Effectiveness and safety of “real” concurrent stereotactic radiotherapy and immunotherapy in metastatic solid tumors: a systematic review

Recommandations francophones pour la pratique clinique concernant la prise en charge des cancers du sein de Saint-Paul-de-Vence 2022-2023

With more than 60,000 new cases of breast cancer in mainland France in 2023 and 8% of all cancer deaths, breast cancer is the leading cancer in women in terms of incidence and mortality. While the number of new cases has almost doubled in 30 years, the percentage of patients at all stages alive at 5 years (87%) and 10 years (76%) testifies to the major progress made in terms of screening, characterisation and treatment. However, this progress, rapid as it is, needs to be evaluated and integrated into an overall strategy, taking into account the characteristics of the disease (stage and biology), as well as those of the patients being treated. These are the objectives of the St Paul-de-Vence recommendations for clinical practice. We report here the summary of the votes, discussions and conclusions of the Saint-Paul-de-Vence 2022-2023 RPCs.

Overview of the synergistic use of radiotherapy and immunotherapy in cancer treatment: current challenges and scopes of improvement

INTRODUCTION

Oncological treatments are changing rapidly due to the advent of several targeted anticancer drugs and regimens. The primary new area of research in oncological medicine is the implementation of a combination of novel therapies and standard care. In this scenario, radioimmunotherapy is one of the most promising fields, as proven by the exponential growth of publications in this context during the last decade.

AREAS COVERED

This review provides an overview of the synergistic use of radiotherapy and immunotherapy and addresses questions like the importance of this subject, aspects clinicians look for in patients to administer this combined therapy, individuals who would benefit the most from this treatment, how to achieve abscopal effect and when does radio-immunotherapy become standard clinical practice.

EXPERT OPINION

Answers to these queries generate further issues that need to be addressed and solved. The abscopal and bystander effects are not utopia, rather physiological phenomena that occur in our bodies. Nevertheless, substantial evidence regarding the combination of radioimmunotherapy is lacking. In conclusion, joining forces and finding answers to all these open questions is of paramount importance.

State of the Art in Combination Immuno/Radiotherapy for Brain Metastases: Systematic Review and Meta-Analysis

OBJECTIVES

Common origins for brain metastases (BMs) are melanoma, lung, breast, and renal cell cancers. BMs account for a large share of morbidity and mortality caused by these cancers. The advent of new immunotherapeutic treatments has made a revolution in the treatment of cancer patients and particularly, as a new concept, if it is combined with radiotherapy, may lead to considerably longer survival. This systematic review and meta-analysis aimed to evaluate the survival rate and toxicities of such a combination in brain metastases.

METHODS

To perform a systematic review of the literature until January 2021 using electronic databases such as PubMed, Cochrane Library, and Embase; the Newcastle-Ottawa Scale was used to evaluate the quality of cohort studies. For data extraction, two reviewers extracted the data blindly and independently. Hazard ratio with 95% confidence interval (CI), fixed-effect model, and inverse-variance method was calculated. The meta-analysis has been evaluated with the statistical software Stata/MP v.16 (The fastest version of Stata).

RESULTS

In the first step, 494 studies were selected to review the abstracts, in the second step, the full texts of 86 studies were reviewed. Finally, 28 studies were selected consisting of 1465 patients. The addition of IT to RT in the treatment of brain metastasis from melanoma and non-small-cell lung carcinoma was associated with a 39% reduction in mortality rate and has prolonged overall survival, with an acceptable toxicity profile. The addition of IT to RT compared with RT alone has a hazard ratio of 0.39(95% CI 0.34-0.44).

CONCLUSIONS

A combination of immuno/radiotherapy (IR) for the treatment of patients with BMs from melanoma and non-small-cell lung carcinoma has prolonged overall survival and reduced mortality rate, with acceptable toxicity. In terms of timing, RT seems to have the best effect on the result when performed before or simultaneously with immunotherapy.

