Impact of homocysteine on acute ischemic stroke severity: possible role of aminothiols redox status.

BACKGROUND: Acute ischemic stroke (AIS) is one of the most common cerebrovascular diseases which accompanied by a disruption of aminothiols homeostasis. To explore the relationship of aminothiols with neurologic impairment severity, we investigated four aminothiols, homocysteine (Hcy), cysteine (Cys), cysteinylglycine (CG) and glutathione (GSH) in plasma and its influence on ischemic stroke severity in AIS patients. METHODS: A total of 150 clinical samples from AIS patients were selected for our study. The concentrations of free reduced Hcy (Hcy), own oxidized Hcy (HHcy), free reduced Cys (Cys), own oxidized Cys (cysteine, Cyss), free reduced CG (CG) and free reduced GSH (GSH) were measured by our previously developed hollow fiber centrifugal ultrafiltration (HFCF-UF) method coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration ratio of Hcy to HHcy (Hcy/HHcy), Cys to Cyss (Cys/Cyss) were also calculated. The neurologic impairment severity of AIS was evaluated using National Institutes of Health Stroke Scale (NIHSS). The Spearman correlation coefficient and logistic regression analysis was used to estimate and perform the correlation between Hcy, HHcy, Cys, Cyss, CG, GSH, Hcy/HHcy, Cys/Cyss and total Hcy with NIHSS score. RESULTS: The reduced Hcy and Hcy/HHcy was both negatively correlated with NIHSS score in AIS patients with P = 0.008, r=-0.215 and P = 0.002, r=-0.249, respectively. There was no significant correlation of Cys, CG, GSH, HHcy, Cyss, Cys/Cyss and total Hcy with NIHSS score in AIS patients with P value > 0.05. CONCLUSIONS: The reduced Hcy and Hcy/HHcy, not total Hcy concentration should be used to evaluate neurologic impairment severity of AIS patient.

Characteristics and prognostic value of gut microbiota in follicular lymphoma.

The pathogenesis and progression of follicular lymphoma (FL) depends on immune evasion mechanisms. The gut microbiota has been reported to be associated with the development and outcome of several human diseases by modulating host immunity. Thus, the present study investigated the characteristics and prognostic value of the gut microbiota in FL. Fecal samples from treatment-naïve patients with FL (n=28) and healthy controls (n=18) were prospectively collected. The gut microbiota diversity and composition were examined by 16S ribosomal RNA sequencing. The results demonstrated that patients with FL had distinct microbiota compositions. The relative abundance of the Ruminococcaceae family was significantly increased in patients with FL (P=0.01). Furthermore, a high level of Ruminococcus was identified as a strong indicator of tumor burden (P=0.001), and was related to the FL International Prognostic Index score and serum lactate dehydrogenase levels. The present results indicated an association between the gut microbiota and FL prognosis. Findings from the present study may provide a rational foundation for further investigation of the role of gut microbiota in lymphoma management.

Lymphoma relapse 1 year or later after immunochemotherapy in DLBCL patients: clinical features and outcome.

Despite great advances in treatment, 30-40% of patients with DLBCL undergo relapses. Patients with a relapse within 1 year or beyond have a distinct outcome. Few clinical characteristics and survival data in the Chinese population have been published. We aimed to define the incidence and clinical features of DLBCL patients with very early relapse after front-line immunochemotherapy who may benefit greatly from the emerging chimeric antigen receptor T-cell therapy. Data of 564 DLBCL patients were analyzed. Among the 413 patients achieving a first complete remission, 59 underwent relapses: 32 patients (54.2%) relapsed within 1 year, and 27 patients (46.8%) relapsed 1 year or more. Patients relapsing within 1 year, in comparison with the other group, showed an inferior risk profile at diagnosis: elevated lactate dehydrogenase level (P = 0.002), high Eastern Cooperative Oncology Group performance score (P = 0.02), and high international prognosis index (P = 0.004). As expected, a worse overall survival was observed in the early relapse group. Multivariate analysis for OS showed that relapse within 1 year was an independent parameter for reduced overall survival (HR 0.241, P = 0.002).

The Gut Microbiome Correlated to Chemotherapy Efficacy in Diffuse Large B-Cell Lymphoma Patients.

