Growth rates of metastatic brain tumors in nonsmall cell lung cancer

GammaTile® (GT) as a brachytherapy platform for rapidly growing brain metastasis

Background

A subset of brain metastasis (BM) shows rapid recurrence post-initial resection or aggressive tumor growth between interval scans. Here we provide a pilot experience in the treatment of these BM with GammaTile® (GT), a collagen tile-embedded Cesium 131 (¹³¹Cs) brachytherapy platform.

Methods

We identified ten consecutive patients (2019-2023) with BM that showed either (1) symptomatic recurrence while awaiting post-resection radiosurgery or (2) enlarged by >25% of tumor volume on serial imaging and underwent surgical resection followed by GT placement. Procedural complication, 30-day readmission, local control, and overall survival were assessed.

Results

For this cohort of ten BM patients, 3 patients suffered tumor progression while awaiting radiosurgery and 7 showed >25% tumor growth prior to surgery and GT placement. There were no procedural complications or 30-day mortality. All patients were discharged home, with a median hospital stay of 2 days (range: 1-9 days). 4/10 patients experienced symptomatic improvement while the remaining patients showed stable neurologic conditions. With a median follow-up of 186 days (6.2 months, range: 69-452 days), no local recurrence was detected. The median overall survival (mOS) for the newly diagnosed BM was 265 days from the time of GT placement. No patients suffered from adverse radiation effects.

Conclusion

Our pilot experience suggests that GT offers favorable local control and safety profile in patients suffering from brain metastases that exhibit aggressive growth patterns and support the future investigation of this treatment paradigm.

Cancer progression and the invisible phase of metastatic colonization

Metastatic dissemination occurs very early in the malignant progression of a cancer but the clinical manifestation of metastases often takes years. In recent decades, 5-year survival of patients with many solid cancers has increased due to earlier detection, local disease control and adjuvant therapies. As a consequence, we are confronted with an increase in late relapses as more antiproliferative cancer therapies prolong disease courses, raising questions about how cancer cells survive, evolve or stop growing and finally expand during periods of clinical latency. I argue here that the understanding of early metastasis formation, particularly of the currently invisible phase of metastatic colonization, will be essential for the next stage in adjuvant therapy development that reliably prevents metachronous metastasis.

Evaluating the natural growth rate of metastatic cancer to the brain

BACKGROUND

Brain metastases are becoming increasingly more prevalent as cancer patients survive longer with both improved local and systemic therapy. Little is known, however, of the natural growth rates of brain metastases. This investigation aims to ascertain this growth rate of these lesions before the initiation of any CNS- directed therapy.

METHODS

A total of 700 patients were screened, identifying 18 cancer patients (13 breast and 5 lung) with 29 brain metastases that were serially imaged from 2011 to 2017 before treatment for their intracranial metastases. Growth rates were measured by contouring lesions serially across at least two MRI studies in iPlan software by independent raters. These values were then compared between primary (breast and lung) cancer cohorts.

RESULTS

The mean age at diagnosis was 53 and 95% were female. The interval between primary cancer diagnosis and brain metastases was 4.6 years and 1.2 years in the breast and lung cancer groups, respectively. Of the breast and lung cancer patients, 23% and 40% were deceased, with respective 5.08 cm3 and 2.44 cm3 initial tumor volumes. The average growth rate of lung and breast tumors was 0.018 and 0.040 cm3/day, respectively, with deceased patients having larger and faster growing tumors. Breast and lung metastases grew 2.39% and 1.14% of their total volumes daily and doubling times were 86 and 139 days, respectively.

CONCLUSION

This investigation provides a unique perspective into the biological growth of metastatic brain lesions. It is our hope that this study guides timing of treatment and informs both clinicians and patients of tumor growth kinetics before initiating treatment for intracranial metastases.

Clinical course of asymptomatic small enhancing brain nodules in patients with nonsmall cell lung cancer: do we have to follow them up?

