Molecular profiling of Chinese R-CHOP treated DLBCL patients: Identifying a high-risk subgroup.

Diffuse large B-cell lymphoma (DLBCL) is a clinically aggressive and heterogenous disease. Although most patients can be cured by immunochemotherapy, 30% to 40% patient will ultimately develop relapsed or refractory disease. Here, we investigated the molecular landscapes of patients with diverse responses to R-CHOP. We performed capture-based targeted sequencing on baseline samples of 105 DLBCL patients using a panel consisting of 112 lymphoma-related genes. Subsequently, 81 treatment-naïve patients with measurable disease and followed for over 1 year were included for survival analysis. Collectively, the most commonly seen mutations included IGH fusion (69%), PIM1(33%), MYD88 (29%), BCL2 (29%), TP53 (29%), CD79B (25%) and KMT2D (24%). Patients with TP53 mutations were more likely to have primary refractory disease (87.0% vs 50.0%, P = .009). For those with TP53 disruptive mutations, 91.7% patients were in the primary refractory group. Interestingly, BCL-2 somatic hypermutation was only seen in patients without primary refractory disease (P = .014). In multivariate analysis, BCL-2 amplification (hazard ratio [HR] = 2.94, P = .022), B2M mutation (HR = 2.99, P = .017) and TP53 mutation (HR = 3.19, P < .001) were independently associated with shorter time to progression (TTP). Furthermore, TP53 mutations was correlated with worse overall survival (P = .049). Next, we investigated mutation landscape in patients with wild-type (WT) TP53 (n = 58) and found that patients harboring MYD88 L265P had significantly inferior TTP than those with WT or non-265P (P = .046). Our study reveals the mutation spectrum of treatment-naive Chinese DLBCL patients. It also confirms the clinical significance of TP53 mutations and indicates the prognostic value of MYD88 L265P in TP53 WT patients.

Exceptional Response of Cryoablation Followed by Pembrolizumab in a Patient with Metastatic Cervical Carcinosarcoma with High Tumor Mutational Burden: A Case Report.

Cervical carcinosarcoma is an extremely rare type of neoplasm that lacks standard of care. Preclinical and clinical evidence has suggested that cryoablation in combination with immunotherapy may result in a synergistic effect, generating a more robust immune response to distant lesions. A few clinical trials have evaluated the efficacy of such combination treatment in a variety of solid tumors, but with conflicting results. This report describes the first clinical efficacy of cryoablation followed by pembrolizumab observed in a patient with tumor mutational burden (TMB)-high metastatic cervical carcinosarcoma that was negative for programmed cell death protein 1 expression, microsatellite instability stable, and had mutations in DNA polymerase epsilon (POLE). She had achieved complete response (CR) after 3 months of pembrolizumab treatment and had maintained CR as of the time of submission of this manuscript, with a progression-free survival of 11 months and counting. The case exhibited an exceptional response to cryoablation followed by pembrolizumab, potentially attributed to mutations in POLE, which lead to an extremely high TMB. This report paves the avenue for establishing treatment regimens for patients with TMB-high cervical carcinosarcoma. KEY POINTS: Owing to its rarity, cervical carcinosarcoma has not been well characterized, and currently, there is no standard of care for this disease. This report describes the first case of clinical efficacy of cryoablation followed by pembrolizumab observed in a patient with tumor mutational burden-high metastatic cervical carcinosarcoma. The case exhibited an exceptional response (maintained CR as of the time of submission of this article: 11 months) to cryoablation followed by pembrolizumab. This is the first POLE-mutated cervical carcinosarcoma case.

A multicenter analysis of genomic profiles and PD-L1 expression of primary lymphoepithelioma-like carcinoma of the lung.

To understand the molecular mechanism of tumorigenesis of pulmonary lymphoepithelioma-like carcinoma and explore potential therapeutic strategies, we investigated the genomic profiles and PD-L1 expression of 29 Chinese pulmonary lymphoepithelioma-like carcinoma patients at various stages. We performed capture-based targeted sequencing on tissue samples collected from 27 patients with sufficient samples using a panel consisting of 520 cancer-related genes, spanning 1.64 Mb of the human genome. We identified 184 somatic mutations in 109 genes from 26 patients. One patient had no mutations detected by this panel. Copy number variations were detected in 52% (14/27) of the patients, with a majority having advanced-stage disease (10/14). Except for the detection of ERBB2 amplification and KRAS mutation in two patients, no other classic lung cancer driver mutations were detected. Interestingly, 78% (21/27) of the patients had mutations in epigenetic regulators. Of the 184 mutations identified, 51 occurred in 29 epigenetics-related genes. Furthermore, we performed PD-L1 immunohistochemistry staining using the Dako 22C3 assay and demonstrated that 69% (20/29) of the cohort had positive PD-L1 expression, of which three patients received and benefited from a PD-1 inhibitor. In conclusion, we elucidated a distinct genomic landscape associated with pulmonary lymphoepithelioma-like carcinoma with no classic lung cancer driver mutation but an enrichment of mutations in epigenetic regulators. The detection of high PD-L1 expression and lack of any canonical druggable driver mutations raises the potential of checkpoint immunotherapy for pulmonary lymphoepithelioma-like carcinoma.

