Radiotherapy for brain metastasis and long-term survival

Dissecting the MUC5AC/ANXA2 signaling axis: implications for brain metastasis in lung adenocarcinoma

Non-small cell lung carcinoma (NSCLC) exhibits a heightened propensity for brain metastasis, posing a significant clinical challenge. Mucin 5ac (MUC5AC) plays a pivotal role in the development of lung adenocarcinoma (LUAD); however, its role in causing brain metastases remains unknown. In this study, we aimed to investigate the contribution of MUC5AC to brain metastasis in patients with LUAD utilizing various brain metastasis models. Our findings revealed a substantial increase in the MUC5AC level in LUAD brain metastases (LUAD-BrM) samples and brain-tropic cell lines compared to primary samples or parental control cell lines. Intriguingly, depletion of MUC5AC in brain-tropic cells led to significant reductions in intracranial metastasis and tumor growth, and improved survival following intracardiac injection, in contrast to the observations in the control groups. Proteomic analysis revealed that mechanistically, MUC5AC depletion resulted in decreased expression of metastasis-associated molecules. There were increases in epithelial-to-mesenchymal transition, tumor invasiveness, and metastasis phenotypes in tumors with high MUC5AC expression. Furthermore, immunoprecipitation and proteomic analysis revealed a novel interaction of MUC5AC with Annexin A2 (ANXA2), which activated downstream matrix metalloproteases and facilitated extracellular matrix degradation to promote metastasis. Disrupting MUC5AC-ANXA2 signaling with a peptide inhibitor effectively abrogated the metastatic process. Additionally, treatment of tumor cells with an astrocyte-conditioned medium or the chemokine CCL2 resulted in upregulation of MUC5AC expression and enhanced brain colonization. In summary, our study demonstrates that the MUC5AC/ANXA2 signaling axis promotes brain metastasis, suggesting a potential therapeutic paradigm for LUAD patients with high MUC5AC expression.

Investigation of high-dose radiotherapy's effect on brain structure aggravated cognitive impairment and deteriorated patient psychological status in brain tumor treatment

This study aims to investigate the potential impact of high-dose radiotherapy (RT) on brain structure, cognitive impairment, and the psychological status of patients undergoing brain tumor treatment. We recruited and grouped 144 RT-treated patients with brain tumors into the Low dose group (N = 72) and the High dose group (N = 72) according to the RT dose applied. Patient data were collected by using the HADS and QLQ-BN20 system for subsequent analysis and comparison. Our analysis showed no significant correlation between the RT doses and the clinicopathological characteristics. We found that a high dose of RT could aggravate cognitive impairment and deteriorate patient role functioning, indicated by a higher MMSE and worsened role functioning in the High dose group. However, the depression status, social functioning, and global health status were comparable between the High dose group and the Low dose group at Month 0 and Month 1, while being worsened in the High dose group at Month 3, indicating the potential long-term deterioration of depression status in brain tumor patients induced by high-dose RT. By comparing patient data at Month 0, Month 1, Month 3, Month 6, and Month 9 after RT, we found that during RT treatment, RT at a high dose could aggravate cognitive impairment in the short term and lead to worsened patient role functioning, and even deteriorate the overall psychological health status of patients in the long term.

Prediction of the treatment response and local failure of patients with brain metastasis treated with stereotactic radiosurgery using machine learning: A systematic review and meta-analysis

BACKGROUND

Stereotactic radiosurgery (SRS) effectively treats brain metastases. It can provide local control, symptom relief, and improved survival rates, but it poses challenges in selecting optimal candidates, determining dose and fractionation, monitoring for toxicity, and integrating with other modalities. Practical tools to predict patient outcomes are also needed. Machine learning (ML) is currently used to predict treatment outcomes. We aim to investigate the accuracy of ML in predicting treatment response and local failure of brain metastasis treated with SRS.

METHODS

PubMed, Scopus, Web of Science (WoS), and Embase were searched until April 16th, which was repeated on October 17th, 2023 to find possible relevant papers. The study preparation adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The statistical analysis was performed by the MIDAS package of STATA v.17.