AIMS

Brain magnetic resonance imaging (MRI) is recommended during the initial work-up for nonsmall cell lung cancer (NSCLC). Although small enhancing brain nodules not radiologically confirmed as metastatic lesions have often been detected, their clinical course has not been well studied.

METHODS

This nested case-control study included NSCLC patients who had small enhancing brain nodules detected by serial brain MRIs from January 2014 through December 2018 at a tertiary university hospital. Small enhancing brain nodules were defined as round enhancing nodules of ≤10 mm diameter without oedema in thin-section (1 mm) contrast MRIs. The incidence, natural course and risk factors of growing nodules were evaluated.

RESULTS

A total of 171 small enhancing brain nodules in 123 patients were observed over an average of 22.1 months. The incidence of nodule growth was 49.1% with mean growth rate of 11 mm·year-1. We found that 25.0% of the growing nodules contributed to clinical upstaging compared to the initial stage. Cerebral events were more common in growing nodules; therefore, local therapy was performed more often. However, there was no difference in the cerebral event-related mortality. Nodule growth was more frequent in younger individuals, multiple nodules, advanced disease, poorly differentiated carcinoma, rim enhancement and larger initial size. In multivariable analysis, predictors of growth were N stage ≥1, existence of epidermal growth factor receptor mutation and larger initial size.

CONCLUSION

Considering the clinical course of small enhancing brain nodules, more intensive evaluation is required for early detection and pre-emptive intervention when accompanied by risk factors.

Cancer recurrence times from a branching process model

As cancer advances, cells often spread from the primary tumor to other parts of the body and form metastases. This is the main cause of cancer related mortality. Here we investigate a conceptually simple model of metastasis formation where metastatic lesions are initiated at a rate which depends on the size of the primary tumor. The evolution of each metastasis is described as an independent branching process. We assume that the primary tumor is resected at a given size and study the earliest time at which any metastasis reaches a minimal detectable size. The parameters of our model are estimated independently for breast, colorectal, headneck, lung and prostate cancers. We use these estimates to compare predictions from our model with values reported in clinical literature. For some cancer types, we find a remarkably wide range of resection sizes such that metastases are very likely to be present, but none of them are detectable. Our model predicts that only very early resections can prevent recurrence, and that small delays in the time of surgery can significantly increase the recurrence probability.

Rapid growth of metastatic brain tumor from gastric undifferentiated pleomorphic sarcoma: A case report

Background:

Brain metastasis from undifferentiated pleomorphic sarcoma (UPS) is a rare occurrence, and its clinical course is little known. In this report, we investigate a case of a rapidly growing brain metastasis from gastric UPS.

Case Description:

An 82-year-old man with a known gastric tumor, pathologically compatible with UPS, underwent partial gastrectomy at an outside facility. 3 months later, a 4-cm brain tumor was detected, which was completely resected. The patient was diagnosed with metastatic tumor from previously treated gastric UPS. Within 2 months of the initial resection, a large recurrent mass was detected in the same location, which was again removed. Although the patient underwent radiotherapy and chemotherapy for other metastatic tumors, he died 5 months after the second craniotomy.

Conclusions:

Brain metastasis from gastric UPS is rare and difficult to treat. Although aggressive treatment, such as surgical intervention, may improve patient survival in some cases, the timing of treatment is challenging because cerebral metastasis rapidly grows and and patients frequently suffer from synchronous systematic metastasis. Therefore, early detection and close follow-up of rapidly progressing brain metastasis are important to improve treatment outcomes.

Probabilistic independent component analysis of dynamic susceptibility contrast perfusion MRI in metastatic brain tumors

PURPOSE

To identify clinically relevant magnetic resonance imaging (MRI) features of different types of metastatic brain lesions, including standard anatomical, diffusion weighted imaging (DWI) and dynamic susceptibility contrast (DSC) perfusion MRI.