Clinicopathologic features and genomic analysis of pulmonary blastomatoid carcinosarcoma.

BACKGROUND: This study was designed to investigate the clinicopathologic features of pulmonary blastomatoid carcinosarcoma and explore the genomic profiles of epithelial and mesenchymal components in this tumor. METHODS: Three cases of pulmonary blastomatoid carcinosarcoma were enrolled in this study. Clinicopathologic information and prognostic data were retrospectively reviewed. Diagnostic immunohistochemistry was performed. The epithelial and mesenchymal components were microdissected to investigate the genomic profiles by performing capture-based targeted next generation sequencing. RESULTS: The epithelial components in patient one consisted of low-grade and high-grade fetal lung adenocarcinoma. Low-grade epithelial cells showed nuclear expression of ß-catenin and missense mutation of CTNNB1. The epithelial components in another two patients consisted of high-grade fetal lung adenocarcinoma/enteric adenocarcinoma. The epithelial cells showed membrane staining of ß-catenin and harbored no mutation of CTNNB1. The mesenchymal components in all three tumors were composed of primitive round/spindle cells without definite differentiation and showed cytoplasmic dot positive of ß-catenin and no corresponding mutation. Within a tumor, both components exhibited relatively comparable molecular profile. In patient one, 4 mutations: RB1, FAT3, PTCH1 and LRP1B were shared by both epithelial and mesenchymal components. Epithelial component had additional mutations in BCOR, CTNNB1, CTCF, FAT1 and DICER1. In patient two, 12 mutations were shared. The epithelial component had BRCA2 mutation and the mesenchymal had mutations in CREBBP, ALK, DNMT3A, ASXL2, MYCN and RICTOR. Patient three had 6 shared mutations. The epithelial component had an additional mutation in KAT6A and the mesenchymal had an additional mutation in APC. Collectively, we observed heterogeneity between epithelial and mesenchymal components of the same tumor. CONCLUSIONS: Blastomatoid carcinosarcoma showed characteristic morphology and immunophenotype. Parallel detection of genetic abnormalities in epithelial and mesenchymal components could provide further evidence for tumor differentiation, molecular targeting and differential diagnosis.

The association between BRAF mutation class and clinical features in BRAF-mutant Chinese non-small cell lung cancer patients.

BACKGROUND: BRAF mutations occur in 2-4% non-small cell lung cancer (NSCLC) patients and can be categorized into three functional classes based on signaling mechanism and kinase activity: RAS-independent kinase-activating V600 monomers (class 1), RAS-independent kinase-activating dimers (class 2) and RAS-dependent kinase-inactivating heterodimers (class 3). The association between functional classes and clinical features in Chinese NSCLC patients remains unexplored. Our multi-center study aimed to survey the BRAF mutation rate and analyze the associated clinical features in this population. METHODS: Capture-based sequencing data of either plasma or tissue samples obtained from 8405 Chinese stage I-IV NSCLC patients were retrospectively analyzed. RESULTS: BRAF mutations were detected in 238 patients, revealing an overall mutation rate of 2.8%. Among them, 32%, 21% and 13% had BRAF mutant class 1, 2 and 3 respectively. The remaining 34% had other BRAF mutations. V600 (32%) and G469 (13%) were the two most predominant BRAF mutations. Patients with class 2 and 3 mutations were more likely to have concurrent KRAS mutations (P = 0.001). Collectively, BRAF mutations, including non-class 1-3 mutations, were more likely to occur in males (P < 0.01). However, females were more likely to harbor class 1 mutations (P < 0.02). We also compared the overall survival (OS) of first-line chemotherapy-treated advanced-stage patients and revealed comparable OS among the three groups. CONCLUSION: Our study revealed a 2.8% BRAF mutation rate in Chinese NSCLC patients. Our data also showed a male predominance when all BRAF mutations were considered collectively, and a female predominance for class 1 mutations. Furthermore, BRAF V600E is less likely to have concurrent KRAS mutations comparing to the other two classes.

A phase 2 randomised controlled trial of mazdutide in Chinese overweight adults or adults with obesity.

