Molecular Landscape and Clinical Implication of CCNE1-amplified Esophagogastric Cancer.

Cyclin E overexpression as a result of CCNE1 amplification is a critical driver of genomic instability in gastric cancer, but its clinical implication is largely unknown. Thus, we integrated genomic, transcriptomic, and immune profiling analysis of 7,083 esophagogastric tumors and investigated the impact of CCNE1 amplification on molecular features and treatment outcomes. We identified CCNE1 amplification in 6.2% of esophageal adenocarcinoma samples, 7.0% of esophagogastric junction carcinoma, 4.2% of gastric adenocarcinoma samples, and 0.8% of esophageal squamous cell carcinoma. Metastatic sites such as lymph node and liver showed an increased frequency of CCNE1 amplification relative to primary tumors. Consistent with a chromosomal instability phenotype, CCNE1 amplification was associated with decreased CDH1 mutation and increased TP53 mutation and ERBB2 amplification. We observed no differences in immune biomarkers such as PD-L1 expression and tumor mutational burden comparing CCNE1-amplified and nonamplified tumors, although CCNE1 amplification was associated with changes in immune populations such as decreased B cells and increased M1 macrophages from transcriptional analysis. Real-world survival analysis demonstrated that patients with CCNE1-amplified gastric cancer had worse survival after trastuzumab for HER2-positive tumors, but better survival after immunotherapy. These data suggest that CCNE1-amplified gastric cancer has a distinct molecular and immune profile with important therapeutic implications, and therefore further investigation of CCNE1 amplification as a predictive biomarker is warranted. SIGNIFICANCE: Advanced gastric cancer has a relatively dismal outcome with a 5-year overall survival of less than 10%. Furthermore, while comprehensive molecular analyses have established molecular subtypes within gastric cancers, biomarkers of clinical relevance in this cancer type are lacking. Overall, this study demonstrates that CCNE1 amplification is associated with a distinct molecular profile in gastric cancer and may impact response to therapy, including targeted therapy and/or immunotherapy.

Comparative molecular profiling of pancreatic ductal adenocarcinoma of the head versus body and tail.

Pancreatic ductal adenocarcinoma (PDAC) of the head (H) and body/tail (B/T) differ in embryonic origin, cell composition, blood supply, lymphatic and venous drainage, and innervation. We aimed to compare the molecular and tumor immune microenvironment (TIME) profiles of PDAC of the H vs. B/T. A total of 3499 PDAC samples were analyzed via next-generation sequencing (NGS) of RNA (whole transcriptome, NovaSeq), DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing), and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Significance was determined as p values adjusted for multiple corrections (q) of <0.05. Anatomic subsites of PDAC tumors were grouped by primary tumor sites into H (N = 2058) or B/T (N = 1384). There were significantly more metastatic tumors profiled from B/T vs. H (57% vs. 44%, p < 0.001). KRAS mutations (93.8% vs. 90.2%), genomic loss of heterozygosity (12.7% vs. 9.1%), and several copy number alterations (FGF3, FGF4, FGF19, CCND1, ZNF703, FLT4, MUTYH, TNFRS14) trended higher in B/T when compared to H (p < 0.05 but q > 0.05). Expression analysis of immuno-oncology (IO)-related genes showed significantly higher expression of CTLA4 and PDCD1 in H (q < 0.05, fold change 1.2 and 1.3) and IDO1 and PDCD1LG2 expression trended higher in B/T (p < 0.05, fold change 0.95). To our knowledge, this is one of the largest cohorts of PDAC tumors subjected to broad molecular profiling. Differences in IO-related gene expression and TIME cell distribution suggest that response to IO therapies may differ in PDAC arising from H vs. B/T. Subtle differences in the genomic profiles of H vs. B/T tumors were observed.

Differential landscape of immune evasion in oncogenic RAS-driven primary and metastatic colorectal cancers.