RESULTS

A total of 17 articles were reviewed, of which seven and eleven were related to the clinical use of ML in predicting local failure and treatment response. The ML algorithms showed sensitivity and specificity of 0.89 (95% CI: 0.84-0.93) and 0.87 (95% CI: 0.81-0.92) for predicting treatment response. The positive likelihood ratio was 7.1 (95% CI: 4.5-11.1), the negative likelihood ratio was 0.13 (95% CI: 0.08-0.19), and the diagnostic odds ratio was 56 (95% CI: 25-125). Moreover, the pooled estimates for sensitivity and specificity of ML algorithms for predicting local failure were 0.93 (95% CI: 0.76-0.98) and 0.80 (95% CI: 0.53-0.94). The positive likelihood ratio was 4.7 (95% CI: 1.6-14.0), the negative likelihood ratio was 0.09 (95% CI: 0.02-0.39), and the diagnostic odds ratio was 53 (95% CI: 5-606).

CONCLUSION

ML holds promise in predicting treatment response and local failure in brain metastasis patients receiving SRS. However, further studies and improvements in the treatment process can refine the models and effectively integrate them into clinical practice.

Treatment outcomes and prognostic factors in patients with driver mutant non-small cell lung cancer and de novo brain metastases

Central nervous system (CNS) metastases can be seen at a rate of 30% in advanced stages for patients with non-small cell lung cancer (NSCLC). Growing evidence indicates the predictive roles of driver gene mutations in the development of brain metastases (BM) in recent years, meaning that oncogene-driven NSCLC have a high incidence of BM at diagnosis. Today, 3rd generation targeted drugs with high intracranial efficacy, which can cross the blood-brain barrier, have made a positive contribution to survival for these patients with an increased propensity to BM. It is important to update the clinical and pathological factors reflected in the survival with real-life data. A multi-center, retrospective database of 306 patients diagnosed with driver mutant NSCLC and initially presented with BM between between November 2008 and September 2022 were analyzed. The median progression-free survival (mPFS) was 12.25 months (95% CI, 10-14.5). While 254 of the patients received tyrosine kinase inhibitor (TKI), 51 patients received chemotherapy as first line treatment. The median intracranial PFS (iPFS) was 18.5 months (95% CI, 14.8-22.2). The median overall survival (OS) was 29 months (95% CI, 25.2-33.0). It was found that having 3 or less BM and absence of extracranial metastases were significantly associated with better mOS and iPFS. The relationship between the size of BM and survival was found to be non-significant. Among patients with advanced NSCLC with de novo BM carrying a driver mutation, long-term progression-free and overall survival can be achieved with the advent of targeted agents with high CNS efficacy with more conservative and localized radiotherapy modalities.

A comparative study of whole brain radiotherapy with concomitant thalidomide versus whole brain radiotherapy alone in brain metastases

BACKGROUND

Brain metastasis increases morbidity and mortality in cancer patients. This study was undertaken to compare tumor response and treatment-related toxicities in patients treated with orally administered thalidomide concomitantly with whole brain radiotherapy to whole brain radiotherapy alone in brain metastases.

METHODS

This randomized control trial was conducted in radiation oncology department, RIMS among 42 patients of brain metastases distributed in two study arms during the period August 2018 to July 2020. Twenty patients in Arm-A received whole brain radiotherapy to a dose of 3,750 cGy in 15 fractions with concomitant oral thalidomide 200 mg daily in first week and 400 mg/day from second week of radiation onward till the end of radiotherapy, whereas 20 patients of Arm-B received whole brain radiation of 3,750 cGy in 15 fractions alone.

RESULTS

Patient characteristics were comparable. Median central nervous system progression free survival was 2 months for Arm-A and 3 months for Arm-B, whereas median overall survival study was 4 months for Arm-A and 3 months for Arm-B. Overall response rate in Arm-A was 56% and in Arm-B was 44%. Treatment-related toxicities were more in arm-A but were manageable.

CONCLUSION

Addition of thalidomide to whole brain radiotherapy makes no significant difference. Though not statistically significant, but still, Arm-A had shown some percentage benefits. Further studies with larger sample sizes should be done.

