Osimertinib readministration for central nervous system metastases in non-small cell lung cancer positive for EGFR activating mutations

BACKGROUND

Osimertinib shows pronounced efficacy for EGFR mutation-positive non-small cell lung cancer (NSCLC) including associated central nervous system (CNS) metastases. Tumors inevitably develop resistance to the drug, however. Osimertinib is sometimes readministered after completion of standard chemotherapy. To clarify which patients might receive benefit from osimertinib readministration, we have retrospectively assessed its efficacy with a focus on CNS metastases.

METHODS

A retrospective analysis of medical records was performed for 21 patients who underwent osimertinib readministration at Kyushu University Hospital between March 2016 and April 2023. CNS metastases were evaluated according to modified Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

Among the 21 enrolled patients, 16 individuals had target lesions on the basis of RECIST. One (6.3%) of these 16 patients achieved a partial response to osimertinib readministration, with the remaining 15 patients showing stable or progressive disease. The median overall progression-free survival (PFS) and median overall survival for all 21 patients were 3.8 and 13.9 months, respectively. The efficacy of osimertinib readministration for CNS metastases was evaluable in eight patients including five individuals with leptomeningeal metastases. The objective response rate for CNS metastases and the improvement rate for leptomeningeal metastases were both 100%. The median PFS with regard to CNS or non-CNS lesions for these eight patients was 24.7 and 10.5 months, respectively.

CONCLUSIONS

Osimertinib readministration showed limited efficacy for non-CNS lesions but excellent efficacy for CNS metastases, suggesting that such treatment is an option for EGFR-mutated NSCLC patients with CNS metastases.

Preclinical and clinical activity of DZD1516, a full blood-brain barrier-penetrant, highly selective HER2 inhibitor

BACKGROUND

Patients with HER2-positive metastatic breast cancer (MBC) are at high risk of developing central nervous system (CNS) metastases. A potent and selective HER2 inhibitor with good blood-brain barrier (BBB) penetration is highly desirable.

METHODS

The design and structure-activity relationship of DZD1516 was described. The potency and selectivity of DZD1516 were determined by enzymatic and cellular assays. The antitumor activity of DZD1516 monotherapy or in combination with HER2 antibody-drug conjugate was assessed in CNS and subcutaneous xenograft mouse models. A phase 1 first-in-human study evaluated the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of DZD1516 in patients with HER2+ MBC who relapsed from standard of care.

RESULTS

DZD1516 showed good selectivity against HER2 over wild-type EGFR in vitro and potent antitumor activity in vivo. Twenty-three patients were enrolled and received DZD1516 monotherapy treatment across six dose levels (25-300 mg, twice daily). Dose-limiting toxicities were reported at 300 mg, and thus 250 mg was defined as the maximum tolerated dose. The most common adverse events included headache, vomiting, and hemoglobin decreased. No diarrhea or skin rash was observed at ≤ 250 mg. The mean Kp,uu,CSF was 2.1 for DZD1516 and 0.76 for its active metabolite DZ2678. With median seven lines of prior systemic therapy, the best antitumor efficacy in intracranial, extracranial and overall lesions was stable disease.

CONCLUSIONS

DZD1516 provides positive proof of concept for an optimal HER2 inhibitor with high BBB penetration and HER2 selectivity. Further clinical evaluation of DZD1516 is warranted, with the RP2D being 250 mg BID.

CLINICALTRIALS

gov identifier NCT04509596. Registered on August 12, 2020; Chinadrugtrial: CTR20202424 Registered on December 18, 2020.

Breast Cancer Brain Metastases: Achilles' Heel in Breast Cancer Patients' Care

Brain metastases (BM) significantly affect the prognosis as well as the quality of life of breast cancer (BC) patients. Although advancements in neurosurgical and radiotherapy techniques improve local control and symptom management, BM remains associated with a poor prognosis. In addition, the efficacy of currently approved systemic therapies in central nervous system (CNS) compartment is still limited, especially after progression on local therapy. The blood-brain barrier (BBB) has been recognized as a mechanism of primary resistance to many chemotherapeutic agents and targeted therapies due to low drug penetration. Other mechanisms of primary and secondary resistance are still unclear and may vary across the BC subtypes. New small molecules have demonstrated efficacy in BM, in particular for the HER2-positive subtype, with a benefit in survival. A new era has begun in the field of BM, and many trials specifically designed for this population are currently ongoing. The BC research community needs to address this call with the final aim of improving the efficacy of systemic therapy in CNS compartment and ultimately preventing the occurrence of BM.

