Management strategies for intracranial progression in ALK-positive non-small cell lung cancer: a real-world cohort study.

PURPOSE: ALK-positive NSCLC patients exhibit a particularly high propensity for the development of brain metastases. Current guidelines suggest transit to next-line therapy (SysTx) or local radiotherapy (RadTx) including whole-brain radiotherapy and radiosurgery. However, the clinical impact of these two strategies remains unclear. METHODS: We conducted a retrospective analysis focusing on patients with stage IV ALK-positive NSCLC who underwent first-line ALK TKI treatment. Patients with intracranial progression may receive two different treatment strategies: SysTx and RadTx. Our objective was to investigate the outcomes associated with these two distinct treatment pathways. RESULTS: A total 20 patients of ALK-positive NSCLC who received first-line ALK TKI therapy and subsequently developed intracranial progression were enrolled. About 55% of patients had brain metastasis initially. Nine patients (45%) were treated with crizotinib at first. Patients treated with crizotinib demonstrated a significantly shorter intracranial PFS1 (crizotinib: 8.27 months vs. others: 27.0 months, p = 0.006). Following intracranial progression, approximately 60% of patients transitioned to the next line of systemic treatment (SysTx), while the remaining 40% opted for local cranial radiotherapy (RadTx). Intriguingly, our analysis revealed no statistically significant difference in intracranial progression-free survival (PFS2) between these two distinct treatment strategies. (SysTx: 20.87 months vs. RadTx: 28.23 months, p = 0.461). CONCLUSION: The intracranial progression-free survival showed no difference between the two strategies suggesting that both local radiotherapy and systemic therapy may be valid options. Individualized strategy, molecular analysis, and multidisciplinary conferences may all play a pivotal role in decision-making.

Treatment and survival of patients with small cell lung cancer and brain metastasis.

PURPOSE: To elucidate treatment patterns and their outcomes in patients with small cell lung cancer (SCLC) and brain metastasis (BM). METHODS: In this retrospective study, patients with SCLC and BM were stratified by treatment modality into three groups: those treated with systemic therapy only, those treated with stereotactic radiosurgery (SRS) and systemic therapy, and those treated with whole-brain radiotherapy (WBRT) and systemic therapy. The primary outcomes were overall survival (OS) and time to central nervous system progression (TTCP). RESULTS: The analysis included 149 patients. After BM diagnosis, 48 patients (32.2%) received systemic therapy alone, 33 received SRS with systemic therapy, and 68 received WBRT with systemic therapy. The median OS and TTCP were 7.2 months and 8.7 months, respectively. Patients receiving WBRT with systemic therapy exhibited better intracranial control, but not better OS, than did the other patients. Key prognostic factors affecting OS were age, BM lesion count, chemotherapy, and immunotherapy. Notably, the Eastern Cooperative Oncology Group performance status and BM lesion count significantly influenced intracranial control in patients treated with SRS and systemic therapy. CONCLUSION: Although WBRT combined with systemic therapy offer better intracranial control in patients with SCLC and BM, this approach is not superior to the other approaches in terms of OS benefits. Emerging systemic therapies, such as immunotherapy, may be used as alternative or adjunctive treatments for specific patient populations. Further studies are warranted to refine treatment selection.

Improved survival and intracranial tumor control of EGFR-mutated NSCLC patients with newly developed brain metastases following stereotactic radiosurgery and EGFR-TKI: a large retrospective cohort study and meta-analyses.