The gut microbiome (GMB) has been extensively reported to be associated with the development and prognosis of human diseases. This study aims to investigate the relationship between GMB composition and chemotherapy efficacy in diffuse large B-cell lymphoma (DLBCL). We demonstrated that DLBCL patients at diagnosis have altered GMB compositions. Significant enrichment of the Proteobacteria phylum in DLBCL patients was observed. Gene analysis showed a high abundance of virulence factors genes. We found baseline GMB to be associated with clinical outcomes. The emergence of Lactobacillus fermentum was correlated with better treatment outcome. Our pilot results suggested a correlation between GMB composition and DLBCL development and prognosis. Clues from our study, together with previous research, provided a rational foundation for further investigation on the pathogenesis, prognosis value, and targeted therapy of GMB in DLBCL.

Germline defects of familial hemophagocytic lymphohistiocytosis-related genes presenting as adult-onset peripheral T-cell lymphoma.

Germline mutations in genes involved in perforin-granzyme-mediated cytotoxicity such as PRF1, UNC13D, STX11, and STXBP2 were known to cause familial hemophagocytic lymphohistiocytosis (FHL). In this study, we reported a unique group of 3 patients with germline mutations of UNC13D and STX11 genes and presented as adult-onset peripheral T-cell lymphoma (PTCL) with cytotoxic T-cell phenotype and atypical lymphoma presentations. CD107a degranulation assay and NK-cell activity analysis demonstrated impaired cytotoxic function of the NK/T-cells of the patients with FHL-related mutations. Gene expression profile study revealed that up-regulated genes of the cytotoxic T-cells were enriched in autoimmune-related pathways. It was possible that impaired cytotoxic lymphocyte-mediated immune surveillance and autoantigen stimulation may both participate in PTCL oncogenesis. Germline defects of FLH-related genes may represent a novel predisposing factor for PTCLs.

Distinct FDG PET/CT avidity among newly diagnosed intravascular large B-cell lymphoma patients: a descriptive observational study.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of aggressive B-cell non-Hodgkin lymphoma that poses a great diagnostic challenge due to its highly heterogenous clinical manifestations. Although 18F-fluorodeoxyglucose (FDG) is widely used as a diagnostic tool for patients suspected of having lymphoma, as it reveals FDG-avid lesions, the FDG avidity of IVLBCL has not been extensively characterized. Here, we present a comprehensive report of FDG avidity in IVLBCL and its association with clinicopathological features and survival. This descriptive observational study included consecutive patients aged at least 18 years diagnosed with IVLBCL in Peking Union Medical Hospital across 9 years. Among 50 screened IVLBCL patients, 42 had undergone 18F-FDG PET/CT to detect possible lesions for biopsy before pathological diagnosis; their FDG PET/CT (positron emission computed tomography, PET/CT) reports were retrospectively reviewed. The primary endpoint was the clinical description of FDG avidity of newly diagnosed intravascular large B-cell lymphoma and frequency. A total of 73.8% patients showed FDG-avid lesions, with a median SUVmax of 7.4 (range 1-27.7), which was lower than that for other aggressive lymphomas. Clinicopathological features were the same between the FDG-avid group and the non-FDG-avid group, except that the latter had a higher Ki-67 index (median 90% in the nonavid group vs. 80% in the avid group, P = 0.043). The overall survival rate was not different between the PET/CT groups. Our findings demonstrate that FDG PET/CT is a useful diagnostic tool for detecting FDG-avid lesions in IVLBCL patients. A random skin biopsy is essential for assisting in the diagnosis of IVLBCL, even for those with negative PET/CT.

The intrinsic defects of T cells impact the efficacy of CAR-T therapy in patients with diffuse large B-cell lymphoma.

CAR-T cell therapy did not achieve the desired efficacy in some patients with diffuse large B-cell lymphoma (DLBCL). We conducted single-cell RNA and TCR sequencing as well as methylation chip profiling of peripheral blood samples in DLBCL patients. Patients who achieved complete remission (CR) showed an upward trend in T-cell levels, especially CD8-effector T cells. The responders exhibited T-cell clone expansion, more active T-cell transformation, and frequent cell communication. Highly expressed genes in the CR group were enriched in functions like leukocyte-mediated cytotoxicity and activation of immune response, while the non-CR group was enriched in pathways related to DNA damage and P53-mediated intrinsic apoptotic. More differentially methylated probes (DMPs) were identified in the baseline of the non-CR group (779 vs 350). GSEA analysis revealed that the genes annotated by DMPs were associated with cellular immune functions in T cells, including the generation of chemokines, leukocyte-mediated cytotoxicity, and cell-killing functions. The genes with low expression in the non-CR group exhibited a high methylation status. There is heterogeneity in the cellular, molecular, and epigenetic characteristics of host T cells in patients with different clinical outcomes. Intrinsic defects in T cells are important factors leading to poor efficacy of CAR-T therapy.

