Detection of circulating tumor DNA with ultradeep sequencing of plasma cell-free DNA for monitoring minimal residual disease and early detection of recurrence in early-stage lung cancer.

BACKGROUND: In early-stage non-small cell lung cancer (NSCLC), recurrence is frequently observed. Circulating tumor DNA (ctDNA) has emerged as a noninvasive tool to risk stratify patients for recurrence after curative intent therapy. This study aimed to risk stratify patients with early-stage NSCLC via a personalized, tumor-informed multiplex polymerase chain reaction (mPCR) next-generation sequencing assay. METHODS: This retrospective cohort study included patients with stage I-III NSCLC. Recruited patients received standard-of-care management (surgical resection with or without adjuvant chemotherapy, followed by surveillance). Whole-exome sequencing of NSCLC resected tissue and matched germline DNA was used to design patient-specific mPCR assays (Signatera, Natera, Inc) to track up to 16 single-nucleotide variants in plasma samples. RESULTS: The overall cohort with analyzed plasma samples consisted of 57 patients. Stage distribution was 68% for stage I and 16% each for stages II and III. Presurgery (i.e., at baseline), ctDNA was detected in 15 of 57 patients (26%). ctDNA detection presurgery was significantly associated with shorter recurrence-free survival (RFS; hazard ratio [HR], 3.54; 95% confidence interval [CI], 1.00-12.62; p = .009). In the postsurgery setting, ctDNA was detected in seven patients, of whom 100% experienced radiological recurrence. ctDNA positivity preceded radiological findings by a median lead time of 2.8 months (range, 0-12.9 months). Longitudinally, ctDNA detection at any time point was associated with shorter RFS (HR, 16.1; 95% CI, 1.63-158.9; p < .0001). CONCLUSIONS: ctDNA detection before surgical resection was strongly associated with a high risk of relapse in early-stage NSCLC in a large unique Asian cohort. Prospective studies are needed to assess the clinical utility of ctDNA status in this setting.

Adjuvant Immunotherapy in Patients with Early-Stage Non-small Cell Lung Cancer and Future Directions.

OPINION STATEMENT: While cisplatin-based adjuvant chemotherapy has been the standard of care for the past two decades, the recent introduction of immunotherapy has heralded an important milestone in the adjuvant landscape of early-stage non-small cell lung cancer (NSCLC). The landmark approval of adjuvant atezolizumab based on disease-free survival (DFS) benefit in IMpower010 was swiftly followed by the recent data for use of adjuvant pembrolizumab in PEARLS/KEYNOTE-091, and similar trials involving other immune checkpoint inhibitors are eagerly anticipated. Although both atezolizumab and pembrolizumab demonstrated a significant DFS benefit in the intention-to-treat population, key subgroup analyses have raised questions about the role of predictive biomarkers such as PD-L1 expression and EGFR-mutation status. In this review, we examine the data from the two important trials (IMpower010 and PEARLS/KEYNOTE-091), discuss the controversies surrounding adjuvant immunotherapy including appropriate endpoints, biomarker selection and highlight key considerations in oncogene-driven NSCLC. Finally, we propose future directions including the impact of neoadjuvant therapy on developments in the adjuvant immunotherapy paradigm and role of minimal residual disease (MRD).

Correction to: Influence of afatinib dose on outcomes of advanced EGFR-mutant NSCLC patients with brain metastases.

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Influence of afatinib dose on outcomes of advanced EGFR-mutant NSCLC patients with brain metastases.

BACKGROUND: Afatinib is an oral irreversible epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor (TKI) indicated in first-line treatment of advanced EGFR-mutant (EGFRm+) non-small cell lung cancer (NSCLC). Dose dependent side effects can limit drug exposure, which may impact on extracranial and central nervous system (CNS) disease control. METHODS: We performed a retrospective study of 125 patients diagnosed with advanced EGFRm+ NSCLC treated with first-line afatinib at a tertiary Asian cancer center, exploring clinicopathological factors that may influence survival outcomes. Median progression free survival (PFS) was estimated using the Kaplan-Meier method. Comparison of PFS between subgroups of patients was done using log-rank tests and Cox proportional hazards models. RESULTS: Out of 125 patients, 62 (49.6%) started on 40 mg once daily (OD) afatinib, 61 (48.8%) on 30 mg OD and 1 (0.8%) on 20 mg OD. After median follow-up of 13.8 months from afatinib initiation, the observed response rate was 70.4% and median PFS 11.9 months (95% CI 10.3-19.3). 42 (33.6%) patients had baseline brain metastases (BM) and PFS of those who started on 40 mg OD (n = 17) vs. 30 mg OD (n = 25) was 13.3 months vs. 5.3 months (HR 0.39, 95% CI 0.15-0.99). BM+ patients who started on 40 mg had similar PFS to patients with no BM (13.3 months vs. 15.0 months; HR 0.79, 95% CI 0.34-1.80). CONCLUSION: In patients with advanced EGFRm+ NSCLC with BM+, initiating patients on afatinib 40 mg OD was associated with improved PFS compared to 30 mg OD, underscoring the potential importance of dose intensity in control of CNS disease.

