Safety of Combined Immunotherapy and Thoracic Radiation Therapy: Analysis of 3 Single-Institutional Phase I/II Trials

Hyperacute Radiation Pneumonitis after Severe irAE

A 54-year-old woman presented to an outpatient clinic with a recurrence of triple-negative breast cancer and multiple bone metastases. The patient had a large mass lesion of 10 cm on the sternum. She received the immune checkpoint inhibitors pembrolizumab and taxane. Initially, the patient responded excellently to treatment, but stopped pembrolizumab for grade IV skin toxicity with multiple ulcerative wounds over the bilateral leg and trunk. The lesions abated following administration of antibiotics and oral prednisolone for two months. After that, she was referred to the radiation oncology department for further treatment. She received radiotherapy for the sternum mass but stopped radiation at 42Gy/21 fractions for severe dyspnea and fever. Blood sampling found leukocytosis with neutrophil predominance. Chest radiography showed bilateral lung infiltration. Pulmonary CT scan yielded bilateral lung patchy consolidation compatible with radiation isodose-line. Bronchial lavage showed positive Pneumocystis jiroveci PCR. Dyspnea improved after titrating methylprednisolone within two days. The patient recovered well with TMP-SMX and glucocorticoids after the initiation of therapy.

M, Gross CP, Slotman BJ, Chiang AC, Park HS. Differential Effect of Consolidative Thoracic Radiation Therapy in Extensive-Stage Small Cell Lung Cancer Based on Sex

Purpose

The landmark randomized trial on chest irradiation in extensive disease small cell lung cancer (CREST) demonstrated that consolidative thoracic radiation therapy (cTRT) improved overall (OS) and progression-free survival (PFS) after initial chemotherapy (chemo) in extensive-stage small cell lung cancer, with potentially increased benefit in women compared with men. It is unknown whether similar findings would apply after chemoimmunotherapy became the standard first-line treatment. In this analysis, we report national practice patterns and survival outcomes of cTRT according to patient sex.

Methods and Materials

We included patients from de-identified electronic health record-derived database diagnosed with stage IV small cell lung cancer (2014-2021) who completed 4 to 6 cycles of first-line systemic therapy (platinum-doublet chemotherapy or chemoimmunotherapy). We evaluated OS and PFS using multivariable Cox proportional hazards regression with receipt of cTRT as an independent variable and stratified by sex. As a sensitivity analysis, we weighted the models by the inverse probability of receiving cTRT.

Results

A total of 1227 patients were included (850 chemotherapy, 377 chemoimmunotherapy). There were no statistically significant differences in baseline characteristics between patients who did and did not receive cTRT. Among women, cTRT was associated with superior OS (adjusted hazard ratio [HR], 0.67; 95% CI, 0.52-0.87) and PFS (HR, 0.63; 95% CI, 0.49-0.82) compared with those not receiving cTRT. Conversely, no OS or PFS benefit with cTRT was observed in men (OS HR, 1.03; 95% CI, 0.80-1.31; PFS HR, 1.12; 95% CI, 0.85-1.47). Findings were similar in weighted analyses.

Conclusions

The survival efficacy of cTRT may be moderated by sex, with female patients appearing more likely to benefit than male patients. These findings reflect sex-based survival trends with similar effect sizes to those observed in the CREST trial. Although the underpinnings of this association need to be elucidated, stratification by sex should be considered for randomized-controlled trials studying cTRT in extensive-stage small cell lung cancer.

Effect of Sequence of Radiotherapy Combined With Immunotherapy on the Incidence of Pneumonitis in Patients With Lung Cancer: A Systematic Review and Network Meta-Analysis

BACKGROUND

With the widespread application of immune checkpoint inhibitor (ICI) combined with radiotherapy (RT) for the treatment of lung cancer, increasing attention has been paid to treatment-related pneumonitis. The effect of the treatment sequence on the incidence of pneumonitis remains unclear.

METHODS

We searched databases including PubMed, Embase, and ClinicalTrials.gov, meeting abstracts, and reference lists of relevant review articles for literature published on radio- and immunotherapy in lung cancer. Stata software (version 16.0) was used for meta-analysis. Data on the incidence of any grade and ≥ grade 3 pneumonitis was pooled using the random effects model. Bayesian network meta-analysis was used for arm-based pairwise comparisons. Subgroup analyses were performed to identify the potential influencing factors.

RESULTS

Thirty-eight studies met our inclusion criteria. The network meta-analysis showed no significant difference between the incidence of pneumonitis in concurrent ICI with RT (concurrent arm) and RT followed by ICI (RT-first arm) (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.10-4.81). In the meta-analysis of single group rates, RT following ICI (ICI-first arm) exhibited higher incidence of any grade pneumonitis compared with concurrent- and RT-first arms, with 0.321 (95% CI: 0.260-0.386) for programmed cell death protein 1 (PD-1) inhibitors from clinical trials, and 0.480 (95% CI: 0.363-0.598) for PD-1 inhibitors from real-world retrospective data, respectively.