Evaluation of progression-free survival as a surrogate end point in primary CNS lymphoma: a systematic review and meta-analysis.

Purpose: To evaluate progression-free survival (PFS) as early surrogate endpoints for overall survival (OS) in primary CNS lymphoma (PCNSL). Methods: PubMed, Embase and Cochrane Central Library were searched up to 7 June 2022. Trial-level analyses were performed by weighted linear regression of logarithmic hazard ratios for PFS and OS. Treatment arm-level analyses were performed between PFS rates and 3- or 5-year OS rates. Results: 1471 PCNSL patients in nine randomized control trials were included. PFS was associated with OS (r = 0.750; 95% CI: 0.228-0.937). Strong linear correlations existed between 1-, 2- and 3-year PFS and 3-year OS (r = 0.896-0.928), moderate or weak correlations existed between 3- to 6-month PFS and 3-year OS, 3-month to 5-year PFS and 5-year OS. Conclusion: Short-term PFS can validly substitute for long-term OS in PCNSL.

COVID-19 Severity and Waning Immunity After up to 4 mRNA Vaccine Doses in 73 608 Patients With Cancer and 621 475 Matched Controls in Singapore: A Nationwide Cohort Study.

Importance: Despite patients with cancer being at risk of poor outcomes from COVID-19, there are few published studies for vaccine efficacy in this group, with suboptimal immunogenicity and waning vaccine efficacy described in small studies being a concern. Objective: To assess the incidence rate of severe COVID-19 disease outcomes associated with the number of vaccine doses received and the waning of protection over time. Design, Setting, and Participants: A prospective multicenter observational cohort study was carried out over 2 time periods (September 15, 2021, to December 20, 2021 [delta wave], and January 20, 2022, to November 11, 2022 [omicron wave]) predominated by SARS-CoV-2 delta and omicron variants, respectively. Overall, 73 608 patients with cancer (23 217 active treatment, 50 391 cancer survivors) and 621 475 controls matched by age, sex, race and ethnicity, and socioeconomic status were included. Exposure: Vaccine doses received, from zero to 4 doses, and time elapsed since last vaccine dose. Outcomes: Competing-risk regression analyses were employed to account for competing risks of death in patients with cancer. Main outcomes were incidence rate ratios (IRRs) of COVID-19 infection, hospitalization, and severe disease (defined as requirement for supplemental oxygen, intensive care, or death). The IRRs stratified by time from last vaccine dose served as indicators of waning of vaccine effectiveness over time. Results: The mean (SD) age of actively treated patients with cancer, cancer survivors, and controls were 62.7 (14.7), 62.9 (12.6), and 61.8 (14.7) years, respectively. Of 73 608 patients with cancer, 27 170 (36.9%) were men; 60 100 (81.6%) were Chinese, 7432 (10.1%) Malay, 4597 (6.2%) Indian, and 1479 (2.0%) were of other races and ethnicities. The IRRs for the 3-dose and 4-dose vs the 2-dose group (reference) for COVID-19 hospitalization and severe disease were significantly lower during both the delta and omicron waves in cancer and control populations. The IRRs for severe disease in the 3-dose group for active treatment, cancer survivors, and controls were 0.14, 0.13, and 0.07 during the delta wave and 0.29, 0.19, and 0.21 during omicron wave, respectively. The IRRs for severe disease in the 4-dose group during the omicron wave were even lower at 0.13, 0.10 and 0.10, respectively. No waning of vaccine effectiveness against hospitalization and severe disease was seen beyond 5 months after a third dose, nor up to 5 months (the end of this study's follow-up) after a fourth dose. Conclusion: This cohort study provides evidence of the clinical effectiveness of mRNA-based vaccines against COVID-19 in patients with cancer. Longevity of immunity in preventing severe COVID-19 outcomes in actively treated patients with cancer, cancer survivors, and matched controls was observed at least 5 months after the third or fourth dose.

Inferring cancer disease response from radiology reports using large language models with data augmentation and prompting.

