Detection of brain metastases from small cell lung cancer: consequences of changing imaging techniques (CT versus MRI)

Brain metastasis burden and management in patients with small cell lung cancer in Canada: a retrospective, population-based cohort study

Background

Patients with small cell lung cancer (SCLC) have historically been characterised by poor overall survival (OS) and high risk for brain metastasis (BM), but large-scale real-world evidence on clinical presentation and treatment in this population is lacking. Our aim was to describe the clinical characteristics and outcomes of patients with SCLC and BM in Ontario, Canada.

Methods

This population-based, retrospective cohort study included all patients in Ontario, Canada, who were diagnosed with SCLC between April 1, 2010, and March 31, 2018. Data were analysed between June 2, 2022, and December 20, 2023. Patients with second cancer diagnosis were excluded. Patients were identified and data retrieved from the Institute for Clinical Evaluative Sciences (ICES) databases. Kaplan-Meier and multivariable Cox regression analyses were performed to compare OS between patient cohorts stratified by disease stage, BM diagnosis, and intracranial treatment modality. Propensity score-matching based on age, disease stage, time to BM, and receipt of chemotherapy was performed to compare OS between intracranial treatment modalities.

Findings

8705 patients were included (male: 4433, female: 4272). Median age at diagnosis was 68 years (interquartile range, IQR, 61-75). Median OS of all patients was 7.46 months (95% confidence interval, CI, 7.23-7.69). 32% (n = 2686) of patients developed BM (synchronous, 43.7%; asynchronous, 56.3%) with median OS of 9.76 months (95% CI, 9.36-10.22). 102 (4%), 1654 (62%), and 930 (35%) patients received stereotactic radiosurgery (SRS), whole brain radiation therapy (WBRT), or no treatment, respectively, for their BM in the first-line setting or after prophylactic cranial irradiation (PCI). In propensity score-matched analyses, OS from time of BM diagnosis was non-inferior between SRS- and WBRT-treated cohorts among patients who did not receive PCI (hazard ratio, HR, 0.68, 95% CI, 0.44-1.06, p = 0.091, n = 86) and in favour of SRS for those who received PCI prior to BM development (HR, 0.47, 95% CI, 0.31-0.72, p = 0.0042, n = 112).

Interpretation

OS for patients with SCLC remains poor, and many patients present with BM. With careful selection, patients with SCLC and BM may benefit from SRS treatment. Future research should incorporate information on burden of intracranial disease and novel immunotherapies.

Funding

None.

Effects of brain radiotherapy strategies on survival in the era of MRI for patients with limited stage small cell lung cancer

BACKGROUND AND PURPOSE

In the context of the widespread availability of magnetic resonance imaging (MRI) and aggressive salvage irradiation techniques, there has been controversy surrounding the use of prophylactic cranial irradiation (PCI) for small-cell lung cancer (SCLC) patients. This study aimed to explore whether regular brain MRI plus salvage brain irradiation (SBI) is not inferior to PCI in patients with limited-stage SCLC (LS-SCLC).

METHODS

This real-world multicenter study, which was conducted between January 2014 and September 2020 at three general hospitals, involved patients with LS-SCLC who had a good response to initial chemoradiotherapy and no brain metastasis confirmed by MRI. Overall survival (OS) was compared between patients who did not receive PCI for various reasons but chose regular MRI surveillance and followed salvage brain irradiation (SBI) when brain metastasis was detected and patients who received PCI.

RESULTS

120 patients met the inclusion criteria. 55 patients received regular brain MRI plus SBI (SBI group) and 65 patients received PCI (PCI group). There was no statistically significant difference in median OS between the two groups (27.14 versus 33.00 months; P = 0.18). In the SBI group, 32 patients underwent whole brain radiotherapy and 23 patients underwent whole brain radiotherapy + simultaneous integrated boost. On multivariate analysis, only extracranial metastasis was independently associated with poor OS in the SBI group.

CONCLUSION

The results of this real-world study showed that MRI surveillance plus SBI is not inferior to PCI in OS for LS-SCLC patients who had a good response to initial chemoradiotherapy.

The changing landscape of small cell lung cancer

BACKGROUND

Small-cell lung cancer (SCLC) is characterized by rapid proliferation and early dissemination. The objective of this study was to examine the demographic trends and outcomes in SCLC.

METHODS

The authors queried the National Cancer Institute's Surveillance, Epidemiology, and End Results database to assess the trends in incidence, demographics, staging, and survival for SCLC from 1975 to 2019. Trends were determined using joinpoint analysis according to the year of diagnosis.

RESULTS

Among the 530,198 patients with lung cancer, there were 73,362 (13.8%) with SCLC. The incidence per 100,000 population peaked at 15.3 in 1986 followed by a decline to 6.5 in 2019. The percentage of SCLC among all lung tumors increased from 13.3% in 1975 to a peak of 17.5% in 1986, declining to 11.1% by 2019. There was an increased median age at diagnosis from 63 to 69 years and an increased percentage of women from 31.4% to 51.2%. The percentage of stage IV increased from 58.6% in 1988 to 70.8% in 2010, without further increase. The most common sites of metastasis at diagnosis were mediastinal lymph nodes (75.3%) liver (31.6%), bone (23.7%), and brain (16.4%). The 1-year and 5-year overall survival rate increased from 23% and 3.6%, respectively, in 1975-1979 to 30.8% and 6.8%, respectively, in 2010-2019.

CONCLUSIONS

The incidence of SCLC peaked in 1988 followed by a gradual decline. Other notable changes include increased median age at diagnosis, the percentage of women, and the percentage of stage IV at diagnosis. The improvement in 5-year overall survival has been statistically significant but clinically modest.

Rational and design of prophylactic cranial irradiation (PCI) and brain MRI surveillance versus brain MRI surveillance alone in patients with limited-stage small cell lung cancer achieving complete remission (CR) of tumor after chemoradiotherapy: a multicenter prospective randomized study

BACKGROUND

Prophylactic cranial irradiation (PCI) is part of standard care in limited-stage small cell lung cancer (SCLC) at present. As evidence from retrospective studies increases, the benefits of PCI for limited-stage SCLC are being challenged.

METHODS

A multicenter, prospective, randomized controlled study was designed. The key inclusion criteria were: histologically or cytologically confirmed small cell carcinoma, age ≥ 18 years, KPS ≥ 80, limited-stage is defined as tumor confined to one side of the chest including ipsilateral hilar, bilateral mediastinum and supraclavicular lymph nodes, patients have received definitive thoracic radiotherapy (regardless of the dose-fractionation of radiotherapy used) and chemotherapy, evaluated as complete remission (CR) of tumor 4-6 weeks after the completion of chemo-radiotherapy. Eligible patients will be randomly assigned to two arms: (1) PCI and brain MRI surveillance arm, receiving PCI (2.5 Gy qd to a total dose of 25 Gy in two weeks) followed by brain MRI surveillance once every three months for two years; (2) brain MRI surveillance alone arm, undergoing brain MRI surveillance once every three months for two years. The primary objective is to compare the 2-year brain metastasis-free survival (BMFS) rates between the two arms. Secondary objectives include 2-year overall survival (OS) rates, intra-cranial failure patterns, 2-year progression-free survival rates and neurotoxicity. In case of brain metastasis (BM) detect during follow-up, stereotactic radiosurgery (SRS) will be recommended if patients meet the eligibility criteria.

DISCUSSION

Based on our post-hoc analysis of a prospective study, we hypothesize that in limited-stage SCLC patients with CR after definitive chemoradiotherapy, and ruling out of BM by MRI, it would be feasible to use brain MRI surveillance and omit PCI in these patients. If BM is detected during follow-up, treatment with SRS or whole brain radiotherapy does not appear to have a detrimental effect on OS. Additionally, this approach may reduce potential neurotoxicity associated with PCI.

PD-L1 inhibitors combined with whole brain radiotherapy in patients with small cell lung cancer brain metastases: Real-world evidence

BACKGROUND

Numerous studies have demonstrated that brain metastases patients may benefit from intracranial radiotherapy combined with immune checkpoint inhibitors (ICIs). However, it is unclear whether this treatment is effective for patients with small cell lung cancer brain metastases (SCLC-BMs).

METHODS

We conducted a retrospective study by analyzing medical records of patients with SCLC-BMs from January 1, 2017 to June 1, 2022. Data related to median overall survival (mOS), median progression-free survival (mPFS), and intracranial progression-free survival (iPFS) were analyzed.

RESULTS

A total of 109 patients were enrolled, of which 60 received WBRT and 49 received WBRT-ICI. Compared to the WBRT alone cohort, the WBRT-ICI cohort showed longer mOS (20.4 months vs. 29.3 months, p = 0.021), mPFS (7.9 months vs. 15.1 months, p < 0.001), and iPFS (8.3 months vs. 16.5 months, p < 0.001). Furthermore, WBRT-ICI cohort had a better response rate for both BMs. (p = 0.035) and extracranial diseases (p < 0.001) compared to those receiving WBRT alone. Notably, the use of WBRT before ICI was associated with longer mOS compared to the use of WBRT after ICI (23.3 months for the ICI-WBRT group vs. 34.8 months for the WBRT-ICI group, p = 0.020).