Oncogenic drivers such as KRAS extensively modulate the tumor inflammatory microenvironment (TIME) of colorectal cancer (CRC). The influence of KRAS on modulating immune cell composition remains unclear. The objective of this study was to identify signatures of infiltrative immune cells and distinctive patterns that differ between RAS wild-type (WT) and oncogenic mutant (MT) CRC that explain immune evasion in MT tumors. A total of 7,801 CRC specimens were analyzed using next-generation DNA sequencing, whole-exome sequencing, and/or whole transcriptome sequencing. Deficiency of mismatch repair (dMMR)/microsatellite instability (MSI) and tumor mutation burden (TMB) were also assessed. KRAS mutations were present in 48% of CRC, similarly distributed in patients younger than vs. 50 years and older. In microsatellite stable (MSS) KRAS MT tumors, composition of the TIME included higher neutrophil infiltration and lower infiltration of B cells. MSI-H/dMMR was significantly more prevalent in RAS WT (9.1%) than in KRAS MT (2.9%) CRC. In MSS CRC, TMB-high cases were significantly higher in RAS MT (3.1%) than in RAS WT (2.1%) tumors. KRAS and NRAS mutations are associated with increased neutrophil infiltration, with codon-specific differences. These results demonstrate significant differences in the TIME of RAS mutant CRC that match previous reports of immunoevasive characteristics of such tumors.

Evaluation of markers of immunity in different metastatic immune microenvironments suggests more suppression within breast to liver metastases in breast cancer.

PURPOSE: Programmed death receptor ligand-1 (PD-L1) expression and tumor mutational burden (TMB) are approved screening biomarkers for immune checkpoint inhibition (ICI) in advanced triple negative breast cancer. We examined these biomarkers along with characterization of the tumor microenvironment (TME) between breast tumors (BrTs), axillary metastases (AxMs), liver metastases (LvMs), non-axillary lymph node metastases, and non-liver metastases to determine differences related to site of metastatic disease. METHODS: 3076 unpaired biopsies from breast cancer patients were analyzed using whole transcriptome sequencing and NextGen DNA depicting TMB within tumor sites. The PD-L1 positivity was determined with VENTANA PD-L1 (SP142) assay. The immune cell fraction within the TME was calculated by QuantiSeq and MCP-counter. RESULTS: Compared to BrT, more LvM samples had a high TMB (≥ 10 mutations/Mb) and fewer LvM samples had PD-L1+ expression. Evaluation of the TME revealed that LvM sites harbored lower infiltration of adaptive immune cells, such as CD4+, CD8+, and regulatory T-cells compared with the BrT foci. We saw differences in innate immune cell infiltration in LvM compared to BrT, including neutrophils and NK cells. CONCLUSIONS: LvMs are less likely to express PD-L1+ tumor cells but more likely to harbor high TMB as compared to BrTs. Unlike AxMs, LvMs represent a more immunosuppressed TME and demonstrate lower gene expression associated with adaptive immunity compared to BrTs. These findings suggest biopsy site be considered when interpreting results that influence ICI use for treatment and further investigation of immune composition and biomarkers expression by metastatic site.

Tissue-specific thresholds of mutation burden associated with anti-PD-1/L1 therapy benefit and prognosis in microsatellite-stable cancers.

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 or its ligand (PD-1/L1) have expanded the treatment landscape against cancers but are effective in only a subset of patients. Tumor mutation burden (TMB) is postulated to be a generic determinant of ICI-dependent tumor rejection. Here we describe the association between TMB and survival outcomes among microsatellite-stable cancers in a real-world clinicogenomic cohort consisting of 70,698 patients distributed across 27 histologies. TMB was associated with survival benefit or detriment depending on tissue and treatment context, with eight cancer types demonstrating a specific association between TMB and improved outcomes upon treatment with anti-PD-1/L1 therapies. Survival benefits were noted over a broad range of TMB cutoffs across cancer types, and a dose-dependent relationship between TMB and outcomes was observed in a subset of cancers. These results have implications for the use of cancer-agnostic and universal TMB cutoffs to guide the use of anti-PD-1/L1 therapies, and they underline the importance of tissue context in the development of ICI biomarkers.