Cancer metastasis: Molecular mechanisms and clinical perspectives

Metastatic progression combined with non-responsiveness towards systemic therapy often shapes the course of disease for cancer patients and commonly determines its lethal outcome. The complex molecular events that promote metastasis are a combination of both, the acquired pro-metastatic properties of cancer cells and a metastasis-permissive or -supportive tumor micro-environment (TME). Yet, dissemination is a challenging process for cancer cells that requires a series of events to enable cancer cell survival and growth. Metastatic cancer cells have to initially detach themselves from primary tumors, overcome the challenges of their intravasal journey and colonize distant sites that are suited for their metastases. The implicated obstacles including anoikis and immune surveillance, can be overcome by intricate intra- and extracellular signaling pathways, which we will summarize and discuss in this review. Further, emerging modulators of metastasis, like the immune-microenvironment, microbiome, sublethal cell death engagement, or the nervous system will be integrated into the existing working model of metastasis.

Measurements of cerebral microvascular blood flow, oxygenation, and morphology in a mouse model of whole-brain irradiation-induced cognitive impairment by two-photon microscopy and optical coherence tomography: evidence for microvascular injury in the cerebral white matter

Whole-brain irradiation (WBI, also known as whole-brain radiation therapy) is a mainstay treatment modality for patients with multiple brain metastases. It is also used as a prophylactic treatment for microscopic tumors that cannot be detected by magnetic resonance imaging. WBI induces a progressive cognitive decline in ~ 50% of the patients surviving over 6 months, significantly compromising the quality of life. There is increasing preclinical evidence that radiation-induced injury to the cerebral microvasculature and accelerated neurovascular senescence plays a central role in this side effect of WBI. To better understand this side effect, male C57BL/6 mice were first subjected to a clinically relevant protocol of fractionated WBI (5 Gy, two doses per week, for 4 weeks). Nine months post the WBI treatment, we applied two-photon microscopy and Doppler optical coherence tomography to measure capillary red-blood-cell (RBC) flux, capillary morphology, and microvascular oxygen partial pressure (PO2) in the cerebral somatosensory cortex in the awake, head-restrained, WPI-treated mice and their age-matched controls, through a cover-glass-sealed chronic cranial window. Thanks to the extended penetration depth with the fluorophore - Alexa680, measurements of capillary blood flow properties (e.g., RBC flux, speed, and linear density) in the cerebral subcortical white matter were enabled. We found that the WBI-treated mice exhibited a significantly decreased capillary RBC flux in the white matter. WBI also caused a significant reduction in capillary diameter, as well as a large (although insignificant) reduction in segment density at the deeper cortical layers (e.g., 600-700 μm), while the other morphological properties (e.g., segment length and tortuosity) were not obviously affected. In addition, we found that PO2 measured in the arterioles and venules, as well as the calculated oxygen saturation and oxygen extraction fraction, were not obviously affected by WBI. Lastly, WBI was associated with a significant increase in the erythrocyte-associated transients of PO2, while the changes of other cerebral capillary PO2 properties (e.g., capillary mean-PO2, RBC-PO2, and InterRBC-PO2) were not significant. Collectively, our findings support the notion that WBI results in persistent cerebral white matter microvascular impairment, which likely contributes to the WBI-induced brain injury and cognitive decline. Further studies are warranted to assess the WBI-induced changes in brain tissue oxygenation and malfunction of the white matter microvasculature as well.

Normal Pressure Hydrocephalus Following Cranial Radiation: Identification of Shunting Responders

BACKGROUND

We examined cognitive, brain MRI, and lumbar infusion test (LIT) features to identify predictors of response to ventriculoperitoneal shunting (VPS) in long-term cancer survivors with suspected normal pressure hydrocephalus (NPH) following cranial radiotherapy (RT).

METHODS

Patients who completed cranial RT at least 2 years before with clinically suspected NPH and an Evans' index (EI) ≥ 0.30 underwent a cognitive and a cerebrospinal fluid (CSF) volumetric (MRI) analysis (n = 36). For those in whom VPS was placed (n = 14), we explored whether adding a CSF volumetric analysis to classical MRI and LIT (Tap Test) features would better identify VPS responders.

RESULTS

Nearly 80% exhibited cognitive impairment. The CSF volume at NPH diagnoses was significantly larger in the group of VPS responders (p = 0.04). The addition of CSF volume to NPH diagnoses increased accuracy to 93%, with a positive and negative predictive value of 91% and 100%, respectively.