Leptomeningeal Metastases: New Opportunities in the Modern Era

Leptomeningeal metastases arise from cancer cell entry into the subarachnoid space, inflicting significant neurologic morbidity and mortality across a wide range of malignancies. The modern era of cancer therapeutics has seen an explosion of molecular-targeting agents and immune-mediated strategies for patients with breast, lung, and melanoma malignancies, with meaningful extracranial disease control and improvement in patient survival. However, the clinical efficacy of these agents in those with leptomeningeal metastases remains understudied, due to the relative rarity of this patient population, the investigational challenges associated with studying this dynamic disease state, and brisk disease pace. Nevertheless, retrospective studies, post hoc analyses, and small prospective trials in the last two decades provide a glimmer of hope for patients with leptomeningeal metastases, suggesting that several cancer-directed strategies are not only active in the intrathecal space but also improve survival against historical odds. The continued development of clinical trials devoted to patients with leptomeningeal metastases is critical to establish robust efficacy outcomes in this patient population, define drug pharmacokinetics in the intrathecal space, and uncover new avenues for treatment in the face of leptomeningeal therapeutic resistance.

Local and systemic therapy in breast cancer patients with central nervous system metastases

PURPOSE

As survival of patients with central nervous system (CNS) metastases from breast cancer is poor and incidence rates are increasing, there is a growing need for better treatment strategies. In the current study, the efficacy of local and systemic therapies was analyzed in breast cancer patients with CNS metastases.

METHODS

Medical records from breast cancer patients with brain and/or leptomeningeal metastases (LM) treated at a tertiary referral center and a teaching hospital between 2010 and 2020 were retrospectively studied. Main outcomes of interest were overall survival (OS) and CNS progression free survival. Analyses were performed among patients with brain metastases (BM) and patients with LM, for the different systemic and local therapies for CNS metastases, and for subgroups based on breast cancer subtypes.

RESULTS

We identified 155 patients, 97 with BM and 58 with LM. Median OS was 15.9 months for patients with BM and 1.5 months for patients with LM. Median OS was significantly longer for HER2-positive patients with BM (22.8 months) vs triple negative (8.4 months) and hormone receptor positive/HER2-negative (5.9 months) (P < 0.001). Patients with BM receiving both local and systemic therapy also had a longer median OS (21.8 months), compared to the other three subgroups (local therapy only: 9.9 months, systemic therapy only: 4.3 months, no therapy: 0.5 months, P < 0.001). No significant difference in OS was observed between different systemic treatment regimens.

CONCLUSION

Breast cancer patients with BM show longest median OS when the subtype is HER2-positive and when they are treated with both local and systemic therapy.

Intracranial efficacy of alectinib in ALK-positive NSCLC patients with CNS metastases-a multicenter retrospective study

BACKGROUND

Central nervous system (CNS) metastases in patients with ALK-positive non-small cell lung cancer (NSCLC) are a cause of substantial morbidity and mortality. Although alectinib had demonstrated promising intracranial efficacy in several clinical trials, data were limited on its CNS activity in real-world settings.

METHODS

In this retrospective study, ALK-positive NSCLC patients with brain metastases (BM) or leptomeningeal metastases (LM) from six hospitals in China were divided into three cohorts based on the treatment history before the administration of alectinib. ALK-TKI-naive patients were enrolled in cohort 1, cohort 2 included patients who experienced intracranial progression with or without extracranial progression after treatment with crizotinib, and cohort 3 included patients who developed progression only in CNS following treatment with other second-generation ALK-TKIs. The definition and evaluation of intracranial and extracranial lesions were based on Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