METHODS

MRI imaging was retrospectively assessed on one hundred and fourteen (N = 114) brain metastases including breast (n = 27), non-small cell lung cancer (NSCLC, n = 43) and 'other' primary tumors (n = 44). Based on 114 patient's MRI scans, a total of 346 individual contrast enhancing tumors were manually segmented. In addition to tumor volume, apparent diffusion coefficients (ADC) and relative cerebral blood volume (rCBV) measurements, an independent component analysis (ICA) was performed with raw DSC data in order to assess arterio-venous components and the volume of overlap (AVOL) relative to tumor volume, as well as time to peak (TTP) of T₂* signal from each component.

RESULTS

Results suggests non-breast or non-NSCLC ('other') tumors had higher volume compare to breast and NSCLC patients (p = 0.0056 and p = 0.0003, respectively). No differences in median ADC or rCBV were observed across tumor types; however, breast and NSCLC tumors had a significantly higher "arterial" proportion of the tumor volume as indicated by ICA (p = 0.0062 and p = 0.0018, respectively), while a higher "venous" proportion were prominent in breast tumors compared with NSCLC (p = 0.0027) and 'other' lesions (p = 0.0011). The AVOL component was positively related to rCBV in all groups, but no correlation was found for arterial and venous components with respect to rCBV values. Median time to peak of arterial and venous components were 8.4 s and 12.6 s, respectively (p < 0.0001). No difference was found in arterial or venous TTP across groups.

CONCLUSIONS

Advanced ICA-derived component analysis demonstrates perfusion differences between metastatic brain tumor types that were not observable with classical ADC and rCBV measurements. These results highlight the complex relationship between brain tumor vasculature characteristics and the site of primary tumor diagnosis.

Brain metastases in ALK-positive NSCLC - time to adjust current treatment algorithms

The progress in molecular biology has revolutionized systemic treatment of advanced non-small-cell lung cancer (NSCLC) from conventional chemotherapy to a treatment stratified by histology and genetic aberrations. Tumors harboring a translocation of the anaplastic-lymphoma-kinase (ALK) gene constitute a distinct genetic and clinico-pathologic NSCLC subtype with patients with ALK-positive disease being at a higher risk for developing brain metastases. Due to the introduction of effective targeted therapy with ALK-inhibitors, today, patients with advanced ALK-positive NSCLC achieve high overall response rates and remain progression-free for long time intervals. Moreover, ALK-inhibitors seem to exhibit efficacy in the treatment of brain metastases. In the light of this, it needs to be discussed how treatment algorithms for managing patients with brain metastases should be modified. By integrating systemic ALK-inhibitor therapy, radiotherapy, in particular whole brain radiotherapy might be postponed deferring potential long-term impairment by neurocognitive deficits to a later time point in the course of the disease. An early treatment of asymptomatic brain metastases might offer patients a longer time without impairment of cerebral symptoms or radiotherapeutic interventions. Based on an updated extensive review of the literature this article provides an overview on the epidemiology and the treatment of patients’ brain metastases. It describes the specifics of ALK-positive disease and proposes an algorithm for the treatment of patients with advanced ALK-positive NSCLC and brain metastases.

Brain imaging before primary lung cancer resection: a controversial topic

Objective

International and national recommendations for brain imaging in patients planned to undergo potentially curative resection of non-small-cell lung cancer (NSCLC) are variably implemented throughout the United Kingdom [Hudson BJ, Crawford MB, and Curtin J et al (2015) Brain imaging in lung cancer patients without symptoms of brain metastases: a national survey of current practice in EnglandClin Radiol https://doi.org/10.1016/j.crad.2015.02.007]. However, the recommendations are not based on high-quality evidence and do not take into account cost implications and local resources. Our aim was to determine local practice based on historic outcomes in this patient cohort.

Methods

This retrospective study took place in a regional thoracic surgical centre in the United Kingdom. Pathology records for all patients who had undergone lung resection with curative intent during the time period January 2012–December 2014 were analysed in October 2015. Electronic pathology and radiology reports were accessed for each patient and data collected about their histological findings, TNM stage, resection margins, and the presence of brain metastases on either pre-operative or post-operative imaging. From the dates given on imaging, we calculated the number of days post-resection that the brain metastases were detected.