Influence of the KDM4A rs586339 polymorphism on overall survival in Asian non-small-cell lung cancer patients.

The critical role of lysine demethylase 4A (KDM4A), in regulating chromatin structure and consequently in driving cellular proliferation and oncogenesis has been the focus of recent studies. Non-small-cell lung cancer (NSCLC) patients with adenocarcinoma histology who were homozygous for KDM4A single nucleotide polymorphism (SNP)-A482 (rs586339) were recently shown to have significantly worse overall survival (OS) compared with patients with the wild-type or the heterozygous genotype at this locus (hazard ratio=1.68, P=0.042). In the current study, we investigated the association between the same polymorphism with OS in our Asian NSCLC-adenocarcinoma patients comprising Chinese (N=572), Malays (N=50), and Indians (N=22). KDM4A SNP-A482 genotype status was determined by Sanger sequencing. OS was calculated from the date of diagnosis to date of death or censored at the date of last follow-up. Kaplan-Meier analysis, log-rank test, and Cox regression methods were utilized to evaluate OS outcomes. KDM4A SNP-A482 had a minor allele (C) frequency of 18.8% and a major allele (A) frequency of 81.2% in our Asian NSCLC (adenocarcinoma) patients. However, the OS in our Asian NSCLC patients homozygous for KDM4A SNP-A482 was not significantly different from those who were wild type or heterozygous at this locus [CC vs. AA/AC: median OS (95% confidence interval): 40.2 (18.7-61.6) vs. 29.6 (26.9-32.3) months; P=0.858]. The results remained statistically nonsignificant even after adjustment for epidermal growth factor receptor mutational status, suggesting that KDM4A SNP-A482 does not significantly influence OS in Asian NSCLC patients.

Randomized trial comparing surgery and adjuvant radiotherapy versus concurrent chemoradiotherapy in patients with advanced, nonmetastatic squamous cell carcinoma of the head and neck: 10-year update and subset analysis.

BACKGROUND: The current study was performed to report the long-term results of a trial comparing concurrent chemotherapy and radiotherapy (CCRT) with surgery and adjuvant radiotherapy (RT) in patients with stage III/IV nonmetastatic head and neck squamous cell carcinoma. METHODS: Patients with stage III/IV resectable head and neck squamous cell carcinoma were randomized to surgery followed by RT or CCRT. The trial was halted prematurely due to poor accrual. Human papillomavirus status was tested on archival material using polymerase chain reaction sequencing. RESULTS: Of the total of 119 patients, 60 patients were randomized to primary surgery (S arm) and 59 patients were randomized to CCRT (C arm). Human papillomavirus status was tested in 75 patients, and only 3 were found to be positive. The median follow-up for surviving patients was 13 years. Analysis of the entire cohort demonstrated no statistically significant difference in overall survival and disease-specific survival (DSS): 5-year rates were 45% versus 35% for overall survival (P = .262) and 56% versus 46% for DSS (P = .637) for the S arm and C arm, respectively. Analysis by subsites indicated that this difference favoring the S arm was mainly driven by survival data among patients with cancers of the oral cavity and maxillary sinus. For patients with oral cavity cancer, survival was significantly better in those who underwent primary surgery compared with CCRT; the 5-year DSS rate was 68% versus 12% for the S arm and C arm, respectively (P = .038). For patients with cancers of the maxillary sinus, the 5-year DSS rate was 71% for patients on the S arm and 0% for patients on the C arm (P = .05). CONCLUSIONS: These long-term results demonstrate a significant advantage for primary surgery in patients with cancers of the oral cavity or maxillary sinus, providing strong support for primary surgery as the main modality of treatment for these subsites. In other subsites, CCRT and surgery with adjuvant RT were found to demonstrate similar efficacy for survival in patients with advanced resectable tumors.

Intertumor heterogeneity of non-small-cell lung carcinomas revealed by multiplexed mutation profiling and integrative genomics.