CONCLUSION

No significant difference in the incidence of any grade and grade ≥ 3 pneumonitis was found between RT-first and concurrent arms. The ICI-first arm exhibited a higher incidence of pneumonitis, which needs to be further confirmed by follow-up studies.

Radiotherapy for extensive-stage small-cell lung cancer in the immunotherapy era

Currently, chemoimmunotherapy is the first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, only 0.8%-2.5% of the patients presented complete response after chemoimmunotherapy. Considering that ES-SCLC is highly sensitive to radiotherapy, the addition of radiotherapy after first-line treatment for ES-SCLC could further improve local control, which may be beneficial for patients' survival. Prior studies have shown that consolidative thoracic radiotherapy (cTRT) can decrease disease progression and improve overall survival in patients with ES-SCLC who respond well to chemotherapy. However, the efficacy and safety of cTRT in the immunotherapy era remain unclear owing to a lack of prospective studies. Prophylactic cranial irradiation (PCI) has been shown to decrease brain metastasis (BM) and prolong survival in patients with limited-stage SCLC in previous reports. However, according to current guidelines, PCI is not commonly recommended for ES-SCLC. Immunotherapy has the potential to reduce the incidence of BM. Whether PCI can be replaced with regular magnetic resonance imaging surveillance for ES-SCLC in the era of immunotherapy remains controversial. Whole brain radiation therapy (WBRT) is the standard treatment for BM in SCLC patients. Stereotactic radiosurgery (SRS) has shown promise in the treatment of limited BM. Considering the potential of immunotherapy to decrease BM, it is controversial whether SRS can replace WBRT for limited BM in the immunotherapy era. Additionally, with the addition of immunotherapy, the role of palliative radiotherapy may be weakened in patients with asymptomatic metastatic lesions. However, it is still indispensable and urgent for patients with obvious symptoms of metastatic disease, such as spinal cord compression, superior vena cava syndrome, lobar obstruction, and weight-bearing metastases, which may critically damage the quality of life and prognosis. To improve the outcome of ES-SCLC, we discuss the feasibility of radiotherapy, including cTRT, PCI, WBRT/SRS, and palliative radiotherapy with immunotherapy based on existing evidence, which may offer specific prospects for further randomized trials and clinical applications.

The role of thoracic consolidative radiotherapy in the setting of immunotherapy in extensive stage small cell lung cancer

The improvement in treatment strategies and outcomes in small cell lung cancer (SCLC) has lagged behind other cancers. The addition of immune checkpoint inhibitors (ICIs), durvalumab and atezolizumab, to the platinum-based chemotherapy in frontline setting has improved the survival in extensive stage SCLC, (ES-SCLC), albeit modestly, and is now the new standard of care. Prior to advent of immunotherapy into the therapeutic armamentarium in ES-SCLC, consolidative thoracic radiotherapy (TRT) was associated with improved thoracic control and survival outcomes. In the era of ICIs, the role of TRT is not well defined, chiefly because TRT was not incorporated in any immunotherapy trials, secondly due to concerns regarding the increased risks of pneumonitis, and finally uncertain magnitude of benefit with this combined approach. In principle, radiation can increase in the immunogenicity of tumor and hence the activity of immune checkpoint blockade, thereby increasing efficacy both locally and distantly. Such an approach has been promising in non-small cell lung cancer with ICIs improving outcomes after concurrent chemoradiation, but remains unanswered in ES-SCLC. It is, thus, possible that the modest improvement in survival by addition of ICIs to chemotherapy in ES-SCLC can be further improved by the incorporation of consolidative TRT in selected patients. Several early phase trials and retrospective studies have suggested that such an approach may be feasible and safe. Prospective trials are ongoing to answer whether adding radiation therapy to chemoimmunotherapy will improve outcomes in ES-SCLC.

Re-evaluating the risk factors for radiation pneumonitis in the era of immunotherapy

As one of the common complications of radiotherapy, radiation pneumonia (RP) limits the prognosis of patients. Therefore, better identifying the high-risk factors that lead to RP is essential to effectively prevent its occurrence. However, as lung cancer treatment modalities are being replaced and the era of immunotherapy has arrived, literature that reviews the parameters and mode of radiotherapy, chemotherapy drugs, targeted drugs and current hot immune checkpoint inhibitors related to RP is lacking. This paper summarizes the risk factors for radiation pneumonia by retrieving and analysing previously published literature and the results of large clinical trials. The literature primarily included retrospective analyses, including clinical trials in different periods and a part of the literature review. A systematic literature search of Embase, PubMed, Web of Science, and Clinicaltrials.gov was performed for relevant publications up to 6 Dec. 2022. Search keywords include, but are not limited to, "radiation pneumonia", "pneumonia", "risk factors", "immunotherapy", etc. The factors related to RP in this paper include physical parameters of radiotherapy, including V₅, V₂₀, and MLD; chemoradiotherapy mode and chemotherapy drugs, including paclitaxel and gemcitabine; EGFR-TKI; ALK inhibitors; antiangiogenic drugs; immune drugs and the underlying disease of the patient. We also introduce the possible mechanism of RP. In the future, we hope that this article not only sounds the alarm for clinicians but also helps to identify a method that can effectively intervene and reduce the occurrence of RP, significantly improve the quality of life and prognosis of patients, and more effectively improve the therapeutic effect of radiation therapy.

