Modern Management of Central Nervous System Metastases in the Era of Targeted Therapy and Immune Oncology

The systemic management of central nervous system metastases and leptomeningeal disease from advanced lung, melanoma, and breast cancer with molecular drivers: An Australian perspective

The advent of systemic therapies with high intracranial efficacy in recent years is changing the therapeutic paradigm and renewing interest in the management of central nervous system (CNS) and leptomeningeal metastases from solid organ tumors. CNS metastases have traditionally heralded a dismal prognosis with median survival of 3-10 months, and were primarily treated with local therapeutic modalities, such as surgery or radiation therapy. Although these modalities still have a role in the management of CNS disease, newer agents, such as small molecule tyrosine kinase inhibitors and immune-checkpoint inhibitors, are now paving the way as an alternative therapeutic option for those with oligometastatic or low-volume intracranial disease, potentially eliminating or delaying the need for local treatment modalities in this setting. Herein, we summarize the systemic treatments with proven intracranial efficacy, currently approved for use in Australia for advanced mutation-driven non-small cell lung cancer, melanoma, and breast cancer, as well as novel agents in preclinical and clinical trial development.

Defining unique clinical hallmarks for immune checkpoint inhibitor-based therapies

IntroductionImmuno-oncology therapies, including immune checkpoint inhibitors (ICIs), have transformed cancer care and have brought into question whether classic oncology efficacy assessments adequately describe the distinctive responses observed with these agents. With more ICI-based therapies being approved across multiple tumor types, it is essential to define unique clinical hallmarks of these agents and their associated assessments to better reflect the therapeutic impact for both patients and physicians. Long-term survival and objective responses, such as depth and durability of responses, treatment-free survival, efficacy in brain metastases, improved health-related quality of life, and unique safety profiles, are among the hallmarks that have emerged for ICI therapies. An established clinical hallmark is a sustained long-term survival, as evidenced by a delayed separation of Kaplan-Meier survival curves, and a plateau at ~3 years. Combination ICI therapies provide the opportunity to raise this plateau, thereby affording durable survival benefits to more patients. Deepening of responses over time is a unique clinical ICI hallmark, with patients responding long term and with more durable complete responses. Depth of response has demonstrated prognostic value for long-term survival in some cancers, and several ICI studies have shown sustained responses even after discontinuing ICI therapy, offering the potential for treatment-free intervals. Although clinical evidence supporting efficacy in brain metastases is limited, favorable ICI intracranial responses have been seen that are largely concordant with extracranial responses. While patient outcomes can be significantly improved with ICIs, they are associated with unique immune-mediated adverse reactions (IMARs), including delayed ICI toxicities, and may require multidisciplinary management for optimal care. Interestingly, patients discontinuing ICIs for IMARs may maintain responses similar to patients who did not discontinue for an IMAR, whether they restarted ICI therapy or not.ConclusionHerein, we comprehensively review and refine the clinical hallmarks uniquely associated with ICI therapies, which not only will rejuvenate our assessment of ICI therapeutic outcomes but also will lead to a greater appreciation of the effectiveness of ICI therapies.

Blood-Brain Barrier in Brain Tumors: Biology and Clinical Relevance

The presence of barriers, such as the blood–brain barrier (BBB) and brain–tumor barrier (BTB), limits the penetration of antineoplastic drugs into the brain, resulting in poor response to treatments. Many techniques have been developed to overcome the presence of these barriers, including direct injections of substances by intranasal or intrathecal routes, chemical modification of drugs or constituents of BBB, inhibition of efflux pumps, physical disruption of BBB by radiofrequency electromagnetic radiation (EMP), laser-induced thermal therapy (LITT), focused ultrasounds (FUS) combined with microbubbles and convection enhanced delivery (CED). However, most of these strategies have been tested only in preclinical models or in phase 1–2 trials, and none of them have been approved for treatment of brain tumors yet. Concerning the treatment of brain metastases, many molecules have been developed in the last years with a better penetration across BBB (new generation tyrosine kinase inhibitors like osimertinib for non-small-cell lung carcinoma and neratinib/tucatinib for breast cancer), resulting in better progression-free survival and overall survival compared to older molecules. Promising studies concerning neural stem cells, CAR-T (chimeric antigen receptors) strategies and immunotherapy with checkpoint inhibitors are ongoing.