Influence of TP53 Comutation on the Tumor Immune Microenvironment and Clinical Outcomes With Immune Checkpoint Inhibitors in STK11-Mutant Non-Small-Cell Lung Cancer.

PURPOSE: Non-small-cell lung cancer (NSCLC) with STK11mut has inferior outcomes to immune checkpoint inhibitors (ICIs). Using multiomics, we evaluated whether a subtype of STK11mut NSCLC with a uniquely inflamed tumor immune microenvironment (TIME) harboring TP53 comutations could have favorable outcomes to ICIs. PATIENTS AND METHODS: NSCLC tumors (N = 16,896) were analyzed by next-generation sequencing (DNA-Seq/592 genes). A subset (n = 5,034) underwent gene expression profiling (RNA-Seq/whole transcriptome). Exome-level neoantigen load for STK11mut NSCLC was obtained from published pan-immune analysis. Tumor immune cell content was obtained from transcriptome profiles using the microenvironment cell population (MCP) counter. ICI data from POPLAR/OAK (n = 34) and the study by Rizvi et al (n = 49) were used to model progression-free survival (PFS), and a separate ICI-treated cohort (n = 53) from Dana-Farber Cancer Institute (DFCI) was used to assess time to treatment failure (TTF) and tumor RECIST response for STK11mutTP53mut versus STK11mutTP53wt NSCLC. RESULTS: Overall, 12.6% of NSCLC tumors had a STK11mut with the proportions of tumor mutational burden (TMB)-high (≥10 mut/Mb), PD-L1 ≥50%, and microsatellite instability-high being 38.3%, 11.8%, and 0.72%, respectively. Unsupervised hierarchical clustering of STK11mut (n = 463) for stimulator of interferon-gamma (STING) pathway genes identified a STING-high cluster, which was significantly enriched in TP53mut NSCLC (P < .01). Compared with STK11mutTP53wt, tumors with STK11mutTP53mut had higher CD8+T cells and natural killer cells (P < .01), higher TMB (P < .001) and neoantigen load (P < .001), and increased expression of MYC and HIF-1A (P < .01), along with higher expression (P < .01) of glycolysis/glutamine metabolism genes. Meta-analysis of data from OAK/POPLAR and the study by Rizvi et al showed a trend toward improved PFS in patients with STK11mutTP53mut. In the DFCI cohort, compared with the STK11mut TP53wt cohort, the STK11mutTP53mut tumors had higher objective response rates (42.9% v 16.7%; P = .04) and also had longer TTF (14.5 v 4.5 months, P adj = .054) with ICI. CONCLUSION: STK11mut NSCLC with TP53 comutation is a distinct subgroup with an immunologically active TIME and metabolic reprogramming. These properties should be exploited to guide patient selection for novel ICI-based combination approaches.

Differential Responses to Immune Checkpoint Inhibitors are Governed by Diverse Mismatch Repair Gene Alterations.

PURPOSE: The response to immune checkpoint inhibitors (ICI) in deficient mismatch repair (dMMR) colorectal cancer and endometrial cancer is variable. Here, we explored the differential response to ICIs according to different mismatch repair alterations. EXPERIMENTAL DESIGN: Colorectal cancer (N = 13,701) and endometrial cancer (N = 3,315) specimens were tested at Caris Life Sciences. Median overall survival (mOS) was estimated using Kaplan-Meier. The prediction of high-, intermediate-, and low-affinity epitopes by tumor mutation burden (TMB) values was conducted using R-squared (R2). RESULTS: Compared with mutL (MLH1 and PMS2) co-loss, the mOS was longer in mutS (MSH2 and MSH6) co-loss in all colorectal cancer (54.6 vs. 36 months; P = 0.0.025) and endometrial cancer (81.5 vs. 48.2 months; P < 0.001) patients. In ICI-treated patients, the mOS was longer in mutS co-loss in colorectal cancer [not reached (NR) vs. 36 months; P = 0.011). In endometrial cancer, the mOS was NR vs. 42.2 months; P = 0.711]. The neoantigen load (NAL) in mutS co-loss compared with mutL co-loss was higher in colorectal cancer (high-affinity epitopes: 25.5 vs. 19; q = 0.017, intermediate: 39 vs. 32; q = 0.004, low: 87.5 vs. 73; q < 0.001) and endometrial cancer (high-affinity epitopes: 15 vs. 11; q = 0.002, intermediate: 27.5 vs. 19; q < 0.001, low: 59 vs. 41; q < 0.001), respectively. R2 ranged from 0.25 in mutS co-loss colorectal cancer to 0.95 in mutL co-loss endometrial cancer. CONCLUSIONS: Patients with mutS co-loss experienced longer mOS in colorectal cancer and endometrial cancer and better response to ICIs in colorectal cancer. Among all explored biomarkers, NAL was higher in mutS co-loss and may be a potential driving factor for the observed better outcomes. TMB did not reliably predict NAL.