Real-World Efficacy and Safety of Thoracic Radiotherapy after First-Line Chemo-Immunotherapy in Extensive-Stage Small-Cell Lung Cancer

(1) Background: At present, the efficacy and safety of thoracic radiotherapy (TRT) after chemo-immunotherapy (CT-IT) in patients with extensive-stage small-cell lung cancer (ES-SCLC) still remain unclear. The purpose of this study was to evaluate the role of TRT after CT-IT in patients with ES-SCLC. (2) Methods: From January 2020 to October 2021, patients with ES-SCLC treated with first-line anti-PD-L1 antibody plus platinum-etoposide chemotherapy were enrolled retrospectively. The survival data and adverse events data of patients treated with or without TRT after CT-IT were collected for analysis. (3) Results: A total of 118 patients with ES-SCLC treated with first-line CT-IT were retrospectively enrolled, with 45 patients with TRT and 73 patients without TRT after CT-IT. The median PFS and OS in the CT-IT + TRT group and CT-IT only group were 8.0 months versus 5.9 months (HR = 0.64, p = 0.025) and 22.7 months versus 14.7 months (HR = 0.52, p = 0.015), respectively. The median PFS and OS in all 118 patients treated with first-line CT-IT were 7.2 and 19.8 months with an ORR of 72.0%. In multivariate analyses, liver metastasis and response to CT-IT were shown to be independent prognostic factors of PFS (p < 0.05), while liver metastasis and bone metastasis were independent predictive factors of OS (p < 0.05). Although TRT was significantly associated with better PFS and OS in univariate analysis, the association of TRT and OS failed to reach statistical significance (HR = 0.564, p = 0.052) in multivariate analysis. There was no significant difference in adverse events (AEs) between two treatment groups (p = 0.58). (4) Conclusions: ES-SCLC patients treated with TRT after first-line CT-IT had prolonged PFS and OS with an acceptable safety profile. Further prospective randomized studies are necessary to explore the efficacy and safety of this treatment modality for ES-SCLC in future.

First-line atezolizumab/durvalumab plus platinum-etoposide combined with radiotherapy in extensive-stage small-cell lung cancer

BACKGROUND

Immunotherapy has made significant advances in the treatment of extensive-stage small-cell lung cancer (ES-SCLC), but data in combination with radiotherapy are scarce. This study aims to assess the safety and efficacy of chemoimmunotherapy combined with thoracic radiotherapy in patients with ES-SCLC.

METHODS

This single-center retrospective study analyzed patients with ES-SCLC who received standard platinum-etoposide chemotherapy combined with atezolizumab or durvalumab immunotherapy as induction treatment, followed by consolidative thoracic radiotherapy (CTRT) before disease progression in the first-line setting. Adverse events during radiotherapy with or without maintenance immunotherapy and survival outcomes were assessed.

RESULTS

Between December 2019 and November 2021, 36 patients with ES-SCLC were identified to have received such treatment modality at one hospital. The number of metastatic sites at diagnosis was 1-4. The biological effective dose of CTRT ranged from 52 to 113 Gy. Only two patients (6%) developed grade 3 toxic effect of thrombocytopenia, but none experienced grade 4 or 5 toxicity. Four patients developed immune-related pneumonitis during the induction treatment period but successfully completed later CTRT. The rate of radiation-related pneumonitis was 8% with grades 1-2 and well tolerated. The median progression-free survival (PFS) was 12.8 months, but the median overall survival (OS) was not determined. The estimated 1-year OS was 80.2% and 1-year PFS was 53.4%.

CONCLUSIONS

Immunotherapy combined with CTRT for ES-SCLC is safe and has ample survival benefit.

Safety and Efficacy of Concurrent or Sequential Radiotherapy Plus (PD-1) Inhibitors in Oligometastatic Esophageal Cancer

Purpose

We assess real-world outcomes, including safety and efficacy, of concurrent or sequential treatment with radiotherapy plus programmed cell death protein 1 (PD-1) inhibitors in patients with oligometastatic esophageal cancer (OMEC).

Methods

This cohort study retrospectively collected clinical data of patients with synchronous or metachronous OMEC. All patients underwent concurrent or sequential treatment with radiotherapy plus PD-1 inhibitors. Each patient had up to five measurable metastatic lesions and up to three organs involved. Study endpoints were progression-free survival (PFS), treatment-related toxicities, locoregional progression-free survival (LRPFS), objective response rate (ORR), and disease control rate (DCR). Description statistics and Kaplan-Meier models were used for statistical analysis.