CONCLUSION

Our results indicated that WBRT combined with immunotherapy improved survival in SCLC-BMs patients compared to WBRT monotherapy. Administering WBRT prior to ICI treatment is associated with improved survival outcomes compared to WBRT following ICI treatment, for patients with SCLC-BMs. These findings highlight the significance of conducting further prospective researches on combination strategies of intracranial radiotherapy and ICI in SCLC-BMs patients.

Using MRI radiomics to predict the efficacy of immunotherapy for brain metastasis in patients with small cell lung cancer

BACKGROUND

Brain metastases (BMs) are common in small cell lung cancer (SCLC), and the efficacy of immune checkpoint inhibitors (ICIs) in these patients is uncertain. In this study we aimed to develop and validate a radiomics nomogram based on magnetic resonance imaging (MRI) for intracranial efficacy prediction of ICIs in patients with BMs from SCLC.

METHODS

The training and validation cohorts consisted of 101 patients from two centers. The interclass correlation coefficient (ICC), logistic univariate regression analysis, and random forest were applied to select the radiomic features, generating the radiomics score (Rad-score) through the formula. Using multivariable logistic regression analysis, a nomogram was created by the combined model. The discrimination, calibration, and clinical utility were used to assess the performance of the nomogram. Kaplan-Meier curves were plotted based on the nomogram scores.

RESULTS

Ten radiomic features were selected for calculating the Rad-score as they could differentiate the intracranial efficacy in the training (area under the curve [AUC], 0.759) and the validation cohort (AUC, 0.667). A nomogram was created by combining Rad-score, treatment lines, and neutrophil-to-lymphocyte ratio (NLR). The training cohort obtained an AUC of 0.878 for the combined model, verified in the validation cohort (AUC = 0.875). Kaplan-Meier analyses showed the nomogram was associated with progression-free survival (PFS) (p = 0.0152) and intracranial progression-free survival (iPFS) (p = 0.0052) but not overall survival (OS) (p = 0.4894).

CONCLUSION

A radiomics nomogram model for predicting the intracranial efficacy of ICIs in SCLC patients with BMs can provide suggestions for exploring individual-based treatments for patients.

Construction of brain metastasis prediction model in limited stage small cell lung cancer patients without prophylactic cranial irradiation

INTRODUCTION

Small cell lung cancer (SCLC) is a highly aggressive lung cancer variant known for its elevated risk of brain metastases (BM). While earlier meta-analyses supported the use of prophylactic cranial irradiation (PCI) to reduce BM incidence and enhance overall survival, modern MRI capabilities raise questions about PCI's universal benefit for limited-stage SCLC (LS-SCLC) patients. As a response, we have created a predictive model for BM, aiming to identify low-risk individuals who may not require PCI.

METHODS

A total of 194 LS-SCLC patients without PCI treated between 2009 and 2021 were included. We conducted both univariate and multivariate analyses to pinpoint the factors associated with the development of BM. A nomogram for predicting the 2- and 3-year probabilities of BM was then constructed.

RESULTS

Univariate and multivariate analyses revealed several significant independent risk factors for the development of BM. These factors include TNM stage, the number of chemotherapy (ChT) cycles, Ki-67 expression level, pretreatment serum lactate dehydrogenase (LDH) levels, and haemoglobin (HGB) levels. These findings underscore their respective roles as independent predictors of BM. Based on the results of the final multivariable analysis, a nomogram model was created. In the training cohort, the nomogram yielded an area under the receiver operating characteristic curve (AUC) of 0.870 at 2 years and 0.828 at 3 years. In the validation cohort, the AUC values were 0.897 at 2 years and 0.789 at 3 years. The calibration curve demonstrated good agreement between the predicted and observed probabilities of BM.

CONCLUSIONS

A novel nomogram has been developed to forecast the likelihood of BM in patients diagnosed with LS-SCLC. This tool holds the potential to assist healthcare professionals in formulating more informed and tailored treatment plans.

Re-examining prophylactic cranial irradiation in small cell lung cancer: a systematic review and meta-analysis

Background

Patients with small cell lung cancer (SCLC) are at high risk for brain metastases. Prophylactic cranial irradiation (PCI) is recommended in this population to reduce the incidence of brain metastases and prolong survival. We aimed to assesses the efficacy of PCI in this population in the era of routine brain imaging. To our knowledge, this is the first systematic review and meta-analysis to examine the use among patients who were radiographically confirmed not to have brain metastases after completion of first-line therapy.

Methods

In this systematic review and meta-analysis, cohort studies and controlled trials reporting on the use of PCI for patients SCLC were identified in EMBASE, MEDLINE, CENTRAL, and grey literature sources. The literature search was conducted on November 12, 2023. Summary data were extracted. Random-effects meta-analyses pooled hazard ratios (HR) for the primary outcome of overall survival between PCI and no intervention groups. This study is registered with the Open Science Framework, DOI:10.17605/OSF.IO/BC359, and PROSPERO, CRD42021249466.

Findings

Of 4318 identified records, 223 were eligible for inclusion. 109 reported on overall survival in formats amenable to meta-analysis; PCI was associated with longer survival in all patients with SCLC (HR 0.59; 95% CI, 0.55-0.63; p < 0.001; n = 56,770 patients), patients with limited stage disease (HR 0.60; 95% CI, 0.55-0.65; p < 0.001; n = 78 studies; n = 27,137 patients), and patients with extensive stage disease (HR 0.59; 95% CI, 0.51-0.70; p < 0.001; n = 28 studies; n = 26,467 patients). Between-study heterogeneity was significant when pooled amongst all studies (I2 = 73.6%; 95% CI 68.4%-77.9%). Subgroup analysis did not reveal sources of heterogeneity. In a subgroup analysis on studies that used magnetic resonance imaging to exclude presence of brain metastases at restaging among all patients, overall survival did not differ significantly between patients who did or did not receive PCI (HR 0.74; 95% CI, 0.52-1.05; p = 0.08; n = 9 studies; n = 1384 patients).

Interpretation

Our findings suggested that administration of PCI is associated with a survival benefit, but not when considering studies that radiographically confirmed absence of brain metastases, suggesting that the survival benefit conferred by PCI might be therapeutic rather than prophylactic.

Funding

No funding.

A brain metastasis liquid biopsy: Where are we now?

Brain metastases remain a challenging and feared complication for patients with cancer and research in this area has lagged behind research into metastases to other organs. Due to their location and the risks associated with neurosurgical biopsies, the biology underpinning brain metastases response to treatment and evolution over time remains poorly understood. Liquid biopsies are proposed to overcome many of the limitations present with tissue biopsies, providing a better representation of tumor heterogeneity, facilitating repeated sampling, and providing a noninvasive assessment of tumor biology. Several different liquid biopsy approaches have been investigated including circulating tumor cells, circulating tumor DNA, extracellular vesicles, and tumor-educated platelets; however, these have generally been less effective in assessing brain metastases compared to metastases to other organs requiring improved techniques to investigate these approaches, studies combining different liquid biopsy approaches and/or novel liquid biopsy approaches. Through this review, we highlight the current state of the art and define key unanswered questions related to brain metastases liquid biopsies.

Systemic Therapy for Small-Cell Lung Cancer: ASCO-Ontario Health (Cancer Care Ontario) Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on the management of patients with small-cell lung cancer.

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2022. Outcomes of interest included response rates, overall survival, disease-free survival or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 95 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address systemic therapy options, timing of therapy, treatment in patients who are older or with poor performance status, role of biomarkers, and use of myeloid-supporting agents in patients with small-cell lung cancer.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

What is the current role of prophylactic cranial irradiation in the treatment algorithm for small cell lung cancer?

Prophylactic cranial irradiation (PCI) is considered an important technological advance made in oncology in an effort to reduce the incidence of brain metastases (BM) and improve overall survival (OS) of patients with small cell lung cancer (SCLC). Although it is often reported that PCI improves the therapeutic potential in limited-stage (LS) SCLC, no randomised trial has ever conclusively confirmed this. Nevertheless, PCI has been considered the standard of care for LS-SCLC since the late 1990s. The data supporting the use of PCI in LS-SCLC are based on an analysis of work performed prior to the current approach to staging [brain magnetic resonance imaging (MRI), positron emission tomography (PET)/computed tomography (CT)]. The evidence for the rationale and feasibility of this approach in the modern diagnostic era should be demonstrated. The situation with extensive stage (ES) SCLC is seemingly easier because, unlike LS-SCLC, we have data from two randomised trials. Unfortunately, their results are in direct conflict with each other. Although it is generally assumed that good control of brain disease leads to better quality of life, this has never been prospectively demonstrated. In fact, PCI is associated not only with increased treatment costs and some patient discomfort, but also with non-negligible potential toxicity. For this reason, efforts have been made to preserve cognitive function by sparing the hippocampus. This concept is called hippocampal avoidance. The optimal fractionation regimen is currently less controversial than the optimal integration of PCI into the treatment algorithm. A dose of 25 Gy administered in 10 fractions should remain the standard for the eventual use of PCI in patients with SCLC. In summary, PCI is not a conditio sine qua non in any indication. Neither in patients with LS-SCLC nor in patients with ES-SCLC has a clear improvement in OS been demonstrated at follow-up using current imaging modalities.