Anti-PD-1/Anti-PD-L1 Drugs and Radiation Therapy: Combinations and Optimization Strategies

Simple Summary

Although immune checkpoint blockade has yielded unprecedented and durable responses in cancer patients, the efficacy of this treatment remains limited. Radiation therapy can induce immunogenic cell death that contributes to the local efficacy of irradiation. However, radiation-induced systemic responses are scarce. Studies combining radiation with checkpoint inhibitors suggest a synergistic potential of this strategy. In this review, we focused on parameters that can be optimized to enhance the anti-tumor immune response that results from this association, in order to achieve data on dose, fractionation, target volume, lymph nodes sparing, radiation particles, and other immunomodulatory agents. These factors should be considered in future trials for better clinical outcomes. To this end, we discussed the main preclinical and clinical data available to optimize the efficacy of the treatment combination.

Abstract

Immune checkpoint inhibitors have been associated with long-term complete responses leading to improved overall survival in several cancer types. However, these novel immunotherapies are only effective in a small proportion of patients, and therapeutic resistance represents a major limitation in clinical practice. As with chemotherapy, there is substantial evidence that radiation therapy promotes anti-tumor immune responses that can enhance systemic responses to immune checkpoint inhibitors. In this review, we discuss the main preclinical and clinical evidence on strategies that can lead to an enhanced response to PD-1/PD-L1 blockade in combination with radiation therapy. We focused on central issues in optimizing radiation therapy, such as the optimal dose and fractionation for improving the therapeutic ratio, as well as the impact on immune and clinical responses of dose rate, target volume, lymph nodes irradiation, and type of radiation particle. We explored the addition of a third immunomodulatory agent to the combination such as other checkpoint inhibitors, chemotherapy, and treatment targeting the tumor microenvironment components. The strategies described in this review provide a lead for future clinical trials.

IRAK2, an IL1R/TLR Immune Mediator, Enhances Radiosensitivity via Modulating Caspase 8/3-Mediated Apoptosis in Oral Squamous Cell Carcinoma

Predicting and overcoming radioresistance are crucial in radiation oncology, including in managing oral squamous cell carcinoma (OSCC). First, we used RNA-sequence to compare expression profiles of parent OML1 and radioresistant OML1-R OSCC cells in order to select candidate genes responsible for radiation sensitivity. We identified IRAK2, a key immune mediator of the IL-1R/TLR signaling, as a potential target in investigating radiosensitivity. In four OSCC cell lines, we observed that intrinsically low IRAK2 expression demonstrated a radioresistant phenotype (i.e., OML1-R and SCC4), and vice versa (i.e., OML1 and SCC25). Next, we overexpressed IRAK2 in low IRAK2-expression OSCC cells and knocked it down in high IRAK2-expression cells to examine changes of irradiation response. After ionizing radiation (IR) exposure, IRAK2 overexpression enhanced the radiosensitivity of radioresistant cells and synergistically suppressed OSCC cell growth both in vitro and in vivo, and vice versa. We found that IRAK2 overexpression restored and enhanced radiosensitivity by enhancing IR-induced cell killing via caspase-8/3-dependent apoptosis. OSCC patients with high IRAK2 expression had better post-irradiation local control than those with low expression (i.e., 87.4% vs. 60.0% at five years, P = 0.055), showing that IRAK2 expression was associated with post-radiation recurrence. Multivariate analysis confirmed high IRAK2 expression as an independent predictor for local control (HR, 0.11; 95% CI, 0.016 – 0.760; P = 0.025). In conclusion, IRAK2 enhances radiosensitivity, via modulating caspase 8/3-medicated apoptosis, potentially playing double roles as a predictive biomarker and a novel therapeutic target in OSCC.