Mazdutide is a once-weekly glucagon-like peptide-1 (GLP-1) and glucagon receptor dual agonist. We evaluated the efficacy and safety of 24-week treatment of mazdutide up to 6 mg in Chinese overweight adults or adults with obesity, as an interim analysis of a randomised, two-part (low doses up to 6 mg and high dose of 9 mg), double-blind, placebo-controlled phase 2 trial (ClinicalTrials.gov, NCT04904913). Overweight adults (body-mass index [BMI] ≥24 kg/m2) accompanied by hyperphagia and/or at least one obesity-related comorbidity or adults with obesity (BMI ≥ 28 kg/m2) were randomly assigned (3:1:3:1:3:1) to once-weekly mazdutide 3 mg, 4.5 mg, 6 mg or matching placebo at 20 hospitals in China. The primary endpoint was the percentage change from baseline to week 24 in body weight. A total of 248 participants were randomised to mazdutide 3 mg (n = 62), 4.5 mg (n = 63), 6 mg (n = 61) or placebo (n = 62). The mean percentage changes from baseline to week 24 in body weight were -6.7% (SE 0.7) with mazdutide 3 mg, -10.4% (0.7) with 4.5 mg, -11.3% (0.7) with 6 mg and 1.0% (0.7) with placebo, with treatment difference versus placebo ranging from -7.7% to -12.3% (all p < 0.0001). All mazdutide doses were well tolerated and the most common adverse events included diarrhoea, nausea and upper respiratory tract infection. In summary, in Chinese overweight adults or adults with obesity, 24-week treatment with mazdutide up to 6 mg was safe and led to robust and clinically meaningful body weight reduction.

A phase 1b randomised controlled trial of a glucagon-like peptide-1 and glucagon receptor dual agonist IBI362 (LY3305677) in Chinese patients with type 2 diabetes.

The success of glucagon-like peptide-1 (GLP-1) receptor agonists to treat type 2 diabetes (T2D) and obesity has sparked considerable efforts to develop next-generation co-agonists that are more effective. We conducted a randomised, placebo-controlled phase 1b study (ClinicalTrials.gov: NCT04466904) to evaluate the safety and efficacy of IBI362 (LY3305677), a GLP-1 and glucagon receptor dual agonist, in Chinese patients with T2D. A total of 43 patients with T2D were enrolled in three cohorts in nine study centres in China and randomised in each cohort to receive once-weekly IBI362 (3.0 mg, 4.5 mg or 6.0 mg), placebo or open-label dulaglutide (1.5 mg) subcutaneously for 12 weeks. Forty-two patients received the study treatment and were included in the analysis, with eight receiving IBI362, four receiving placebo and two receiving dulaglutide in each cohort. The patients, investigators and study site personnel involved in treating and assessing patients in each cohort were masked to IBI362 and placebo allocation. Primary outcomes were safety and tolerability of IBI362. Secondary outcomes included the change in glycated haemoglobin A1c (HbA1c), fasting plasma glucose (FPG) and post-mixed-meal tolerance test (post-MTT) glucose levels. IBI362 was well tolerated. Most commonly-reported treatment-emergent adverse events were diarrhoea (29.2% for IBI362, 33.3% for dulaglutide, 0% for placebo), decreased appetite (25.0% for IBI362, 16.7% for dulaglutide, 0% for placebo) and nausea (16.7% for IBI362, 16.7% for dulaglutide and 8.3% for placebo). HbA1c, FPG and post-MTT glucose levels were reduced from baseline to week 12 in patients receiving IBI362 in all three cohorts. IBI362 showed a favourable safety profile and clinically meaningful reductions in blood glucose in Chinese patients with T2D.

A heavily pre-treated adenocarcinoma patient with EGFR exon 20 insertion mutation responded to pembrolizumab plus nab-paclitaxel/bevacizumab: a case report.

Non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) exon 20 insertions are often associated with poor clinical outcomes due to low response rate to EGFR tyrosine kinase inhibitors. Although recent studies have demonstrated that several novel small molecule compounds could selectively inhibit these mutations, there are still some patients who cannot benefit from them. Another potential therapeutic approach is the use of immune checkpoint inhibitors. Growing evidence suggests that patients harboring EGFR mutations show low efficacy with the use of immunotherapy. However, according to the different immunogenicity of different EGFR mutations, the role of immunotherapy in EGFRex20ins NSCLCs needs further confirmation. Herein we report a case of a 39-year-old woman with NSCLC harboring EGFRex20ins who was diagnosed as postoperative recurrence of lung cancer. She failed with oral poziotinib, then underwent four cycles of systemic chemotherapy with pemetrexed plus carboplatin and bevacizumab. CT scan after chemotherapy showed the metastatic tumors increased in size. The patient then received osimertinib plus cetuximab. CT evaluation performed one month after treatment revealed the enlargement of bilateral lung metastasis. Pembrolizumab plus nab-paclitaxel/bevacizumab was given every three weeks afterwards. Significant shrinkage in multiple metastatic tumors was observed through CT, resulting in a partial response and a progression-free survival of more than 5.0 months. This case highlighted that the use of pembrolizumab in combination with nab-paclitaxel/bevacizumab could help in the management of the uncommon EGFRex20ins in heavily pretreated patients.