PURPOSE: To examine the differential effects of SRS and TKI on EGFR-mutated NSCLC patients with brain metastases (BMs) and outcomes following continuation of the same TKI agent in case of new BMs. METHODS: This study included 608 NSCLC patients (2,274 BMs) while meta-analyses included 1,651 NSCLC patients (> 3,944 BMs). Overall survival (OS) and intracranial progression free survival (iPFS) were estimated using Kaplan-Meier methods. Hazard ratios (95% CI) of prognostic factors were estimated using Cox regression models. RESULTS: The median OS/iPFS (95% CI) (months) for patients with wildtype EGFR/ALK, EGFR mutations, and ALK rearrangements were 17.7 (12.9-23.6)/12.1 (9.8-15.6), 28.9 (23.8-33.3)/17.7 (14.8-21.2), and 118.0 (not reached)/71.7 (15.1-not reached), respectively. In EGFR-mutated patients, meta-analyses combining our data showed significantly improved OS and iPFS of patients who received SRS and TKI (OS:35.1 months, iPFS:20.0 months) when compared to those who have SRS alone (OS:20.8 months, iPFS:11.8 months) or TKI alone (OS:24.3 months, iPFS:13.8 months). Having SRS for newly diagnosed BMs while keeping the existing TKI agent yielded OS (30.0 vs. 32.1 months, p = 0.200) non-inferior to patients who started combined SRS and TKI therapy for their newly diagnosed NSCLC with BMs. Multivariable analyses showed that good performance score and TKI therapy were associated with improved outcomes. CONCLUSIONS: Combined SRS and TKI resulted in favorable outcomes in EGFR-mutated NSCLC patients with newly diagnosed BMs. Continuation of the same TKI agent plus SRS in case of new brain metastases yielded good clinical outcomes and may be considered a standard-of-care treatment.

Leukoencephalopathy in patients with brain metastases who received radiosurgery with or without whole brain radiotherapy.

BACKGROUND: Whole brain radiation therapy (WBRT) for brain metastases (BMs) is a common cause of radiation-induced leukoencephalopathy; however the safety of alternative stereotactic radiosurgery (SRS) remains unclear. This study examined the incidence of leukoencephalopathy in patients treated with SRS alone versus WBRT plus SRS for BMs with a focus on the relationship between prognostic factors and leukoencephalopathy. METHODS: Analysis was performed between 2002 and 2021. The total enrollment was 993 patients with the distribution: WBRT plus SRS (n = 291) and SRS only (n = 702). Leukoencephalopathy was graded from 0 to 3 for changes in white matter indicated by the MRI after WBRT or SRS. Patient characteristics and SRS dosimetric parameters were reviewed to identify factors that contributed to the incidence of leukoencephalopathy or overall survival. RESULTS: The incidence of leukoencephalopathy was consistently higher in WBRT plus SRS group than in SRS alone group (p < 0.001). Leukoencephalopathy was also associated with a larger total tumor volume (≧28cm3; p = 0.028) and age (> 77 years; p = 0.025). Nonetheless, the SRS integral dose to skull in the subgroup of WBRT plus SRS treatment was not demonstrated significance in development of leukoencephalopathy (p = 0.986 for integral dose 1-2 J, p = 0.776 for integral dose > 2 J). CONCLUSIONS: This study revealed that SRS is safe for oligo-BMs in terms of leukoencephalopathy development. Patient age and total tumor volume were identified as important factors in assessing the development of leukoencephalopathy. The additional of SRS (even at an integral dose > 2 J) did not increase the incidence of leukoencephalopathy.

Natural history of lung squamous cell brain metastases in patients treated with radiosurgery: a thirty-year experience at a tertiary medical center.

PURPOSE: In this study we report our 30-year experience in stereotactic radiosurgery (SRS) treatment of lung squamous cell carcinoma (LUSC) brain metastases (BMs). It will serve to provide detailed longitudinal outcomes and predictors of efficacy in treating LUSC-BMs with SRS. METHOD: We retrospectively reviewed 51 patients and 109 tumors treated with SRS at our center between 1993 and 2022. Patient demographics, PDL1 genotype, immunotherapy use and mortality cause were recorded. Radiological and clinical outcomes were followed at 1-3-month intervals post-SRS. Cox-regression analysis and Kaplan-Meier survival curves were performed in statistical analysis. RESULTS: We included 37 male and 14 female patients (median age 62.7 years at BM diagnosis). Median overall survival (OS) time was 6.9 months, 6-month OS rate was 62.1%, and Karnofsky performance scale (KPS) was the only independent predictor. Median time for local control maintenance was 7.6 months, 6-month local control rate was 69.1%, with TKI as the only independent predictor. Median time to distant failure was 5.13 months, 6-month distant failure rate was 51.1%, and factors with significant impact included gender (p = 0.002), presence of extracranial metastases (p < 0.001), use of immunotherapy(p < 0.001), PDL1 genotype (p = 0.034), and total intracranial metastases number (p = 0.008). However, no definitive benefits of immunotherapy were identified in patients with higher PDL1 mutational tumors. CONCLUSION: In this study we defined the natural history of disease progression and outcomes in SRS-treated LUSC-BM patients. We also identified predictors of OS and tumor control among these patients. The findings of this study will serve as a guide when counseling these patients for SRS.

