, KRAS, and KRAS G12C/V, were documented. PM2.5 exposure was assessed using state-of-the art ensemble models five and ten years before lung cancer diagnosis. We also explored the role of NO2 using inverse-distance-weighting approaches. We fitted logistic regression models to estimate odds ratio (OR) and their 95% confidence intervals (CIs). Among 435 participants (median age: 67, female: 51%), an IQR increase in NO2 exposure (3.5 μg/m3) five years before cancer diagnosis was associated with an increased risk in TP53 mutation (OR, 95% CI: 1.30, 0.99–1.71). We found an association between highly-exposed participants to PM2.5 (>12 μg/m3) five and ten years before cancer diagnosis and TP53 mutation (OR, 95% CI: 1.61, 0.95–2.73; 1.57, 0.93–2.64, respectively). Future studies are needed to confirm this association and better understand how air pollution impacts somatic profiles and the molecular mechanisms through which they operate.

Prognostic Factors of Survival in Patients with Peritoneal Metastasis from Colorectal Cancer.

Objectives: The aim of this study was to analyze the prognostic factors of survival in patients with peritoneal metastasis (PM) from colorectal cancer (CRC). The type of relationship between survival and the PM time of detection was used to determine whether it was synchronous with the primary tumor or metachronous. Patients and Methods: Retrospective observational study. It included patients treated for colorectal adenocarcinoma diagnosed between January 2005 and December 2019 who presented PM at the time of diagnosis or during follow-up. Variables, such as sex, age, differentiation grade, positive adenopathy (pN+), tumor size (pT), tumor location, mucinous component, peritoneal carcinomatosis index (PCI), and KRAS mutational status, were analyzed. Results: During the study period, 1882 patients were surgically treated for CRC in our hospital. Of these, 240 patients (12.8%) were included in the study after evidence of PM. The mean age was 67 ± 12 years (range: 32–92 years), and 114 patients were female (47.5%). The mean follow-up was 20 ± 13 months (median 12 months). The Kaplan–Meier survival at 36 months was higher in patients with metachronous PM (24% vs. 8%; p = 0.002), WT-KRAS tumors (31% vs. 15%; p < 0.001), N0 stage (30% vs. 19%; p < 0.001), T3 stage tumors (18% vs. 19% in T4A and 3% in T4B; p > 0.001), and tumors with classic adenocarcinoma histology (18% vs. 8%; p = 0.011). Patients with a PCI of 1–10 showed a likelihood of survival at 36 months of 56%, which was longer than that found in patients with a PCI of 11–20 (8%) or a PCI of >20 (0%) (p < 0.001). In the multiple regression analysis, the factors with an independent prognostic value were: poor grade of differentiation (HR 1.995; 95% CI: 1.294–3.077), KRAS mutation (HR 1.751; 95% CI: 1.188–2.581), PCI 11–20 (HR: 9.935; 95% CI: 5.204–18.966) and PCI > 20 (HR: 4.011; 95% CI: 2.291–7.023). Conclusions: PCI should continue as the as the most useful prognostic indicator in order to assess prognostic estimations as well as therapeutic and surgical decisions, but tumor grade and KRAS mutational status may help in the treatment decision process by providing complementary information. The time of PM detection did not achieve statistical significance in the multiple regression analysis.

KRAS mutation status between left- and right-sided colorectal cancer: are there any differences in computed tomography?

To investigate the differences in clinicopathological and imaging features according to KRAS mutation status in left- and right-sided colorectal cancer. A total of 157 patients with pathologically proven colorectal cancer and preoperative contrast-enhanced multidetector CT examinations were enrolled. According to the tumor location and KRAS status, they were divided into two groups: the left-sided colorectal cancer (LCC) group (wild type, mutant type) and the right-sided colorectal cancer (RCC) group (wild type, mutant type). Clinicopathological and imaging features were recorded in each group. The imaging observation indicators included short axis diameter (SAD), longitudinal tumor length (LTL), tumor shape, pericolic fat stranding, bowel stenosis, intratumoral low-density range, enhancement pattern, and bowel obstruction. Univariate and multivariate logistic regression analyses were performed to compare the difference in KRAS mutation status between groups. In the LCC group, SAD, tumor shape, degree of pericolic fat stranding, and bowel obstruction were significant indicators for predicting KRAS status (P < 0.05). In the RCC group, CA19-9, SAD, and intratumoral low-density range were significant indicators for predicting KRAS status (P < 0.05.). The area under the curve (AUC) of the combination image indicators in the LCC group was 0.802 [cutoff point 0.372, 95% confidence interval (CI) 0.718-0.888, sensitivity 85.4%, specificity 72.0%]. The AUC in the RCC group was 0.828 (cutoff point 0.647, 95% CI 0.726-0.931, sensitivity 79.5%, specificity 75.0%). The CT imaging features associated with KRAS mutation status in the LCC and RCC groups were different. The combination of tumor location and imaging features can help to further improve the predictive value of KRAS status.