Sixty-five patients were eligible and included in our study (cohort 1: 20, cohort 2: 32, cohort 3: 13). For the overall population and patients with uncontrolled CNS metastases, similar intracranial response in CNS target lesions was observed: cohort 1: 81.8% and 80%; cohort 2: 76.5% and 86.7%; cohort 3: 42.8% and 33.3%. For patients in these three cohorts, 75% (6/8), 78.6% (11/14), and 83.3% (5/6) were reported to have significant improvement in CNS-related symptoms respectively. The number of patients who were in need of mannitol or corticosteroids decreased remarkably after the treatment of alectinib (p < 0.001), and there was also a steep fall-over in the number of patients with ECOG ≥2 points before and after the administration of alectinib (p = 0.003). All patients (8/8) diagnosed with LM ± BM experienced substantial alleviation in CNS-related symptoms. In cohort 1 and cohort 2, no significant difference in CNS-time to progression was found between patients with symptomatic or asymptomatic BM when treated with alectinib alone.

CONCLUSIONS

Our study substantiated the potent CNS activity of alectinib in real-world settings. Patients with symptomatic and asymptomatic BM could benefit from alectinib comparatively, which indicated that alectinib alone might defer the timing of local treatment. However, our results should be treated cautiously owing to limited sample size.

Risk of development of brain metastases according to the IASLC/ATS/ERS lung adenocarcinoma classification in locally advanced and metastatic disease

INTRODUCTION

Brain metastases (BM) are frequent among lung cancer patients, affecting prognosis and quality of life. The International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS) and European Respiratory Society (ERS) lung adenocarcinoma (LADC) classification (IASLC/ATS/ERS) has prognostic impact in early-stage disease; however, its role in the advanced setting is not precise. This study aims to determine the correlation between the predominant histological subtype and the risk of developing brain metastases (BM) in locally advanced and metastatic (stages IIIB-IV) LADC.

METHODS

A total of 710 patients with LADC were treated at our institution from January 2010 to December 2017. After excluding patients with brain metastases at diagnoses (n = 151), they were categorized according to the IASLC/ATS/ERS LADC classification to estimate the risk of developing brain metastases. A competing risk analysis was employed, considering death a competing risk event.

RESULTS

From 559 patients, the mean age was 59 ± 13.2 years, women (52.4 %), and clinical-stage IV (79.2 %). LADC subtypes distribution was lepidic (11.6 %), acinar (37.9 %), papillary (10.2 %), micropapillary (6.8 %), and solid (33.5 %). A total of 27.0 % of patients developed BM, 32.9 % died without brain affection, and 40.0 % did not progress. The predominantly solid subtype showed the greatest probability of all subtypes for developing BM [HR 4.0; 95 % CI (1.80-8.91), p = 0.0006], followed by micropapillary [HR1.11; 95 % CI (0.36-3.39), p = 0.85). The solid subtype, moderately differentiated tumors, age, and ECOG PS (>2) were associated with increased hazards in the multivariate analysis.

CONCLUSION

According to the IASLC/ATS/ERS classification, the predominantly solid pattern was significantly associated with an increased risk of developing BM in patients with locally advanced and metastatic LADC. Its prognostic value might help explore novel clinical approaches, modify monitoring for earlier detection, prevent complications, and reduce morbidity.

Combined Immunotherapy and Stereotactic Radiotherapy Improves Neurologic Outcomes in Patients with Non-small-cell Lung Cancer Brain Metastases

BACKGROUND

The purpose of this study was to compare the outcomes of patients with non-small cell lung cancer (NSCLC) brain metastases treated with stereotactic radiotherapy (SRT) alone versus SRT and immune checkpoint inhibitors (ICIs).

PATIENTS AND METHODS

Patients treated for their first diagnosis of intracranial metastases with SRT or SRT plus ICI were retrospectively identified. Overall survival (OS), local control (LC), distant brain failure (DBF), neurologic death, and rates of radiation necrosis were calculated. Univariate (UVA) and multivariable (MVA) analyses with competing risk analysis were performed.