Low radiotherapy dose is suitable for brain metastases in SCLC compared with high dose

Objective

This study was designed to evaluate the suitable radiotherapy dose in SCLC patients with BM.

Methods

A retrospective analysis was performed among 121 patients on the prognosis of BM of SCLC who were admitted to our hospital from 2013 to 2023. They all received first line chemotherapy. 80 patients of them received TRT after chemotherapy. The Chi square method was used to compare the categorical data. Univariate survival analysis was estimated by Kaplan Meier method and the logrank was used to compare survival curves between groups. A multivariate prognostic analysis was made by the Cox proportional hazard model. The iOS and iLC of two groups of low dose and high dose were analyzed after propensity score matching (PSM).

Results

In all the patients, the median follow-up time was 18.6 months (range 6.30~85.7), the 2-year iOS and iLC rates were 15.4% and 70.3%, respectively, and cerebral necrosis occurred in 2 patients. In univariate analysis related to iOS, extracranial disease control (p=0.023), higher DS-GPA (≥2) (p=0.016), immunotherapy (p=0.049), low-dose(p=0.030), and WBRT+SIB (p=0.009) were significantly associated with an increase in survival rate. After PSM, the 2-year iOS of low dose (n=49) was significantly higher than that of high dose (n=49) (P=0.025), while the 2-year iLC was not significantly improved (P=0.267). In DS-GPA < 2 subgroup, the iOS of low dose group was significantly higher than that of high dose group (p=0.019). In the DS-GPA ≥ 2 subgroup, the 2-year iLC of the low dose group was significantly inferior than that of the high dose group (p=0.044).

Conclusions

The iLC was improved along with increasing radiotherapy dose, but high dose had inferior iOS compared to low dose, while there were not significantly improving iLC when radiotherapy BED >56Gy. But in patients with DS-GPA≥2 subgroup, high dose brought better iLC benefits.

Circulating hsa_circ_0072309, acting via the miR-100/ACKR3 pathway, maybe a potential biomarker for the diagnosis, prognosis, and treatment of brain metastasis from non-small-cell lung cancer

BACKGROUND

One of the main causes of lung cancer-related death is brain metastasis (BM). Finding early indicators of BM derived from lung cancer is crucial. Therefore, this study was designed to determine if serum hsa_circ_0072309 may be employed as a potential biomarker for BM induced by non-small-cell lung cancer (NSCLC) and to understand its possible underlying mechanism.

METHODS

Primary lung cancer and healthy neighboring tissues were obtained from all patients, while BM tissues were taken from BM+ patients. Serum specimens were collected from all patients and healthy volunteers. Hsa_circ_001653, miR-100, and ACKR3 RNA expressions were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and atypical chemokine receptor 3 (ACKR3) protein expression by western blotting (WB), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA). In order to examine the effect of serum hsa_circ_0072309 and its relevant mechanism on BM development, an NSCLC-associated BM model in mice was established.

RESULTS

According to the results, miR-100 expression was down-regulated in primary lung cancer tissues compared to healthy lung tissues in all NSCLC patients, and circ_0072309 and ACKR3 expression were up-regulated. In BM tissues compared with primary lung tumors of BM+ patients, in serum samples from all patients compared to healthy volunteers, and in lung tumors of BM+ patients compared to those from BM- patients. Patients' serum exhibits the same level of hsa_circ_0072309/miR-100/ACKR3 expression as in BM samples. Advanced tumor-node-metastasis (TNM) stage, higher BM, shorter post-operative overall survival (OS), and progression-free survival (PFS) are all substantially associated with increased serum circ_0072309 levels in BM+ patients. In animal models, serum owning hsa_circ_0072309 from BM+ patients facilitates BM formation by regulating the miR-100/ACKR3 pathway.

CONCLUSIONS

The current preliminary research reveals serum hsa_circ_0072309 as a possible biomarker and target for early diagnosis, prognosis, and therapy of NSCLC-derived BM and suggests a substantial role for the hsa_circ_0072309/miR-100/ACKR3 axis in the formation of BM from NSCLC.

Magnetic resonance imaging characteristics of brain metastases in small cell lung cancer

BACKGROUND

Lung is the most common primary site of brain metastases (BMs). For different pathological types of BMs have some similar characteristics, it is still a challenge to confirm the origin based on their characteristics directly. BMs of small cell lung cancer (SCLC) have favorable therapeutic expectations due to their high sensitivity to radiotherapy. This study sought to identify unique characteristics of BMs in SCLC, aiming to assist in clinical decision-making.

METHODS

Patients diagnosed with BMs of lung cancer who received radiotherapy from January 2017 to January 2022 were reviewed (N = 284). Definitive diagnosis of BMs of SCLC was reached for 36 patients. All patients underwent head examination using magnetic resonance imaging. The number, size, location, and signal characteristics of lesions were analyzed.

RESULTS

There were 7 and 29 patients with single focus and non-single focus, respectively. Ten patients had diffuse lesions, and the remaining 26 patients had a total of 90 lesions. These lesions were divided into three groups according to size: <1, 1-3, and >3 cm (43.33%, 53.34%, and 3.33%, respectively). Sixty-six lesions were located in the supratentorial area, primarily including cortical and subcortical lesions (55.56%) and deep brain lesions (20%). Moreover, 22 lesions were located in the infratentorial area. According to diffusion-weighted imaging and T1-weighted contrast enhancement, the imaging characteristics were classified into six patterns. Hyperintensity in diffusion-weighted imaging and homogeneous enhancement was the most common pattern of BMs in SCLC (46.67%), while partial lesions showed hyperintensity in diffusion-weighted imaging without enhancement (7.78%).

CONCLUSIONS

The manifestations of BMs in SCLC were multiple lesions (diameter: 1-3 cm), hyperintensity in diffusion-weighted imaging, and homogeneous enhancement. Interestingly, hyperintensity in diffusion-weighted imaging without enhancement was also one of the characteristics.

Canadian Consensus Recommendations on the Management of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive, neuroendocrine tumour with high relapse rates, and significant morbidity and mortality. Apart from advances in radiation therapy, progress in the systemic treatment of SCLC had been stagnant for over three decades despite multiple attempts to develop alternative therapeutic options that could improve responses and survival. Recent promising developments in first-line and subsequent therapeutic approaches prompted a Canadian Expert Panel to convene to review evidence, discuss practice patterns, and reach a consensus on the treatment of extensive-stage SCLC (ES-SCLC). The literature search included guidelines, systematic reviews, and randomized controlled trials. Regular meetings were held from September 2022 to March 2023 to discuss the available evidence to propose and agree upon specific recommendations. The panel addressed biomarkers and histological features that distinguish SCLC from non-SCLC and other neuroendocrine tumours. Evidence for initial and subsequent systemic therapies was reviewed with consideration for patient performance status, comorbidities, and the involvement and function of other organs. The resulting consensus recommendations herein will help clarify evidence-based management of ES-SCLC in routine practice, help clinician decision-making, and facilitate the best patient outcomes.

ACR Appropriateness Criteria® Staging of Renal Cell Carcinoma: 2022 Update

Renal cell carcinoma is a complex group of highly heterogenous renal tumors demonstrating variable biological behavior. Pretreatment imaging of renal cell carcinoma involves accurate assessment of the primary tumor, presence of nodal, and distant metastases. CT and MRI are the key imaging modalities used in the staging of renal cell carcinoma. Important imaging features that impact treatment include tumor extension into renal sinus and perinephric fat, involvement of pelvicalyceal system, infiltration into adrenal gland, involvement of renal vein and inferior vena cava, as well as the presence of metastatic adenopathy and distant metastases. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A tumor-targeting and ROS-responsive iron-based T1 magnetic resonance imaging contrast agent for highly specific tumor imaging

T₁ contrast agents (CAs) exhibit outstanding capacity in enhancing the magnetic resonance imaging (MRI) contrast between tumor tissues and normal tissues for generating bright images. However, the clinical application of representative gadolinium(III) chelate-based T₁ CAs is limited due to their potential toxicity and low specificity for pathological tissues. To obtain MRI CAs with a combination of low toxicity and high tumor specificity, herein, we report a reactive oxygen species (ROS)-responsive T₁ CA (GA-Fe(II)-PEG-FA), which was constructed by chelating Fe(II) with gallic acid (GA), and modified with tumor-targeted folic acid (FA). The resultant CA could accumulate in tumor tissues via the affinity between FA and their receptors on the tumor cell membrane. It realized the switch from Fe(II) to Fe(III), and further enhancing the longitudinal relaxation rate (r₁) under the stimuli of ROS in the tumor microenvironment. The r₁ of GA-Fe(II)-PEG-FA on a 0.5 T nuclear magnetic resonance analyzer increased to 2.20 mM^-1 s^-1 under ROS stimuli and was 5 times greater than the r₁ (0.42 mM^-1 s^-1) before oxidation. The cell and in vivo experiments demonstrated that GA-Fe(II)-PEG-FA exhibited good biocompatibility and significant targeting specificity to tumor cells and tumor tissues. Furthermore, in vivo MRI studies demonstrated that the enhanced T₁ contrast effect against tumors could be achieved after injecting the CA for 3 h, indicating that GA-Fe(II)-PEG-FA has the potential as an ideal tumor MRI CA to increase the contrast and improve the diagnostic precision.