Targeting oncogenic KRAS with molecular brush-conjugated antisense oligonucleotides

The mutant form of the guanosine triphosphatase (GTPase) KRAS is a key driver in human tumors but remains a challenging therapeutic target, making KRASMUT cancers a highly unmet clinical need. Here, we report a class of bottlebrush polyethylene glycol (PEG)-conjugated antisense oligonucleotides (ASOs) for potent invivo KRAS depletion. Owing to their highly branched architecture, these molecular nanoconstructs suppress nearly all side effects associated with DNA-protein interactions and substantially enhance the pharmacological properties of the ASO, such as plasma pharmacokinetics and tumor uptake. Systemic delivery to mice bearing human non-small-cell lung carcinoma xenografts results in a significant reduction in both KRAS levels and tumor growth, and the antitumor performance well exceeds that of current popular ASO paradigms, such as chemically modified oligonucleotides and PEGylation using linear or slightly branched PEG. Importantly, these conjugates relax the requirement on the ASO chemistry, allowing unmodified, natural phosphodiester ASOs to achieve efficacy comparable to that of chemically modified ones. Both the bottlebrush polymer and its ASO conjugates appear to be safe and well tolerated in mice. Together, these data indicate that the molecular brush-ASO conjugate is a promising therapeutic platform for the treatment of KRAS-driven human cancers and warrant further preclinical and clinical development.

Does Molecular Profiling of KRAS-Mutant Non-Squamous Non-Small Cell Lung Cancer (NSCLC) Help in Treatment Strategy Planning?

Background: Several studies suggest that patients with KRAS-mutant NSCLC fail to benefit from standard systemic therapies and do not respond to EGFR inhibitors. Most recently, KRAS 12c data suggest specific treatment for improving ORR and OS. There is a clear need for therapies specifically developed for these patients. Moreover, data that might be suggestive of a response to specific therapies, such as BRCA1, are needed, and two mutations that were studied in other malignancies show more response to PARP inhibitors. Molecular profiling has the potential to identify other potential targets that may provide better treatment and novel targeted therapy for KRAS-mutated NSCLC. Methods: We purified RNA from archived tissues of patients with stage I and II NSCLC with wild-type (wt) and mutant (mt) KRAS tumors; paired normal tissue adjacent to the tumor from 20 and 17 patients, respectively, and assessed, using real-time reverse transcriptase–polymerase chain reaction (RT-PCR), the expression of four genes involved in DNA synthesis and repair, including thymidylate synthase (TS), BRCA1, ECCR1, RAP80, and the proto-oncogene SRC. Additionally, we assessed the expression of PD-L1 in mt KRAS tumors with immunohistochemistry using an antibody against PD-L1. Results: Our results show that in mt KRAS tumors, the level of expression of ERCC1, TS, and SRC was significantly increased in comparison to paired normal lung tissue (p ≤ 0.04). The expression of BRCA1 and RAP80 was similar in both mt KRAS tumors and paired normal tissue. Furthermore, the expression of BRCA1, TS, and SRC was significantly increased in wt KRAS tumors relative to their expression in the normal lung tissue (p < 0.044). The expression of ERCC1 and RAP80 was similar in wt KRAS tumors and paired normal tissue. Interestingly, SRC expression in mt KRAS tumors was decreased in comparison to wt KRAS tumors. Notably, there was an expression of PD-L1 in the tumor and stromal cells in a few (5 out of 20) mt KRAS tumors. Our results suggest that a greater ERCC1 expression in mt KRAS tumors might increase platinum resistance in this group of patients, whereas the greater expression of BRCA1 in wt KRAS tumor might be suggestive of the sensitivity of taxanes. Our data also suggest that the combination of an SRC inhibitor with a TS inhibitor, such as pemetrexed, might improve the outcome of patients with NSCLC and in particular, patients with wt KRAS tumors. PD-L1 expression in tumors, and especially stromal cells, suggests a better outcome. Conclusion: mt KRAS NSCLC patients might benefit from a treatment strategy that targets KRAS in combination with therapeutic agents based on pharmacogenomic markers, such as SRC and BRCA1. mt KRAS tumors are likely to be platinum-, taxane-, and pemetrexed-resistant, as well as having a low level of PD-L1 expression; thus, they are less likely to receive single-agent immunotherapy, such as pembrolizumab, as the first-line therapy. wt KRAS tumors with BRCA1 positivity tend to be sensitive to taxane therapy and, potentially, platinum. Our results suggest the need to develop targeted therapies for KRAS-mutant NSCLC or combine the targeting of oncogenic KRAS in addition to other therapeutic agents specific to the molecular profile of the tumor.