Molecular Profiling and the Impact of Treatment on Outcomes in Adenoid Cystic Carcinoma Type I and II.

PURPOSE: Adenoid cystic carcinoma (ACC) is an uncommon salivary gland cancer with no approved therapies available to treat advanced, incurable disease. Recent molecular profiling efforts have identified two important subtypes: the more aggressive ACC-I is characterized by Notch pathway alterations and MYC amplification whereas ACC-II demonstrates a more indolent phenotype and TP63 overexpression. EXPERIMENTAL DESIGN: This retrospective observational cohort study involved de-identified samples from 438 patients with ACC with tumor samples sent for commercially-available molecular profiling (Caris Life Sciences). Next-generation whole-exome and whole-transcriptomic sequencing was performed on primary and metastatic samples. Immunostaining for PD-L1 and RNA deconvolution (quanTIseq) was used to explore the tumor immune microenvironment (TME). Real-world clinical and survival outcome metrics were extracted from insurance claims data. RESULTS: MYC expression was 1.61-fold higher (39.8 vs. 24.7; P < 0.0001) among NOTCH1-mutant ACC-I tumors, whereas MYB/L1 fusion rates were similar among ACC-I/II. The median B-cell fraction in the TME was higher among ACC-II (7.1% vs. 5.8%; P < 0.01), although infiltrating T cells subsets were low among either ACC subgroup (both <1%). When pooling systemic treatment categories, ACC-I patients had worse outcomes with available therapies (HR, 3.06; 95% confidence interval, 1.65-5.68; P < 0.01), with no significant difference in overall survival between ACC-I/II based on chemotherapy or VEGFR tyrosine kinase inhibitor exposure in smaller subsets. CONCLUSIONS: We confirmed the previously reported associations with MYC and TP63 in the prognostically relevant subgroups of ACC-I and -II, respectively, and report immunologic differences among these subtypes. Survival outcomes are comparatively worse in ACC-I regardless of treatment type.

Predictive value of CDC37 gene expression for targeted therapy in metastatic colorectal cancer.

BACKGROUND: CDC37 is a key determinant of client kinase recruitment to the HSP90 chaperoning system. We hypothesized that kinase-specific dependency on CDC37 alters the efficacy of targeted therapies for metastatic colorectal cancer (mCRC). MATERIAL AND METHODS: Two independent mCRC cohorts were analyzed to compare the survival outcomes between CDC37-high and CDC37-low patients (stratified by the median cutoff values): the CALGB/SWOG 80405 trial (226 and 207 patients receiving first-line bevacizumab- and cetuximab-containing chemotherapies, respectively) and Japanese retrospective (50 refractory patients receiving regorafenib) cohorts. A dataset of specimens submitted to a commercial CLIA-certified laboratory was utilized to characterize molecular profiles of CDC37-high (top quartile, N = 5055) and CDC37-low (bottom quartile, N = 5055) CRCs. RESULTS: In the bevacizumab-treated group, CDC37-high patients showed significantly better progression-free survival (PFS) (median 13.3 vs 9.6 months, hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.44-0.79, p < 0.01) than CDC37-low patients. In the cetuximab-treated group, CDC37-high and CDC37-low patients had similar outcomes. In the regorafenib-treated group, CDC37-high patients showed significantly better overall survival (median 11.3 vs 6.0 months, HR 0.24, 95% CI 0.11-0.54, p < 0.01) and PFS (median 3.5 vs 1.9 months, HR 0.51, 95% CI 0.28-0.94, p = 0.03). Comprehensive molecular profiling revealed that CDC37-high CRCs were associated with higher VEGFA, FLT1, and KDR expressions and activated hypoxia signature. CONCLUSIONS: CDC37-high mCRC patients derived more benefit from anti-VEGF therapies, including bevacizumab and regorafenib, but not from cetuximab. Molecular profiles suggested that such tumors were dependent on angiogenesis-relating pathways.