RESULTS

Seventy-seven patients with 132 lesions were analyzed, including 44 patients with 68 lesions in the SRT group and 33 patients with 64 lesions in the SRT plus ICI group. There were no differences in baseline factors between groups. Use of ICI predicted for decreased DBF (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.24-0.84; P = .01), decreased rates of neurologic death (HR, 0.29; 95% CI, 0.10-0.85; P = .02), and better OS (HR, 0.46; 95% CI, 0.23-0.91; P = .03). Two-year LC was 97% for the SRT + ICI group, and 86% for the SRT-alone group (P = .046). Actuarial 2-year DBF was 39% for the SRT + ICI group and 66% for the SRT alone group (P = .016). On MVA, ICI use persisted in predicting lower incidence of neurologic death (HR, 0.25; 95% CI, 0.09-0.72; P = .01) and DBF (HR, 0.47; 95% CI, 0.25-0.85; P = .01) when adjusted for competing risk of death.

CONCLUSION

In this cohort of patients with NSCLC brain metastases, ICI use combined with SRT predicted for improved LC and OS and decreased DBF and risk of neurologic death.

Management of CNS metastases in patients with EGFR mutation-positive NSCLC

Central nervous system (CNS) metastases are a frequent and severe complication associated with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). The first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) have shown considerable efficacy in EGFR-mutated NSCLC. However, their limited potential to cross the blood-brain barrier (BBB) renders them less effective in the management of CNS metastases in NSCLC. Osimertinib, a third-generation irreversible EGFR-TKI with good potential to cross the BBB, has shown significant clinical activity and acceptable safety profile in patients with EGFR-positive NSCLC brain and leptomeningeal metastases. The progression-free survival (PFS) of up to 15.2 months in CNS metastases patients in the FLAURA trial and the CNS objective response rates (ORRs) of 54% and 43% in the AURA/AURA2 and BLOOM trials, respectively, have established the role of osimertinib in patients with NSCLC with CNS metastases. The AURA3 trial also reported a PFS of 8.5 months and overall ORR of 71%. These data have supported osimertinib to be recognized as a "preferred" first-line treatment for EGFR-positive metastatic NSCLC by the National Comprehensive Cancer Network (NCCN). With limited treatment options available, upfront administration of osimertinib in patients with NSCLC irrespective of EGFR T790M and CNS metastases may improve the overall response rate and potentially reduce the adverse effects of radiotherapy. Our review focuses on the management of EGFR-mutated NSCLC CNS metastases in the context of recent NCCN guidelines.

Durable response to pulsatile icotinib for central nervous system metastases from EGFR-mutated non-small cell lung cancer: A case report

BACKGROUND

Central nervous system (CNS) metastases are a catastrophic complication of non-small cell lung cancer (NSCLC), including brain and leptomeningeal carcinomatosis, and are always accompanied by a poor prognosis. Despite the continuous development of existing treatments, the therapy of CNS metastases remains challenging.

CASE SUMMARY

We report a patient who was definitively diagnosed with brain and leptomeningeal metastases from NSCLC with a targeted mutation in epidermal growth factor receptor (EGFR). A standard dosage of icotinib (125 mg three times daily) was implemented but ineffective. CNS lesions developed despite stable systemic control, so pulsatile icotinib (1125 mg every 3 d) was administered. This new strategy for administration has lasted 25 mo so far, and resulted in complete remission of neurological symptoms, almost vanished lesions, and longer survival with no notable side effects.

CONCLUSION

This is the first successful example of pulsatile icotinib for treating isolated CNS progression from EGFR mutation-positive NSCLC, providing a new alternative for the local treatment of CNS metastases.

Leptomeningeal metastasis from solid tumors

Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges (pia, subarachnoid space and arachnoid mater), and dura. Leptomeningeal metastases (LM), also known by different terms including neoplastic meningitis and carcinomatous meningitis, occur in both solid tumors and hematologic malignancies. This review will focus exclusively on LM arising from solid tumors with a goal of providing the reader an understanding of the epidemiology, pathophysiology, clinical presentation, prognostication, current management and future directions.

Development of central nervous system metastases as a first site of metastatic disease in breast cancer patients treated in the neoadjuvant trials GeparQuinto and GeparSixto

Background

The incidence of central nervous system (CNS) metastases in breast cancer patients is rising and has become a major clinical challenge. Only few data are published concerning risk factors for the development of CNS metastases as a first site of metastatic disease in breast cancer patients. Moreover, the incidence of CNS metastases after modern neoadjuvant treatment is not clear.