Results

A total of 86 patients were included, most of whom were diagnosed with squamous cell carcinoma histology (98%) and presented with synchronous OMEC (64%). The median follow-up period was 17 months (range: 6-32 months), the median PFS was 15.2 months (95% confidence interval: 12.1-18.2 months); and the 1- and 2-year PFS rates were 61.4% and 26.7%, respectively. The 1- and 2-year LRPFS were 91.3% and 57.3%, respectively. The ORR and DCR were 46.5% and 91.8%, respectively. Forty-two patients (48.8%) experienced grade 3 or higher treatment-related adverse events (TRAEs); a grade 5 treatment-related adverse event was observed in one patient (1.2%) who died of immune-related pneumonitis.

Conclusion

Combining radiotherapy with PD-1 inhibitors is a safe and effective treatment option for patients with OMEC. No new safety concerns were identified in this study. However, due to the potential risk of cumulative toxicity, an individual risk-benefit assessment for each patient is required prior to treatment initiation.

Ovarian Cancer Radiosensitivity: What Have We Understood So Far?

Radiotherapy has been increasingly considered as an active treatment to combine with other approaches (i.e., surgery, chemotherapy, and novel target-based drugs) in ovarian cancers to palliate symptoms and/or to prolong chemotherapy-free intervals. This narrative review aimed to summarize the current knowledge of the radiosensitivity/radioresistance of ovarian cancer which remains the most lethal gynecological cancer worldwide. Indeed, considering the high rate of recurrence in and out of the radiotherapy fields, in the era of patient-tailored oncology, elucidating the mechanisms of radiosensitivity and identifying potential radioresistance biomarkers could be crucial in guiding clinical decision-making.

Radiotherapy improves the outcomes of immunotherapy with Sintilimab in non-small-cell lung cancer: A real-world analysis

Introduction

Radiotherapy may augment systemic antitumor responses to immunotherapy. We did a retrospective study to infer whether radiotherapy improves outcomes to immunotherapy in patients with stage III and IV non-small-cell lung cancer (NSCLC).

Methods

This retrospective study conducted at Enze Medical Center enrolled 259 patients with histopathology confirmed NSCLC from December 2018 to December 31, 2021. All were treated with Sintilimab, some patients received radiotherapy at an appropriate time point. Radiation type includes conventional radiotherapy and stereotactic body radiotherapy. The progression-free survival (PFS), and overall survival (OS) were the primary endpoint.

Results

A retrospective analysis was performed on 259 patients, of whom 140 had been treated with immunotherapy lonely and 119 had been remedied with immunotherapy plus radiotherapy. Baseline variables were well balanced between the two groups, including gender, age, smoking status, TNM staging, number of metastases, ECOG score, pathological type and lines of previous systemic therapy. The median PFS in the immunotherapy alone group was 5.00 months (95%CI 4.38-5.62) versus immunotherapy plus radiotherapy was 9.00 months (5.95-12.05; p<0.001). The median OS in the immunotherapy alone group was 16.00 months (12.59-19.42) versus immunotherapy plus radiotherapy was 30.00 months (20.75-39.25; p=0.027). PFS was finer in the radiotherapy plus immunotherapy group than the immunotherapy group alone in both stage III(P=0.0069) and Stage IV(P=0.006) patients. In the univariate analysis, radiotherapy, male, ECOG=0 and <2 lines of previous systemic therapy were connected with an observably better PFS (P<0.001; P=0.03; P=0.002;P=0.021). In a multivariate analysis, radiotherapy, ECOG=0 and <2 lines of previous systemic therapy were independent prognostic factors with a markedly better PFS (P<0.001; P=0.006;P=0.009). An univariate analysis, radiotherapy, male, stage III, non-metastasis, ECOG=0 and squamous carcinoma were associated with a significantly better OS (P=0.032, P=0.036,P=0.002,P<0.001,P=0.002,P=0.025). A multivariate analysis, non-metastasis was a standalone prognostic indicator with a significantly better OS (P=0.006). However, radiotherapy was a tendency indicator with a better OS (HR0.70 95% CI 0.47-1.06). There were also no obvious increases in adverse events in the combination group.

Conclusions

Radiotherapy with addition of immunotherapy was observably linked to a better outcome in patients with III and IV staging NSCLC.

The Combined Clinical Efficacy and Safety Analysis of Adoptive Immunotherapy with Radiotherapy and Chemotherapy in Non-Small-Cell Lung Cancer: Systematic Review and Meta-Analysis

Objective

To explore the differential efficacy of chemoradiotherapy combined with adoptive immunotherapy and radiochemotherapy alone in patients with non-small-cell lung cancer (NSCLC).