Evaluating the impact of early identification of asymptomatic brain metastases in metastatic renal cell carcinoma

BACKGROUND

Brain metastases (BM) in metastatic renal cell carcinoma (mRCC) have been reported to be present in up to 25% of patients diagnosed with mRCC. There is limited published literature evaluating the role of routine intra-cranial imaging for the screening of asymptomatic BM in mRCC.

AIMS

To evaluate the potential utility of routine intra-cranial imaging, a retrospective cohort study was conducted to characterize the outcomes of mRCC patients who presented with asymptomatic BM, as compared to symptomatic BM.

METHODS AND RESULTS

The Canadian Kidney Cancer Information System (CKCis) database was used to identify mRCC patients diagnosed with BM. This cohort was divided into two groups based on the presence or absence of BM symptoms. Details regarding patient demographics, disease characteristics, systemic treatments, BM characteristics and survival outcomes were extracted. Statistical analysis was through chi-square tests, analysis of variance, and Kaplan-Meier method to characterize survival outcomes. A p-value of <0.05 was considered statistically significant for all analyses. A total of 267 mRCC patients with BM were identified of which 106 (40%) presented with asymptomatic disease. The majority of patients presented with multiple (i.e., >1) BM (75%) with no significant differences noted in number of BM or BM-directed therapy received in symptomatic, as compared to asymptomatic BM patients. Median [95% confidence interval (CI)] overall survival (OS) from mRCC diagnosis was 42 months (95% CI: 32-62) for patients with asymptomatic BM, and 39 months (95% CI: 29-48) with symptomatic BM (p = 0.10). OS from time of BM diagnosis was 28 months (95% CI: 18-42) for the asymptomatic BM group, as compared to 13 months (95% CI: 10-21) in the symptomatic BM group (p = 0.04).

CONCLUSIONS

Given a substantial proportion of patients may present with asymptomatic BM, limiting intra-cranial imaging to patients with symptomatic BM, may be associated with a missed opportunity for timely diagnosis and treatment. The utility of routine intra-cranial imaging in patients with renal cell carcinoma, warrants further prospective evaluation.

Forthcoming Phase II Study of Durvalumab (MEDI4736) Plus Chemotherapy for Small Cell Lung Cancer with Brain Metastases

BACKGROUND

The standard of care for extensive-stage small cell lung cancer (ES-SCLC) is an immune checkpoint inhibitor (ICI) combined with platinum-etoposide (PE) chemotherapy. At initial diagnosis, about 25% of ES-SCLC patients have brain metastases, which are associated with a poor prognosis. The decision as to whether to treat brain metastases with local therapies such as surgery or radiotherapy before initiation of systemic chemoimmunotherapy is based on symptoms due to the brain lesions and the general condition of the patient. Subset analysis of the CASPIAN study showed that combination therapy with PE plus durvalumab (MEDI4736) is promising for ES-SCLC with brain metastases. However, data required in daily clinical practice, such as intracranial response rate and duration of intracranial response, are insufficient for such patients.

PATIENTS AND METHODS

We have designed a single-arm phase II trial of durvalumab plus PE for patients aged ≥20 years with chemotherapy-naïve ES-SCLC and at least one brain metastasis ≥5 mm in size that has not been previously treated. Patients receive durvalumab intravenously combined with four cycles of PE. Enrollment of 50 patients over 2 years at 25 oncology facilities in Japan is planned. The primary endpoint is intracranial response rate.

CONCLUSION

This is the first prospective study to evaluate the effects of an ICI with PE specifically in ES-SCLC patients with brain metastases. If it demonstrates intracranial efficacy, this regimen will be a potential treatment option for such individuals, and radiation therapy or surgery for brain metastases can be avoided or postponed.

The Use of Palliative Radiotherapy in the Treatment of Lung Cancer

There have been significant advances in the systemic treatment of stage IV lung cancer, which is now recommended first line in patients with adequate fitness. This includes some patients with brain metastases due to the increased understanding of the central nervous system penetration of targeted therapies. The trials evidence base for palliative radiotherapy pre-dated this routine use of systemic therapy in our practice, which means that the sequence and role of palliative radiotherapy are not currently well defined in the first-line treatment setting. However, due to its efficacy in symptom control, radiotherapy remains a core component in the palliative management of lung cancer, particularly in the second-line setting and those unsuited to primary systemic treatment. This overview focuses on the evidence behind palliative radiotherapy to the thorax and brain for non-small cell and small cell lung cancer and the potential for future studies, including the TOURIST Trial Platform, to guide the future direction of these treatments.

Construction of Brain Metastasis Prediction Model and Optimization of Prophylactic Cranial Irradiation Selection for Limited-Stage Small-Cell Lung Cancer

Prophylactic cranial irradiation (PCI), as an essential part of the treatment of limited-stage small-cell lung cancer (LS-SCLC), inevitably leads to neurotoxicity. This study aimed to construct a brain metastasis prediction model and identify low-risk patients to avoid PCI; 236 patients with LS-SCLC were retrospectively analyzed and divided into PCI (63 cases) and non-PCI groups (173 cases). The nomogram was developed based on variables determined by univariate and multivariate analyses in the non-PCI group. According to the cutoff nomogram score, all patients were divided into high- and low-risk cohorts. A log-rank test was used to compare the incidence of brain metastasis between patients with and without PCI in the low-risk and high-risk groups, respectively. The nomogram included five variables: chemotherapy cycles (ChT cycles), time to radiotherapy (RT), lactate dehydrogenase (LDH), pro-gastrin-releasing peptide precursor (ProGRP), and lymphocytes−monocytes ratio (LMR). The area under the receiver operating characteristics (AUC) of the nomogram was 0.763 and 0.782 at 1 year, and 0.759 and 0.732 at 2 years in the training and validation cohorts, respectively. Based on the nomogram, patients were divided into high- and low-risk groups with a cutoff value of 165. In the high-risk cohort, the incidence of brain metastasis in the non-PCI group was significantly higher than in the PCI group (p < 0.001), but there was no difference in the low-risk cohort (p = 0.160). Propensity score-matching (PSM) analysis showed similar results; the proposed nomogram showed reliable performance in assessing the individualized brain metastasis risk and has the potential to become a clinical tool to individualize PCI treatment for LS-SCLC.

Prophylactic cranial irradiation (PCI) versus active surveillance in patients with limited-stage small cell lung cancer: a retrospective, multicentre study

Background

The recommendation of PCI for limited-stage small cell lung cancer (LS-SCLC) is primarily based on evidence from the pre-magnetic resonance imaging (MRI) era. However, as MRI accuracy improves and stereotactic radiosurgery advances, the role of PCI for LS-SCLC has become uncertain. This study aims to compare the contemporary survival outcomes of patients with LS-SCLC treated with PCI versus active surveillance.

Methods

We conducted a retrospective cohort study in which 1068 patients with LS-SCLC who achieved a good response to first-line chemoradiotherapy were consecutively enrolled from 5 tertiary medical centres between June 2009 and June 2019. Of these patients, 440 received PCI, while 628 received surveillance without PCI. Propensity score matching with a 1:1 ratio was performed to balance the baseline characteristics of the two cohorts. The endpoints were overall survival (OS) and the incidence of brain metastasis (BM).

Results

In total, 648 patients were matched. The baseline characteristics were generally well balanced. At a median follow-up of 64.5 months (range 2–190), patients who underwent PCI had a significantly lower risk for BM than those who underwent surveillance. The 3-year cumulative incidence rate of BM was 28.2% (95% CI 22.5–33.8%) in the PCI cohort and 38.5% (32.6–44.5%) in the surveillance cohort (Gray’s p = 0.002). However, the lower incidence of BM in the PCI cohort did not translate into a significant extension of OS. The median OS was 35.8 months (95% CI 27.6–44.0 months) in the PCI cohort versus 32 months (26.4–37.6 months) in the surveillance cohort (HR 0.90, 95% CI 0.74–1.10, p = 0.29). Multivariable analysis showed that disease stage, chemoradiotherapy sequence, and response to chemoradiotherapy were independent prognostic factors for BM or OS.