Methods

We analyzed clinical factors associated with the occurrence of CNS metastases as the first site of metastatic disease in breast cancer patients after neoadjuvant treatment in the trials GeparQuinto and GeparSixto (n = 3160) where patients received targeted treatment in addition to taxane and anthracycline-based chemotherapy.

Results

After a median follow-up of 61 months, 108 (3%) of a total of 3160 patients developed CNS metastases as the first site of recurrence and 411 (13%) patients had metastatic disease outside the CNS. Thirty-six patients (1%) developed both CNS metastases and other distant metastases as the first site of metastatic disease. Regarding subtypes of the primary tumor, 1% of luminal A-like (11/954), 2% of luminal B-like (7/381), 4% of HER2-positive (34/809), and 6% of triple-negative patients (56/1008) developed CNS metastases as the first site of metastatic disease.

In multivariate analysis, risk factors for the development of CNS metastases were larger tumor size (cT3–4; HR 1.63, 95% CI 1.08–2.46, p = 0.021), node-positive disease (HR 2.57, 95% CI 1.64–4.04, p < 0.001), no pCR after neoadjuvant chemotherapy (HR 2.29, 95% CI 1.32–3.97, p = 0.003), and HER2-positive (HR 3.80, 95% CI 1.89–7.64, p < 0.001) or triple-negative subtype (HR 6.38, 95% CI 3.28–12.44, p < 0.001).

Conclusions

Especially patients with HER2-positive and triple-negative tumors are at risk of developing CNS metastases despite effective systemic treatment. A better understanding of the underlying mechanisms is required in order to develop potential preventive strategies.

Primary Results from SAUL, a Multinational Single-arm Safety Study of Atezolizumab Therapy for Locally Advanced or Metastatic Urothelial or Nonurothelial Carcinoma of the Urinary Tract

BACKGROUND

Atezolizumab, a humanised monoclonal antibody targeting PD-L1, is approved for locally advanced/metastatic urothelial carcinoma. SAUL evaluated atezolizumab in a broader, pretreated population, including patients ineligible for the pivotal IMvigor211 phase 3 trial of atezolizumab.

OBJECTIVE

To determine the safety and efficacy of atezolizumab in an international real-world setting.

DESIGN, SETTING, AND PARTICIPANTS

Between November 2016 and March 2018 (median follow-up 12.7mo), 1004 patients with locally advanced or metastatic urothelial or nonurothelial urinary tract carcinoma who experienced progression during or after one to three prior therapies for inoperable, locally advanced, or metastatic disease were enrolled. Patients with renal impairment, treated central nervous system metastases, or stable controlled autoimmune disease were eligible; 10% had Eastern Cooperative Oncology Group performance status (ECOG PS) 2 and 98% were platinum pretreated (Clinicaltrials.gov: NCT02928406).

INTERVENTION

Atezolizumab 1200mg every 3wk until progression or unacceptable toxicity.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was safety. Secondary efficacy endpoints included overall survival (OS), progression-free survival (PFS), and overall response rate (ORR).

RESULTS AND LIMITATIONS

The median treatment duration was 2.8mo (range 0-19); 22% remained on treatment and 8% discontinued because of toxicity. Grade ≥3 adverse events occurred in 45% of patients. The most common grade ≥3 treatment-related adverse events were fatigue, asthenia, colitis, and hypertension (each in 1%). Median OS was 8.7mo (95% confidence interval [CI] 7.8-9.9). The 6-mo OS rate was 60% (95% CI 57-63%), median PFS was 2.2mo (95% CI 2.1-2.4), and the ORR was 13% (95% CI 11-16%; 3% complete responses). Among IMvigor211-like patients (excluding ECOG PS 2 and other IMvigor211 exclusion criteria), median OS was 10.0mo (95% CI 8.8-11.9) and 6-mo OS was 65% (95% CI 61-69%).

CONCLUSIONS

SAUL confirms the tolerability of atezolizumab in a real-world pretreated population with urinary tract carcinoma. Efficacy overall and in the IMvigor211-like subgroup is consistent with previous pivotal anti-PD-L1/PD-1 urothelial carcinoma trials. These results support the use of atezolizumab in urinary tract carcinoma, including patients with limited treatment options.