Methods

Qualified randomized controlled trial (randomized controlled trial, RCT), or nonrandomized concurrent controlled trial (NRCCT), published in various databases, including PubMed, EMBASE, Chinese journal full-text database, Medline, Cochrane database, and VIP Chinese database, and the Revman5. 0 software performed the data analysis.

Results

We found the significantly different curative effect between the experimental and control groups (OR = 1.94, 95% CI (1.46, 2.58), P < 0.001, I 2 = 0%, Z = 4.59), effect of adoptive immunotherapy on the progression of disease (OR = 1.80, 95% CI (1.38, 2.35), P < 0.001, I 2 = 0%, Z = 4.33), adoptive immunotherapy on overall survival (OR = 2.19, 95% CI (1.60, 2.99), P < 0.001, I 2 = 0%, Z = 4.91), and adverse effects of adoptive immunotherapy (OR = 1.76, 95% CI (1.25, 2.48), P = 0.001, I 2 = 0%, Z = 3.26).

Conclusion

Adoptive immunotherapy combined with microradiotherapy can decrease the recurrence of NSCLC and improve patient survival, as well as early patients can be benefited more significantly from immunotherapy.

Optimize Local Therapy for Oligometastatic and Oligoprogressive Non-Small Cell Lung Cancer to Enhance Survival

Metastatic non-small cell lung cancer (NSCLC) is highly heterogeneous, and there are patients with limited areas of metastases (oligometastases) or progression (oligoprogression) whose natural history and prognosis can be considerably more favorable. As a result, local therapy may offer these patients a chance at clinically meaningful disease control and/or cure. This review begins by describing the current status of the existing prospective data, including evidence of overall survival improvements from multiple randomized trials. Given the nascence of this realm, the review then examines ongoing controversies and unresolved issues regarding local therapy for oligometastatic and oligoprogression. First, the role of local therapy in the setting of targeted therapies and immunotherapy is discussed, because most published randomized trials of local therapy have been performed in the context of chemotherapy, which is no longer the standard of care for most patients with metastatic NSCLC. Refining patient selection for local therapy is then reviewed, including clinical factors (such as control of the primary and regional lymph node sites, the heterogeneous definitions of oligometastases/oligoprogression, and the underrepresentation of brain metastases in existing randomized data) and novel pathologic/molecular biomarkers. Next, because there also remains no consensus regarding the optimal modality of local therapy, the advantages and disadvantages of stereotactic radiotherapy, surgery, and other ablative techniques are discussed. Subsequently, methods to optimize radiotherapy are examined, including controversies regarding the optimal dose/fractionation and timing/sequencing scheme. A discussion regarding potentially extending the existing data to polymetastatic NSCLC follows. The review concludes with remarks regarding prudently designing randomized trials of local therapy going forward, including the benefits and drawbacks of specific endpoints meriting further testing in this unique population.

Dosimetric Risk Factors for Acute Radiation Pneumonitis in Patients With Prior Receipt of Immune Checkpoint Inhibitors

Purpose

Dosimetric parameters (e.g., mean lung dose (MLD), V20, and V5) can predict radiation pneumonitis (RP). Constraints thereof were formulated before the era of combined immune checkpoint inhibitors (ICIs) and radiotherapy, which could amplify the RP risk. Dosimetric predictors of acute RP (aRP) in the context of ICIs are urgently needed because no data exist thus far.

Methods and Materials

All included patients underwent thoracic intensity-modulated radiotherapy, previously received ICIs, and followed-up at least once. Logistic regression models examined predictors of aRP (including a priori evaluation of MLD, V20, and V5), and their discriminative capacity was assessed by receiver operating characteristic analysis.

Results

Median follow-up of the 40 patients was 5.3 months. Cancers were lung (80%) or esophageal (20%). ICIs were PD-1 (85%) or PD-L1 (15%) inhibitors (median 4 cycles). Patients underwent definitive (n=19), consolidative (n=14), or palliative (n=7) radiotherapy; the median equivalent dose in 2 Gy fractions (EQD2) was 60 Gy (IQR, 51.8-64 Gy). Grades 1-5 aRP occurred in 25%, 17.5%, 15%, 2.5%, and 5%, respectively. The only variables associated with any-grade aRP were V20 (p=0.014) and MLD (p=0.026), and only V20 with grade ≥2 aRP (p=0.035). Neither the number of prior ICI cycles nor the delivery of concurrent systemic therapy significantly associated with aRP risk. Graphs were constructed showing the incrementally increasing risk of aRP based on V20 and MLD (continuous variables).

Conclusions

This is the first study illustrating that V20 and MLD may impact aRP in the setting of prior ICIs. However, these data should not be extrapolated to patients without pre-radiotherapy receipt of prior ICIs, or to evaluate the risk of chronic pulmonary effects. If these results are validated by larger studies with more homogeneous populations, the commonly accepted V20/MLD dose constraints could require revision if utilized in the setting of ICIs.