CONCLUSION

The addition of a quantitative MRI analysis of CSF volume to classical MRI and LIT NPH criteria, along with a high clinical suspicion of NPH, may help to identify VPS responders, thus improving the clinical management and prognosis of long-term survivors.

Five-Fraction Stereotactic Radiotherapy for Brain Metastases-A Retrospective Analysis

PURPOSE

To determine the safety and outcome profile of five-fraction stereotactic radiotherapy (FSRT) for brain metastases (BM), either as a definitive or adjuvant treatment.

METHODS

We assessed clinical data of patients receiving five fractions of 7 Gy each (cumulative physical dose of 35 Gy) to BM or surgical cavities. The primary endpoints were toxicity and radiation necrosis (RN) rates. Secondary endpoints were 1-year cumulative local control rate (LCR) and estimated overall survival (OS).

RESULTS

A total of 36 eligible patients receiving FSRT to a total of 49 targets were identified and included. The median follow up was 9 (1.1-56.2) months. The median age was 64.5 (34-92) years, the median ECOG score was 1, and the median Diagnostic-Specific Graded Prognostic Assessment (DS-GPA) score was 2. Treatment was well tolerated and there were no grade 3 adverse events or higher. The overall RN rate was 14.3% and the median time to RN was 12.9 (1.8-23.8) months. RN occurrence was associated with immunotherapy, young age (≤45 years), and large PTV. The cumulative 1-year local control rate was 83.1% and the estimated median local progression free-survival was 18.8 months. The estimated median overall survival was 11 (1.1-56.2) months and significantly superior in those patients presenting with RN.

CONCLUSIONS

FSRT with 5 × 7 Gy represents a feasible, safe, and efficient fast track approach of intensified FSRT with acceptable LC and comparable RN rates for both the adjuvant and definitive RT settings.

Malignant Brain and Spinal Tumors Originating from Bone or Cartilage

Malignant bone tumors affecting the brain and spine are a rare and exceedingly difficult-to-treat group of diseases. Most commonly consisting of chordoma and chondrosarcoma, these tumors also include giant-cell tumors and osteosarcomas. This chapter will cover the background, epidemiology, genetics, molecular biology, histopathology, radiographic features, clinical manifestations, therapeutic approaches, and clinical management of each entity.

Correlation of EGFR mutation subtypes and survival in surgically treated brain metastasis from non-small-cell lung cancer

OBJECTIVE

Epidermal growth factor receptor (EGFR) mutation is a positive prognostic factor for survival in patients with non-small-cell lung cancer (NSCLC). In such patients, brain metastasis signifies negative outcomes. Patients with NSCLC brain metastasis that may benefit from neurosurgery is under investigation. We aim to investigate the impact of different mutation loci in surgically treated NSCLC brain metastasis patients.

METHODS

This retrospective cohort study included patients with NSCLC brain metastasis who underwent brain lesionectomy, followed by radiotherapy and chemotherapy or targeted therapy. Demographics and tumor characteristics were compared between the EGFR mutant type and wild type groups. Postoperative survival and risk factors were analyzed using log rank and Cox regression methods.

RESULTS

Overall, 101 patients were included, with 57 belonging to the EGFR mutant type group and 44 to the EGFR wild type group. The median postoperative survival was 17 months for the entire cohort, with the duration being 19 and 14 months for EGFR mutant type and wild type patients (p = 0.013), respectively. Multivariate analysis revealed that exon 19 del (p = 0.02) and a high Karnofsky Performance Scale score (p < 0.01) were independent positive prognostic factors to predict survival. The timing of development of the brain metastasis or the location of the intracranial metastasis was not associated with EGFR mutations.

CONCLUSION

EGFR mutations are associated with better survival outcomes in patients with NSCLC brain metastasis suitable for surgical treatment. This advantage was attributed to patients having a specific mutation of exon 19 deletion.

Diagnostic Value of 18 F-FACBC PET/MRI in Brain Metastases

PURPOSE

The study aims to evaluate whether combined 18 F-FACBC PET/MRI could provide additional diagnostic information compared with MRI alone in brain metastases.

PATIENTS AND METHODS

Eighteen patients with newly diagnosed or suspected recurrence of brain metastases received dynamic 18 F-FACBC PET/MRI. Lesion detection was evaluated on PET and MRI scans in 2 groups depending on prior stereotactic radiosurgery (SRS group) or not (no-SRS group). SUVs, time-activity curves, and volumetric analyses of the lesions were performed.