Non-small-cell lung cancer (NSCLC) is a heterogeneous disease, with a burden of genomic alterations exceeding most other tumors. The goal of our study was to evaluate the frequencies of co-occurring mutations and copy-number aberrations (CNAs) within the same tumor and to evaluate their potential clinical impact. Mass-spectrometry based mutation profiling using a customized lung cancer panel evaluating 214 mutations across 26 key NSCLC genes was performed on 230 nonsquamous NSCLC and integrated with genome-wide CNAs and clinical variables. Among the 138 cases having at least one mutation, one-third (41, 29.7%) showed two or more mutations, either in the same gene (double mutation) or in different genes (co-mutations). In epidermal growth factor receptor (EGFR) mutant cancers, there was a double mutation in 18% and co-mutations in the following genes: TP53 (10%), PIK3CA (8%), STK11 (6%) and MET (4%). Significant relationships were detected between EGFR mutation and 1p, 7p copy gains (harboring the EGFR gene) as well as 13q copy loss. KRAS mutation was significantly related with 1q gain and 3q loss. For Stage I, tumors harboring at least one mutation or PIK3CA mutation were significantly correlated with poor prognosis (p-value = 0.02). When combining CNAs and mutational status, patients having both KRAS mutation and the highest related CNA (3q22.3 copy loss) showed a significant poorer prognosis (p-value = 0.03). Our study highlights the clinical relevance of studying tumor complexity by integrative genomic analysis and the need for developing assays that broadly screen for both "actionable" mutations and copy-number alterations to improve precision of stratified treatment approaches.

Longitudinal post-radiotherapy plasma Epstein-Barr virus DNA trends inform on optimal risk stratification in endemic nasopharyngeal carcinoma.

OBJECTIVES: To characterize longitudinal changes in Epstein-Barr virus (EBV) DNA post-radiotherapy in nasopharyngeal carcinoma (NPC) patients, and investigate whether an early (0-2 weeks) or delayed (8-12 weeks) EBV DNA result better predicts for disease-free survival (DFS). MATERIALS AND METHODS: Histologically-confirmed NPC patients with ≥1 EBV DNA test quantified using the harmonized BamHI-W polymerase chain reaction-based assay at 0-2 and 8-12 weeks post-radiotherapy were included. RESULTS: We identified 302 patients with EBV DNA measured at 0-2 weeks post-radiotherapy; of which, 110 (36.4 %) underwent a repeat test at 8-12 weeks post-treatment. Patients harboring a detectable EBV DNA at 0-2 weeks experienced an inferior DFS (adjusted HR1-264 copies 1.72 [95 %CI: 1.05-2.83], P = 0.031; AHR≥265 copies 4.39 [95 %CI: 1.68-11.44], P = 0.002 relative to 0 copies/mL). At 8-12 weeks, we observed substantial shifts in EBV DNA readings from 0 to 2 weeks; 76/110 (69.1 %) and 34/110 (30.9 %) patients at 0-2 weeks versus 90/110 (81.8 %) and 20/110 (18.2 %) at 8-12 weeks recorded undetectable and detectable EBV DNA, respectively. Positive EBV DNA at 8-12 weeks was strongly associated with relapse (73.3 % [11/15] for 1-264; 80.0 % [4/5] for ≥265 subgroups had relapses versus 15.6 % [14/90] for 0 copies/mL). Area under receiver operating curve values for 2-year relapse rates were 0.817 (95 %CI: 0.725-0.909) for stage + EBV DNA8-12w versus 0.654 (95 %CI: 0.542-0.765) for stage + EBV DNA0-2w. CONCLUSION: EBV DNA is dynamic post-radiotherapy, and delayed EBV DNA testing better enriched for higher-risk NPC patients. This implicates trials investigating adjuvant chemotherapy intensification based on early EBV DNA testing.

Combinatorial Hypofractionated Radiotherapy and Pembrolizumab in Anaplastic Thyroid Cancer.