OBJECTIVE: To assess large language models on their ability to accurately infer cancer disease response from free-text radiology reports. MATERIALS AND METHODS: We assembled 10 602 computed tomography reports from cancer patients seen at a single institution. All reports were classified into: no evidence of disease, partial response, stable disease, or progressive disease. We applied transformer models, a bidirectional long short-term memory model, a convolutional neural network model, and conventional machine learning methods to this task. Data augmentation using sentence permutation with consistency loss as well as prompt-based fine-tuning were used on the best-performing models. Models were validated on a hold-out test set and an external validation set based on Response Evaluation Criteria in Solid Tumors (RECIST) classifications. RESULTS: The best-performing model was the GatorTron transformer which achieved an accuracy of 0.8916 on the test set and 0.8919 on the RECIST validation set. Data augmentation further improved the accuracy to 0.8976. Prompt-based fine-tuning did not further improve accuracy but was able to reduce the number of training reports to 500 while still achieving good performance. DISCUSSION: These models could be used by researchers to derive progression-free survival in large datasets. It may also serve as a decision support tool by providing clinicians an automated second opinion of disease response. CONCLUSIONS: Large clinical language models demonstrate potential to infer cancer disease response from radiology reports at scale. Data augmentation techniques are useful to further improve performance. Prompt-based fine-tuning can significantly reduce the size of the training dataset.

Insulin-like growth factor 1 receptor inhibits the proliferation of acute myeloid leukaemia cells via NK cell activation.

Acute myeloid leukaemia (AML) denotes a heterogeneous category of cancers occurring within the bone marrow that are initiated by the unrestricted proliferation of haematopoietic stem cells. Various factors effectuate the dysregulation of AML cell proliferation; for instance, the upregulation of insulin-like growth factor 1 receptor (IGF1R) within AML cells influences their proliferation. However, there is a current dearth of research assessing the association between IGF1R and prognostic risk as well as its potential as an AML immunotherapeutic. This study aims to elucidate the role of IGF1R in AML progression and evaluate its prognostic value. To this end, RNA-sequencing (RNA-seq) data from The Cancer Genome Atlas (TCGA) database was analysed to compare IGF1R expression between AML and normal tissues. Moreover, a Kaplan-Meier survival analysis was performed to determine whether IGF1R expression correlates with patient overall survival (OS). TCGA data revealed upregulated IGF1R expression in the peripheral blood of AML patients compared to that in healthy individuals. Meanwhile, IGF1R expression positively correlates with patient OS. Additionally, elevated IGF1R expression promotes NK cell expansion and enhances its functional activation, thereby inhibiting AML cell proliferation. Collectively, these findings highlight the clinical potential of IGF1R in the effective treatment of AML through the activation of NK cell proliferation and function and suggest that it may represent a potential predictive marker of AML prognosis.

Mutation profiling, tumour burden assessment, outcome prediction and disease monitoring by circulating tumour DNA in peripheral T-cell lymphoma.

In this prospective study, we aimed to evaluate the utility of circulating tumour DNA (ctDNA) in peripheral T-cell lymphomas (PTCLs). Plasma cell-free DNA (cfDNA) was obtained, and the mutational profile was assessed in 47 patients with newly diagnosed mature T- and NK-cell lymphoma. To validate the mutations detected in cfDNA, paired tumour tissue samples were available for 36 patients. Targeted next-generation sequencing was performed. A total of 279 somatic mutations involving 149 genes were identified in the 47 cfDNA samples. The overall sensitivity of plasma cfDNA in discovering biopsy-confirmed mutations was 73.9% with a specificity of 99.6%. When we considered only mutations with variant allele frequency >5% in the tumour biopsy, the sensitivity increased to 81.9%. Pretreatment ctDNA concentration and the number of mutations were highly correlated with tumour burden indicators including lactate dehydrogenase, Ann Arbor stage and International Prognostic Index score. Patients with high ctDNA level (>1.9 log ng/mL) had significantly lower overall response rates, inferior 1-year progression-free survival and overall survival rates than those with low level. Longitudinal analysis of ctDNA showed a strong agreement between ctDNA dynamics and the radiographic response. In conclusion, our study demonstrates that ctDNA may serve as a promising tool for mutational profiling, tumour burden assessment, outcome prediction and disease monitoring in PTCLs.

Long-time follow-up of patients with untreated peripheral T cell lymphoma following chidamide combined with cyclophosphamide, epirubicin, vindesine, prednisone, and etoposide therapy: a single-center propensity score-matching study.