Consolidative Thoracic Radiation Therapy After First-Line Chemotherapy and Immunotherapy in Extensive-Stage Small Cell Lung Cancer: A Multi-Institutional Case Series

Purpose

Survival for patients with extensive-stage small cell lung cancer (ES-SCLC) remains poor. Consolidative thoracic radiation therapy (cTRT) and upfront immunotherapy with chemotherapy have each incrementally improved patient outcomes, but have not yet been combined in clinical trials. We sought to characterize outcomes and toxicities after first-line chemotherapy and immunotherapy followed by cTRT.

Methods and Materials

Patients with ES-SCLC who were treated with first-line chemotherapy and immunotherapy followed by cTRT were identified at 2 institutions. Patient outcomes including overall survival (OS), progression-free survival, local progression-free survival, distant progression free-survival, and toxicity were assessed.

Results

Twenty patients were included in our data set treated from 2018 to 2021 with a median follow-up of 12 months. Median OS in this cohort was 16 months with 6-month OS of 94.7% and 12-month OS of 77.5% (comparable to historical controls). There were also low rates of toxicity, including 0% grade 3+ toxicity, 0% grade 2 pneumonitis, and 5% grade 2 esophagitis.

Conclusions

Treatment of ES-SCLC with first-line chemoimmunotherapy followed by cTRT appears to be safe and to have outcomes comparable to published modern clinical trials. Further studies are warranted to determine the therapeutic effect of cTRT after chemoimmunotherapy.

Prospective Clinical Investigation of the Efficacy of Combination Radiation Therapy With Immune Checkpoint Inhibition

Immune checkpoint inhibitors (ICIs) lead to durable responses in a subset of patients with cancer, but most patients do not respond to ICI, prompting interest in combining immunotherapy with other therapeutic regimens. Preclinical evidence supports the potential for therapeutic synergy between immunotherapy and radiation therapy through modulation of the tumor microenvironment and antitumor immune responses. Local therapy also has the potential to overcome localized sites of relative immune suppression and resistance. Prospective clinical trials have been initiated to test these hypotheses in the clinic as well as to investigate the toxicities and adverse events associated with combination immunotherapy and radiation therapy. In this review, we discuss the emerging results from prospective clinical trials of combination immunotherapy and radiation therapy, the safety and efficacy of their combination, concordance with preclinical and retrospective data, and some of the remaining open questions to be addressed by future clinical trials.

Pulsed Radiation Therapy to Improve Systemic Control of Metastatic Cancer

Radiation therapy (RT) is emerging as an interventional modality in the cancer-immunity cycle, augmenting the activation of an adaptive immune response against tumors. RT, particularly in combination with immunotherapy, can enhance immune memory effects and shape the tumor-directed T-cell populations. However, a single cycle of RT delivered to a limited number of polymetastatic lesions is rarely sufficient to achieve systemic control. We hypothesize that several rounds of RT, akin to several rounds of immunotherapeutic drugs, is likely to provide greater clinical benefit to patients with metastatic disease. We propose that the repeated exposure to tumor antigens released by “pulsed-RT” (i.e., treating 2-4 tumor lesions with 3 irradiation cycles given one month apart) may amplify the adaptive immune response by expanding the tumor-specific T-cell receptor repertoire, the production of high-affinity tumor antibodies, and the generation of memory lymphocytes and thereby improve immune control of systemic disease.

High-dose irradiation in combination with non-ablative low-dose radiation to treat metastatic disease after progression on immunotherapy: Results of a phase II trial

AIM

To report early findings from a phase II trial of high-dose radiotherapy (HD-RT) with or without low-dose RT (LD-RT) for metastatic cancer.

METHODS

Eligible patients had metastatic disease that progressed on immunotherapy within 6 months. Patients were given either HD-RT (20-70 Gy total; 3-12.5 Gy/f), or HD-RT + LD-RT (0.5-2 Gy/f up to 1-10 Gy total) to separate lesions, with continued immunotherapy. Radiographic response was assessed per RECIST 1.1 and Immune-Related Response Criteria (irRC). Primary endpoints: (1) 4-month disease control (DCR, complete/partial response [CR/PR] or stable disease [SD]) or an overall response (ORR, CR/PR) at any point in ≥10% of patients, per RECIST 1.1; (2) dose-limiting toxicity within 3 months not exceeding 30%. Secondary endpoint was lesion-specific response.

RESULTS

Seventy-four patients (NSCLC, n = 38; melanoma n = 21) were analyzed (39 HD-RT and 35 HD-RT + LD-RT). The median follow-up time was 13.6 months. The primary endpoint was met for 72 evaluable patients, with a 4-month DCR of 42% (47% [16/34] vs. 37% [14/38] in HD-RT + LD-RT vs. HD-RT, P = 0.38), and 19% ORR at any time (26% [9/34] vs. 13% [5/38] in HD-RT + LD-RT vs. HD-RT, P = 0.27). Three patients had toxicity ≥grade 3. LD-RT lesion response (53%) was improved compared to nonirradiated lesions in HD-RT + LD-RT (23%, P = 0.002) and HD-RT (11%, P < 0.001). T- and NK cell infiltration was enhanced in lesions treated with LD-RT.