Targeted Sequencing Analysis of Predominant Histological Subtypes in Resected Stage I Invasive Lung Adenocarcinoma.

Objective: Lung adenocarcinoma (LADC) is classified into five main histological subtypes with distinct clinicopathologic characteristics: lepidic-predominant adenocarcinoma (LPA), acinar-predominant adenocarcinoma (APA), papillary-predominant adenocarcinoma (PPA), micropapillary-predominant adenocarcinoma (MPA) and solid-predominant adenocarcinoma (SPA). However, the mutational profiles of predominant histological subtypes have not been well defined. In this study, we aimed to reveal the genomic landscape of 5 main histological subtypes. Patients and Methods: We performed next-generation sequencing (NGS) in a cohort of 86 stage I invasive adenocarcinoma (IAC) patients, using a customized panel including 168 cancer-associated genes. Results: Our analysis identified a total of 302 genomic alterations. Five subtypes showed different mutation profiles with LPA, APA, PPA, MPA and SPA had an average mutation rate of 1.95 (range: 0-5), 2.56 (range: 1-6), 3.5 (range: 1-7), 3.75 (range: 1-8) and 6.05 (range: 2-12), respectively (p=4.17e-06). Driver mutations occurred in 96.55% (83/86) of all patients. EGFR (73.3%), KRAS (9.3%), ALK (4.7%) and MET (4.7%) are the most commonly mutated lung cancer driver genes, TP53 is the top mutated tumor suppressor gene. SPA patients harbored more driver mutations and higher frequency of TP53 than LPA patients. Interestingly, LRP1B mutations, which has been reported to be associated with high tumor mutation burden and better response to immunotherapy, were only detected from 5 SPA patients (p=0.001). No patients from other four cohorts harbored LRP1B mutations. Conclusions: We revealed distinctive mutation landscape of the 5 major histological subtypes of LADC, evident by distinctive average mutation rate with SPA and LPA having the highest and lowest average mutation rate, respectively. SPA patients showed higher mutation rate of LRP1B and higher rates for PD-L1 positivity, indicating that SPA patients may have better response to immunotherapy.

Characterization of Frequently Mutated Cancer Genes and Tumor Mutation Burden in Chinese Breast Cancer.

OBJECTIVES: Various genomic alterations and genomic signatures, including ERBB2 amplification, mutations in PIK3CA, AKT1, and ESR1, and tumor mutational burden (TMB), have become important biomarkers for treatment selection in breast cancer (BC). This study aimed to investigate the mutational features of Chinese early-stage BC patients. METHODS: Tumors and matched blood samples collected from 589 Chinese patients with early-stage BC were sequenced using a commercial gene panel consisting of 520 cancer-related genes to analyze all types of genomic alterations and estimate the TMB status. RESULTS: A total of 18 genes were found to be more frequently mutated (P<0.05) or amplified (P<0.05) in stage T3-4 tumors as compared with T1-2 tumors. A total of 18 genes were found to be differentially mutated (P<0.05) or amplified (P<0.05) in patients with lymph node metastasis than those without lymph node metastasis. Younger patients (≤35 years) were more frequently identified with mutations or gene amplifications in eleven genes (P<0.05). TMB >10mutations/Mb were found in 5.7% of our cohort. Although the TMB was similar for various molecular subtypes between our cohort and the BC cohort of The Cancer Genome Atlas (TCGA) study, the TMB were statistically different for HR+/HER-, HR+/HER2+, and triple-negative subtypes between our cohort and African Americans in the TCGA study. As compared to the TCGA BC cohort, our cohort had a much earlier median age of diagnosis (48 vs. 58 years, P<0.001), and had significantly lower frequency of triple-negative subtype (11.5% vs. 18.4%, P<0.001) and invasive lobular BC (2.4% vs. 19.0%, P<0.001). Further subgroup analyses revealed that mutation rates in various genes including TP53, ERBB2, and PIK3CA were distinct for patients who were younger (≤35 years), had triple-negative or invasive lobular BC in our cohort than in the TCGA cohort. CONCLUSIONS: This study revealed distinct mutational features of various molecular subtypes of early-stage BC among Chinese patients. Moreover, we provide new insights into the differences in early-stage BC between the East and West.

Mutational Landscape of PI3K-AKT-mTOR Pathway in Breast Cancer: Implications for Targeted Therapeutics.