Multianalyte Prognostic Signature Including Circulating Tumor DNA and Circulating Tumor Cells in Patients With Advanced Pancreatic Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is associated with a poor prognosis. Multianalyte signatures, including liquid biopsy and traditional clinical variables, have shown promise for improving prognostication in other solid tumors but have not yet been rigorously assessed for PDAC. We performed a prospective cohort study of patients with newly diagnosed locally advanced pancreatic cancer (LAPC) or metastatic PDAC (mPDAC) who were planned to undergo systemic therapy. We collected peripheral blood before systemic therapy and assessed circulating tumor cells (CTCs), cell-free DNA concentration (cfDNA), and circulating tumor KRAS (ctKRAS)-variant allele fraction (VAF). Association of variables with overall survival (OS) was assessed in univariate and multivariate survival analysis, and comparisons were made between models containing liquid biopsy variables combined with traditional clinical prognostic variables versus models containing traditional clinical prognostic variables alone. One hundred four patients, 40 with LAPC and 64 with mPDAC, were enrolled. CTCs, cfDNA concentration, and ctKRAS VAF were all significantly higher in patients with mPDAC than patients with LAPC. ctKRAS VAF (cube root; 0.05 unit increments; hazard ratio, 1.11; 95% CI, 1.03 to 1.21; P = .01), and CTCs ≥ 1/mL (hazard ratio, 2.22; 95% CI, 1.34 to 3.69; P = .002) were significantly associated with worse OS in multivariate analysis while cfDNA concentration was not. A model selected by backward selection containing traditional clinical variables plus liquid biopsy variables had better discrimination of OS compared with a model containing traditional clinical variables alone (optimism-corrected Harrell's C-statistic 0.725 v 0.681). A multianalyte prognostic signature containing CTCs, ctKRAS, and cfDNA concentration outperformed a model containing traditional clinical variables alone suggesting that CTCs, ctKRAS, and cfDNA provide prognostic information complementary to traditional clinical variables in advanced PDAC.

Descriptive, analytical and molecular epidemiology of pancreatic cancer

The purpose of the study was to present current data on the role of lifestyle and heredity factors in the etiology of pancreatic cancer (PC). Material and Methods. A systemic literature search was conducted using Medline and Elibrary databases. Results. Pancreatic cancer is the 9th leading cause of cancer-related deaths worldwide. PC has an extremely poor prognosis. The 5-year survival rate of patients with PC does not exceed 9 %. The highest incidence and mortality rates from PC are found in Eastern Europe, including Russia. The incidence of PC in 2019 was 9.3 per 100,000 males and 5.7 per 100,000 females. In Russia, PC incidence and mortality rates in both males and females show a steady increase. Risk factors associated with PC include smoking, heavy alcohol drinking, overweight and obesity, diabetes and chronic pancreatitis. The microbiome of the oral cavity and colon infuence the risk of PС. Approximately 10 % of PC is estimated to have familial inheritance. The risk of PC in patients with inherited syndromes ranges from 2 (hereditary breast and ovarian cancer syndrome) to 132 (Peutz-Jeghers syndrome). Regions of the genome containing variants of single nucleotide polymorphism (SNPs), which are more common in patients with PC than in healthy people, were identifed. The most common somatic mutations include mutations in the driver genes of prostate cancer, which include the KRAS oncogene and tumor suppressor genes TP53, CDKN2A, and SMAD4.The less common mutations of genes include AIB1/NCOA, ERBB2/HER2/EGFR2, AKT2, BRAF, CCND1, RB1, etc. They are identifed as “passenger” mutations although the combined effect of polymorphism of these genes can be signifcant and comparable to the infuence of the driver gene. Conclusion. A signifcant disadvantage of our understanding of the process of carcinogenesis is the lack of information about carcinogenic factors that cause specifc mutations, i.e. the formation of mutational signatures. To solve this problem, in 2017, the international scientifc project GRAND CHALLENGE “Mutograph” was launched. The scientists of the Department of Cancer Epidemiology of N. N. Blokhin National Medical Research Center of Oncology are members of the international team working on this project.