Is it advisable to perform radiosurgery for EGFR-TKI-controlled brain metastases? A retrospective study of the role of radiosurgery in lung cancer treatment.

PURPOSE: Given the availability of TKIs with high central nervous system efficacy, the question arises as to whether upfront SRS provides additional clinical benefits. The goal of this study was to characterize the clinical outcomes of SRS as salvage therapy for TKI-uncontrolled BMs. METHODS: This retrospective study included EGFR-mutant NSCLC patients presenting BMs at the time of primary tumor diagnosis. BMs were categorized into three subgroups, referred to as "Nature of TKI-treated BMs", "TKI-controlled brain metastases ± SRS", and "SRS salvage therapy". The first subgroup analysis characterized the effects of TKIs on tumor behavior. In the second subgroup, we compared outcomes of TKI-controlled BMs treated with TKI alone versus those treated with combined TKI-SRS therapy. The third subgroup characterized the outcomes of TKI-uncontrolled BMs treated with SRS as salvage therapy Clinical outcomes include local and distant tumor control. RESULTS: This study included 106 patients with a total of 683 BMs. TKI treatment achieved control in 63% of local tumors at 24 months. Among the TKI-controlled BMs, local tumor control was significantly higher in the combined TKI-SRS group (93%) than in the TKI-alone group (65%) at 24 months (p < 0.001). No differences were observed between the two groups in terms of distant tumor control (p = 0.832). In dealing with TKI-uncontrolled BMs, salvage SRS achieved local tumor control in 58% of BMs at 24 months. CONCLUSIONS: While upfront TKI alone proved highly effective in BM control, this study also demonstrated the outcomes of SRS when implemented concurrently with TKI or as salvage therapy for TKI-uncontrolled BMs. This study also presents a strategy of the precise timing and targeting of SRS to lesions in progression.

EGFR mutant status and tyrosine-kinase inhibitors affect the GKRS outcomes for NSCLC brain metastases.

OBJECTIVE: Tyrosine kinase inhibitors (TKIs) is the first-line treatment for EGFR-positive non-small cell lung cancer (NSCLC); however, its applicability to patients with wild-type NSCLC remains an issue of contention. This study compared the effects of gamma knife radiosurgery (GKRS) alone versus combining GKRS and TKIs in treating two genetic forms of NSCLC. METHODS: This retrospective study examined 479 NSCLC patients with 1982 brain metastases who underwent GKRS and for whom imaging follow-up data or death records were available. All our patients were consecutive. All gene mutations were confirmed by lung biopsy. The three main endpoints in this study were overall survival (OS), local intracranial tumor control (LC), and distal intracranial tumor control (DC). RESULTS: There were 296 NSCLC patients with EGFR positive: TKI treatment (n = 262) and without TKI treatment (n = 34). GKRS + TKIs was more effective than GKRS alone in terms of OS (HR 0.53, p = 0.085) and DC (HR 0.51, p < 0.001). There were 150 NSCLC patients with wild-type EGFR: TKI treatment (n = 50) and without TKI treatment (n = 100). GKRS + TKIs was less effective than GKRS alone in terms of OS (HR 1.82, p = 0.049) and DC (HR: 1.40, p = 0.011). We observed no difference in terms of LC in both genetic groups. CONCLUSIONS: Combining GKRS with TKIs proved effective in EGFR positive NSCLC patients; however, we do not observe the similar results when combining GKRS with TKIs for patients with wild-type NSCLC.