Background: Comprehensive analysis of PI3K-AKT-mTOR pathway gene alterations in breast cancer may be helpful for targeted therapy. Methods: We performed targeted sequencing using a panel of 520 cancer-related genes to investigate gene alterations in the PI3K-AKT-mTOR pathway from 589 consecutive Chinese women diagnosed with stage I-III breast cancer. Analyses of overall survival (OS) were performed using the publicly available clinical and genomic data from METABRIC. Results: PI3K-AKT-mTOR pathway gene alterations were detected in 62.6% (369/589) of our cohort. The most commonly altered genes were PIK3CA (45%), PTEN (7.5%), AKT1 (5.9 %), PIK3R1 (2.7%), and PIK3CG (2%). Four PIK3CA mutations (E545K, H1047R, E542K, and H1047L) were detected in all the breast cancer molecular subtypes. Seven PIK3CA mutations (E545G, E418_L422delinsV, E726K, E110del, G1049R, G118D, and D350G) were only detected in HR+ subtypes. Two PIK3CA mutations (C420R and N345K) were only detected in non-triple-negative subtypes. Most cases with PTEN mutation were HR+/HER2- subtype (77.3%), followed by triple-negative subtype (18.2%). In the METABRIC breast cancer dataset, no significant OS difference was observed between the PIK3CA-mutant and wild-type groups. However, patients with multiple PIK3CA mutations (mOS: 131 vs. 159 months, P= 0.029), or PIK3CA mutations located in the C2 domain had significantly shorter OS (mOS, 130 vs. 154 months, P=0.020) than those without the mutations. Conclusions: Our study reveals the heterogeneity in PI3K-AKT-mTOR pathway among the breast cancer molecular subtypes in our cohort. Moreover, the number and specific sites of PIK3CA mutations have distinct prognostic impact.

Liquid biopsy in extranodal NK/T-cell lymphoma: a prospective analysis of cell-free DNA genotyping and monitoring.

Satisfactory tumor material is often hard to obtain for molecular analysis in extranodal natural killer (NK)/T-cell lymphoma (NKTCL) at present. However, the accuracy and utility of circulating cell-free DNA (cfDNA) genotyping have not been adequately assessed in NKTCL. We therefore performed targeted next-generation sequencing on tumor tissues and a series of longitudinal plasma samples prospectively collected from a cohort of high-risk NKTCL patients. Concordance of genotyping results of paired baseline tumor and cfDNA and the predictive value of dynamic cfDNA monitoring were evaluated. At baseline, 59 somatic variants in 31 genes were identified in tumor and/or plasma cfDNA among 19 out of 24 high-risk NKTCL patients (79.2%). Plasma cfDNA had a sensitivity of 72.4% for detection of somatic variants identified in tumor biopsies before treatment. Plasma cfDNA also allowed the identification of mutations that were undetectable in tumor biopsies. These results were also verified in a validation cohort of an additional 23 high-risk NKTCL patients. Furthermore, longitudinal analysis showed that patients with rapid clearance of NKTCL-related mutations from plasma had higher complete remission rates (80.0% vs 0%; P = .004) and more favorable survival (1-year progression-free survival [PFS] rate, 79.0% vs 20.0%; P = .002) compared with those with persisting or emerging mutations in plasma. In addition, low cfDNA concentration before treatment was associated with favorable survival outcome for patients with NKTCL (1-year PFS, 90.0% vs 36.4%; P = .012). In conclusion, cfDNA mirrors tumor biopsy for detection of genetic alterations in NKTCL and noninvasive dynamic plasma cfDNA monitoring might be a promising approach for tracking response and survival outcome for patients with NKTCL.

IBI362 (LY3305677), a weekly-dose GLP-1 and glucagon receptor dual agonist, in Chinese adults with overweight or obesity: A randomised, placebo-controlled, multiple ascending dose phase 1b study.