RESULTS

In the no-SRS group, 29/29 brain lesions were defined as "MRI positive." With PET, 19/29 lesions were detected and had high tumor-to-background ratios (TBRs) (D max MR , ≥7 mm; SUV max , 1.2-8.4; TBR, 3.9-25.9), whereas 10/29 lesions were undetected (D max MR , ≤8 mm; SUV max , 0.3-1.2; TBR, 1.0-2.7). In the SRS group, 4/6 lesions were defined as "MRI positive," whereas 2/6 lesions were defined as "MRI negative" indicative of radiation necrosis. All 6 lesions were detected with PET (D max MR , ≥15 mm; SUV max , 1.4-4.2; TBR, 3.6-12.6). PET volumes correlated and were comparable in size with contrast-enhanced MRI volumes but were only partially congruent (mean DSC, 0.66). All time-activity curves had an early peak, followed by a plateau or a decreasing slope.

CONCLUSIONS

18 F-FACBC PET demonstrated uptake in brain metastases from cancer of different origins (lung, gastrointestinal tract, breast, thyroid, and malignant melanoma). However, 18 F-FACBC PET/MRI did not improve detection of brain metastases compared with MRI but might detect tumor tissue beyond contrast enhancement on MRI. 18 F-FACBC PET should be further evaluated in recurrent brain metastases.

The Extent of Necrosis in Brain Metastases May Predict Subtypes of Primary Cancer and Overall Survival in Patients Receiving Craniotomy

Although necrosis is common in brain metastasis (BM), its biological and clinical significances remain unknown. We evaluated necrosis extent differences by primary cancer subtype and correlated BM necrosis to overall survival post-craniotomy. We analyzed 145 BMs of patients receiving craniotomy. Necrosis to tumor ratio (NTR) was measured. Patients were divided into two groups by NTR: BMs with sparse necrosis and with abundant necrosis. Clinical features were compared. To investigate factor relevance for BM necrosis, multivariate logistic regression, random forests, and gradient boosting machine analyses were performed. Kaplan−Meier analysis and log-rank tests were performed to evaluate the effect of BM necrosis on overall survival. Lung cancer was a more common origin for BMs with abundant necrosis (42/72, 58.33%) versus sparse necrosis (23/73, 31.51%, p < 0.01). Primary cancer subtype and tumor volume were the most relevant factors for BM necrosis (p < 0.01). BMs harboring moderately abundant necrosis showed longer survival, versus sparse or highly abundant necrosis (p = 0.04). Lung cancer BM may carry larger necrosis than BMs from other cancers. Further, moderately abundant necrosis in BM may predict a good prognosis post-craniotomy.

Metastases in the Pineal Region: A Systematic Review of Clinical Features, Management Strategies, and Survival Outcomes

BACKGROUND

Pineal region metastases are rare but often cause severe neurologic deficits. Surgical resection and chemoradiotherapy can provide therapeutic benefit. We investigated the literature to analyze clinical characteristics, management strategies, and survival of adult patients with pineal region metastases.

METHODS

PubMed, Embase, Scopus, and Cochrane were searched following the PRISMA guidelines, including studies reporting clinical outcomes of patients with pineal region metastases. Clinical presentation, management, and survival were reviewed.

RESULTS

We included 31 studies comprising 47 patients. Lung cancer (29.8%) and carcinomas of unknown origin (14.9%) were the most frequent primary tumors. In 48.9% of patients, symptomatic pineal metastases preceded primary tumor diagnosis. Headache (67.4%) and confusion (46.5%) were the most common symptoms. Parinaud syndrome (46.5%) and hydrocephalus (87.2%) were noted. Biopsy (65.9%) was preferred over resection (34.1%), and shunting strategies used were endoscopic third ventriculostomy (43.9%) and ventriculoperitoneal (26.8%). Eleven patients (32.3%) received adjuvant chemotherapy and 32 (68%) received radiotherapy. Posttreatment improvement in symptoms (56.6%) and hydrocephalus (80.5%) were noted. In patients who received adjuvant chemotherapy/radiotherapy, significant improvement in posttreatment performance status occurred with both biopsy (P < 0.001) and resection (P = 0.007). No survival differences were reported between surgery and biopsy (P = 0.912) or between complete and partial resection (P = 0.220). Overall survival was neither influenced by surgical approach (P = 0.157) nor by shunting strategy (P = 0.822). Mean follow-up was 8 months and median overall survival 3 months. Only 2 cases (4.8%) of pineal metastasis showed recurrence.

