Emerging Trends in the Management of Brain Metastases from Non-small Cell Lung Cancer

The value of stereotactic biopsy of primary and recurrent brain metastases in the era of precision medicine

Background

Brain metastases (BM) represent the most frequent intracranial tumors with increasing incidence. Many primary tumors are currently treated in protocols that incorporate targeted therapies either upfront or for progressive metastatic disease. Hence, molecular markers are gaining increasing importance in the diagnostic framework of BM. In cases with diagnostic uncertainty, both in newly diagnosed or recurrent BM, stereotactic biopsy serves as an alternative to microsurgical resection particularly whenever resection is not deemed to be safe or feasible. This retrospective study aimed to analyze both diagnostic yield and safety of an image-guided frame based stereotactic biopsy technique (STX).

Material and methods

Our institutional neurosurgical data base was searched for any surgical procedure for suspected brain metastases between January 2016 and March 2021. Of these, only patients with STX were included. Clinical parameters, procedural complications, and tissue histology and concomitant molecular signature were assessed.

Results

Overall, 467 patients were identified including 234 (50%) with STX. Median age at biopsy was 64 years (range 29 - 87 years). MRI was used for frame-based trajectory planning in every case with additional PET-guidance in 38 cases (16%). In total, serial tumor probes provided a definite diagnosis in 230 procedures (98%). In 4 cases (1.7%), the pathological tissue did not allow a definitive neuropathological diagnosis. 24 cases had to be excluded due to non-metastatic histology, leaving 206 cases for further analyses. 114 patients (49%) exhibited newly diagnosed BM, while 46 patients (20%) displayed progressive BM. Pseudoprogression was seen in 46 patients, a median of 12 months after prior therapy. Pseudoprogression was always confirmed by clinical course. Metastatic tissue was found most frequently from lung cancer (40%), followed by breast cancer (9%), and malignant melanoma (7%). Other entities included gastrointestinal cancer, squamous cell cancer, renal cell carcinoma, and thyroid cancer, respectively. In 9 cases (4%), the tumor origin could not be identified (cancer of unknown primary). Molecular genetic analyses were successful in 137 out of 144 analyzed cases (95%). Additional next-generation sequencing revealed conclusive results in 12/18 (67%) cases. Relevant peri-procedural complications were observed in 5 cases (2.4%), which were all transient. No permanent morbidity or mortality was noted.

Conclusion

In patients with BM, frame-based stereotactic biopsy constitutes a safe procedure with a high diagnostic yield. Importantly, this extended to discerning pseudoprogression from tumor relapse after prior therapy. Thus, comprehensive molecular characterization based on minimal-invasive stereotactic biopsies lays the foundation for precision medicine approaches in the treatment of primary and recurrent BM.

Analysis of Immunotherapy Combined with Radiotherapy in Patients with Brain Metastasis of Driver Gene-Negative Non-Small-Cell Lung Cancer

Purpose. To observe the remission rate and side effects of immunotherapy combined with radiotherapy in patients with brain metastasis of driver gene-negative non-small-cell lung cancer (NSCLC). Methods. 152 patients with NSCLC brain metastasis admitted to our hospital from January 2019 to December 2021 were selected as the research objects. Patients were divided into a single group (85 cases) and a combined group (67 cases) according to treatment methods. The therapeutic effects and side effects of the single group and combined group were compared. In addition, the patients who received immunotherapy combined with radiotherapy were divided into three subgroups: A, B, and C, and the therapeutic effects and side effects of different radiotherapy modes were compared among group A [whole brain radiotherapy (WBRT)], group B (WBRT combined with local radiotherapy) and group C (local radiotherapy). Results. The objective response rate (ORR) and disease control rate (DCR) in the combined group were higher than those in the single group ( $P<0.05$ ). The incidence of reactive capillary hyperplasia and immune-related pneumonia in the combined group were higher than that in the single group ( $P<0.05$ ). There was no significant difference in the incidence of other side effects between the two groups ( $P>0.05$ ). ORR and DCR in group B were higher than those in group A ( $P<0.05$ ). There was no significant difference in the incidence of side effects among the three groups ( $P>0.05$ ). Conclusion. Immunotherapy combined with radiotherapy is effective in patients with brain metastasis of driver gene-negative NSCLC, which can improve the disease control rate without increasing the side effects. In addition, WBRT combined with local push radiotherapy is effective and safe. Clinical Study Registration Number. The Clinical study registration number is K2019086.