CONCLUSIONS

HD-RT plus LD-RT safely improved lesion-specific response in patients with immune resistant solid tumors by promoting infiltration of effector immune cells into the tumor microenvironment.

Imaging Features of Pulmonary Immune-related Adverse Events

Pulmonary immune-related adverse events represent rare but potentially severe side effects of immunotherapies. Diagnosis is often challenging, as symptoms and imaging features are not specific and may mimic other lung diseases, thus potentially delaying appropriate patient management. In this setting, an accurate imaging evaluation is essential for a prompt detection and correct management of these drug-induced lung diseases. The purpose of this article is to review the different types of pulmonary immune-related adverse events, describe their imaging characteristics on both high-resolution computed tomography and positron emission tomography/computed tomography and stress their underlying diagnostic challenge by presenting the mimickers.

Modified Glasgow Prognostic Score is predictive of prognosis for non-small cell lung cancer patients treated with stereotactic body radiation therapy: a retrospective study

We aimed to assess the predictive value of the modified Glasgow prognostic score (mGPS) in patients with non-small cell lung cancer (NSCLC) who underwent stereotactic body radiation therapy (SBRT). We retrospectively reviewed the records of 207 patients, with a median age of 79 years. The pretreatment mGPS was calculated and categorized as high (mGPS = 1-2) or low (mGPS = 0). The median follow-up duration was 40.7 months. The five-year overall survival (OS), progression-free survival (PFS) and time to progression (TTP) rates were 44.3%, 36% and 54.4%, respectively. Multivariate analysis revealed that mGPS was independently predictive of OS (hazard ratio [HR] 1.67; 95% confidence interval 1.14-2.44: P = 0.009), PFS (HR 1.58; 1.10-2.28: P = 0.014) and TTP (HR 1.66; 1.03-2.68: P = 0.039). Patients who had high mGPS showed significantly worse OS (33.3 vs 64.5 months, P = 0.003) and worse PFS (23.8 vs 39 months, P = 0.008) than those who had low mGPS. The data showed a trend that patients with high mGPS suffered earlier progression compared to those with low mGPS (54.3 vs 88.1 months, P = 0.149). We confirmed that mGPS is independently predictive of prognosis in NSCLC patients treated with SBRT.

The utilization of immunotherapy with radiation therapy in lung cancer: a narrative review

Despite decreasing smoking rates, lung cancer remains the leading cause of death from cancer in the United States. Radiation therapy has been established as an effective locoregional therapy for both early stage and locally advanced disease and is known to stimulate local immune response. Past treatment paradigms have established the role of combining cytotoxic chemotherapy regimens and radiation therapy to help address the local and systemic nature of lung cancer. However, these regimens have limitations in their tolerability due to toxicity. Additionally, cytotoxic chemotherapy has limited efficacy in preventing systemic spread of lung cancer. Newer systemic agents such as immune checkpoint inhibitors have shown improved survival in metastatic and locally advanced lung cancer and have the advantage of more limited toxicity profiles compared to cytotoxic chemotherapy. Furthermore, improved overall response rates and systemic tumor responses have been observed with the combination of radiation therapy and immunotherapy, leading to numerous active clinical trials evaluating the combination of immune checkpoint inhibition with radiotherapy. This comprehensive review discusses the current clinical data and ongoing studies evaluating the combination of radiation therapy and immunotherapy in both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

The NIPRO Study: An Observational, Retrospective, Multicenter Study on the Safety of the Radiotherapy and Immunotherapy Combination for Advanced-Stage NSCLC

INTRODUCTION

In this observational, retrospective, multicenter study, we aimed to assess the safety of the combination of local metastasis-directed radiotherapy (RT) and immunotherapy (IT) in a cohort of advanced non-small-cell lung cancer (aNSCLC) patients.

MATERIAL AND METHODS

We collected clinical data of aNSCLC patients who received concomitant RT and anti-PD-1/PD-L1 inhibitors in seven Italian centers from September 2015 to June 2019. Concomitant RT was defined as delivered ≤4 weeks before or after the first or last administration of immunotherapy, or within two consecutive cycles of ICI. All adverse events apparently related to RT and/or IT were graded according to the Common Terminology Criteria for Adverse Events, version 4.0, and reported in terms of incidence and severity as immune related or RT related, or combined.

RESULTS

We analyzed the clinical charts of 187 patients. Median follow-up time was 23 months, and median overall survival was 16.5 months (range, 3-162). Thirteen patients developed pure RT-related side effects, and 43 patients (23.9%) developed immune-related side effects. No additive toxic effects were observed. A case of grade 5 pulmonary toxicity was recorded as a possible consequence of a combined effect.