BACKGROUND: IBI362 (LY3305677) is a novel weekly-dose glucagon-like peptide-1 and glucagon receptor dual agonist being developed for the treatment of obesity and type 2 diabetes. The aim of this randomised, placebo-controlled, multiple ascending dose phase 1b study was to evaluate the safety, tolerability, pharmacokinetics and efficacy of IBI362 in Chinese adults with overweight or obesity. METHODS: This study enrolled adults with overweight (body mass index [BMI]≥24 kg/m2) accompanied by hyperphagia and/or at least one comorbidity or obesity (BMI≥28 kg/m2) from six study centres in China. Eligible participants were randomised 2:1 to receive once-weekly subcutaneous injection of IBI362 or placebo in each of the three ascending dose cohorts for 12 weeks with additional 8 weeks of safety follow-up. The dose-escalation regimens were: 3.0 mg cohort (1.0 mg weeks 1-4; 2.0 mg weeks 5-8; 3.0 mg weeks 9-12); 4.5 mg cohort (1.5 mg weeks 1-4; 3.0 mg weeks 5-8; 4.5 mg weeks 9-12); 6.0 mg cohort (2.0 mg weeks 1-4; 4.0 mg weeks 5-8; 6.0 mg weeks 9-12). The participants, investigators and study site personnel involved in treating and assessing participants within each cohort were masked to treatment allocation. The primary endpoints were safety and tolerability of IBI362. This study is registered with ClinicalTrials.gov, number NCT04440345. FINDINGS: Between June 15th, 2020 and January 15th, 2021, 12 participants were enrolled and randomised in each cohort. Throughout the study, no participant discontinued the treatment due to safety reason and no serious adverse event was reported. Gastrointestinal adverse events and decreased appetite were the most common adverse events and mostly mild in severity. Three participants receiving IBI362 reported mild and asymptomatic cardiac disorders revealed by electrocardiogram. Estimated percent changes in mean body weight from baseline to week 12 were -4.81% (95%CI -6.61 to -3.02), -6.40% (-8.23 to -4.58) and -6.05% (-7.91 to -4.18) for participants receiving IBI362 in the 3.0 mg, 4.5 mg and 6.0 mg cohort, respectively, compared with 0.60% (-0.86 to 2.07) for those receiving placebo. INTERPRETATION: IBI362 was well tolerated and showed a body weight-lowering effect in Chinese adults with overweight or obesity. FUNDING: Innovent Biologics.

EGFR Thr790Leu as a Potential Resistance Mechanism to First-Generation EGFR Tyrosine Kinase Inhibitor May Respond to Osimertinib in Patients With Lung Adenocarcinoma.

INTRODUCTION: It has been well established that EGFR Thr790Met is one of the major resistance mechanisms to first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). Nevertheless, whether EGFR Thr790Leu (T790L), which shares the mutation site of Thr790 with EGFR Thr790Met, mediates resistance to EGFR TKIs remains elusive. The treatment options for patients harboring this rare mutation have not been reported. METHODS: Capture-based targeted ultradeep sequencing was performed on tumor and plasma samples collected at various treatment milestones from three patients with advanced lung adenocarcinoma undergoing targeted therapy. RESULTS: Needle biopsy of lymph node metastasis from patient 1 revealed EGFR T790L at disease progression on first-line treatment of gefitinib. Patient 2 had EGFR T790L identified from needle biopsy of lung tissue at disease progression on icotinib treatment. This patient was subsequently treated with osimertinib and achieved stable disease with a progression-free survival of 9 months. For patient 3, at disease recurrence after surgery, resected lung tumor tissue was retrieved for molecular profiling and revealed EGFR exon 19 deletion and EGFR T790L. The patient subsequently received osimertinib treatment and continued to benefit for 16 months and counting. She has maintained stable disease at the time of submission of this manuscript. CONCLUSIONS: We revealed for the first time that EGFR T790L may serve as a potential resistance mechanism to first-generation EGFR TKIs. We also report the first clinical evidence of efficacy generated by osimertinib in patients with lung adenocarcinoma harboring primary or acquired EGFR T790L, shedding light on treatment options for this subset of patients.

Distinctive genomic characteristics in POLE/POLD1-mutant cancers can potentially predict beneficial clinical outcomes in patients who receive immune checkpoint inhibitor.

BACKGROUND: Mutations in POLE /POLD1 proofreading domain can cause deficiencies in DNA repair, conferring ultramutated cancer phenotypes. Preliminary clinical studies have revealed an association between POLE/POLD1 mutations and beneficial clinical outcomes to immune checkpoint inhibitor (ICI) therapy This study aims to investigate the genomic characteristics of POLE/POLD-mutant tumors and the prognostic value of POLE/POLD mutation for ICI treatment. METHODS: Genomic data of 21,074 patients with 23 cancer types were retrieved from Burning Rock variant database (BR VarDB). The prevalence and spectra of POLE and POLD1 mutations were assessed and compared with that in The Cancer Genome Atlas (TCGA) samples. The correlations of POLE/POLD1 mutation with tumor mutational burden (TMB) and microsatellite instability (MSI) were investigated. The prognostic value of POLE/POLD1 mutations was also explored in 2,487 ICI-treated patients from published studies. RESULTS: BR VarDB samples displayed a similar mutational prevalence of POLE (3.2% vs. 3.2%) and POLD1 (1.4% vs. 1.6%, P=0.248) versusTCGA samples, but a slightly lower frequency of POLE and POLD1 co-mutations (0.21% vs. 0.43%, P<0.001). POLE/POLD1-mutant tumors harbored increased TCT→TAT and TCG→TTG transversions, and genomic signatures associated with DNA mismatch repair (MMR) deficiency and ultra-hypermuation. Furthermore, tumors with POLE/POLD1 proofreading mutation showed a significantly higher TMB than tumors with non-proofreading mutations (P<0.01), although both possessed a higher TMB than POLE/POLD1 wild-type (WT) tumors (P<0.0001 and P<0.0001, respectively). MSI was commonly observed in tumors harboring dominant clone of POLE/POLD1 mutation (10.2%), but occurred rarely in POLE/POLD1 WT tumors (0.5%) and tumors with accumulating sub-cloned POLE/POLD1 mutation (0%). Survival analysis revealed that POLE/POLD1 mutation was not independently correlated with longer survival after adjusting for TMB and other factors (HR =0.86, P=0.372). However, patients harboring POLE/POLD1 mutation demonstrated a higher response rate than patients with POLE/ POLD1 WT tumors (35.2% vs. 19.6%, P=0.0165). CONCLUSIONS: We delineated distinctive genomic characteristics in POLE/POLD1-mutant tumors, suggesting the potential predictive role of POLE/POLD1 mutations, especially those in the proofreading domain, for beneficial outcomes of immunotherapy. Our results also suggest that MSI caused by a loss-of-function mutation in the MMR pathway tends to result from POLE/POLD1 proofreading deficiency in POLE/POLD1-mutant tumors with MSI.