PATIENT SUMMARY

In this international study we investigated the efficacy and safety of atezolizumab treatment for advanced urinary tract cancer in a large population of pretreated patients, including those who would not normally be candidates for clinical trials. Patients tolerated the treatment well, even if they had autoimmune disease, were being treated with corticosteroids, or had disease that had spread to their brain. Life expectancy in this study for patients typical of everyday clinical practice was similar to that seen in trials that enrolled only selected fitter patients.

Pembrolizumab for non-small cell lung cancer with central nervous system metastases: A two-case report

Non-small cell lung cancer (NSCLC) accounts for up to 85% of all lung cancers. Central nervous system metastases are a common complication of NSCLC and confer a poor prognosis and a dismal survival rate. Treatment is limited, has poor outcomes, and affects patient quality of life. Pembrolizumab is an anti-PD-1 antibody that has shown good results for the management of NSCLC. However, its penetration of the central nervous system has not been well studied, and patients with untreated brain metastases are excluded from most clinical trials. Herein, we report two cases of NSCLC with brain metastases in patients successfully treated with pembrolizumab, and discuss the efficacy and safety of pembrolizumab in these patients. Pembrolizumab has shown good control and the patients have had long progression-free survival with a high quality of life. Neither patient has experienced serious or grade 3-4 treatment-related adverse events. Pembrolizumab demonstrates activity in brain metastases in NSCLC patients with an acceptable safety profile. Thus, there may be a role for systemic immunotherapy in patients with untreated or progressive brain metastases.

Clinical presentation, risk factors and outcome of central nervous system metastasis vs stroke in cancer patients

BACKGROUND AND PURPOSE

Cancer and stroke are the second and third causes of death worldwide; brain metastases (BM) occur in one third of patients with cancer, any neurologic deficit in these population always prompts the clinician to discard metastases for their presence carries a bad outcome. Both might share clinical presentation and differences in their outcome are not entirely known. The aim was to compare risk factors, clinical presentation, and outcome of cancer patients with BM vs stroke.

METHODS

A descriptive study with prospectively acquired data from a cancer referral center included patients seen at the neuro-oncologic unit from March 2011 to February 2018 with confirmed cancer who had BM or stroke.

RESULTS

Six hundred and thirteen BM patients were compared with 268 with stroke and cancer. Demographic factors, cancer type, risk factors, clinical presentation, and outcome are presented. Median overall survival in months for those with any stroke was 15 (95%confidence interval [CI] 8.6-21.4)-5 (95%CI 0.12.4) for hemorrhagic stroke and 22 (95%CI 13.4-30.6) in the ischemic group-and for those with BM 12 (95%CI 10.4-13.6). Hemorrhagic stroke commonly found in stroke patients as well as focal motor weakness, aphasia, and altered mental status. BM was more common in breast and lung cancer with headache, visual complaint, and/or vertigo.

CONCLUSION

Survival in cancer patients with BM is not that different than those with stroke, but clinical presentation and risk factors were found different.

RADIANS: A Multidisciplinary Central Nervous System Clinic Model for Radiation Oncology and Neurosurgery Practice

BACKGROUND

Radiation therapy for central nervous system disease commonly involves collaboration between Radiation Oncology and Neurosurgery. We describe our early experience with a multidisciplinary clinic model.

METHODS

In 2016, the novel RADIANS (RADIation oncology And NeuroSurgery) clinic model was initiated at a community hospital. Disease and treatment demographics were collected and analyzed. Patient satisfaction was assessed via a blinded survey questionnaire.

RESULTS

Forty-two patients have been seen since the inception of RADIANS. The median age was 65; and the median patient distance from RADIANS was 42.7 miles (mean = 62.6; range = 0.7-285). Half of the patients traveled >50 miles to receive care, and >80% were seen for central nervous system metastases. Of the patients receiving radiation, 75% received stereotactic radiosurgery/stereotactic body radiation therapy. The mean overall satisfaction from 0 (not satisfied) to 5 (very satisfied) was 4.8.

CONCLUSIONS

The RADIANS clinic model has proved viable and well-liked by patients in a community setting, with the majority of radiation therapy administered being stereotactic radiosurgery/stereotactic body radiation therapy rather than conventional fractionation.