Exploring Co-occurring POLE Exonuclease and Non-exonuclease Domain Mutations and Their Impact on Tumor Mutagenicity.

POLE driver mutations in the exonuclease domain (ExoD driver) are prevalent in several cancers, including colorectal cancer and endometrial cancer, leading to dramatically ultra-high tumor mutation burden (TMB). To understand whether POLE mutations that are not classified as drivers (POLE Variant) contribute to mutagenesis, we assessed TMB in 447 POLE-mutated colorectal cancers, endometrial cancers, and ovarian cancers classified as TMB-high ≥10 mutations/Mb (mut/Mb) or TMB-low <10 mut/Mb. TMB was significantly highest in tumors with "POLE ExoD driver plus POLE Variant" (colorectal cancer and endometrial cancer, P < 0.001; ovarian cancer, P < 0.05). TMB increased with additional POLE variants (P < 0.001), but plateaued at 2, suggesting an association between the presence of these variants and TMB. Integrated analysis of AlphaFold2 POLE models and quantitative stability estimates predicted the impact of multiple POLE variants on POLE functionality. The prevalence of immunogenic neoepitopes was notably higher in the "POLE ExoD driver plus POLE Variant" tumors. Overall, this study reveals a novel correlation between POLE variants in POLE ExoD-driven tumors, and ultra-high TMB. Currently, only select pathogenic ExoD mutations with a reliable association with ultra-high TMB inform clinical practice. Thus, these findings are hypothesis-generating, require functional validation, and could potentially inform tumor classification, treatment responses, and clinical outcomes. SIGNIFICANCE: Somatic POLE ExoD driver mutations cause proofreading deficiency that induces high TMB. This study suggests a novel modifier role for POLE variants in POLE ExoD-driven tumors, associated with ultra-high TMB. These data, in addition to future functional studies, may inform tumor classification, therapeutic response, and patient outcomes.

CCR5 and CCL5 gene expression in colorectal cancer: comprehensive profiling and clinical value.

BACKGROUND: The C-C motif chemokine receptor 5 (CCR5)/C-C motif chemokine ligand 5 (CCL5) axis plays a major role in colorectal cancer (CRC). We aimed to characterize the molecular features associated with CCR5/CCL5 expression in CRC and to determine whether CCR5/CCL5 levels could impact treatment outcomes. METHODS: 7604 CRCs tested with NextGen Sequencing on DNA and RNA were analyzed. Molecular features were evaluated according to CCR5 and CCL5 tumor gene expression quartiles. The impact on treatment outcomes was assessed in two cohorts, including 6341 real-world patients and 429 patients from the Cancer and Leukemia Group B (CALGB)/SWOG 80405 trial. RESULTS: CCR5/CCL5 expression was higher in right-sided versus left-sided tumors, and positively associated with consensus molecular subtypes 1 and 4. Higher CCR5/CCL5 expression was associated with higher tumor mutational burden, deficiency in mismatch repair and programmed cell death ligand 1 (PD-L1) levels. Additionally, high CCR5/CCL5 were associated with higher immune cell infiltration in the tumor microenvironment (TME) of MMR proficient tumors. Ingenuity pathway analysis revealed upregulation of the programmed cell death protein 1 (PD-1)/PD-L1 cancer immunotherapy pathway, phosphatase and tensin homolog (PTEN) and peroxisome proliferator-activated receptors (PPAR) signaling, and cytotoxic T-lymphocyte antigen 4 (CTLA-4) signaling in cytotoxic T lymphocytes, whereas several inflammation-related pathways were downregulated. Low CCR5/CCL5 expression was associated with increased benefit from cetuximab-FOLFOX treatment in the CALGB/SWOG 80405 trial, where significant treatment interaction was observed with biologic agents and chemotherapy backbone. CONCLUSIONS: Our data show a strong association between CCR5/CCL5 gene expression and distinct molecular features, gene expression profiles, TME cell infiltration, and treatment benefit in CRC. Targeting the CCR5/CCL5 axis may have clinical applications in selected CRC subgroups and may play a key role in developing and deploying strategies to modulate the immune TME for CRC treatment.