Conclusions

Overall, PCI reduces the risk for BM but does not substantially prolong OS compared with active surveillance. A phase 3, prospective clinical trial (NCT04829708) we initiated is currently underway, which is expected to corroborate our results.

Prophylactic cranial irradiation for limited-stage small-cell lung cancer in the magnetic resonance imaging era

BACKGROUND

We investigated the role of prophylactic cranial irradiation (PCI) in limited-stage small-cell lung cancer (LS-SCLC) according to tumor response in the magnetic resonance imaging (MRI) era.

METHODS

We retrospectively evaluated patients with LS-SCLC without brain metastases (BMs) on MRI who achieved either complete response (CR) or partial response (PR) after initial chemoradiotherapy at our center from 2006 to 2017.

RESULTS

This study comprised 116 patients (median age, 58 years; men, 92; women, 24). After initial chemoradiotherapy, 53 patients achieved CR, while 63 patients achieved PR. Eighty-three patients received PCI. Patients who received PCI had better overall survival (OS, 5-year: 52.5% vs. 35.1%; p = 0.012) and progression-free survival (PFS, 5-year: 45.0% vs. 28.2%; p = 0.001) and a lower incidence of BMs (5-year: 18.3% vs. 39.4%; p = 0.010). In the subgroup analysis, PCI improved OS (5-year: 67.8% vs. 46.7%, p = 0.005) and PFS (5-year: 65.2% vs. 35.0%, p = 0.021) and decreased BM risk (5-year: 12.1% vs. 52.4%, p = 0.002) for patients with CR. However, PCI had no benefit (5-year OS: 40.5% vs. 35.6%, p = 0.763; 5-year BMs: 24.6% vs. 31.9%, p = 0.561) for patients with PR.

CONCLUSIONS

Tumor response remained an important factor for selecting patients for PCI in the MRI era. PCI should be recommended for patients with LS-SCLC who achieve CR after initial thoracic chemoradiotherapy.

Usefulness of pro-gastrin-releasing peptide as a predictor of the incidence of brain metastasis and effect of prophylactic cranial irradiation in patients with limited-stage small-cell lung cancer

Prophylactic cranial irradiation (PCI) is recommended for patients with limited-stage small-cell lung cancer (LS-SCLC) who respond well to initial treatment. However, PCI is often omitted because of its potential neurotoxicity in the era of modern diagnostic imaging devices. In the present study, we aimed to investigate the risk factors for brain metastasis (BM) in patients eligible for PCI and who may benefit more from it. Patients with LS-SCLC who responded well to definitive thoracic chemoradiotherapy were included in the present study. Competing risk regression was used to identify factors associated with BM, and the Kaplan-Meier method was used to assess overall survival (OS). Between 2004 and 2017, 62 patients were eligible for PCI and were analyzed. Of these, 38 (61.3%) underwent PCI. Overall, 17 patients (27.4%) developed BM, with a 2-year cumulative incidence of 22.8%. Multivariate analysis (MVA) revealed that pretreatment elevated pro-gastrin-releasing peptide (ProGRP) levels were associated with an increased risk for BM (HR, 7.96, P = 0.0091). PCI tended to reduce the risk of BM (HR, 0.33; P = 0.051). The use of PCI was associated with improved OS in patients with ProGRP levels > 410 pg/mL (P = 0.008), but not in those with ProGRP ≤ 410 pg/mL (P = 0.9). Pretreatment ProGRP levels may be useful in predicting the development of BM in patients with LS-SCLC who achieved a good response to initial therapy and to determine which patients should undergo PCI.

New perspectives in the management of small cell lung cancer

The treatment of small cell lung cancer (SCLC) is a challenge for all specialists involved. New treatments have been added to the therapeutic armamentarium in recent months, but efforts must continue to improve both survival and quality of life. Advances in surgery and radiotherapy have resulted in prolonged survival times and fewer complications, while more careful patient selection has led to increased staging accuracy. Developments in the field of systemic therapy have resulted in changes to clinical guidelines and the management of patients with advanced disease, mainly with the introduction of immunotherapy. In this article, we describe recent improvements in the management of patients with SCLC, review current treatments, and discuss future lines of research.

First-Line Treatment for Advanced SCLC: What Is Left Behind and Beyond Chemoimmunotherapy

Small cell lung cancer (SCLC) is still a lethal disease. Three phase III randomized clinical trials (IMpower133, CASPIAN, and KEYNOTE-604) have highlighted the survival gain of adding immune checkpoint inhibitors to first-line standard chemotherapy in advanced SCLC patients. In this review, we discuss the data from the three trials above. Furtherly, we analyze issues that still need to be elucidated, like the role of biomarkers, poor performance status at baseline, the presence of brain metastases, and the platinum compound's choice. Moreover, we depict the future of SCLC first-line therapy management, focusing on new therapeutic strategies currently under investigation.

Benefits of Prophylactic Cranial Irradiation in the MRI Era for Patients With Limited Stage Small Cell Lung Cancer

Purpose

Previous studies have shown that prophylactic cranial irradiation (PCI) can improve the survival of patients with limited-stage small cell lung cancer (LS-SCLC). PCI is recommended for patients who respond well to chemoradiotherapy. However, whether PCI could be extrapolated to the LS-SCLC patients in the modern era of MRI is unknown. This study aimed to explore the value of PCI in patients with LS-SCLC in the era of brain MRI.

Methods

This study included 306 patients with LS-SCLC at the Cancer Hospital of China Medical University. All patients received brain MRI at diagnosis and after radiochemotherapy to exclude brain metastases. A propensity score matching was performed to reduce the influence of potential confounders. Overall survival (OS), progression-free survival (PFS), and recurrence failure types were compared between PCI and non-PCI groups.

Results

Among the 306 eligible patients, 81 underwent PCI, and 225 did not. After propensity score matching, there was no statistical difference in baseline data between the two groups, with 75 patients in each group. PCI did not achieve OS (median OS: 35 vs. 28 months, p = 0.128) or PFS (median PFS: 15 vs. 10 months, p = 0.186) benefits. During follow-up, 30 patients (20.0%) developed brain metastases, including 13 patients (17.3%) in the PCI group and 17 patients (22.7%) in the non-PCI group. Regarding death as a competitive risk, patients who received PCI had a lower cumulative incidence of brain metastasis than those who did not (3 years: 14.7% vs. 22.7%; Gray’s test, p = 0.007).

Conclusions

When brain MRI was performed at diagnosis and pre-PCI, PCI could reduce the cumulative rate of brain metastases, but it did not achieve survival benefits for LS-SCLC patients.

Managing Central Nervous System Spread of Lung Cancer: The State of the Art

Brain metastases (BrM) are common in both non-small-cell lung cancer and small-cell lung cancer. Substantial progress in BrM management has occurred in the past decade related to advances in both radiation and medical oncology. Recent and ongoing radiation trials have focused on increasing the candidacy for focal therapy of BrM with stereotactic radiosurgery; reducing the toxicity and improving patient selection for whole brain radiotherapy; and, in small-cell lung cancer, evaluating brain magnetic resonance imaging surveillance without prophylactic cranial irradiation, hippocampal avoidance in prophylactic cranial irradiation and whole brain radiotherapy, and the role of upfront stereotactic radiosurgery for BrM. In medical oncology, the development of multiple tyrosine kinase inhibitors with encouraging CNS activity and emerging data on the CNS activity of immune checkpoint inhibitors in some patients have opened the door to novel systemic and multidisciplinary treatment strategies for the management of BrM. Future research will focus on more robust characterizations of the CNS activity of targeted therapy and immunotherapies, as well as optimal integration and patient selection for multidisciplinary strategies involving CNS-active drugs, radiation therapy, and CNS surveillance.

Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer: A Controversial Area

Small-cell lung cancer (SCLC) is a highly aggressive malignant tumor that is prone to lead to the development of brain metastases (BM). The application of prophylactic cranial irradiation (PCI) has been regarded as an important technological advance made in cancer therapy to reduce the occurrence of BM and improve patient survival. The benefits of PCI in the treatment of limited-stage SCLC have been confirmed. However, there has been continuous controversy about the indications and advantages of PCI for extensive-stage SCLC (ES-SCLC) because of the conflicting results from two prospective trials. In this review, we aimed to discuss the relevant controversy and progress made in the clinical application of PCI in ES-SCLC.

Survival impact of prophylactic cranial irradiation in small-cell lung cancer in the modern era of magnetic resonance imaging staging

Background

In the modern era of magnetic resonance imaging (MRI) staging, the benefit of prophylactic cranial irradiation (PCI) in patients with small-cell lung cancer (SCLC) has been controversial. This study evaluated the prognostic impact of PCI in patients with limited- or extensive-stage SCLC who had no brain metastases at diagnosis according to MRI.