Results

585 patients were identified who had undergone resection of their lung cancer. Of these, 471 had accessible electronic radiology records to assess for the radiological evidence of brain metastases. When their electronic records were evaluated, 25/471 (5.3%) patients had radiological evidence of brain metastasis. Of these, five patients had been diagnosed with a brain metastasis at initial presentation and had undergone primary resection of the brain metastasis followed by resection of the lung primary. One patient had been diagnosed with both a primary lung and a primary bowel adenocarcinoma; on review of the case, it was felt that the brain metastasis was more likely to have originated from the bowel cancer. One had been clinically diagnosed with a cerebral abscess while the radiology had been reported as showing a metastatic deposit. Of the remaining 18/471 (3.8%) patients who presented with brain metastases after their surgical resection, 12 patients had adenocarcinoma, four patients had squamous cell carcinoma, one had basaloid, and one had large-cell neuroendocrine. The mean number of days post-resection that the brain metastases were identified was 371 days, range 14–1032 days, median 295 days (date of metastases not available for two patients).

Conclusion

The rate of brain metastases identified in this study was similar to previous studies. This would suggest that preoperative staging of the central nervous system may change the management pathway in a small group of patients. However, for this group of patients, the change would be significant either sparing them non-curative surgery or allowing aggressive management of oligometastatic disease. Therefore, we would recommend pre-operative brain imaging with MRI for all patients undergoing potentially curative lung resection.

The Efficacy of Postoperative Chemotherapy for Patients with Metastatic Brain Tumors from Non-Small Cell Lung Cancer

BACKGROUND

The purpose of this study is to evaluate the effect of postoperative chemotherapy on recurrence and survival in patients after resection of metastatic brain tumors from non-small cell lung cancers.

METHODS

Patients who went through resection of a single metastatic brain tumor from non-small cell lung cancer from July 2001 to December 2012 were reviewed. Those selected were 77 patients who survived more than 3 months after surgery were selected. Among them, 44 patients received various postoperative systemic chemotherapies, 33 patients received postoperative adjuvant whole brain radiotherapy (WBRT). Local/distant recurrence rate, local/distant recurrence free survival, disease free survival (DFS), and overall survival were compared between the two groups.

RESULTS

Among the 77 patients, there were 19 (24.7%) local recurrences. Local recurrence occurred in 7 (21.2%) of 33 patients in the adjuvant radiotherapy (RT) group and in 12 (27.3%) of the 44 patients in the chemotherapy group (p=0.542). Among the 77 patients, there were 34 (44.1%) distant recurrences. Distant recurrence occurred in 7 (21.2%) of the 33 patients in the adjuvant RT group and in 27 (61.4%) of the 44 patients in the chemotherapy group (p<0.0005). Patients' survival in terms of local recurrence free survival, distant recurrence free survival, DFS, and overall survival was not shown to be statistically different between the two groups before and after adjusting for covariates.

CONCLUSION

There was no significant difference observed between postoperative adjuvant chemotherapy and adjuvant WBRT in terms of patients' survival. Postoperative chemotherapy is more feasible and may be an appropriate option for simultaneous control of both primary and metastatic lesions.

Brain metastases following radical surgical treatment of non-small cell lung cancer: is preoperative brain imaging important?

OBJECTIVES

There is a lack of good quality evidence or a clear consensus of opinion internationally regarding who should receive preoperative imaging of the brain prior to radical treatment for non-small cell lung cancer (NSCLC). We aimed to establish the proportion of patients who developed brain metastases following curative surgery and to estimate how many could have been detected by preoperative magnetic resonance imaging (MR).

METHODS

We performed a retrospective analysis of 646 patients who underwent surgery for lung cancer with curative intent at a regional thoracic surgical centre in the United Kingdom. We identified those who developed brain metastases in the postoperative period and, by using volume doubling times, estimated the size of the metastasis at the time of surgery. We then determined the proportion of metastases that would have been seen on preoperative MR brain at detection thresholds of 2 and 5mm diameter.