Genetic Profiling of African American Patients With Prostatic Adenocarcinoma Metastatic to the Lymph Nodes: A Pilot Study.

CONTEXT.­: Genetic profiling data of prostatic adenocarcinoma are derived from predominantly White patients. In African Americans, prostatic adenocarcinoma has a poorer prognosis, raising the possibility of distinct genetic alterations. OBJECTIVE.­: To investigate the genomic alterations of prostatic adenocarcinoma metastatic to regional lymph nodes in African American patients, with an emphasis on SPOP mutation. DESIGN.­: We retrospectively reviewed African American patients with pN1 prostatic adenocarcinoma managed with radical prostatectomy and lymph node dissection. Comprehensive molecular profiling was performed, and androgen receptor signaling scores were calculated. RESULTS.­: Nineteen patients were included. The most frequent genetic alteration was SPOP mutations (5 of 17; 29.4% [95% CI: 10.3-56.0]). While most alterations were associated with a high androgen receptor signaling score, mutant SPOP was exclusively associated with a low median and interquartile range (IQR) androgen receptor signaling score (0.788 [IQR 0.765-0.791] versus 0.835 [IQR 0.828-0.842], P = .003). In mutant SPOP, mRNA expression of SPOP inhibitor G3BP1 and SPOP substrates showed a significantly decreased expression of AR (33.40 [IQR 28.45-36.30] versus 59.53 [IQR 53.10-72.83], P = .01), TRIM24 (3.95 [IQR 3.28-5.03] versus 9.80 [IQR 7.39-11.70], P = .008), and NCOA3 (15.19 [IQR 10.59-15.93] versus 21.88 [IQR 18.41-28.33], P = .046). CONCLUSIONS.­: African American patients with metastatic prostate adenocarcinoma might have a higher prevalence of mutant SPOP (30%), compared to ∼10% in unselected cohorts with lower expressions of SPOP substrates. In our study, in patients with mutant SPOP, the mutation was associated with decreased SPOP substrate expression and androgen receptor signaling, raising concern for suboptimal efficacy of androgen deprivation therapy in this subset of patients.

Multi-omic profiling reveals discrepant immunogenic properties and a unique tumor microenvironment among melanoma brain metastases.

Melanoma brain metastases (MBM) are clinically challenging to treat and exhibit variable responses to immune checkpoint therapies. Prior research suggests that MBM exhibit poor tumor immune responses and are enriched in oxidative phosphorylation. Here, we report results from a multi-omic analysis of a large, real-world melanoma cohort. MBM exhibited lower interferon-gamma (IFNγ) scores and T cell-inflamed scores compared to primary cutaneous melanoma (PCM) or extracranial metastases (ECM), which was independent of tumor mutational burden. Among MBM, there were fewer computationally inferred immune cell infiltrates, which correlated with lower TNF and IL12B mRNA levels. Ingenuity pathway analysis (IPA) revealed suppression of inflammatory responses and dendritic cell maturation pathways. MBM also demonstrated a higher frequency of pathogenic PTEN mutations and angiogenic signaling. Oxidative phosphorylation (OXPHOS) was enriched in MBM and negatively correlated with NK cell and B cell-associated transcriptomic signatures. Modulating metabolic or angiogenic pathways in MBM may improve responses to immunotherapy in this difficult-to-treat patient subset.

Multiomic Characterization Reveals a Distinct Molecular Landscape in Young-Onset Pancreatic Cancer.