Cerebrospinal fluid diversion and outcomes for lung cancer patients with leptomeningeal carcinomatosis.

OBJECTIVE: To investigate the outcomes of cerebrospinal fluid (CSF) diversion in lung cancer patients with leptomeningeal carcinomatosis (LMC). METHODS: A retrospective review of consecutive lung cancer patients with LMC suffering from increased intracranial pressure (IICP) and hydrocephalus between February 2017 and February 2020. We evaluated the survival benefit of CSF diversion surgery and assessed the outcomes of treatments administered post-LMC in terms of overall survival and shunt-related complications. RESULTS: The study cohort included 50 patients (median age: 59 years). Ventricular peritoneal (VP) shunts were placed in 33 patients, and lumbar peritoneal (LP) shunts were placed in 7 patients. Programmable shunts were placed in 36 patients. Shunt adjustment was performed in 19 patients. Kaplan-Meier analysis revealed that shunt placement increased overall survival from 1.95 months to 6.21 months (p = 0.0012) and increased Karnofsky Performance Scores (KPS) from 60 to 70. Univariate analysis revealed no difference between VP or LP shunts in terms of survival. No differences in post-shunt systemic treatments (tyrosine kinase inhibitors (TKIs) or systemic treatments) were observed in overall survival. Shunt-related complications were noted in 7 patients, including shunt obstruction (n = 4), infection (n = 1), and over-drainage (n = 2). CONCLUSION: CSF diversion (VP or LP shunt) appears to be an effective and safe treatment for lung cancer patients with LMC and hydrocephalus. Programmable shunts should be considered for complex cases, which commonly require pressure adjustments as the disease progresses.

Dynamic Assessment of Tissue and Plasma EGFR-Activating and T790M Mutations with Droplet Digital PCR Assays for Monitoring Response and Resistance in Non-Small Cell Lung Cancers Treated with EGFR-TKIs.

Assessing tumor EGFR mutation status is necessary for the proper management of patients with advanced non-small cell lung cancer (NSCLC). We evaluated the impact of dynamic analyses of the plasma and tissue EGFR mutation using ultra-sensitive droplet digital PCR (ddPCR) assays to manage NSCLC patients treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs). Paired tumor tissues and plasma samples from 137 EGFR-mutated lung adenocarcinoma patients prior to the first-line EGFR-TKIs treatment (at baseline) and at disease progression were subjected to EGFR mutation analysis using ddPCR, together with the analyses of the clinicopathological characteristics and treatment outcomes. Patients with EGFR-activating mutations detected in baseline plasma were associated with bone metastasis (p = 0.002) and had shorter progression-free survival (12.9 vs. 17.7 months, p = 0.02) and overall survival (24.0 vs. 39.4 months, p = 0.02) compared to those without. Pre-treatment EGFR T790M mutation found in baseline tumor tissues of 28 patients (20.4%; 28/137) was significantly associated with brain metastasis (p = 0.005) and a shorter brain metastasis-free survival (p = 0.001). The presence of EGFR T790M mutations in baseline tumor tissues did not correlate with the emergence of acquired EGFR T790M mutations detected at progression. At disease progression, acquired EGFR T790M mutations were detected in 26.6% (21/79) of the plasma samples and 42.9% (15/35) of the rebiopsy tissues, with a concordance rate of 71.4% (25/35). The dynamic monitoring of tissue and plasma EGFR mutation status at baseline and progression using ddPCR has a clinical impact on the evaluation of EGFR-TKIs treatment efficacy and patient outcomes, as well as the emergence of resistance in NSCLC.

State-of-the-Art Molecular Oncology of Lung Cancer in Taiwan.