Methods

Data from newly diagnosed patients in 2014 from the Korean Association for Lung Cancer Registry database were used. Patients with limited- or extensive-stage SCLC who had no brain metastases according to MRI were identified. Univariate and multivariate survival analyses were conducted to assess the prognostic association of PCI.

Results

Of 107 and 122 patients with limited- and extensive-stage SCLC, 24% and 14% received PCI, respectively. In the limited-stage SCLC group, the 2-year overall survival (OS) rates of patients who received PCI and those who did not were 50% and 29% (P = 0.018), respectively. However, there was no significant difference in OS for patients with extensive-stage SCLC (P = 0.336). After adjusting for other covariates, PCI was found to be associated with improved OS in the limited-stage SCLC group (P = 0.005). Based on the time-course hazard rate function plots in the limited-stage SCLC group, the OS benefit of PCI was maximized within the first year of follow-up.

Conclusions

In the modern era of MRI staging, PCI might be beneficial for patients with limited-stage SCLC but not for those with extensive-stage SCLC. Further studies with a large sample size are needed to verify the prognostic association of PCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-01994-8.

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Treatment and Prevention of Brain Metastases in Small Cell Lung Cancer

Central nervous system (CNS) metastasis will develop in 50% of small cell lung cancer (SCLC) patients throughout disease course. Development of CNS metastasis poses a particular treatment dilemma due to the accompanied cognitive changes, poor permeability of the blood-brain barrier to systemic therapy and relatively advanced state of disease. Survival of patients with untreated SCLC brain metastases is generally <3 months with whole brain radiotherapy used as first-line management in most SCLC patients. To prevent development of CNS metastasis prophylactic cranial irradiation (PCI) is recommended in limited stage disease, after response to chemotherapy and radiation, while PCI may be considered in extensive stage disease after favorable response to upfront treatment. Neurocognitive toxicity with whole brain radiotherapy and PCI is a concern and remains difficult to predict. The mechanism of toxicity is likely multifactorial, but a potential mechanism of injury to the hippocampus has led to hippocampal sparing radiation techniques. Treatment of established non-small cell lung cancer CNS metastases has increasingly focused on using stereotactic radiotherapy (SRS) and it is tempting to extrapolate these results to SCLC. In this review, we explore the evidence surrounding the prediction, prevention, detection, and treatment of CNS metastases in SCLC. We further review whether existing evidence supports extrapolating less toxic treatments to SCLC patients with CNS metastases and discuss trials that may shed more light on this question.

Value of screening and follow-up brain MRI scans in patients with metastatic melanoma

Background

Novel treatments make long‐term survival possible for subsets of patients with melanoma brain metastases. Brain magnetic resonance imaging (MRI) may aid in early detection of brain metastases and inform treatment decisions. This study aimed to determine the impact of screening MRI scans in patients with metastatic melanoma and follow‐up MRI scans in patients with melanoma brain metastases.

Methods

This retrospective cohort study included patients diagnosed with metastatic melanoma or melanoma brain metastases between June 2015 and January 2018. The impact of screening MRI scans was evaluated in the first 2 years after metastatic melanoma diagnosis. The impact of follow‐up MRI scans was examined in the first year after brain metastases diagnosis. The number of MRI scans, scan indications, scan outcomes, and changes in treatment strategy were analyzed.

Results

In total, 116 patients had no brain metastases at the time of the metastatic melanoma diagnosis. Twenty‐eight of these patients (24%) were subsequently diagnosed with brain metastases. Screening MRI scans detected the brain metastases in 11/28 patients (39%), of which 8 were asymptomatic at diagnosis. In the 96 patients with melanoma brain metastases, treatment strategy changed after 75/168 follow‐up MRI scans (45%). In patients treated with immune checkpoint inhibitors, the number of treatment changes after follow‐up MRI scans was lower when patients had been treated longer.

Conclusion(s)

Screening MRI scans aid in early detection of melanoma brain metastases, and follow‐up MRI scans inform treatment strategy. In patients with brain metastases responding to immune checkpoint inhibitors, treatment changes were less frequently observed after follow‐up MRI scans. These results can inform the development of brain imaging protocols for patients with immune checkpoint inhibitor sensitive tumors.

Advances in the management of breast cancer brain metastases

The development of breast cancer (BC) brain metastases (BrM) is a common complication of advanced disease, occurring in up to half of the patients with advanced disease depending on the subtype. The management of BCBrM requires complex multidisciplinary care including local therapy, surgical resection and/or radiotherapy, palliative care, and carefully selected systemic therapies. Significant progress has been made in the human epidermal growth factor receptor 2-positive (HER2+) BCBrM population due to novel brain penetrable systemic therapies. Increased inclusion of patients with BCBrM in clinical trials using brain-penetrant systemic therapies recently led to the first FDA approval of a HER2-directed therapy specifically in the BCBrM population in the last year. Advances for the treatment of HR+/HER2- and TNBC BCBrM subgroups continue to evolve. In this review, we will discuss the diagnosis and multidisciplinary care of BCBrM. We focus on recent advances in neurosurgery, radiation therapy, and systemic treatment therapies with intracranial activity. We also provide an overview of the current clinical trial landscape for patients with BCBrM.

Trends and variations in the treatment of stage I-III small cell lung cancer from 2008 to 2019: A nationwide population-based study from the Netherlands

OBJECTIVES

Recent treatment patterns for small cell lung cancer (SCLC) in the Netherlands were unknown. This nationwide population-based study describes trends and variations in the treatment of stage I-III SCLC in the Netherlands over the period 2008-2019.

MATERIALS AND METHODS

Patients were selected from the population-based Netherlands Cancer Registry. Treatments were studied stratified for clinical stage. In stage II-III, factors associated with the use of concurrent (cCRT) versus sequential chemoradiation (sCRT) and accelerated versus conventionally fractionated radiotherapy in the context of cCRT were identified.

RESULTS

In stage I (N = 535), 29% of the patients underwent surgery in 2008-2009 which increased to 44% in 2018-2019. Combined use of chemotherapy and radiotherapy decreased in stage I from 47% to 15%, remained constant (64%) in stage II (N = 472), and increased from 57% (2008) to 70% (2019) in stage III (N = 5,571). Use of cCRT versus sCRT in stage II-III increased over time (odds ratio (OR) _{2008-2011 vs 2016-2019}: 0.53 (95%-confidence interval (95%CI): 0.41-0.69)) and was strongly associated with lower age, WHO performance status 0, and diagnosis in a hospital with in-house radiotherapy. Forty-six percent of patients with stage III received cCRT in 2019. Until 2012, concurrent radiotherapy was mainly conventionally fractionated, thereafter a hyperfractionated accelerated scheme was administered more frequently (57%). Accelerated radiotherapy was strongly associated with geographic region (OR_{south vs north}: 4.13 (95%CI: 3.00-5.70)), WHO performance (OR_{1 vs 0}: 0.50 (95%CI: 0.35-0.71)), and radiotherapy facilities treating ≥ 16 vs < 16 SCLC patients annually (OR: 3.01 (95%CI: 2.38-3.79)).

CONCLUSIONS

The use of surgery increased in stage I. In stages II and III, the use of cCRT versus sCRT increased over time, and since 2012 most radiotherapy in cCRT was accelerated. Treatment regimens and radiotherapy fractionation schemes varied between patient groups, regions and hospitals. Possible unwarranted treatment variation should be countered.

Stereotactic radiosurgery for brain metastases from small cell lung cancer without prior whole-brain radiotherapy: A meta-analysis

OBJECTIVES

Assess upfront Stereotactic radiosurgery (SRS) effectiveness for small cell lung cancer (SCLC) brain metastases (BM). Where possible, a comparison with whole-brain radiotherapy (WBRT) was performed.

METHODS

Following PRISMA and MOOSE guidelines, eligible studies were identified on Medline, Embase, Cochrane Library, and proceedings of annual meetings between inception and July 01, 2020.

RESULTS

Nine observational studies with 1638 patients were included. The median overall survival (OS) was 8.3 months (95% CI 7.1-9.5 months, I2 = 0%). OS rate at 12 months was 39% (95% CI 31-44%, I2 = 0%). The relative risk between SRS and WBRT for the OS at 12 months was 1.33 (95% CI 1.13-1.51, P = 0.0001). The projected OS for 6, 12, 18- and 24-months comparing SRS with WBRT was 67% vs. 57%, 39% vs. 29%, 22% vs. 15% and 15% vs 9%, favoring SRS (P < 0.001). The LC rate at 12 months was 93% (95% CI 91-94%, I2 = 0%). The distant brain failure rate (DBFR) at 12 months was 41% (95% CI 33-48%, I2 = 52%, P = 0.08). The SRS or WBRT as salvage treatment after upfront SRS was 32% and 19%, respectively. The freedom from neurologic death at 12 months was 87% (95% CI 84-89%).