Recapitulated Crosstalk between Cerebral Metastatic Lung Cancer Cells and Brain Perivascular Tumor Microenvironment in a Microfluidic Co-Culture Chip

Non-small cell lung carcinoma (NSCLC), which affects the brain, is fatal and resistant to anti-cancer therapies. Despite innate, distinct characteristics of the brain from other organs, the underlying delicate crosstalk between brain metastatic NSCLC (BM-NSCLC) cells and brain tumor microenvironment (bTME) associated with tumor evolution remains elusive. Here, a novel 3D microfluidic tri-culture platform is proposed for recapitulating positive feedback from BM-NSCLC and astrocytes and brain-specific endothelial cells, two major players in bTME. Advanced imaging and quantitative functional assessment of the 3D tri-culture model enable real-time live imaging of cell viability and separate analyses of genomic/molecular/secretome from each subset. Susceptibility of multiple patient-derived BM-NSCLCs to representative targeted agents is altered and secretion of serpin E1, interleukin-8, and secreted phosphoprotein 1, which are associated with tumor aggressiveness and poor clinical outcome, is increased in tri-culture. Notably, multiple signaling pathways involved in inflammatory responses, nuclear factor kappa-light-chain-enhancer of activated B cells, and cancer metastasis are activated in BM-NSCLC through interaction with two bTME cell types. This novel platform offers a tool to elucidate potential molecular targets and for effective anti-cancer therapy targeting the crosstalk between metastatic cancer cells and adjacent components of bTME.

The incidence and predictors of new brain metastases in patients with non-small cell lung cancer following discontinuation of systemic therapy

OBJECTIVE

Patients with non-small cell lung cancer (NSCLC) metastatic to the brain are living longer. The risk of new brain metastases when these patients stop systemic therapy is unknown. The authors hypothesized that the risk of new brain metastases remains constant for as long as patients are off systemic therapy.

METHODS

A prospectively collected registry of patients undergoing radiosurgery for brain metastases was analyzed. Of 606 patients with NSCLC, 63 met the inclusion criteria of discontinuing systemic therapy for at least 90 days and undergoing active surveillance. The risk factors for the development of new tumors were determined using Cox proportional hazards and recurrent events models.

RESULTS

The median duration to new brain metastases off systemic therapy was 16.0 months. The probability of developing an additional new tumor at 6, 12, and 18 months was 26%, 40%, and 53%, respectively. There were no additional new tumors 22 months after stopping therapy. Patients who discontinued therapy due to intolerance or progression of the disease and those with mutations in RAS or receptor tyrosine kinase (RTK) pathways (e.g., KRAS, EGFR) were more likely to develop new tumors (hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.33-3.81, p = 2.5 × 10-3; HR 2.51, 95% CI 1.45-4.34, p = 9.8 × 10-4, respectively).

CONCLUSIONS

The rate of new brain metastases from NSCLC in patients off systemic therapy decreases over time and is uncommon 2 years after cessation of cancer therapy. Patients who stop therapy due to toxicity or who have RAS or RTK pathway mutations have a higher rate of new metastases and should be followed more closely.

Combination of Immune Checkpoint Inhibitors and Anti-Angiogenic Agents in Brain Metastases From Non-Small Cell Lung Cancer

Brain metastases remain a critical issue in the management of non-small cell lung cancer (NSCLC) because of the high frequency and poor prognosis, with survival rates often measured in just months. The local treatment approach remains the current standard of care, but management of multiple asymptomatic brain metastases always involves systemic therapy. Given that anti-angiogenic agents and immune checkpoint inhibitors (ICIs) both target the tumor microenvironment (TME), this combination therapy has become a promising strategy in clinical practice. Increasing number of preclinical and clinical studies have shown remarkable anti-tumor activity of the combination therapy, but the efficacy in brain metastases is unclear due to the strict selection criteria adopted in most clinical trials. This review briefly summarizes the potential synergistic anti-tumor effect and clinical development of the combination of anti-angiogenic agents and ICIs in NSCLC brain metastases, and discusses the existing challenges and problems.

Local ablative therapy of brain metastasis from non-small cell lung cancer: benefits and limitations

Brain metastases (BMs) are the most common intracranial tumors and non-small cell lung cancer (NSCLC) are responsible for BM more than any other solid tumor. Its frequency is increasing due to of the availability of new imaging techniques, earlier diagnosis and improvement in treatment techniques and survival rates. NSCLC patients with BM represent heterogeneous prognostic group. The possibility of better prognostic stratification associated with more systemic therapy options and imaging and radiation technology advances have led to an increment of evaluation and indication of local ablative radiotherapy. The definite increment in quality of life and the potential overall survival (OS) benefit of its indication must be balanced with eventual higher risk of brain disseminated disease when whole brain irradiation is postponed. Therefore, a multidisciplinary evaluation is recommended to refine and personalize the therapeutic approach. The development of clinical nomograms or evaluation of circulating tumor cells/tumoral DNA that predict the survival free of new lesions may be the tools that will warranty further optimization of the treatment of NSCLC patients with BM. In this review, we report the main aspects of diagnosis, prognosis and therapeutic options and dilemmas evolving local ablative radiotherapy essentially based on seminal, updated prospective studies and ongoing trials.