HER2 transmembrane domain mutation: comprehensive characteristics and real-world evidence of treatment response in Chinese lung adenocarcinoma.

BACKGROUND: HER2 transmembrane domain (TMD) mutation has been reported as a rare driver mutation associated with advanced stage disease and a poor prognosis in patients with lung adenocarcinoma (LUAD). We aimed to comprehensively profile the genetic landscape and treatment response information of HER2 TMD-mutant LUAD. METHODS: An in-house database of 7,812 LUAD patients was screened for mutation prevalence. A multi-center cohort of 16 HER2 V659E-mutant patients and an external cohort of 38 HER2-mutant patients from cBioPortal with overall survival (OS) data were analyzed. Eight patients from the in-house cohort were included in the real-world study of treatment response. Molecular docking simulation and binding affinity prediction were performed. RESULTS: In Chinese LUAD, the prevalence of HER2 TMD mutation was 0.18% (14/7,812), and 0.14% (11/7,812) for the HER2 V659E mutation. The most recurrent co-alteration was TP53 mutation (n=4, 25%) and HER2 amplification (n=2, 12.5%). TMD-mutant patients were diagnosed at more advance stages (P<0.001) and had poorer OS (median OS 10.0 vs. 61.6 months, HR =7.9, 95% CI: 1.0-61.0, P<0.001) than non-TMD mutations. The overall response rate of targeted therapy, chemo-based therapy, and immunotherapy was 57.1%, 22.2%, and 0%, respectively. We postulated to challenge the resistance of tyrosine kinase inhibitor (TKI) with another with stronger binding energy to HER2 and supported the conclusion with a successful case. Additionally, we demonstrated a three-month response to the off-label use of pyrotinib in fifth-line therapy. CONCLUSIONS: Comapred with non-TMD mtuations, HER2 TMD mutation is a rare driver mutation with poorer prognosis in LUAD. Targeted therapy is the dominant choice for patients harboring this targetable mutation and longer OS could possibly be achieved through rechallenge with TKI of stronger binding affinity. Response to fifth-line pyrotinib was observed.

Ultrasensitive detection of circulating tumour DNA via deep methylation sequencing aided by machine learning.

The low abundance of circulating tumour DNA (ctDNA) in plasma samples makes the analysis of ctDNA biomarkers for the detection or monitoring of early-stage cancers challenging. Here we show that deep methylation sequencing aided by a machine-learning classifier of methylation patterns enables the detection of tumour-derived signals at dilution factors as low as 1 in 10,000. For a total of 308 patients with surgery-resectable lung cancer and 261 age- and sex-matched non-cancer control individuals recruited from two hospitals, the assay detected 52-81% of the patients at disease stages IA to III with a specificity of 96% (95% confidence interval (CI) 93-98%). In a subgroup of 115 individuals, the assay identified, at 100% specificity (95% CI 91-100%), nearly twice as many patients with cancer as those identified by ultradeep mutation sequencing analysis. The low amounts of ctDNA permitted by machine-learning-aided deep methylation sequencing could provide advantages in cancer screening and the assessment of treatment efficacy.

The prevalence and prognostic value of KRAS co-mutation subtypes in Chinese advanced non-small cell lung cancer patients.