RESULTS

There was a 6.3% incidence of postoperative brain metastases, with the majority occurring within 12 months of surgery. Those who developed metastases were more likely to have adenocarcinoma and the majority had early stage malignancy (73% stage I or stage II). We estimate that 71% of those who developed cerebral metastases might have been detected had they undergone MR brain as part of their staging (4.4% of all patients).

CONCLUSION

Based on our findings we suggest that, in addition to standard staging investigations, patients have brain imaging (MR or equivalent) prior to curative surgery in NSCLC regardless of preoperative stage.

Growth rate of newly developed metastatic brain tumors after thoracotomy in patients with non-small cell lung cancer

Among 1372 lung cancer patients without brain metastasis that underwent resection of lung cancer at our center from 2001 to 2007, brain metastases developed in 72 patients (5.2%) during their hospital course. We hypothesized that there were micro-metastases in the brain at the time of lung surgery in these patients, even though there were no detectable brain metastases on the MRI. The purpose of this study was to evaluate the growth rates of metastatic brain tumors in this unique subset of patients, and to compare the findings with our previous study that calculated the growth rate of brain metastases during chemotherapy. Among 72 patients, 23 with cystic or hemorrhagic metastases were excluded. Seventy-six metastatic brain tumors in 49 patients were reviewed. Twenty-five patients underwent adjuvant or neoadjuvant chemotherapy; however, for the rest of the patients, chemotherapy was not added after lung cancer surgery. The tumor volume was determined using V-works software (v. 4.0) (Cybermed, Seoul, Korea) and T1 gadolinium enhanced MR images. The overall median tumor growth rate was 11.7 mm³/day (interquartile range, 4.9-26.8). There were no statistically significant differences in the tumor growth among the lung cancer stages and the growth rate was similar regardless of the use of chemotherapy. The growth rate reported in this study shows consistency with that of our previous report (12.1 mm³/day). These findings may help optimize patient management during follow up.

Bevacizumab safety in patients with central nervous system metastases

PURPOSE

Patients with central nervous system (CNS) metastases were excluded from bevacizumab trials following a case of fatal cerebral hemorrhage in a patient with hepatocellular carcinoma in 1997. Safety information for bevacizumab-treated patients with CNS metastases was reviewed to determine whether general exclusion of these patients from bevacizumab treatment is still justified.

EXPERIMENTAL DESIGN

A retrospective exploratory analysis was conducted using datasets from 13 randomized controlled phase II/III trials (dataset A), two open-label single-arm safety trials (dataset B), and two prospective studies including patients with treated CNS metastases (dataset C). In datasets A and B, known CNS metastasis was an exclusion criterion; patients with CNS metastasis had unrecognized CNS metastases at study entry or developed them during the trial. All reported cerebral hemorrhage grades in patients with CNS metastases were quantified.

RESULTS

In dataset A, occult brain metastases were identified in 187 of 8,443 patients (91 in bevacizumab arms and 96 in non-bevacizumab arms). Three bevacizumab-treated patients (3.3%) developed grade 4 cerebral hemorrhage, whereas one control-arm patient (1.0%) developed grade 5 cerebral hemorrhage. In dataset B, 321 of 4,382 patients had initially occult CNS metastases, in whom two grade 1 and one grade 3 cerebral hemorrhage (0.9%) were reported. In 131 patients with treated CNS metastases in dataset C, one bevacizumab-treated patient (0.8%) developed grade 2 cerebral hemorrhage.

CONCLUSIONS

In this selected population, patients with CNS metastases are at similar risk of developing cerebral hemorrhage, independent of bevacizumab therapy. Consequently, such patients with CNS metastases from advanced/metastatic breast cancer, non-small cell lung carcinoma, and renal and colorectal cancer should not be generally excluded from bevacizumab therapy or clinical trials.