WBRT for brain metastases from non-small cell lung cancer: for whom and when?-Contemporary point of view

The incidence of brain metastases (BM) is estimated between 20% and 40% of patients with solid cancer. The most common cause of this failure is lung cancer, and in locally advanced non-small cell lung cancer (NSCLC) BM represent a common site of relapse in 30-55% cases. The basic criteria of therapeutic decision-making are based on the significant prognostic factors which are components of prognostic scores. The standard approach to treatment of BM from NSCLC include whole brain radiotherapy (WBRT) which is used as adjuvant modality after local therapy (surgery or stereotactic radiosurgery) or as primary treatment and it remains the primary modality of treatment for patients with multiple metastases. WBRT is also used in combination with systemic therapy. The aim of presented review of literature is trying to answer which patients with BM from NSCLC should receive WBRT and when it could be omitted. There were presented the aspects of application of WBRT in relation to (I) choice between WBRT or the best supportive care and (II) employment of WBRT in combination with local treatment modalities [surgical resection or stereotactic radio-surgery (SRS)] and/or with systemic therapy. According to data from literature we concluded that the most important factor that needs to be considered when assessing the suitability of a patient for WBRT is the patient's prognosis based on the Lung-molGPA score. WBRT should be applied in treatment of multiple BM from lung cancer in patients with favourable prognosis and in in patients with presence of EML4-ALK translocation before therapy with crizotinib. Whereas WBRT could be omitted in patients with poor prognosis and after primary SRS.

Death Anxiety in Patients With Metastatic Non-Small Cell Lung Cancer With and Without Brain Metastases

CONTEXT

Death anxiety is common in patients with metastatic cancer, but its relationship to brain metastases and cognitive decline is unknown. Early identification of death anxiety and its determinants allows proactive interventions to be offered to those in need.

OBJECTIVES

To identify psychological, physical, and disease-related (including brain metastases and cognitive impairment) factors associated with death anxiety in metastatic non-small cell lung cancer (mNSCLC) patients.

METHODS

A cross-sectional pilot study with mNSCLC outpatients completing standardized neuropsychological tests and validated questionnaires measuring death anxiety, cognitive concerns, illness intrusiveness, depression, demoralization, self-esteem, and common cancer symptoms. We constructed a composite for objective cognitive function (mean neuropsychological tests z-scores).

RESULTS

Study measures were completed by 78 patients (50% females; median age 62 years [range 37-82]). Median time since mNSCLC diagnosis was 11 months (range 0-89); 53% had brain metastases. At least moderate death anxiety was reported by 43% (n = 33). Objective cognitive impairment was present in 41% (n = 32) and perceived cognitive impairment in 27% (n = 21). Death anxiety, objective, and perceived cognitive impairment did not significantly differ between patients with and without brain metastases. In univariate analysis, death anxiety was associated with demoralization, depression, self-esteem, illness intrusiveness, common physical cancer symptoms, and perceived cognitive impairment. In multivariate analysis, demoralization (P < 0.001) and illness intrusiveness (P = 0.001) were associated with death anxiety.

CONCLUSION

Death anxiety and brain metastases are common in patients with mNSCLC but not necessarily linked. The association of death anxiety with both demoralization and illness intrusiveness highlights the importance of integrated psychological and symptom management. Further research is needed on the psychological impact of brain metastases.

Management of oligometastatic non-small cell lung cancer patients: Current controversies and future directions

Oligometastatic non-small cell lung cancer (NSCLC) describes an intermediate stage of NSCLC between localized and widely-disseminated disease. This stage of NSCLC is characterized by a limited number of metastases and a more indolent tumor biology. Currently, the management of oligometastatic NSCLC involves radical treatment (radiotherapy or surgery) that targets the metastatic lesions and the primary tumor to achieve disease control. This approach offers the potential to achieve prolonged survival in patients who, in the past, would have only received palliative measures. The optimal therapeutic strategies for the different scenarios of oligometastatic disease (intracranial vs extracranial disease, synchronous vs metachronous) remain undefined. Given the lack of head-to-head studies comparing radiotherapy to surgery in these patients, the decision to apply surgery or radiotherapy (with or without systemic treatment) must be based on prognostic factors that allow us to classify patients. This classification will allow us to select the most appropriate therapeutic strategy on an individualized basis. In the future, the molecular or microRNA profiles will likely improve the treatment selection process. The objective of the present article is to review the most relevant scientific evidence on the management of patients with oligometastatic NSCLC, focusing on the role of radiotherapy and surgery. We also discuss areas of controversy and future directions.