Objectives Anaplastic thyroid cancer (ATC) is an aggressive disease associated with poor outcomes and resistance to therapies. Our study aim was to evaluate the activity of a combinatorial regimen of sandwich sequencing of pembrolizumab immunotherapy and hypofractionated radiotherapy (RT). Methods In this case series, patients with ATC received hypofractionated RT (QUAD-shot) and intravenous pembrolizumab 200mg every 3-4 weeks. Pembrolizumab was continued until disease progression or up till 24 months. Concurrent Lenvatinib treatment was allowed. Primary endpoint was best overall response (BOR) and progression-free survival (PFS). Additionally, we performed immune profiling of circulating T cells in a responder to investigate the immune response to our combinatorial treatment. Results At median follow-up of 32.6 months (IQR: 26.4-38.8), of a cohort of 5 patients, BOR was 80%; with 2 complete responses (CR) and 2 partial responses (PR). Patients who achieved CR remained disease-free at last follow-up. Median PFS was 7.6 months (IQR: 6.2-NR), and 1-year PFS and overall survival rate was 40% (95% CI: 13.7-100) for both. Treatment was well-tolerated, with mostly grade 1-2 adverse events. Immune profiling of one partial responder revealed an increase in activated CD4 and CD8 T cells post-QUAD-shot RT, which was further enhanced during the maintenance phase of pembrolizumab. Conclusions Herein, we reported a case series of 5 patients with ATC, with 2 long-term survivors who were treated with surgical debulking followed by QUAD-shot RT and pembrolizumab, possibly due to synergy of local and systemic treatments in activating anti-tumour immunogenic cytotoxicity. This regimen warrants further investigation in a larger cohort of patients.

Real-world outcomes of pemetrexed-platinum chemotherapy plus osimertinib after progression on first-line osimertinib in advanced EGFR-mutated NSCLC.

OBJECTIVES: First-line pemetrexed-platinum chemotherapy + osimertinib(Pem-Plat-Osi) improves progression-free survival as compared to osimertinib alone in advanced epidermal growth factor (EGFR)-mutated non-small cell lung cancer (NSCLC). However, many patients are hesitant to commence chemotherapy upfront. We describe outcomes to Pem-Plat-Osi after first-line osimertinib failure. MATERIALS AND METHODS: Patients with advanced EGFR-mutated (ex19del/L858R) NSCLC who had Pem-Plat-Osi between 1/7/2018-30/9/2023 after progression on first-line osimertinib at National Cancer Centre Singapore, Prince of Wales Hospital and Chinese University of Hong Kong were identified. Key endpoints were time to treatment failure (TTF) and overall survival (OS). RESULTS: A total of 60 patients were included. Median age at diagnosis was 62, 53.3 % (32/60) were male and 76.7 % (46/60) were never smokers. Ex19del comprised 56.7 % (34/60) and L858R 43.3 % (26/60). Baseline central nervous system (CNS) metastases were present in 66.7 % (40/60). Median TTF on osimertinib (TTF1) was 14.4 months(m) and median time to initiation of Pem-Plat-Osi was 41 days(d) (range 0-652) after progression on osimertinib. Partial response (PR) or stable disease to Pem-Plat-Osi was achieved in 81.7 %(49/60). Intracranial disease control was achieved in 90.6 % (29/32) of patients with measurable CNS metastases, including those who did not undergo brain radiotherapy. At median follow up of 31.2 m, median TTF on Pem-Plat-Osi (TTF2) was 6.6 m. Median TTF1 + TTF2 was 23.4 m and median OS was 34.2 m. Survival outcomes were similar comparing ex19del and L858R (median TTF1 + TTF2 21.8 m vs 23.5 m, p = 0.90; median OS 34.2 m vs 36.8 m, p = 0.37) and in patients without/with baseline CNS metastases (median TTF1 + TTF2 21.8 m vs 23.4 m, p = 0.44; median OS 36.2 m vs 31.9 m, p = 0.65). TTF1 duration was not significantly associated with TTF2 (p = 0.76). Patients who started Pem-Plat-Osi within 20d of progression on osimertinib had significantly longer TTF2 as compared to patients who started after 20d (median 8.4 m versus 6.0 months, p = 0.03), which remained statistically significant on multivariable analysis. CONCLUSIONS: Our real-world data supports the efficacy of Pem-Plat-Osi after progression on first-line osimertinib, including L858R and baseline CNS metastases. Chemotherapy initiation within 20d of Osi progression was predictive of superior TTF2.

Oncogene-Driven Non-Small Cell Lung Cancers in Patients with a History of Smoking Lack Smoking-Induced Mutations.