PURPOSE: This is a retrospective, single-center PSM study evaluating the efficacy and safety of chidamide combined with the CHOEP (C-CHOEP) regimen versus the single CHOEP regimen in patients with untreated peripheral T cell lymphomas (PTCL). PATIENTS: Patients newly diagnosed with PTCL between January 2015 and June 2021 were recruited, and were 1:1 divided into C-CHOEP and CHOEP groups according to their first-line chemotherapy regimens. The PSM method was used to match the baseline variables to balance the confounding factors. RESULTS: A cohort of 33 patients each in the C-CHOEP and CHOEP groups was generated after propensity score-matching (PSM). The complete remission (CR) rates of the C-CHOEP regimen were higher than that of the CHOEP regimen (56.3 vs. 25.8%, p = 0.014), whereas the duration of response of the C-CHOEP group was shorter (median DOR 30 vs. 57 months), resulting in roughly similar progression-free survival (PFS) and (overall survival) OS between the two groups. The responding patients who received chidamide maintenance therapy showed a trend of superior PFS and OS compared with patients who did not receive maintenance therapy. CONCLUSIONS: The C-CHOEP regimen was well tolerated but failed to show advantages over the CHOEP regimen in patients with untreated PTCL; however, the chidamide maintenance may contribute to a more durable response and stable long-term survival.

A more accurate indicator to evaluate oxidative stress in rat plasma with osteoporosis.

Background: oxidative stress is linked to various human diseases which developed into the idea of "disrupted redox signaling". Osteoporosis (OP) is a chronic skeletal disorder characterized by low bone mineral density and deterioration of bone microarchitecture among which estrogen deficiency is the main cause. Lack of estrogen leads to the imbalance between oxidation and anti-oxidation in patients, and oxidative stress is an important link in the pathogenesis of OP. The ratio of the reduced to the oxidized thiols can characterize the redox status. However, few methods have been reported for the simultaneous determination of reduced forms and their oxidized forms of thiols in plasma. Methods: we developed a hollow fiber centrifugal ultrafiltration (HFCF-UF) method for sample preparation and validated a high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method to determine two reduced forms of thiols-homocysteine (Hcy), cysteine (Cys) levels and their respective oxidized compounds, homocystine (HHcy) and cystine (Cyss) in rat plasma simultaneously for the first time. Thirty-six female rats were randomly divided into three groups: normal control (NC), oxidative stress (ovariectomy, OVX) and ovariectomy with hydrogen-rich saline administration (OVX + HRS). Results: the validation parameters for the methodological results were within the acceptance criteria. There were both significant differences of Hcy/HHcy (Hcy reduced/oxidized) and Cys/Cyss (Cys reduced/oxidized) in rat plasma between three groups with both p < 0.05 and meanwhile, the p values of malondialdehyde, superoxide dismutase and glutathione peroxidase were all less than 0.01. The value of both Hcy/HHcy and Cys/Cyss were significantly decreased with the change of Micro-CT scan result of femoral neck in OVX group (both the trabecular thickness and trabecular number significantly decreased with a significant increase of trabecular separation) which demonstrate OP occurs. The change of Hcy/HHcy is more obvious and prominent than Cys/Cyss. Conclusions: the Hcy/HHcy and Cys/Cyss could be suitable biomarkers for oxidative stress and especially Hcy/HHcy is more sensitive. The developed method is simple and accurate. It can be easily applied in clinical research to further evaluate the oxidative stress indicator for disease risk factors.

Zinc finger protein 671 has a cancer-inhibiting function in colorectal carcinoma via the deactivation of Notch signaling.

Zinc finger protein 671 (ZNF671) has been described as a vital cancer inhibitor in multiple neoplasms, yet the functional roles of ZNF671 in colorectal carcinoma (CRC) remain unresolved. This project examined the possible link between ZNF671 and CRC. Lower levels of ZNF671 were observed in CRC tissue compared with noncancerous tissue, which were related to a worse survival rate in CRC patients. High methylation levels at the ZNF671 gene promoter region were shown in CRC tissue, which were inversely correlated with ZNF671 expression. Treatment with demethylation agents restored ZNF671 levels in CRC cell lines. Up-regulation of ZNF671 resulted in suppressive effects on the proliferative ability and metastatic potency of CRC cells. Moreover, the up-regulation of ZNF671 reinforced the chemosensitivity of CRC cells. A mechanism study determined ZNF671 to be a vital mediator of Notch signaling. The up-regulation of ZNF671 decreased the expression of Notch1 and lowered the levels of NICD, HES1, and HEY1. The overexpression of NICD1 diminished ZNF671-mediated antitumor effects. ZNF671 depletion reinforced Notch signaling, and Notch suppression reversed ZNF671-depletion-elicited protumor effects. Moreover, the overexpression of ZNF671 weakened the tumorigenicity of CRC cells in a xenograft model in vivo. In summary, ZNF671 exerts a cancer-inhibiting function in CRC via the deactivation of Notch signaling. Low ZNF671 levels caused by gene promoter hypermethylation contribute to the malignant transformation of CRC. This work underlines the interest of ZNF671 as a target candidate for exploiting novel anti-CRC therapies.