OBJECTIVE: KRAS mutation plays a critical role in the initiation and development of non-small cell lung cancer (NSCLC). KRAS-mutant patients exhibit diverse response to chemotherapy. KRAS co-mutation subtypes and their prognosis value in advanced Chinese NSCLC patients remain largely elusive. METHODS: A total of 1126 Chinese advanced NSCLC patients from Xiangya hospital were screened by capture-based ultra-deep sequencing for KRAS mutation between January 2015 and December 2016. Survival analyses were performed using Kaplan-Meier analysis. RESULTS: Among the patients screened, 84 cases were detected with KRAS mutation (7.5%). All of them were non-squamous NSCLC and received pemetrexed plus platinum as the first-line treatment. The most frequent KRAS co-mutation genes were TP53 (29%), TP53/LKB1 (19%), and LKB1 (14%). Our data revealed that patients with KRAS co-mutation had poorer prognosis in comparison with those harboring single KRAS mutation. Furthermore, patients with KPL (KRAS mutated with TP53 and LKB1) subtype, which was a novel subtype, had the shortest progression-free survival (PFS) in all types of KRAS co-mutation patients (P < .0001). The PFS and overall survival (OS) of patients with KRASG12D mutation were inferior than those with KRASG12C mutation or KRASG12V mutation. Patients in KRASG>T type had significantly longer survival than those in KRASG>C type or KRASG>A type. CONCLUSION: Our study revealed that concurrent genomic alterations can further stratify KRAS-mutant lung adenocarcinoma patients into various subgroups with distinctive therapeutic responses and differential survival outcomes. The KPL is a novel and less responsive subtype among KRAS-mutated NSCLC, and further investigation of effective treatment for this subtype is warranted.

An EGFR-Amplified Cervical Squamous Cell Carcinoma Patient with Pulmonary Metastasis Benefits from Afatinib: A Case Report.

Currently, women with metastatic or recurrent cervical cancer still have very limited treatment options. Despite the rapid advancements in targeted therapies, no targeted therapy was approved for cervical cancer, except for bevacizumab. In the present study, we reported a 52-year-old heavily pre-treated EGFR amplified patient with metastatic cervical squamous cancer who benefited from afatinib with a progression-free survival (PFS) of 5.5 months. The patient was administered with a first-line treatment of chemotherapy and bevacizumab with a PFS of 4.3 months. Subsequently the patient was treated with a second-line regimen of angiogenesis inhibitor apatinib plus chemotherapy and a third-line treatment of pembrolizumab. Genomic profiling revealed significant EGFR amplification in both primary (copy number [CN] =15.9) and metastatic lesions (CN =18). Afatinib monotherapy was then administered as the fourth-line regimen. She achieved partial response (PR) with a PFS of 5.5 months. At disease progression, the CN of EGFR was elevated to 39.9 accompanied by the emergence of PIK3CA amplification (CN =4.2). The patient was treated with everolimus and afatinib and achieved stable disease (SD) after 3 months. To the best of our knowledge, this is the first clinical evidence of an EGFR-amplified metastatic cervical cancer patient benefiting from afatinib as a single agent.

Perioperative Circulating Tumor DNA in Colorectal Liver Metastases: Concordance with Metastatic Tissue and Predictive Value for Tumor Burden and Prognosis.

BACKGROUND: The surgical resection of colorectal cancer with liver metastases (CLM) has proven to be the most important modality for long-term survival, while effective biomarkers for outcome prediction or postoperative surveillance are still lacking. Currently, circulating biomarkers obtained from a liquid biopsy are widely used to assess the treatment response, disease recurrence and progression. In this study, we analyzed the value of the liquid biopsy, which includes circulating tumor DNA (ctDNA) and cell-free DNA (cfDNA), in patients with CLM. METHODS: Capture-based targeted deep sequencing was performed on matched pre-surgery, post-surgery and liver metastatic tissues of 20 CRC patients who underwent the resection of liver metastases between May and September 2017 using a panel consisting of 41 genes. Mutation landscapes obtained from pre-surgery plasma samples and metastatic tissue samples were compared. RESULTS: Collectively, we identified 47 mutations from 17 pre-surgery plasma samples (85%), and the remaining 3 patients had no mutation detected from the panel. We revealed a high by-variant concordance rate of 82.14% between pre-surgery plasma samples and liver metastatic tissue samples. We further analyzed the correlation between ctDNA, cfDNA, CEA and tumor burden and revealed a positive correlation between ctDNA and tumor burden (R=0.69, p=0.002). As of the date for data cutoff, 8/20 patients experienced relapse. Our study also demonstrated that pre-surgery ctDNA (p<0.001), cfDNA (p=0.001) and CEA (p=0.012) levels had predictive value for relapse. Patients with low pre-surgery ctDNA (p<0.001), cfDNA (p=0.001) or CEA (p=0.012) levels were more likely to experience prolonged progression-free survival. CONCLUSION: Our data demonstrate that the genomic profile obtained from ctDNA is comparable with the genomic profile obtained from metastatic liver tumors. Furthermore, our study also show that pre-surgery ctDNA levels are positively correlated with tumor burden. In addition, pre-surgery ctDNA, cfDNA and CEA levels have predictive value for relapse.