CONCLUSION

Based on the pooling of a large sample of retrospective studies our meta-analysis suggests that for high selected SCLC patients with limited BM upfront SRS produces favorable lesion control and survival outcomes. These findings support the design of randomized clinical trial to confirm the role of SRS in this clinical scenario.

Prophylactic cranial irradiation confers favourable prognosis for patients with limited-stage small cell lung cancer in the era of MRI: A propensity score-matched analysis

INTRODUCTION

Prophylactic cranial irradiation (PCI) is recommended for patients with limited-stage small cell lung cancer (LS-SCLC) who achieve good response after chemoradiotherapy. But PCI is neurotoxic. Magnetic resonance imaging (MRI) is the standard tool for evaluating brain metastasis (BM). This study was to retrospectively analyse the necessity of PCI in the era of MRI in LS-SCLC.

METHODS

From July 2013 to June 2017, 190 patients with LS-SCLC who were treated with definitive chemoradiotherapy were included and analysed in this study. They were divided into the PCI group and non-PCI group. Propensity score matching (PSM) analysis was used to balance the variable differences. The Kaplan-Meier method was applied to estimate survival with log-rank test to ascertain significance between different groups.

RESULTS

Seventy-seven patients (40.5%) received PCI after chemoradiotherapy. After adjustment for propensity scores, 69 pairs of patients were matched between two groups. After PSM, the 1-year and 3-year OS rates were 96.9% and 48.5% in PCI group versus 89.9% and 25.0% in non-PCI group (HR: 0.419, 95% CI: 0.251-0.701, P = 0.001). The 1-year and 3-year BMFS in PCI group were 96.8% and 67.5% versus 62.3% and 37.9% in non-PCI group (HR: 0.247, 95% CI: 0.132-0.460, P < 0.001).

CONCLUSION

For patients showing no BM on MRI after definitive CRT, PCI confers less BM and better OS in LS-SCLC.

Consensus recommendations for a standardized brain tumor imaging protocol for clinical trials in brain metastases

A recent meeting was held on March 22, 2019, among the FDA, clinical scientists, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocacy groups to discuss challenges and potential solutions for increasing development of therapeutics for central nervous system metastases. A key issue identified at this meeting was the need for consistent tumor measurement for reliable tumor response assessment, including the first step of standardized image acquisition with an MRI protocol that could be implemented in multicenter studies aimed at testing new therapeutics. This document builds upon previous consensus recommendations for a standardized brain tumor imaging protocol (BTIP) in high-grade gliomas and defines a protocol for brain metastases (BTIP-BM) that addresses unique challenges associated with assessment of CNS metastases. The "minimum standard" recommended pulse sequences include: (i) parameter matched pre- and post-contrast inversion recovery (IR)-prepared, isotropic 3D T1-weighted gradient echo (IR-GRE); (ii) axial 2D T2-weighted turbo spin echo acquired after injection of gadolinium-based contrast agent and before post-contrast 3D T1-weighted images; (iii) axial 2D or 3D T2-weighted fluid attenuated inversion recovery; (iv) axial 2D, 3-directional diffusion-weighted images; and (v) post-contrast 2D T1-weighted spin echo images for increased lesion conspicuity. Recommended sequence parameters are provided for both 1.5T and 3T MR systems. An "ideal" protocol is also provided, which replaces IR-GRE with 3D TSE T1-weighted imaging pre- and post-gadolinium, and is best performed at 3T, for which dynamic susceptibility contrast perfusion is included. Recommended perfusion parameters are given.

Utility of Prophylactic Cranial Irradiation for Limited Stage Small Cell Lung Cancer in the Modern Era with Magnetic Resonance Imaging Surveillance

AIMS

To retrospectively analyse the impact of prophylactic cranial irradiation (PCI) on survival and intracranial progression in patients with limited stage small cell lung cancer (LS-SCLC) in the modern era of widespread magnetic resonance imaging brain screening.

MATERIALS AND METHODS

Patients with LS-SCLC treated within our network between 2009 and 2020 who responded to initial therapy were stratified by receipt of PCI and stage of disease. A propensity score match analysis was carried out for stage II-III patients. Overall and neurological survival were defined as time to death and presumed death due to uncontrolled intracranial disease, respectively. Brain metastasis-free survival and symptomatic brain metastasis-free survival were defined as freedom from intracranial progression and symptomatic intracranial progression, respectively. The effect of PCI on these outcomes was assessed using Kaplan-Meier and Cox proportional hazards models.

RESULTS

In total, 243 (69.6%) of 349 patients received PCI. On multivariate analysis in the propensity matched stage II-III cohort, PCI was a significant predictor of improved neurological survival (hazard ratio 0.23, 95% confidence interval 0.08-0.65; P = 0.01), brain metastasis-free survival (hazard ratio 0.25, 95% confidence interval 0.12-0.51; P < 0.01) and symptomatic brain metastasis-free survival (hazard ratio 0.21, 95% confidence interval 0.08-0.55; P < 0.01), but not improved overall survival. Two-year neurological survival estimates within the propensity matched cohort were 96.8% (95% confidence interval 87.6-99.2%) with PCI and 77.2% (95% confidence interval 63.0-86.4%) without PCI and 1- and 2-year estimates of incidence of brain metastases were 3.9% (95% confidence interval 1.3-11.7%) and 11.7% (95% confidence interval 5.6-23.5%) in the PCI group and 31.6% (95% confidence interval 22.1-43.9%) and 40.4% (95% confidence interval 29.2-54.0%) in the no PCI group, respectively.

CONCLUSIONS

In the modern era of magnetic resonance imaging screening, PCI was associated with reduced incidence of intracranial progression in patients with stage II-III LS-SCLC who respond to initial therapy. This, importantly, translated to a decreased risk of neurological death within our propensity matched cohort, without significant improvement in overall survival.

GOECP/SEOR radiotherapy guidelines for small-cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 20% of all lung cancers. The main treatment is chemotherapy (Ch). However, the addition of radiotherapy significantly improves overall survival (OS) in patients with non-metastatic SCLC and in those with metastatic SCLC who respond to Ch. Prophylactic cranial irradiation reduces the risk of brain metastases and improves OS in both metastatic and non-metastatic patients. The 5-year OS rate in patients with limited-stage disease (non-metastatic) is slightly higher than 30%, but less than 5% in patients with extensive-stage disease (metastatic). The present clinical guidelines were developed by Spanish radiation oncologists on behalf of the Oncologic Group for the Study of Lung Cancer/Spanish Society of Radiation Oncology to provide a current review of the diagnosis, planning, and treatment of SCLC. These guidelines emphasise treatment fields, radiation techniques, fractionation, concomitant treatment, and the optimal timing of Ch and radiotherapy. Finally, we discuss the main indications for reirradiation in local recurrence.

Trends in imaging utilization for small cell lung cancer: a decision tree analysis of the NCCN guidelines

PURPOSE

To investigate the differences in small cell lung cancer (SCLC) diagnostic imaging utilization relative to National Comprehensive Cancer Network (NCCN) guidelines.

METHODS

We retrospectively reviewed SCLC records at our institution between January 1, 2003 and August 1, 2019 (n = 529). Patients were grouped by extensive-stage versus limited-stage and diagnosis date. Clinical, CT, MRI, and nuclear imaging data was collected. Imaging utilization was compared using Student's t-test or Kruskal-Wallis-test/Wilcoxon-Rank-Sums test. Survival was compared using Log-rank-test and Kaplan-Meier-curves.

RESULTS

SCLC patients had a median survival of 290 days. Extensive-stage patients with SCLC demonstrated an increase in emergency imaging utilization when diagnosed in 2011-2019 compared to 2003-2010 (CT abdomen/pelvis p < 0.001, CTA chest for pulmonary embolism p < 0.01, CT head p < 0.003). Limited-stage patients with SCLC demonstrated an increase in inpatient imaging utilization (CT abdomen/pelvis p < 0.04) and decreased total/outpatient imaging utilization (CT chest-abdomen-pelvis p < 0.05, CT head p < 0.003) when diagnosed in 2011-2019 compared to 2003-2010. All patients with SCLC had decreased average number of bone-scan studies when diagnosed in 2011-2019 compared to 2003-2010 (Extensive-stage p < 0.006, Limited-stage p < 0.0006).

CONCLUSION

Imaging utilization trends in the management of patients with SCLC at our institution differed between 2003 and 2010 and 2011-2019 reflecting the changes in the NCCN guidelines.

Prophylactic cranial irradiation or MRI surveillance for extensive stage small cell lung cancer

The treatment paradigm for extensive stage small cell lung cancer (ES-SCLC) is evolving. Prophylactic cranial irradiation (PCI) has long been considered a component of standard treatment in patients with extensive stage disease who respond to chemotherapy. However, in the modern era of magnetic resonance imaging, the role of PCI has become an area of controversy following conflicting level I evidence. Due to conflicting data and toxicity concerns, the routine use of PCI has declined. Recent improvements in systemic disease control with the use of immunotherapy and reductions in the toxicity attributable to PCI with hippocampal avoidance and memantine have reignited the discussion. As such, we present here a narrative review of PCI with a focus on historical milestones, randomized data, risk mitigation and future directions.