PURPOSE: Using a real-world database with matched genomic-transcriptomic molecular data, we sought to characterize the distinct molecular correlates underlying clinical differences between patients with young-onset pancreatic cancer (YOPC; younger than 50 years) and patients with average-onset pancreatic cancer (AOPC; 70 years and older). METHODS: We analyzed matched whole-transcriptome and DNA sequencing data from 2,430 patient samples (YOPC, n = 292; AOPC, n = 2,138) from the Caris Life Sciences database (Phoenix, AZ). Immune deconvolution was performed using the quanTIseq pipeline. Overall survival (OS) data were obtained from insurance claims (n = 4,928); Kaplan-Meier estimates were calculated for age- and molecularly defined cohorts. Significance was determined as FDR-corrected P values (Q) < .05. RESULTS: Patients with YOPC had higher proportions of mismatch repair-deficient/microsatellite instability-high, BRCA2-mutant, and PALB2-mutant tumors compared with patients with AOPC, but fewer SMAD4-, RNF43-, CDKN2A-, and SF3B1-mutant tumors. Notably, patients with YOPC demonstrated significantly lower incidence of KRAS mutations compared with patients with AOPC (81.3% v 90.9%; Q = .004). In the KRAS wild-type subset (n = 227), YOPC tumors demonstrated fewer TP53 mutations and were more likely driven by NRG1 and MET fusions, whereas BRAF fusions were exclusively observed in patients with AOPC. Immune deconvolution revealed significant enrichment of natural killer cells, CD8+ T cells, monocytes, and M2 macrophages in patients with YOPC relative to patients with AOPC, which corresponded with lower rates of HLA-DPA1 homozygosity. There was an association with improved OS in patients with YOPC compared with patients with AOPC with KRAS wild-type tumors (median, 16.2 [YOPC-KRASWT] v 10.6 [AOPC-KRASWT] months; P = .008) but not KRAS-mutant tumors (P = .084). CONCLUSION: In this large, real-world multiomic characterization of age-stratified molecular differences in pancreatic ductal adenocarcinoma, YOPC is associated with a distinct molecular landscape that has prognostic and therapeutic implications.

Pan-tumor survey of ROS1 fusions detected by next-generation RNA and whole transcriptome sequencing.

BACKGROUND: Two ROS1 tyrosine kinase inhibitors have been approved for ROS1 fusion positive (ROS1+) non-small cell lung cancer (NSCLC) tumors. We performed a pan-tumor analysis of the incidence of ROS1 fusions to assess if more ROS1+ patients who could benefit from ROS1 TKIs could be identified. METHODS: A retrospective analysis of ROS1 positive solid malignancies identified by targeted RNA sequencing and whole transcriptome sequencing of clinical tumor samples performed at Caris Life Science (Phoenix, AZ). RESULTS: A total of 259 ROS1+ solid malignancies were identified from approximately 175,350 tumors that underwent next-generation sequencing (12% from targeted RNA sequencing [Archer]; 88% from whole transcriptome sequencing). ROS1+ NSCLC constituted 78.8% of the ROS1+ solid malignancies, follow by glioblastoma (GBM) (6.9%), and breast cancer (2.7%). The frequency of ROS1 fusion was approximately 0.47% among NSCLC, 0.29% for GBM, 0.04% of breast cancer. The mean tumor mutation burden for all ROS1+ tumors was 4.8 mutations/megabase. The distribution of PD-L1 (22C3) expression among all ROS1+ malignancies were 0% (18.6%), 1%-49% (29.4%), and ≥ 50% (60.3%) [for NSCLC: 0% (17.8%); 1-49% (27.7%); ≥ 50% (53.9%). The most common genetic co-alterations of ROS1+ NSCLC were TP53 (29.1%), SETD2 (7.3%), ARIAD1A (6.3%), and U2AF1 (5.6%). CONCLUSIONS: ROS1+ NSCLC tumors constituted the majority of ROS1+ solid malignancies with four major fusion partners. Given that > 20% of ROS1+ solid tumors may benefit from ROS1 TKIs treatment, comprehensive genomic profiling should be performed on all solid tumors.