Non-small cell lung cancers (NSCLC) in nonsmokers are mostly driven by mutations in the oncogenes EGFR, ERBB2, and MET and fusions involving ALK and RET. In addition to occurring in nonsmokers, alterations in these "nonsmoking-related oncogenes" (NSRO) also occur in smokers. To better understand the clonal architecture and genomic landscape of NSRO-driven tumors in smokers compared with typical-smoking NSCLCs, we investigated genomic and transcriptomic alterations in 173 tumor sectors from 48 NSCLC patients. NSRO-driven NSCLCs in smokers and nonsmokers had similar genomic landscapes. Surprisingly, even in patients with prominent smoking histories, the mutational signature caused by tobacco smoking was essentially absent in NSRO-driven NSCLCs, which was confirmed in two large NSCLC data sets from other geographic regions. However, NSRO-driven NSCLCs in smokers had higher transcriptomic activities related to the regulation of the cell cycle. These findings suggest that, whereas the genomic landscape is similar between NSRO-driven NSCLC in smokers and nonsmokers, smoking still affects the tumor phenotype independently of genomic alterations. SIGNIFICANCE: Non-small cell lung cancers driven by nonsmoking-related oncogenes do not harbor genomic scars caused by smoking regardless of smoking history, indicating that the impact of smoking on these tumors is mainly nongenomic.

Boosted abscopal effect from radiotherapy and pembrolizumab in anaplastic thyroid cancer: a mini-review and case report.

BACKGROUND: The abscopal effect, in which radiation induces a systemic anti-tumour immune response, has been demonstrated with radiotherapy. Immunotherapy boosts the abscopal effect by facilitating the immune response to radiation. Radiotherapy and programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) blockade has resulted in the boosted abscopal effect in solid cancers, but its role in anaplastic thyroid cancer (ATC) is unknown. In this mini-review, we describe the abscopal effect and summarise its proposed underlying mechanisms. We then present a potential case of boosted abscopal effect in ATC. CASE DESCRIPTION: In our case presentation, we describe a 51-year-old female who presented with 3 weeks of rapidly enlarging thyroid mass. Examination revealed a 3-cm thyroid nodule which was Bethesda V on fine needle aspiration cytology (FNAC). Intraoperatively, there was a gross extrathyroidal extension into the cricoid cartilage. After total thyroidectomy, post-operative histopathology showed widely invasive follicular thyroid cancer with anaplastic transformation (>50%). Immunohistochemistry showed high PD-L1 expression [combined positive score (CPS) >70%]. Due to residual cricoid cartilage disease and several peri-hilar and lung metastases on positron emission tomography-computed tomography (PET-CT) scan, she underwent post-operative palliative radiotherapy and pembrolizumab. After two cycles of pembrolizumab, repeat PET-CT scan showed complete response (CR) of local and distant disease. She remained well for 32 months, before recent discovery of a right mandible bony metastasis planned for radiotherapy. CONCLUSIONS: This case demonstrates exceptional response to radiotherapy and anti-PD-1 immunotherapy in ATC, potentially illustrating the first known abscopal effect in ATC with this treatment.

Efficacy of Anti-PD1 Blockade in Treating Recurrent or Metastatic Nasopharyngeal Cancer: A Systematic Review and Meta-analysis.

OBJECTIVES: Anti-PD1 antibody has emerged as a promising immunotherapeutic option in patients with recurrent and/or metastatic nasopharyngeal cancers (RM-NPC). We aim to summarise existing evidence on the use of anti-PD1 antibodies in the treatment of these patients and compare its effectiveness with standard-of-care palliative chemotherapy. Our secondary aim is to explore potential combination therapies with anti-PD1 antibodies. MATERIALS AND METHODS: PubMed, Embase and Cochrane databases were systematically searched for studies comparing the efficacy of various anti-PD1 antibodies in the treatment of RM-NPC (either as first or second line treatment) from inception to 2 September 2022. Meta-analyses were performed to correlate the various anti-PD1 antibodies with primary endpoints including overall response rate disease control rate (DCR), progression free survival (PFS) and overall survival (OS). RESULTS: Eighteen studies with 1,887 patients met the inclusion criteria. The use of anti-PD1 antibody monotherapy as second-line treatment of RM-NPC revealed an ORR of 23 % (95 % CI = 19 %-28 %) and DCR of 51 % (95 % CI = 42 %-60 %). The ORRs for first-line as well as a combination of first and second-line treatments were 21 % (95 % CI = 15 % - 30 %) and 22 % (95 % CI = 6 % - 56 %, I2 = 75 %) respectively. The 12-month PFS and 12-month OS was also 27 % (95 % CI = 21 %-33 %) and 63 % (95 % CI = 53 %-72 %) respectively. ORR was much higher at 73 % (95 % CI = 32 %-94 %) when anti-PD1 antibodies were combined with Gemcitabine plus Cisplatin. CONCLUSION: Anti-PD1 antibody demonstrate considerable activity in previously treated RM-NPC patients. Combining anti-PD1 antibodies with gemcitabine and cisplatin chemotherapy enhanced the efficacy of treatment.