Lung cancers are life-threatening malignancies that cause great healthcare burdens in Taiwan and worldwide. The 5-year survival rate for Taiwanese patients with lung cancer is approximately 29%, an unsatisfactorily low number that remains to be improved. We first reviewed the molecular epidemiology derived from a deep proteogenomic resource in Taiwan. The nuclear factor erythroid 2-related factor 2 (NRF2)antioxidant mechanism was discovered to mediate the oncogenesis and tumor progression of lung adenocarcinoma. Additionally, DNA replication, glycolysis and stress response are positively associated with tumor stages, while cell-to-cell communication, signaling, integrin, G protein coupled receptors, ion channels and adaptive immunity are negatively associated with tumor stages. Three patient subgroups were discovered based on the clustering analysis of protein abundance in tumors. The first subgroup is associated with more advanced cancer stages and visceral pleural invasion, as well as higher mutation burdens. The second subgroup is associated with EGFR L858R mutations. The third subgroup is associated with PI3K/AKT pathways and cell cycles. Both EGFR and PI3K/AKT signaling pathways have been shown to induce NRF2 activation and tumor cell proliferation. We also reviewed the clinical evidence of patient outcomes in Taiwan given various approved targeted therapies, such as EGFR-tyrosine kinase inhibitors and anaplastic lymphoma kinase (ALK)inhibitors, in accordance with the patients' characteristics. Somatic mutations occurred in EGFR, KRAS, HER2 and BRAF genes, and these mutations have been detected in 55.7%, 5.2%, 2.0% and 0.7% patients, respectively. The EGFR mutation is the most prevalent targetable mutation in Taiwan. EML4-ALK translocations have been found in 9.8% of patients with wild-type EGFR. The molecular profiling of advanced NSCLC is critical to optimal therapeutic decision-making. The patient characteristics, such as mutation profiles, protein expression profiles, drug-resistance profiles, molecular oncogenic mechanisms and patient subgroup systems together offer new strategies for personalized treatments and patient care.

Spectrum of cancer risk among Taiwanese with chronic obstructive pulmonary disease.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are liable to develop significant comorbidities, including lung cancer. Whether they are at a higher risk for cancer of other types remains debatable, especially for Asians. We studied the risk of incident cancer in COPD patients using a nationwide representative database, the Taiwan National Health Insurance Research Database. METHODS: From 1995 to 2008, 50,875 COPD patients who were free of antecedent malignancy were identified and followed up to development of malignancy, death or end of 2008, whichever came first. The risk of cancer was determined with the standardized incidence ratio (SIR), which is based on comparison to the national cancer incidence among the general population. RESULTS: During a median follow-up period of 5.61 years, 3623 (7.02 %) patients developed cancer and the SIR was 1.2 [95 % confidence interval (CI) 1.16-1.24, p < 0.001]. The risk remained higher at <1, 1-5, and even ≥5 years after the diagnosis of COPD (SIR 1.83, 1.07, and 1.11, respectively). Furthermore, the risk was significantly higher for some specific types of cancer, including head and neck cancer (SIR 1.23, 95 % CI 1.08-1.39, p = 0.002), esophageal cancer (SIR 1.35, 95 % CI 1.08-1.67, p = 0.010), lung and mediastinal cancer (SIR 1.86, 95 % CI 1.74-1.99, p < 0.001), breast cancer (SIR 1.19, 95 % CI 1.01-1.4, p = 0.041), prostate cancer (SIR 1.20, 95 % CI 1.06-1.35, p < 0.001), cancer of the central nervous system (SIR 1.58, 95 % CI 1.05-2.28, p = 0.030), lymphoma (SIR 1.53, 95 % CI 1.22-1.90, p < 0.001), and multiple myeloma (SIR 1.95, 95 % CI 1.31-2.80, p = 0.001). CONCLUSION: COPD patients had increased risk for incident cancers, including lung cancer and several extrapulmonary cancers.

Dynamic immune signatures of patients with advanced non-small-cell lung cancer for infection prediction after immunotherapy.