Combination of immunotherapy and radiotherapy in the treatment of brain metastases from non-small cell lung cancer

It was commonly assumed in the past that blood-brain barrier could efficiently prohibit penetration of large peptide molecules, such as monoclonal antibodies, including programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors. This belief has been recently revised by studies that demonstrate the presence of functional lymphatic vessels lining the dural sinuses. Furthermore, the activated circulating T cells have been shown to cross the blood-brain barrier. Such observations created strong rationale for attempts of immunotherapy for patients with brain metastases, used either alone or in combination with radiotherapy. The expected benefit from immunotherapy particularly refers to patients without targetable “driver” mutations who are not considered as candidates for novel targeted therapies. Current inference on efficacy and safety of combination of immunotherapy and radiotherapy in the treatment of brain metastases from non-small cell lung cancer (NSCLC) origins, in most, from the retrospective studies. The existing data suggest that use of immune checkpoint inhibitors (ICIs) with brain radiotherapy improves patients outcome, compared to brain radiotherapy alone. The available data also suggest that concurrent use of ICI and stereotactic radiation therapy (SRT) for brain metastases from NSCLC is tolerable and appears more effective than sequential combination of radiotherapy and ICI. Use of steroids appeared detrimental. Since a dependence between the risk of adverse events and type of ICI therapy as well as tumor pathology was found, further studies are required to establish optimal dosage, selection of drugs and sequence of ICI and brain radiotherapy in patients with brain metastases from NSCLC.

PD-1/PD-L1 Inhibitor Combined with Chemotherapy Can Improve the Survival of Non-Small Cell Lung Cancer Patients with Brain Metastases

Introduction

Immune checkpoint inhibitor (ICI) monotherapy has limited efficacy in patients with non-small cell lung cancer (NSCLC) and brain metastases (BMs). With the wide use of ICI-based combinations, the efficacy of different ICI combination strategies in patients with NSCLC and BMs needs to be further elucidated.

Methods

We retrospectively reviewed 526 patients with non-small cell lung cancer (NSCLC) treated with ICIs from January 2016 to December 2019 in the Shanghai Pulmonary Hospital. Patients with BMs treated with ICIs were further divided into two groups: those with BM prior to the ICI treatment (pBM group), and those with BM after the treatment (aBM group). We assessed intracranial progression-free survival (IPFS), systemic progression-free survival (SPFS), overall survival (OS), intracranial objective response rate (IORR), and intracranial disease control rate (IDCR).

Results

We found 77 patients out of 526 with BMs; 69 presented the BMs prior to the ICI treatments and 8 showed BMs after the ICI treatments. In the pBM group, the median IPFS and SPFS were 7.39 months and 5.39 months, respectively. Combination therapy significantly improved both the IPFS (p=0.007) and the SPFS (p=0.007) when compared with monotherapy. Further analysis demonstrated that ICIs combined with chemotherapy significantly improved both the IPFS (p=0.009) and the SPFS (p=0.006) when compared with monotherapy. While ICIs combined with anti-angiogenic therapy improved the SPFS (p=0.005) but not the IPFS (p=0.139). The median OS was 27.43 months for patients in the pBM group. Further analyses suggested that combination treatment also improved the OS when compared with monotherapy (p=0.003). Subgroup analysis results showed that ICIs combined with chemotherapy led to better OS than ICIs monotherapy (p=0.006). Radiotherapy had no significant impact on survival (IPFS p=0.272, OS p=0.142) in the patients of the pBM group.

Conclusion

ICIs combined with chemotherapy demonstrated survival benefits over ICI monotherapy in patients with NSCLCs and BMs.

Gamma Knife Radiosurgery for Brain Metastases in Non-Small Cell Lung Cancer Patients Treated with Immunotherapy or Targeted Therapy

Simple Summary

In non-small cell lung cancer patients with brain metastases, combined Gamma Knife radiosurgery and immunotherapy or targeted therapy showed an increase in overall survival. The combination of Gamma Knife radiosurgery and immunotherapy or targeted therapy did not increase complications related to radiosurgery. Therefore, the combined treatment seems to be a safe and powerful treatment option for non-small cell lung cancer patients with brain metastases.