Clinicopathologic characteristics, outcomes, and prognostic factors of angioimmunoblastic T-cell lymphoma in China.

BACKGROUND: This study aimed to better characterize the clinicopathologic characteristics, outcomes, and prognostic factors of AITL in China. METHODS: We retrospectively analyzed 312 patients with AITL enrolled between January 2011 and December 2020 from five institutions in China. RESULTS: The median age was 65 years, with 92.6% advanced stage, 59.7% elevated LDH, 46.1% anemia, and 44.0% hypergammaglobulinemia. The majority of patients (84.9%) received anthracycline-based regimens with or without etoposide, and only 6.1% underwent autologous stem cell transplantation following first remission. The 5-year OS and PFS estimates were 43.4% and 25.0% with no significant improvement of survival between patients treated during 2011-2015 and 2016-2020, respectively. Both the International Prognostic Index (IPI) and the prognostic index for PTCL, not otherwise specified (PIT), were predictive for OS. In multivariate analysis, age >70 years, elevated LDH, and albumin level <35 g/L were independent prognostic factors for OS. Combining these three factors, a novel prognostic model (the Chinese AITL score) was constructed, which stratified patients into low-, intermediate-, and high-risk groups, with 5-year OS rates of 69.0%, 41.5%, and 23.7%, respectively. This new model was successfully validated in an independent cohort. CONCLUSIONS: Patients with AITL were mainly treated with anthracycline-based regimens, and the outcomes were still unsatisfactory in China. Our novel prognostic model may improve our ability to identify patients at different risks for alternative therapies.

Brief Report: Droplet Digital Polymerase Chain Reaction Versus Plasma Next-Generation Sequencing in Detecting Clearance of Plasma EGFR Mutations and Carcinoembryonic Antigen Levels as a Surrogate Measure.

Introduction: To compare the performance of droplet digital polymerase chain reaction (ddPCR) and plasma next-generation sequencing (NGS) in detecting clearance of plasma EGFR (pEGFR) mutations. Methods: Patients with treatment-naive advanced EGFR-mutated lung cancer treated with first-line tyrosine kinase inhibitors (TKIs) were included. pEGFR were measured at baseline and first response assessment using ddPCR and NGS. Clearance of pEGFR was defined as undetectable levels after a positive baseline result. Results were correlated with time-to-treatment failure (TTF). In exploratory analysis, corresponding change in carcinoembryonic antigen (CEA) levels was evaluated. Results: Between January 1, 2020, and December 31, 2021, 27 patients were recruited. Ex19del comprised 74% (20 of 27) and L858R 26% (seven of 27). Osimertinib was used in 59% (16 of 27), dacomitinib 4% (one of 27), and gefitinib/erlotinib 37% (10 of 27). Sensitivity of ddPCR and NGS in detecting pEGFR mutation at baseline was 70% (19 of 27) and 78% (21 of 27), respectively (p = 0.16). All patients with detectable pEGFR by ddPCR were detected by NGS.At a median of 8 (range 3-24) weeks post-TKI initiation, clearance of pEGFR was achieved in 68% (13 of 19) and 71% (15 of 21) using ddPCR and NGS, respectively. Concordance between ddPCR and NGS was 79% (kappa = 0.513, p = 0.013). Clearance of pEGFR was associated with longer median TTF (not reached versus 6 months, p = 0.03) and median decrease in CEA levels by 70% from baseline.In another cohort of 124 patients, decrease in CEA levels by greater than 70% within 90 days of TKI initiation was associated with doubling of both TTF and overall survival. Conclusions: Plasma NGS trended toward higher sensitivity than ddPCR in detecting pEGFR, although both had similar concordance in detecting pEGFR clearance. Our results support using NGS at diagnosis and interchangeability of NGS and ddPCR for monitoring, whereas CEA could be explored as a surrogate for pEGFR clearance.