Background: Pulmonary infections are a crucial health concern for patients with advanced non-small-cell lung cancer (NSCLC). Whether the clinical outcome of pulmonary infection is influenced by immunotherapy(IO) remains unclear. By evaluating immune signatures, this study investigated the post-immunotherapy risk of pulmonary infection in patients with lung cancer and identified circulating biomarkers that predict post-immunotherapy infection. Methods: Blood specimens were prospectively collected from patients with NSCLC before and after chemotherapy(C/T) and/or IO to explore dynamic changes in immune signatures. Real-world clinical data were extracted from medical records for outcome evaluation. Mass cytometry and ELISA were employed to analyze immune signatures and cytokine profiles to reveal potential correlations between immune profiles and the risk of infection. Results: The retrospective cohort included 283 patients with advanced NSCLC. IO was associated with a lower risk of pneumonia (odds ratio=0.46, p=0.012). Patients receiving IO and remained pneumonia-free exhibited the most favorable survival outcomes compared with those who received C/T or developed pneumonia (p<0.001). The prospective cohort enrolled 30 patients. The proportion of circulating NK cells significantly increased after treatment in IO alone (p<0.001) and C/T+IO group (p<0.01). An increase in cell densities of circulating PD-1+CD8+(cytotoxic) T cells (p<0.01) and PD-1+CD4+ T cells (p<0.01) were observed in C/T alone group after treatment. In IO alone group, a decrease in cell densities of TIM-3+ and PD-1+ cytotoxic T cells (p<0.05), and PD-1+CD4+ T cells (p<0.01) were observed after treatment. In C/T alone and C/T+IO groups, cell densities of circulating PD-1+ cytotoxic T cells significantly increased in patients with pneumonia after treatment(p<0.05). However, in IO alone group, cell density of PD-1+ cytotoxic T cells significantly decreased in patients without pneumonia after treatment (p<0.05). TNF-α significantly increased after treatment with IO alone (p<0.05) but decreased after C/T alone (p<0.01). Conclusions: Our results indicate that the incorporation of immunotherapy into treatment regimens may potentially offer protective effects against pulmonary infection. Protective effects are associated with reduction of exhausted T-cells and augmentation of TNF-α and NK cells. Exhausted T cells, NK cells, and TNF-α may play crucial roles in immune responses against infections. These observations highlight the potential utility of certain circulating biomarkers, particularly exhausted T cells, for predicting post-treatment infections.

Clinical utility of immunohistochemical subtyping in patients with small cell lung cancer.

OBJECTIVES: Molecular subtyping of small cell lung cancer (SCLC) tumors based on the expression of four transcription factors (ASCL1, NEUROD1, POU2F3, and YAP1) using immunohistochemical (IHC) staining has recently emerged as a proposed approach. This study was aimed to examine this subtyping method in Asian patients with SCLC and investigate its correlation with treatment efficacy. MATERIALS AND METHODS: Seventy-two tumor samples from patients with SCLC, including de novo cases and those transformed from EGFR-mutant tumors, were analyzed. IHC staining was used to measure the expression of the four transcription factors and conventional SCLC markers. Subtypes were defined based on relative expression levels. The treatment response and outcome of patients receiving immune checkpoint inhibitors and chemotherapy were also reviewed. RESULTS: ASCL1 was the most common subtype, observed in 55.2 % of the samples, followed by NEUROD1 (26.9 %) and POU2F3 (9 %). No tumor exhibited predominant YAP1 positivity, while 41.8 % of the samples demonstrated positivity for two subtype markers. Approximately 50 % of the patients experienced a subtype switch after disease progression. Patients with the ASCL1/NEUROD1 (SCLC-A/N) subtype had similar progression-free survival (PFS) compared to non-SCLC-A/N patients after treatment with immune checkpoint inhibitors plus chemotherapy. Transformed SCLC patients had significantly worse PFS than de novo SCLC patients after chemoimmunotherapy. (2.1 vs. 5.4 months, P = 0.023) CONCLUSIONS: This study revealed the challenges associated with using IHC alone for molecular subtyping, highlighting the frequent co-expression of subtypes and temporal changes following treatment. Further research is warranted to explore the prognostic and therapeutic implications of IHC subtyping in patients with SCLC.