Timing of Development of Symptomatic Brain Metastases from Non-Small Cell Lung Cancer: Impact on Symptoms, Treatment, and Survival in the Era of Molecular Treatments

Simple Summary

In order to clarify whether an early development of brain metastases from non-small cell lung cancer represents a poor prognostic factor for further survival we analyzed 377 patients with brain metastases, treated by radiosurgery or surgery at two German institutions. Our results show that an early appearance of brain metastasis does not influence further survival in a comprehensive treatment setting.

Abstract

Objective: We attempted to analyze whether early presentation with brain metastases (BM) represents a poor prognostic factor in patients with non-small cell lung cancer (NSCLC), which should guide the treatment team towards less intensified therapy. Patients and methods: In a retrospective bi-centric analysis, we identified patients receiving surgical treatment for NSCLC BM. We collected demographic-, tumor-, and treatment-related parameters and analyzed their influence on further survival. Results: We included 377 patients. Development of BM was precocious in 99 (26.3%), synchronous in 152 (40.3%), and metachronous in 126 (33.4%) patients. The groups were comparable in terms of age (p = 0.76) and number of metastases (p = 0.11), and histology (p = 0.1); however, mutational status significantly differed (p = 0.002). The precocious group showed the worst clinical status as assessed by Karnofsky performance score (KPS) upon presentation (p < 0.0001). Resection followed by postoperative radiotherapy was the predominant treatment modality for precocious BM, while in syn- and metachronous BM surgical and radio-surgical treatment was balanced. Overall survival (OS) did not differ between the groups (p = 0.76). A good postoperative clinical status (KPS ≥ 70) and the application of any kind of adjuvant systemic therapy were independent predictive factors for OS. Conclusion: Early BM presentation was not associated with worse OS in NSCLC BM patients.

Endocrine therapy for the treatment of leptomeningeal carcinomatosis in luminal breast cancer: a comprehensive review

Leptomeningeal disease (LMD) represents a devastating complication of advanced breast cancer (ABC), with survival of <5 months with multimodal treatment. The role of endocrine therapy (ET), due to its favorable toxicity profile and first-line indication in luminal ABC, appears promising in the setting of LMD, where symptom stabilization and quality-of-life preservation are the main goals; however, evidenced-based data are lacking. We conducted a thorough review of published evidence, aiming to investigate the role of ET in LMD treatment in luminal ABC. Twenty-one of 342 articles, evaluating 1302 patients, met inclusion criteria. ET use was rarely reported. New targeted agents show CNS activity. Research is lacking on the role of ET and targeted agents in BC-LMD treatment.

First-line pemetrexed and carboplatin plus anlotinib for epidermal growth factor receptor wild-type and anaplastic lymphoma kinase-negative lung adenocarcinoma with brain metastasis: A case report and review of the literature

RATIONALE

Brain metastasis (BM) is a serious complication in non-small cell lung cancer (NSCLC) patients. Pemetrexed is one of the preferred agents in nonsquamous NSCLC with BM; however, the traditional chemotherapy demonstrated limited efficacy partly due to drug resistance and the blood-brain barrier.

PATIENT CONCERNS

A 52-year-old male non-smoker was admitted for irritating cough, chest distress, and back pain.

DIAGNOSES

Epidermal growth factor receptor wild-type, anaplastic lymphoma kinase-negative primary lung adenocarcinoma with an asymptomatic solitary BM (cTxNxM1b, IVA).