Prognostic value of site-specific metastases in lung cancer: A population based study

Background: Studies on prognosis of different metastasis sites in patients with lung cancer are limited. The aim of present study was to investigate the prognostic value of metastases sites among patients with metastatic lung cancer.

Methods: Between 2010 and 2014, patients diagnosed with metastatic lung cancer were selected using the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier methods were adopted and multivariable Cox regression models were built to compare the prognosis of different metastasis sites.

Results: A total of 54,697 eligible patients were identified, including 10,945 (20.0%) patients had isolated bone metastases, 8,294(15.2%) with isolated brain metastases, 5,677(10.4%) with isolated liver metastases, 9,430(17.2%) with isolate lung metastases, and 20,351(37.2%) with multiple organ metastases. The percentage of bone, brain, liver, lung and multisite metastases were 22.3%, 15.4%, 6.1%, 20.1% and 36.1% for non-small cell lung cancer (NSCLC), 12.5%, 14.3%, 24.3%, 7.9%, and 40.9% for small cell lung cancer (SCLC), the difference was statistical(P<0.001). In univariate and multivariable analysis, patients with liver metastases demonstrated a statistically significant disadvantage in cause-specific survival, while those with lung metastases have reduced risk of died of metastases when compared with brain metastases(P<0.001).The difference was consistent when make subgroup analysis in both NSCLC and SCLC(P<0.001).

Conclusions: In patients with distant metastases, those with liver metastases have the poorest survival, whereas those with lung metastases have the best survival. Therefore, we should take into consideration of such discrepancy when making treatment strategies.

Direct comparison between surface imaging and orthogonal radiographic imaging for SRS localization in phantom

Purpose

Surface imaging (SI) offers a nonionizing, near real time alternative to radiographic imaging for intrafraction radiosurgery localization. In this work, we systematically compared a commercial SI system vs a commercial room mounted x‐ray localization system in phantom.

Methods

An anthropomorphic head phantom with fiducial markers was imaged with linear accelerator on‐board x‐ray imaging, SI, and room mounted x‐ray imaging (RM) at ±45° and ±90° couch angles for three different head tilts and six different isocenters (72 total positions). The shifts generated by the three systems were compared as functions of couch angle, head tilt, and isocenter position with the on‐board imaging shifts used as ground truth. Two sample Kolmogorov–Smirnov tests were used to evaluate equivalence of the groups.

Results

The magnitude of the displacement vectors for RM minus on‐board imaging and SI minus on‐board imaging over all 72 phantom positions were 0.7 ± 0.3 mm for both cases. The RM and SI showed no significant difference based on couch angle or isocenter position. Both systems showed decreasing accuracy with increasing couch angle, but both systems agreed with ground truth to <=1.1 mm at all couch angles. The exaggerated chin‐up head orientation showed significantly different shifts for SI and RM based on increased variance in the SI measurements, although both had submillimeter accuracy on average. The standard deviation of the real time SI displacement vector was <0.06 mm over all measurements, during which the on‐board imaging panels partially blocked the lateral camera pods for half the time.

Conclusions

RM and SI showed similar accuracy over measurements at 72 different phantom positions. SI showed minimal performance loss with camera pods blocked. SI is a feasible option for intra‐fraction radiosurgery localization based on these phantom measurements.

ALK expression favorably impacts the prognosis of NRAS-mutated metastatic melanomas

Recent studies reported the expression of anaplastic lymphoma kinase (ALK) in malignant melanomas. The aim of this study was to investigate whether ALK expression is associated with specific clinical and molecular characteristics of melanoma metastases, and to evaluate its correlation with survival outcomes. Seventy-one patients with metastatic melanoma were investigated. Clinical features and survival outcomes were analyzed and correlated to ALK expression, as detected by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction, and to the mutational status of BRAF, KRAS, NRAS, and PIK3CA. No translocations or ALK alternative isoforms were identified. ALK expression was mainly detected in NRAS mutated metastatic lesions. Interestingly, among NRAS-mutated patients, ALK positive samples displayed a significantly more favorable outcome in terms of disease specific survival, as compared to ALK negative ones. In conclusion, we suggest that ALK positive/NRAS mutated metastases represent a specific subset of metastatic melanomas, associated with a better prognosis. Validation of these observations in larger cohorts could contribute to understand the molecular events cooperating to melanoma progression, in addition to open new perspectives in the clinical and therapeutic management of this subgroup of patients.