Atezolizumab-induced subacute cerebellar ataxia in a patient with extensive-stage small cell lung cancer.

Recently, immune checkpoint inhibitors (ICIs) have become the standard treatment option for patients with lung cancer, including small cell lung cancer (SCLC). ICI-induced neurological immune-related adverse events are rare and exhibit diverse clinical manifestations, often leading to missed or delayed diagnosis. Herein, we report the case of a patient with extensive-stage SCLC who received atezolizumab with etoposide/platinum and gradually developed neurological symptoms after three cycles of chemoimmunotherapy. Subsequently, the patient received a diagnosis of subacute immune-related cerebellar ataxia and was treated successfully with pulse steroid therapy. The patient exhibited almost complete remission of neurological symptoms and had progression-free survival for >24 months.

Prognosticators of osimertinib treatment outcomes in patients with EGFR-mutant non-small cell lung cancer and leptomeningeal metastasis.

PURPOSE: Leptomeningeal metastasis (LM) is a serious complication of non-small cell lung cancer (NSCLC), particularly in patients with EGFR mutations. In this study, we investigated the survival outcomes of patients with EGFR-mutant NSCLC who have developed LM and explored the factors associated with their survival. METHODS: From April 2018 to November 2021, patients with EGFR-mutant NSCLC who underwent cerebrospinal fluid (CSF) sampling under the clinical suspicion of LM were enrolled. The patients' clinicodemographic characteristics, treatment history including whole-brain radiation therapy (WBRT), overall survival (OS), and intracranial progression-free survival (icPFS) were measured. EGFR mutations in cell-free tumor DNA (ctDNA) of CSF, including T790M mutation, were analyzed. RESULTS: We enrolled 62 patients with NSCLC. The median time form diagnosis to LM was 23.1 months and 16 (25.8%) patients had history of prior third-generation EGFR-TKI use. EGFR mutation in CSF ctDNA was detected in 53 patients (85.5%); of them, 10 (16.1%) had T790M mutation. The patients' icPFS and OS after osimertinib were 6.43 and 9.37 months, respectively, and were comparable among patients with different sensitive EGFR mutations, indicating that EGFR mutation status did not affect osimertinib efficacy. Patients who received WBRT after LM had numerically higher icPFS and OS compared to those without. Multivariate analysis revealed that lack of prior exposure to third-generation EGFR-TKI was associated with better OS. CONCLUSIONS: Osimertinib is effective in patients with EGFR-mutant NSCLC who developed LM and prior third-generation EGFR-TKI use was associated with poor survival in these patients. The role of WBRT warrants further investigation.

Gamma Knife Radiosurgery Irradiation of Surgical Cavity of Brain Metastases: Factor Analysis and Gene Mutations.

(1) Background: Surgical resection for the removal of brain metastases often fails to prevent tumor recurrence within the surgical cavity; hence, researchers are divided as to the benefits of radiation treatment following surgical resection. This retrospective study assessed the effects of post-operative stereotactic radiosurgery (SRS) on local tumor control and overall survival. (2) Methods: This study examined the demographics, original tumor characteristics, and surgical outcomes of 97 patients who underwent Gamma Knife Radiosurgery (GKRS) treatment (103 brain metastases). Kaplan-Meier plots and Cox regression were used to correlate clinical features to tumor control and overall survival. (3) Results: The overall tumor control rate was 75.0% and overall 12-month survival was 89.6%. Tumor control rates in the radiation group versus the non-radiation group were as follows: 12 months (83.1% vs. 57.7%) and 24 months (66.1% vs. 50.5%). During the 2-year follow-up period after SRS, the intracranial response rate was higher in the post-craniotomy radiation group than in the non-radiation group (p = 0.027). Cox regression multivariate analysis determined that post-craniotomy irradiation of the surgical cavity is predictive of tumor control (p = 0.035). However, EGFR mutation was not predictive of overall survival or tumor control. (4) Conclusions: Irradiating the surgical cavity after surgery can enhance local tumor control; however, it does not have a significant effect on overall survival.