Preventing central nervous system metastases in non-small cell lung cancer

INTRODUCTION

There are no effective central nervous system (CNS) metastases prevention methods in lung cancer patients. Prophylactic cranial irradiation has a limited effectiveness and relatively high toxicity. Systemic chemotherapy is not relevant in reducing the risk of CNS in lung cancer patients. The understanding of molecular background of brain metastases in non-small cell lung cancer (NSCLC) patients could contribute to the development of personalized treatments for such patients. Areas covered: This article summarizes the latest clinical trials concerning the use of radiotherapy, chemotherapy, molecularly targeted therapies, and immunotherapy in lung cancer patients, with particular consideration of brain lung cancer metastasis prevention. The literature search was undertaken via PubMed and EMBASE searches and relevant articles are included in this review. Expert commentary: The recent data supports that EGFR-TKIs and ALK inhibitors are clinically relevant for first-line treatment to prevent and treat CNS metastases in molecularly selected NSCLC patients. In the future, high hopes for the prevention of CNS metastases in NSCLC patients are associated with immunotherapy concerning immune check-points inhibitors.

Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors for Central Nervous System Metastases from Non-Small Cell Lung Cancer

Central nervous system (CNS) metastases are a common complication in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), resulting in a poor prognosis and limited treatment options. Treatment of CNS metastases requires a multidisciplinary approach, and the optimal treatment options and sequence of therapies are yet to be established. Many systemic therapies have poor efficacy in the CNS due to the challenges of crossing the blood-brain barrier (BBB), creating a major unmet need for the development of agents with good BBB-penetrating biopharmaceutical properties. Although the CNS penetration of first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) is generally low, EGFR-TKI treatment has been shown to delay time to CNS progression in patients with CNS metastases from EGFR-mutated disease. However, a major challenge with EGFR-TKI treatment for patients with NSCLC is the development of acquired resistance, which occurs in most patients treated with a first-line EGFR-TKI. Novel EGFR-TKIs, such as osimertinib, have been specifically designed to address the challenges of acquired resistance and poor BBB permeability and have demonstrated efficacy in the CNS. A rational, iterative drug development process to design agents that could penetrate the BBB could prevent morbidity and mortality associated with CNS disease progression. To ensure a consistent approach to evaluating CNS efficacy, special consideration also needs to be given to clinical trial endpoints.

IMPLICATIONS FOR PRACTICE

Historically, treatment options for patients who develop central nervous system (CNS) metastases have been limited and associated with poor outcomes. The development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has improved outcomes for patients with EGFR-mutated disease, and emerging data have demonstrated the ability of these drugs to cross the blood-brain barrier and elicit significant intracranial responses. Recent studies have indicated a role for next-generation EGFR-TKIs, such as osimertinib, in the treatment of CNS metastases. In the context of an evolving treatment paradigm, treatment should be individualized to the patient and requires a multidisciplinary approach.

Prevalence of NRAS, PTEN and AKT1 gene mutations in the central nervous system metastases of non-small cell lung cancer

Somatic mutations in NRAS, PTEN and AKT1 genes are rarely (~1%) reported in primary NSCLC, but their role in carcinogenesis have been proven. Therefore, we assessed the frequency of them in 145 FFPE tissue samples from CNS metastases of NSCLC using the real-time PCR technique. We identified four (two NRAS and single AKT1 and PTEN) mutations in CNS metastases of NSCLC. All mutations were observed in current male smokers (4% out of the male group; 4/100 and 4.25% out of smokers; 4/94). Three mutations have been detected in patients with SqCC (10.3% out of SqCC patients; 3/29), and only one mutation in the NRAS gene—in a patient with adenocarcinoma (1.25% out of AC patients; 1/80). The examined genes were mutually exclusive in terms of molecular background in KRAS; EGFR; DDR2; PIK3CA; HER2 and MEK1 genes that were evaluated in our previous studies. The OS of the patients who harbored NRAS, AKT1 and PTEN mutations was 10.1, 12.1, 7.3 and 4 months, respectively (vs 13.5 months of the studied group). Our results suggest that the presence of NRAS, PTEN and AKT1 gene mutations may have an influence on the occurrence of CNS metastases in patients with SqCC.