PD-L1 score as a prognostic biomarker in asian early-stage epidermal growth factor receptor-mutated lung cancer.

AIM: To determine the prognostic value of programmed death-ligand 1 (PD-L1) score in early-stage epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), contrasted against EGFR-wildtype NSCLC. METHODS: Consecutive patients with Stage IA-IIIA NSCLC diagnosed 1st January 2010-31st December 2019 at National Cancer Centre Singapore with evaluable EGFR and PD-L1 status were included. Co-primary end-points were 2-year disease-free survival (DFS) and 5-year overall survival (OS) by Kaplan-Meier method. RESULTS: 455 patients were included (267 EGFR-mutated, EGFR-M+; 188 EGFR-wildtype, wt). Median age at diagnosis was 65 years, 52.3% (238/455) of patients were males, 62.9% (286/455) of patients were never-smokers and 92.5% (421/455) of patients had R0 resection. Stage IA comprised 42.4% (193/455) of patients, Stage IB comprised 23.1% (105/455) of patients, Stage IIA comprised 10.8% of patients (49/455), Stage IIB comprised 5.1% of patients (23/455) and Stage IIIA comprised 18.7% (85/455) of patients. Among EGFR-M+, 45.3% (121/267) were Ex19del and 41.9% (112/267) were L858R. PD-L1 ≥1% among EGFR-M+ and EGFR-wt was 45.3% (121/267) and 54.8% (103/188) respectively (p = 0.047). At median follow-up of 47 months, 178 patients had relapsed. Among EGFR-M+, 2-year DFS comparing PD-L1 <1% and PD-L1 ≥1% was 78.1% and 67.6% (p = 0.007) while 5-year OS was 59.5% and 42.8% (p = 0.001), respectively. Controlling for age, gender, lymphovascular invasion, adjuvant therapy and resection margin status, PD-L1 ≥1% (hazard ratio, HR 2.18, 95% CI 1.04-4.54, p = 0.038), stage IIB (HR 7.78, 95% CI 1.72-35.27, p = 0.008) and stage IIIA (HR 4.45, 95% CI 1.44-13.80, p = 0.01) emerged as independent predictors of inferior OS on multivariable analysis. In exploratory analysis, genomic analysis of 81 EGFR-M+ tumours was performed. PD-L1 ≥1% tumours had significantly higher rates of TP53 mutations (36.1% versus 15.6%, p = 0.04), with predominantly missense mutations. CONCLUSION: PD-L1 ≥1% is an independent predictor of worse OS among early-stage EGFR-mutated NSCLC and is associated with inferior DFS regardless of EGFR status. PD-L1 score as a risk stratification factor should be evaluated in prospective adjuvant studies among EGFR-mutated NSCLC.

Clinical efficacy and biomarker analysis of dual PD-1/CTLA-4 blockade in recurrent/metastatic EBV-associated nasopharyngeal carcinoma.

Single-agent checkpoint inhibitor (CPI) activity in Epstein-Barr Virus (EBV) related nasopharyngeal carcinoma (NPC) is limited. Dual CPI shows increased activity in solid cancers. In this single-arm phase II trial (NCT03097939), 40 patients with recurrent/metastatic EBV-positive NPC who failed prior chemotherapy receive nivolumab 3 mg/kg every 2 weeks and ipilimumab 1 mg/kg every 6 weeks. Primary outcome of best overall response rate (BOR) and secondary outcomes (progression-free survival [PFS], clinical benefit rate, adverse events, duration of response, time to progression, overall survival [OS]) are reported. The BOR is 38% with median PFS and OS of 5.3 and 19.5 months, respectively. This regimen is well-tolerated and treatment-related adverse events requiring discontinuation are low. Biomarker analysis shows no correlation of outcomes to PD-L1 expression or tumor mutation burden. While the BOR does not meet pre-planned estimates, patients with low plasma EBV-DNA titre (<7800 IU/ml) trend to better response and PFS. Deep immunophenotyping of pre- and on-treatment tumor biopsies demonstrate early activation of the adaptive immune response, with T-cell cytotoxicity seen in responders prior to any clinically evident response. Immune-subpopulation profiling also identifies specific PD-1 and CTLA-4 expressing CD8 subpopulations that predict for response to combined immune checkpoint blockade in NPC.

Real world efficacy of osimertinib in second line/beyond in patients with metastatic EGFR+ non-small cell lung cancer and role of paired tumour-plasma T790M testing at tyrosine kinase inhibitor resistance.