Abstract

The combination of Gamma Knife radiosurgery (GKRS) and systemic immunotherapy (IT) or targeted therapy (TT) is a novel treatment method for brain metastases (BMs) in non-small cell lung cancer (NSCLC). To elucidate the safety and efficacy of concomitant IT or TT on the outcome after GKRS, 496 NSCLC patients with BMs, who were treated with GKRS were retrospectively reviewed. The median time between the initial lung cancer diagnosis and the diagnosis of brain metastases was one month. The survival after the initial BM diagnosis was significantly longer than the survival predicted by prognostic BM scores. After the first Gamma Knife radiosurgery treatment (GKRS1), the estimated median survival was 9.9 months (95% CI = 8.3–11.4). Patients with concurrent IT or TT presented with a significantly longer survival after GKRS1 than patients without IT or TT (p < 0.001). These significant differences in the survival were also apparent among the four treatment groups and remained significant after adjustment for Karnofsky performance status scale (KPS), recursive partitioning analysis (RPA) class, sex, and multiple BMs. About half of all our patients (46%) developed new distant BMs after GKRS1. Of note, no statistically significant differences in the occurrence of radiation reaction, radiation necrosis, or intralesional hemorrhage in association with IT or TT at or after GKRS1 were observed. In NSCLC-BM patients, the concomitant use of GKRS and IT or TT showed an increase in overall survival without increased complications related to GKRS. Therefore, the combined treatment with GKRS and IT or TT seems to be a safe and powerful treatment option and emphasizes the role of radiosurgery in modern BM treatment.

Management of oligometastatic and oligoprogressive renal cell carcinoma: state of the art and future directions

INTRODUCTION

The aim of this paper was to perform a narrative review of the literature on the available approaches in the treatment of two emerging subpopulations of metastatic renal cell carcinoma (mRCC) patients: the oligometastatic disease (less than 5 metastasis) and the oligoprogressive disease, defined as worsening in maximum 3-5 sites while all other tumor sites are controlled by systemic therapy.

AREAS COVERED

We explore all possible approaches in these settings of patients: the role of local therapies, considering both surgical metastasectomy and/or ablative techniques, the efficacy of systemic therapies and the rationale behind active surveillance. We also discuss ongoing clinical trials in these settings.

EXPERT OPINION

Two different strategies are emerging as the most promising for the approach to the oligometastatic/oligoprogressive mRCC patient: (1) the use of immunocheckpoint inhibitors following metastasectomy; (2) the use of stereotactic radiotherapy alone or combined with immunotherapy for oligometastatic disease. The lack of validated biomarkers of response in these mRCC patient subpopulations is opening the way to the employment of novel technologies. Among them, the use of artificial intelligence seems to be the candidate to contribute to precision oncology in patients with mRCC.

Treatment Outcome of metastatic lesions from renal cell carcinoma underGoing Extra-cranial stereotactic body radioTHERapy: The together retrospective study

OBJECTIVES

stereotactic body radiation therapy (SBRT) use has increased overtime for the management of metastatic renal cell carcinoma (mRCC) patients, with a likely good control of irradiated lesions. We planned a retrospective multicenter Italian study, with the aim of investigating the outcome of treatment with SBRT for non-brain secondary lesions in mRCC patients.

METHODS

all consecutive metastatic non-brain lesions from mRCC that underwent SBRT at nine Italian institutions from January 2015 to June 2017 were considered. The primary endpoint of the study was the lesion-PFS, calculated from SBRT initiation to the local progression of the irradiated lesion.

RESULTS

57 extracranial metastatic lesions from 48 patients with primary mRCC were treated with SBRT. At the median follow-up of 26.4 months, the median lesion-PFS was not reached (43 censored); 72.4% of lesions were progression-free at 40 months, with significantly better lesion-PFS for small metastatic lesions (<14 mm). SBRT was safe and the 1-year local disease control was 87.7%. After SBRT, 18 patients (37.5%) permanently interrupted systemic therapy.

CONCLUSIONS

consistently with the previous literature, our findings support the use of SBRT in selected mRCC patients.