Efficacy of different platforms in detecting EGFR mutations using cerebrospinal fluid cell-free DNA from non-small-cell lung cancer patients with leptomeningeal metastases.

BACKGROUND: Cell-free tumor DNA (ctDNA) obtained through liquid biopsy is useful for the molecular analysis of advanced non-small-cell lung cancer (NSCLC). Few studies have directly compared analysis platforms in terms of their diagnostic performance in analyzing ctDNA obtained from the cerebrospinal fluid (CSF) of patients with leptomeningeal metastasis (LM). METHODS: We prospectively analyzed patients with epidermal growth factor receptor (EGFR)-mutant NSCLC who were subjected to CSF analysis for suspected LM. To detect EGFR mutations, CSF ctDNA was analyzed using the cobas EGFR Mutation Test and droplet digital polymerase chain reaction (ddPCR). CSF samples from osimertinib-refractory patients with LM were also subjected to next-generation sequencing (NGS). RESULTS: Significantly higher rates of valid results (95.1% vs. 78%, respectively, p = 0.04) and EGFR common mutation detection (94.3% vs. 77.1%, respectively, p = 0.047) were obtained through ddPCR than through the cobas EGFR Mutation Test. The sensitivities of ddPCR and cobas were 94.3% and 75.6%, respectively. The concordance rate for EGFR mutation detection through ddPCR and the cobas EGFR Mutation Test was 75.6% and that for EGFR mutation detection in CSF and plasma ctDNA was 28.1%. In osimertinib-resistant CSF samples, all original EGFR mutations were detected through NGS. MET amplification and CCDC6-RET fusion were demonstrated in one patient each (9.1%). CONCLUSIONS: The cobas EGFR Mutation Test, ddPCR, and NGS appear to be feasible methods for analyzing CSF ctDNA in patients with NSCLC and LM. In addition, NGS may provide comprehensive information regarding the mechanisms underlying osimertinib resistance.

Characteristics, treatment patterns, and clinical outcomes in patients with advanced non-small cell lung cancer harboring EGFR exon 20 insertions.

PURPOSE: Epidermal growth factor receptor (EGFR) exon 20 insertions (ex20ins) are associated with poor prognosis and resistance to traditional therapies in patients with non-small cell lung cancer (NSCLC). We aimed to elucidate the characteristics and treatment patterns to improve outcomes among this population in Taiwan. METHODS: Patients with advanced or recurrent NSCLC harboring EGFR ex20ins from 2011 to 2021 were reviewed. The treatment groups were classified as platinum-based chemotherapy (PtC), EGFR tyrosine kinase inhibitor (TKI), and others. The response to therapy, objective response rate (ORR), disease control rate (DCR), overall survival (OS), progression-free survival (PFS), and factors associated with survival were analyzed. RESULTS: Among the 71 patients, most were never-smoking males with stage IVB adenocarcinoma. The most common first-line (1L) regimen was PtC, followed by TKI. The most common second-line (2L) regimen was TKI. The median PFS of 1L treatment was 5.03 months, and the median OS was 18.43 months. Compared with that of TKI, 1L PtC use was associated with a higher ORR (26.3% vs. 9.1%) and DCR (60.5% vs. 18.2%) and a longer PFS (5.37 vs. 3.13 months, p = 0.044). PFS was also significantly longer in the 2L PtC group than in the 2L TKI group (4.73 vs. 2.25 months, p = 0.047). No patients receiving an immune checkpoint inhibitor-based regimen exhibited a therapeutic response. CONCLUSION: This study demonstrated the heterogeneous clinical characteristics and treatment pattern of NSCLC patients with EGFR ex20ins, underscoring the need for more effective therapies for this distinct molecular subtype.