Background: Osimertinib is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) approved for use in EGFR-mutant lung cancer. We examined its performance in the second/subsequent line after resistance to first- and second-generation (1/2G) EGFR-TKI. Methods: We reviewed electronic records of 202 patients who received osimertinib from July 2015 to January 2019 in the second/subsequent line after progression on prior EGFR-TKI. Of these, complete data from 193 patients were available. Clinical data including patient characteristics, primary EGFR mutation, T790M mutation status, presence of baseline brain metastases (BM), first-line EGFR-TKI use, and survival outcomes were extracted, and results retrospectively analyzed. Results: Of 193 evaluable patients, 151 (78.2%) were T790M+ (T790M positive) with 96 (49.2%) tissue confirmed; 52% of patients received osimertinib in the second line setting. After median follow up of 37 months, median progression-free survival (PFS) of the entire cohort was 10.3 [95% confidence interval (CI): 8.64-11.50] months and median overall survival (OS) was 20 (95% CI: 15.61-23.13) months. Overall response rate (ORR) to osimertinib was 43% (95% CI: 35.9-50.3%); 48.3% in T790M+ vs. 20% in T790M- (T790M negative) patients. OS in T790M+ patients was 22.6 vs. 7.9 months in T790M- patients (HR 0.43, P=0.001), and PFS was 11.2 vs. 3.1 months respectively (HR 0.52, P=0.01). Tumour T790M+ was significantly associated with longer PFS (P=0.007) and OS (P=0.01) compared to tumour T790M- patients, however this association was not seen with plasma T790M+. Of the 22 patients with paired tumor/plasma T790M testing, response rate (RR) to osimertinib was 30% for those plasma T790M+/tumour T790M-, compared to 63% and 67% for those who were plasma T790M+/tumour T790M+ and plasma T790M-/tumour T790M+, respectively. By multivariable analysis (MVA), Eastern Cooperative Oncology Group (ECOG) performance status ≥2 was associated with shorter OS (HR 2.53, P<0.001) and PFS (HR 2.10, P<0.001), whereas presence of T790M+ was associated with longer OS (HR 0.50, P=0.008) and PFS (HR 0.57, P=0.027). Conclusions: This cohort demonstrated the efficacy of osimertinib in second line/beyond for EGFR+ (EGFR mutation-positive) non-small cell lung cancer (NSCLC). Tissue T790M result appeared more predictive of osimertinib efficacy compared to plasma, highlighting potential T790M heterogeneity and the advantage with paired tumor-plasma T790M testing at TKI resistance. T790M- disease at resistance remains an unmet treatment need.

Keratin 15, transcobalamin I and homeobox gene Hox-B13 expression in breast phyllodes tumors: novel markers in biological classification.

Breast phyllodes tumors are rare neoplasms which present challenges for histological classification. Microscopic features are not always predictive of clinical behavior, and scarce data exist on the prognostic role of biological markers. Our study evaluated a series of 145 phyllodes tumors diagnosed at the Department of Pathology, Singapore General Hospital between 2006 and 2009, incorporating 91 (62.8%) benign, 40 (27.6%) borderline, and 14 (9.7%) malignant phyllodes tumors. Antibodies to keratin 15 (KRT15), transcobalamin I (TCN1), and homeobox gene Hox-B13 (HOXB13) were applied to sections cut from tissue microarray blocks. KRT15 and TCN1 positivity was defined when there was reactivity of 1% or more stromal cells, while HOXB13 positivity was defined using a H-score of 100 and above. Positive immunohistochemical expression for KRT15, TCN1, and HOXB13 was seen in 21 (14.5%), 96 (66.2%), and 66 (45.5%) of tumors, respectively. Stromal expression of KRT15, TCN1, and HOXB13 was significantly correlated with tumor grade (P < 0.001, P < 0.001, P = 0.012), stromal hypercellularity (P = 0.005, P < 0.001, P = 0.023), mitotic activity (P < 0.001), and microscopic borders (P = 0.006, P < 0.001, P = 0.011). Co-expression of TCN1 and HOXB13 was seen in 21 of 91 (23.1%) benign, 18 of 40 (45.0%) borderline, and 11 of 14 (78.6%) malignant tumors, suggesting that the dual-marker panels of TCN1 and HOXB13 might be helpful in classifying borderline and malignant tumors. Although expression of TCN1 alone was present in all malignant and 34 of 40 (85.0%) borderline tumors, a combined panel with HOXB13 excluded some benign cases and was a better discriminant for a significant proportion of borderline and malignant tumors.