INTERVENTIONS

Pemetrexed (500 mg/m of body surface area) and carboplatin (area under the curve of 5) were firstly administered every 3 weeks for 3 cycles, followed by pemetrexed/carboplatin plus anlotinib (12 mg daily; 2 weeks on and 1 week off) for another 3 cycles. Then maintenance anlotinib monotherapy was continued for a year, without unacceptable adverse events.

OUTCOMES

The BM was slightly enlarged after 3 cycles of pemetrexed/carboplatin; however, a complete remission was achieved after the combination therapy. His intracranial progression-free survival was more than 2 years.

LESSONS

Pemetrexed/carboplatin plus anlotinib could be considered for the treatment of epidermal growth factor receptor wild-type, anaplastic lymphoma kinase-negative lung adenocarcinoma with BM. Further well-designed trials are warranted to verify this occasional finding.

Surgical resection of symptomatic brain metastases improves the clinical status and facilitates further treatment

Background

Brain metastases (BM) frequently cause focal neurological deficits leading to a reduced Karnofsky performance score (KPS). Since KPS is routinely used to guide the choice of adjuvant therapy, we hypothesized that improving KPS by surgical resection may improve the chance for adjuvant treatment and ultimately result in better survival. We therefore analyzed the course of a large cohort undergoing resection of symptomatic brain metastases in the context of further treatment and clinical outcome.

Patients and methods

In a bi‐centric retrospective analysis we retrieved baseline, clinical, and treatment‐related parameters of patients operated on BM between 2010 and 2019. Survival was calculated using Kaplan‐Meier estimates; prognostic factors for survival were analyzed by Log‐rank test and Cox proportional hazards.

Results

We included 750 patients with a median age of 61 (19‐87) years. The functional status was significantly improved by surgical resection, with a median preoperative (KPS) of 80 (10‐100) increasing to 90 (0‐100) after surgery (P < .0001). Moreover, surgery improved the RTOG recursive partitioning analysis (RPA) class from III to I/II in 82 patients. Postoperative local radiotherapy and systemic treatment were associated with significantly longer survival (P < .0001 for each). Systemic treatment was provided significantly more frequently in patients with a fair postoperative clinical status (KPS ≥ 70; P < .0001). The postoperative clinical status, postoperative radiotherapy, systemic treatment, controlled systemic disease and < 4 BM were independent predictors for survival.

Conclusion

The resection of symptomatic BM may restore clinical status, so enhancing the likelihood of receiving adjuvant treatment, and therefore leading to improved overall survival.

Brain Metastases From Gynecologic Malignancies: Prevalence and Management

OBJECTIVE

The objective of this study was to investigate the prevalence, clinicopathologic characteristics, management, and outcomes of patients with brain metastasis (BM) from gynecologic malignancies in a large hospital-based database.

MATERIALS AND METHODS

The National Cancer Database (NCDB) was accessed and patients with ovarian, uterine, or cervical cancer and BM were identified. We identified those who received radiation therapy (RT) as whole-brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS). Kaplan-Meier curves were generated to determine median overall survival (OS) and compared with the log-rank test.

RESULTS

A total of 853 patients with BM were identified. The rate of BMs upon diagnosis was 0.4% (211/57,160) for patients with cervical cancer, 0.2% (498/243,785) for patients with uterine, and 0.2% (144/92,301) for ovarian malignancies. Only 30.4% had isolated BM, while 52.2% had lung metastasis. Approximately half of the patients (50.1%) received chemotherapy, while brain RT was administered to 324 (38%) patients. Among patients who received brain RT, only 60 (18.5%) had SRS, while 264 (81.5%) had WBRT. Patients who underwent SRS had a better survival (n=47, median OS=9 mo) than those who received WBRT (n=201, median OS=4.73 mo, P=0.018), or those who did not receive any brain RT (n=370, median OS=4.01 mo, P=0.007).

CONCLUSIONS

The incidence of BM among patients with gynecologic malignancies is rare and associated with poor survival. For select patients, SRS may be associated with prolonged survival.