In regards to Chu et al.: Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer

We read the article entitled “Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer” with great interest. In that study, the author reported about the importance of PCI timing in limited stage small cell lung cancer (LS-SCLC) in the era of MRI surveillance. In addition, the authors raise the issue of neurotoxicity of PCI. In this letter, we aimed to clarify the value of PCI in LS-SCLC and present ongoing trials regarding PCI and MRI surveillance in SCLC. As a result, we see the need for the development of a prediction tool to estimate the risk of intracranial relapse in LS-SCLC after chemoradiotherapy in order to support shared decision making through improved guidance.

Efficacy and safety of PD-1/PD-L1 inhibitor plus chemotherapy versus chemotherapy alone as first-line treatment for extensive-stage small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Immunotherapy has afforded new treatment options for extensive small cell lung cancer (ES-SCLC). However, reports on the effectiveness of immune checkpoint inhibitors (ICIs) combined with chemotherapy on survival in ES-SCLC patients are inconsistent. Therefore, we conducted a meta-analysis on the efficacy and safety of ICI combined with chemotherapy for ES-SCLC.

METHODS

We searched for randomized controlled clinical trials related to first-line treatment of ES-SCLC with ICI combined with chemotherapy in PUBMED, ESMO, ASCO, and WCLC since 2018. The primary outcome was overall survival (OS).

RESULTS

Four studies were included. Compared to chemotherapy alone, ICI in combination with chemotherapy as first-line treatment reduced the risk of death (hazard ratio [HR]: 0.76; 95% CI: 0.68-0.86; P < 0.00001) and disease progression (HR: 0.76; 95% CI: 0.68-0.84; P < 0.00001). The objective response rate (ORR) with ICI plus chemotherapy was significantly higher than that with chemotherapy alone (HR: 1.10; 95% CI: 1.02-1.19, P = 0.01). The duration of response (DoR) rate at one year was also better with ICI plus chemotherapy (HR: 3.46; 95% CI: 2.24-5.33; P < 0.00001). Security analysis revealed that the incidence of immune-mediated adverse events (imAEs) (HR: 3.77; 95% CI: 1.99-7.15, P < 0.0001) and grade 3/4 imAEs (HR: 7.01; 95% CI: 2.48-19.81; P = 0.0002) increased significantly with ICI plus chemotherapy.

CONCLUSIONS

ICI combined with chemotherapy as first-line treatment can significantly improve the OS and progression-free survival (PFS) of ES-SCLC patients, but the toxicity caused by immunotherapy should be carefully considered.

KEY POINTS

Significant findings of the studyOur meta-analysis shows that PD-L1/PD-1 plus chemotherapy can significantly improve the OS and PFS of ES-SCLC patients when used as first-line therapy.

WHAT THIS STUDY ADDS

This study fills gaps regarding the efficacy of immunotherapy combined with chemotherapy as first-line treatment for ES-SCLC, and provides better evidence for the use of PD-L1/PD-1 immunotherapy plus chemotherapy for patients with ES-SCLC.

Brain Metastases From Lung Adenocarcinoma May Preferentially Involve the Distal Middle Cerebral Artery Territory and Cerebellum

Although whole-brain radiation therapy (WBRT) is the mainstay of treatment for brain metastases (BMs), the concept of saving eloquent cortical lesions has been promoted. If BMs from lung cancer are spatially biased to certain regions, this approach can be justified more. We evaluated whether BMs from lung cancer show a preference for certain brain regions and if their distribution pattern differs according to the histologic subtype of the primary lung cancer. In this retrospective study, 562 BMs in 80 patients were analyzed (107 BMs from small cell carcinoma, 432 from adenocarcinoma, and 23 from squamous cell carcinoma). Kernel density estimation was performed to investigate whether BM spatial patterns differed among lung cancer subtypes. Further, we explored more detailed subregions where BMs from adenocarcinomas occur frequently using one-way analysis of variance. Finally, we divided our cohort into those with fewer (≤10) and more (>10) BMs and evaluated whether this biased pattern was maintained across limited and extensive stages. For small cell carcinoma, BMs were biased to the cerebellum, but this did not reach statistical significance. For adenocarcinoma, BMs were found more frequently near the distal middle cerebral artery (MCA) territory and cerebellum than in other arterial territories (p < 0.01). The precentral and postcentral gyri were the most significant subregions within the distal anterior cerebral artery (ACA) and MCA territories (p < 0.01). Crus I and Lobule VI were significant regions within the cerebellum (p < 0.01). Regardless of the number of BMs, the affinity to the distal MCA territory and cerebellum was maintained. The present data confirm that BMs from lung adenocarcinoma may preferentially involve the distal MCA territory and cerebellum.

Emerging drugs for small cell lung cancer: a focused review on immune checkpoint inhibitors

INTRODUCTION

Small cell lung cancer (SCLC) is an aggressive malignancy that accounts for 15% of all lung cancers. It is characterized by initial responsiveness to therapy followed by rapid disease progression that is relatively resistant to further treatment. Recently, the addition of an immune checkpoint inhibitor (ICI) to chemotherapy has improved survival in patients with advanced disease, the first advance in systemic therapy in SCLC in over 30 years.

AREAS COVERED

In this review, we present an overview of SCLC with a focus on the scope of the problem and standard treatment, followed by a critical assessment of scientific rationale for immunotherapy in SCLC and the clinical trials that have been performed with ICIs in SCLC. Finally, we address ongoing hurdles for the development of ICIs in SCLC and potential avenues for further study.

EXPERT OPINION

Despite solid biological rationale, the results of clinical trials of ICIs in SCLC have yielded modest benefits. A small subset of patients does achieve long-term benefit, but further development of ICIs in SCLC will depend on the identification of predictive biomarkers and the design of combination regimens that take advantage of the molecular alterations that drive the immune-avoidance mechanisms and survival of SCLC cells.

Current Management and Progress in Radiotherapy for Small Cell Lung Cancer

Radiotherapy (RT) and chemotherapy continue to be widely utilized in small cell lung cancer (SCLC) management. In most limited stage (LS)-SCLC cases, the standard initial therapy remains concurrent chemoradiotherapy (CRT), typically with an etoposide and platinum-based regimen. Hyperfractionated twice daily (BID) RT remains the standard of care, though conventional daily (QD) RT is now a viable alternative supported by randomized evidence. In LS-SCLC patients who experienced good response to CRT, prophylactic cranial irradiation (PCI) remains the standard of care. Brain imaging, ideally with MRI, should be performed prior to PCI to screen for clinically apparent brain metastases that may require a higher dose of cranial irradiation. Platinum doublet chemotherapy alone is the historic standard initial therapy in extensive stage (ES)-SCLC. Addition of immunotherapy such as atezolizumab and durvalumab to chemotherapy is now recommended after their benefits were demonstrated in recent trials. In patients with response to chemotherapy, consolidation thoracic RT and PCI could be considered, though with caveats. Emergence of hippocampal avoidance cranial irradiation and SRS in SCLC patients may supplant whole cranial irradiation as future standards of care. Incorporation of novel systemic therapies such as immunotherapies has changed the treatment paradigm and overall outlook of patients with SCLC. This narrative review summarizes the current state, ongoing trials, and future directions of radiotherapy in management of SCLC.

Age, pathology and CA-125 are prognostic factors for survival in patients with brain metastases from gynaecological tumours

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The largest cohort of brain metastases patients from gynaecological tumours.

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CA-125, age and primary tumour type are prognostic for survival.

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This will inform clinical practice and aid the development of new prognostic tools.

Background and purpose

Brain metastases originating from gynaecological tumours are a rare phenomenon, but have an increasing incidence due to better targeted therapies. This study aimed to identify factors that predict survival in these patients, which can be used in creating a robust prognostic tool for shared decision making.

Materials and methods

We identified a consecutive cohort of 73 patients treated for gynaecological brain metastases in two tertiary institutions. Baseline demographics, pathology and serum CA-125 were included in a multivariable Cox proportional hazards model.

Results

Median overall survival in our cohort was 14.4 months, with a one-year survival of 56.4% and a two-year survival of 39.1%. Thirty-eight patients (52.1%) had ovarian carcinoma as the primary malignancy. The following factors were significantly associated with survival: age (HR 1.05 per year), CA-125 (HR 1.02 par 50 U/ml), and uterine and vulvar primary tumours (when compared to ovarian carcinoma, with HRs 3.07 and 8.70). A post-hoc analysis with primary tumour site reclassified into ovary versus non-ovary showed a HR of 0.50 for ovarian primary tumour type.

Conclusion

We have found that age, pathology and CA-125 are prognostic factors for survival in patients with brain metastases from gynaecological tumours. Our findings may provide a foundation for future development of prediction models, for the benefit of both patients and physicians.