CONCLUSIONS

Pineal region metastases carry significant morbidity. Biopsy or surgical resection, combined with adjuvant chemotherapy/radiotherapy and/or shunting, may significantly improve performance status.

The effect of smoking on survival in lung carcinoma patients with brain metastasis: a systematic review and meta-analysis

The effects of smoking on survival in BM patients have yet to be reviewed and meta-analysed. However, previous studies have shown that smokers had a greater risk of dying from lung cancer compared to non-smokers. This meta-analysis, therefore, aimed to analyse the effects of cigarette smoking on overall survival (OS) and progression-free survival (PFS) in lung cancer BM patients. PubMed, Embase, Web of Science, Cochrane and Google Scholar were searched for comparative studies regarding the effects of smoking on incidence and survival in brain metastases patients up to December 2020. Three independent reviewers extracted overall survival (OS) and progression-free survival data (PFS). Random-effects models were used to pool multivariate-adjusted hazard ratios (HR). Out of 1890 studies, fifteen studies with a total of 2915 patients met our inclusion criteria. Amongst lung carcinoma BM patients, those who were smokers (ever or yes) had a worse overall survival (HR: 1.34, 95% CI 1.13, 1.60, I2: 72.1%, p-heterogeneity < 0.001) than those who were non-smokers (never or no). A subgroup analysis showed the association to remain significant in the ever/never subgroup (HR: 1.34, 95% CI 1.11, 1.63) but not in the yes/no smoking subgroup (HR: 1.30, 95% CI 0.44, 3.88). This difference between the two subgroups was not statistically significant (p = 0.91). Amongst lung carcinoma BM patients, smoking was associated with a worse OS and PFS. Future studies examining BMs should report survival data stratified by uniform smoking status definitions.

Orbital Metastases: A Systematic Review of Clinical Characteristics, Management Strategies, and Treatment Outcomes

BACKGROUND

Orbital metastases often lead to severe functional impairment. The role of resection, orbital exenteration, and complementary treatments is still debated. We systematically reviewed the literature on orbital metastases.

METHODS

PubMed, Scopus, Web-of-Science, and Cochrane were searched upon PRISMA guidelines to identify studies on orbital metastases. Clinical characteristics, management strategies, and survival were analyzed.

RESULTS

We included 262 studies comprising 873 patients. Median age was 59 years. The most frequent primary tumors were breast (36.3%), melanoma (10.1%), and prostate (8.5%) cancers, with median time interval of 12 months (range, 0-420). The most common symptoms were proptosis (52.3%) and relative-afferent-pupillary-defect (38.7%). Most metastases showed a diffuse location within the orbit (19%), with preferential infiltration of orbital soft tissues (40.2%). In 47 cases (5.4%), tumors extended intracranially. Incisional biopsy (63.7%) was preferred over fine-needle aspiration (10.2%), with partial resection (16.6%) preferred over complete (9.5%). Orbital exenteration was pursued in 26 patients (3%). A total of 305 patients (39.4%) received chemotherapy, and 506 (58%) received orbital radiotherapy. Post-treatment symptom improvement was significantly superior after resection (p = 0.005) and orbital radiotherapy (p = 0.032). Mean follow-up was 14.3 months, and median overall survival was 6 months. Fifteen cases (1.7%) demonstrated recurrence with median local control of six months. Overall survival was statistically increased in patients with breast cancer (p < 0.001) and in patients undergoing resection (p = 0.024) but was not correlated with orbital location (p = 0.174), intracranial extension (p = 0.073), biopsy approach (p = 0.344), extent-of-resection (p = 0.429), or orbital exenteration (p = 0.153).

CONCLUSIONS

Orbital metastases severely impair patient quality of life. Surgical resection safely provides symptom and survival benefit compared to biopsy, while orbital radiotherapy significantly improves symptoms compared to not receiving radiotherapy.