Clinical and Genomic Features of HER2 Exon 20 Insertion Mutations and Characterization of HER2 Expression by Immunohistochemistry in East Asian Non-Small-Cell Lung Cancer.

PURPOSE: HER2-altered non-small-cell lung cancer (NSCLC) represents a diverse subgroup, including mutations, amplifications, and overexpression. However, HER2 exon 20 insertion mutations are emerging as a distinct molecular subtype with expanding therapeutic options. We describe the molecular epidemiology and genomic features of HER2-altered NSCLC in an Asian tertiary cancer center. METHODS: We identified patients with HER2-mutated NSCLC in our institutional database, collating clinicopathological features and treatment outcomes. The genomic landscape of human epidermal growth factor receptor 2 (HER2)-mutated NSCLC was further evaluated using whole-exome sequencing (WES) data from combined local and publicly available data sets. HER2 amplification and overexpression as selection biomarkers in NSCLC were further interrogated using HER2 immunohistochemistry and correlations with WES and RNA sequencing data. RESULTS: Among 1,252 patients with consecutive lung adenocarcinoma undergoing routine next-generation sequencing, the prevalence of HER2 mutations was 3.1%-exon 20 insertion mutations comprised 2.7%. We examined the clinicopathological features in 55 patients with HER2-mutated NSCLC comprising 40 exon 20 insertion and 15 nonexon 20 insertion mutations. The most common exon 20 insertion mutation was HER2Y772_A775dup in 30 (75%), followed by HER2G776delinsVC in five patients (13%). There were limited responses to HER2-directed therapies apart from trastuzumab-deruxtecan, and no responses were seen with immunotherapy monotherapy. Evaluating the genomics features of HER2 exon 20 insertion mutations using WES data revealed low tumor mutational burden (TMB), low incidence of cancer driver comutations, and a predominance of aging mutational signature-similar to EGFR-mutated tumors. In contrast, uncommon (or nonexon 20 insertion) HER2-mutated tumors resembled EGFR wild-type tumors with higher TMB, higher frequency of cancer driver comutations, and greater presence of smoking and APOBEC mutational signature. Finally, in evaluating HER2 immunohistochemistry in all lung adenocarcinoma, there was significant discordance comparing different scoring systems and poor correlation with HER2 RNA expression and HER2 amplification. CONCLUSION: The incidence of HER2 mutations is 3.1% in East Asian nonsquamous NSCLC. HER2 exon 20 insertion-mutated tumors appear genomically distinct from uncommon (nonexon 20 insertion) HER2 mutations, the latter demonstrating higher TMB, co-occurring drivers, and predominant nonaging mutational signature. The therapeutic implications of the genomic and clinical features of HER2-mutated NSCLC warrant further investigation.

A Randomized Phase 2 Trial of Nivolumab Versus Nivolumab-Ipilimumab Combination in EGFR-Mutant NSCLC.

Introduction: Although immune checkpoint inhibitors (ICIs) have dramatically improved outcomes for nononcogene-addicted NSCLC, monotherapy with programmed cell death protein-1 (PD1) inhibition has been associated with low efficacy in the EGFR-mutant setting. Given the potential for synergism with combination checkpoint blockade, we designed a trial to test the activity of combination nivolumab (N)-ipilimumab (NI) in EGFR-mutant NSCLC. Methods: This is a randomized phase 2 study (NCT03091491) of N versus NI combination in EGFR tyrosine kinase inhibitor (TKI)-resistant NSCLC, with crossover permitted on disease progression. The primary end point was the objective response rate, and the secondary end points included progression-free survival, overall survival, and safety of ICI after EGFR TKI. Results: Recruitment ceased owing to futility after 31 of 184 planned patients were treated. A total of 15 patients received N and 16 received NI combination. There were 16 patients (51.6%) who had programmed death-ligand (PDL1) 1 greater than or equal to 1%, and 15 (45.2%) harbored EGFR T790M. Five patients derived clinical benefits from ICI with one objective response (objective response rate 3.2%), and median progression-free survival was 1.22 months (95% confidence interval: 1.15-1.35) for the overall cohort. None of the four patients who crossed over achieved salvage response by NI. PDL1 and tumor mutational burden (TMB) were not able to predict ICI response. Rates of all grade immune-related adverse events were similar (80% versus 75%), with only two grade 3 events. Conclusions: Immune checkpoint inhibition is ineffective in EGFR TKI-resistant NSCLC. Whereas a small subgroup of EGFR-mutant NSCLC may be immunogenic and responsive to ICI, better biomarkers are needed to select appropriate patients.