Sensitive methods for screening of the MEK1 gene mutations in patients with central nervous system metastases of non-small cell lung cancer

BACKGROUND

The mitogen-activated protein kinases 1 and 2 (MEK1, MEK2) are fundamental partners in the RAS-RAF-MEK-ERK pathway that is involved in regulation of cell proliferation, differentiation and survival. Downregulation of the MEK cascades has been implicated in acquiring of the malignant phenotype in various cancers. Somatic mutations in MEK1 gene (substitutions K57N, Q56P, D67N) were described in <1 % of non-small cell lung cancer (NSCLC) and they were more commonly reported in adenocarcinoma patients with current or former smoking status.

MATERIALS AND METHODS

In the following study, we assessed the MEK1 gene mutations in 145 FFPE tissue samples from central nervous system (CNS) metastases of NSCLC using HRM-PCR and ASP-qPCR techniques. The studied group was heterogeneous in terms of histopathology and smoking status. The prevalence of the MEK1 gene mutation was correlated with the occurrence of mutations in KRAS, EGFR, DDR2, PIK3CA, NRAS, HER2, AKT1 and PTEN genes.

RESULTS

Using HRM and ASP-qPCR methods we identified one (0.7 %; 1/145) MEK1 substitution (Q56P) in CNS metastases of NSCLC. The mutation was identified in a single, 50-year-old, current smoking men with adenocarcinoma (1.25 %; 1/80 of all adenocarcinomas).

CONCLUSIONS

According to the current knowledge, the incidence of MEK1 gene mutation in CNS metastatic lesion of NSCLC is the first such report worldwide. The analysis of gene profile in cancer patients may extend the scope of molecularly targeted therapies used both in patients with primary and metastatic tumors of NSCLC.

Analysis of KRAS and BRAF genes mutation in the central nervous system metastases of non-small cell lung cancer

KRAS mutations are associated with tumor resistance to EGFR TKIs (erlotinib, gefitinib) and to monoclonal antibody against EGFR (cetuximab). Targeted treatment of mutated RAS patients is still considered as a challenge. Inhibitors of c-Met (onartuzumab or tiwantinib) and MEK (selumetinib—a dual inhibitor of MEK1 and MEK2) signaling pathways showed activity in patients with mutations in KRAS that can became an effective approach in carriers of such disorders. BRAF mutation is very rare in patients with NSCLC, and its presence is associated with sensitivity of tumor cells to BRAF inhibitors (vemurafenib, dabrafenib). In the present study, the frequency and type of KRAS and BRAF mutation were assessed in 145 FFPE tissue samples from CNS metastases of NSCLC. In 30 patients, material from the primary tumor was simultaneously available. Real-time PCR technique with allele-specific molecular probe (KRAS/BRAF Mutation Analysis Kit, Entrogen, USA) was used for molecular tests. KRAS mutations were detected in 21.4 % of CNS metastatic lesions and in 23.3 % of corresponding primary tumors. Five mutations were identified both in primary and in metastatic lesions, while one mutation only in primary tumor and one mutation only in the metastatic tumor. Most of mutations were observed in codon 12 of KRAS; however, an individual patient had diagnosed a rare G13D and Q61R substitutions. KRAS mutations were significantly more frequent in adenocarcinoma patients and smokers. Additional analysis indicated one patient with rare coexistence of KRAS and DDR2 mutations. BRAF mutation was not detected in the examined materials. KRAS frequency appears to be similar in primary and CNS.

Hurthle cell carcinoma presenting as a single choroid plexus metastasis

Choroid plexus masses represent approximately 0.3-0.8% of intracranial tumors. Herein we present, to our knowledge, the first reported patient with an isolated Hurthle cell papillary thyroid carcinoma metastasis to the choroid plexus of the lateral ventricle. Unresponsive to iodine ablation and refusing surgery, the patient underwent Gamma Knife radiosurgery (Elekta AB, Stockholm, Sweden), receiving 15Gy to the 50% isodose line. The lesion regressed until 5years later at which time it was unresponsive to 18Gy and required surgical resection. Although extraneural metastatic cancers are recognized as potential sources for the single choroid plexus mass, we must consider even the unusual culprit in patients with a history of cancer.