Opposing Roles of SPOP Mutations in Human Prostate and Endometrial Cancers.

PURPOSE: Recurrent gene mutations in speckle-type POZ protein (SPOP), the substrate-binding component of E3 ubiquitin ligase, are associated with tumor progression in prostate and endometrial cancers. Here, we characterized SPOP mutations in these cancers and explored their association with molecular and immune signatures and patient outcomes. METHODS: There were 7,398 prostate cancer and 19,188 endometrial cancer samples analyzed for clinical and molecular profiles at Caris Life Sciences. Overall survival (OS) was analyzed using Kaplan-Meier survival curves. Statistical significance was determined using chi-square and Mann-Whitney U tests, with P values adjusted for multiple comparisons. RESULTS: SPOP mutations were identified in 9.2% of prostate and 4.3% of endometrial cancers. Mutations clustered in the SPOP meprin and TRAF-C homology domain, with no significant overlap between cancer types. SPOP mutation was associated with differential comutation profiles and opposing tumor immune microenvironment signatures for each cancer, with greater immune infiltration in SPOP-mutated endometrial cancer. SPOP-mutated prostate and endometrial cancers displayed altered epigenetic gene expression, including opposite regulation of BRD2 transcripts. In SPOP-mutant prostate cancer, higher expression of androgen receptor-regulated transcripts and improved OS after treatment with hormonal agents were observed. In endometrial cancer, hormone receptor expression was significantly lower in SPOP-mutated tumors and differences in OS were highly dependent on the particular hotspot mutation and histologic subtype. CONCLUSION: These data indicate that SPOP mutations drive opposing molecular and immune landscapes in prostate and endometrial cancers-suggesting a loss-of-function mechanism in prostate cancer and gain-of-function mechanism in endometrial cancer-and provide a rationale for tailored therapeutic approaches.

Differential outcomes and immune checkpoint inhibitor response among endometrial cancer patients with MLH1 hypermethylation versus MLH1 "Lynch-like" mismatch repair gene mutation.

OBJECTIVES: To identify differential survival outcomes and immune checkpoint inhibitor (ICI) response in MLH1 hypermethylated versus MLH1 mutated ("Lynch-like") endometrial tumors and determine whether their molecular profiles can elucidate the differential outcomes. METHODS: 1673 mismatch repair deficient endometrial tumors were analyzed by next-generation sequencing and whole transcriptome sequencing (Caris Life Sciences, Phoenix, AZ). PD-L1, ER, and PR were tested by immunohistochemistry and immune cell infiltrates were calculated using MCP-counter. Significance was determined using Chi-square and Mann-Whitney U tests and adjusted for multiple comparisons. Overall survival (OS) was depicted using Kaplan-Meier survival curves. RESULTS: The endometrial cancer cohort comprised 89.2% patients with MLH1 hypermethylated tumors and 10.8% with MLH1 mutated tumors, with median ages of 67 and 60 years, respectively (p < 0.01). Patients with MLH1 hypermethylated tumors had significantly worse OS and trended toward worse OS following ICI treatment than patients with MLH1 mutated tumors. The immune microenvironment of MLH1 hypermethylated relative to MLH1 mutated was characterized by decreased PD-L1 positivity, immune checkpoint gene expression, immune cell infiltration, T cell inflamed scores, and interferon gamma (IFNγ) scores. MLH1 hypermethylation was also associated with decreased mutation rates in TP53 and DNA damage repair genes, but increased rates of JAK1, FGFR2, CCND1, and PTEN mutations, as well as increased ER and PR positivity. CONCLUSIONS: Endometrial cancer patients with MLH1 hypermethylation display significantly decreased survival and discrepant immunotherapy responses compared to patients with MLH1 mutated tumors, which was associated with differential mutational profiles, a more immune cold phenotype, and increased ER/PR expression in MLH1 hypermethylated tumors. Providers may consider early transition from single agent ICI to a multi-agent regimen or hormonal therapy for patients with MLH1 hypermethylated tumors.