CONCLUSION

This analysis suggests that the combination of concomitant RT and anti-PD-1/PD-L1 agents is safe, and the two toxicity profiles are independent.

PD-1 restrains IL-17A production from γδ T cells to modulate acute radiation-induced lung injury

Background

Combining radiotherapy (RT) with programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors has been shown to enhance anti-tumor effects in the treatment of non-small cell lung carcinoma (NSCLC). Pulmonary toxicity is a major adverse effect of thoracic RT in NSCLC patients, whether it is administered alone or in combination with PD-1/PD-L1 inhibitors. This study aimed to evaluate the potential pulmonary toxicity of RT combined with concurrent PD-1 inhibitor and to clarify the underlying mechanisms.

Methods

Radiation-induced lung injury (RILI) was induced in C57BL/6 mice by given 24 Gy in three fractions on consecutive days, with or without concurrent injection of anti-PD-1 antibody. On days 3, 7, 14, and 28 after the first exposure to irradiation, lung tissue and peripheral blood samples were collected from the mice. Histological injury was analyzed, and inflammatory cell infiltration and interleukin (IL)-17A production in the lung tissues were quantified.

Results

Mice that received irradiation with concurrent administration of anti-PD-1 antibody had the highest histological score for RILI. In the murine lung tissues, the levels of PD-1 and IL-17A expression were increased in γδ T cells but not in the other CD3⁺ T cells after irradiation. Concurrent blockade of PD-1 enhanced IL-17A production from γδ T cells in the lung tissues after irradiation. In the mice with acute RILI, concurrent administration of anti-PD-1 antibody exaggerated pulmonary inflammation, with significantly increased levels of neutrophilic infiltration and IL-17A detected in both the lung and blood.

Conclusions

PD-1 could restrain IL-17A production from γδ T cells to modulate acute RILI. The concurrent administration of anti-PD-1 antibody aggravates the severity of acute RILI. More attention should be paid to pulmonary toxicity in patients undergoing thoracic RT with concurrent anti-PD-1 immunotherapy.

Synergy between early-incorporation immunotherapy and extracranial radiotherapy in metastatic non-small cell lung cancer

Background

Combining radiotherapy (RT) and immunotherapy (IT) may enhance outcomes for metastatic non-small cell lung cancer (mNSCLC). However, data on the immunomodulatory effects of extracranial RT remains limited. This retrospective database analysis examined real-world practice patterns, predictors of survival, and comparative effectiveness of extracranial radioimmunotherapy (RT + IT) versus early-incorporation immunotherapy (eIT) in patients with mNSCLC.

Methods

Patients diagnosed with mNSCLC between 2004-2016 treated with eIT or RT + IT were identified in the National Cancer Database. Practice patterns were assessed using Cochrane-Armitrage trend test. Cox proportional hazards and Kaplan-Meier method were used to analyze overall survival (OS). Propensity score matching was performed to account for baseline imbalances. Biologically effective doses (BED) were stratified based on the median (39 Gy₁₀). Stereotactic body radiotherapy (SBRT) was defined as above median BED in ≤5 fractions.

Results

eIT utilization increased from 0.3% in 2010 to 13.2% in 2016 (P<0.0001). Rates of RT + eIT increased from 38.8% in 2010 to 49.1% in 2016 among those who received eIT (P<0.0001). Compared to eIT alone, RT + eIT demonstrated worse median OS (11.2 vs. 13.2 months) while SBRT + eIT demonstrated improved median OS (25 vs. 13.2 months) (P<0.0001). There were no significant differences in OS based on sequencing of eIT relative to RT (log-rank P=0.4415) or irradiated site (log-rank P=0.1606). On multivariate analysis, factors associated with improved OS included chemotherapy (HR 0.86, P=0.0058), treatment at academic facilities (HR 0.83, P<0.0001), and SBRT (HR 0.60, P=0.0009); after propensity-score multivariate analysis, SBRT alone showed improved OS (HR 0.28, P<0.0001).

Conclusions

Utilization of RT + eIT in mNSCLC is increasing. SBRT + eIT was associated with improved OS on propensity-score matched analysis. There were no significant differences in OS based on RT + eIT sequencing or site irradiated. Whether these observations reflect patient selection or possible immunomodulatory benefits of RT is unclear and warrants further study.

Phase I/II Study of Stereotactic Body Radiation Therapy for Pulmonary Metastases in Pediatric Patients

Purpose

Pulmonary metastases are common in many pediatric solid tumors; however, little is known about safety and efficacy of lung stereotactic body radiation therapy (SBRT) for pediatric patients. We conducted a phase I/II study to investigate the minimum effective dose level of SBRT with an acceptable safety profile in pediatric patients.

Methods and Materials

Patients with sarcoma and metastatic pulmonary lesions ≤3 cm in diameter and ≤21 years of age were enrolled. Dose levels 1, 2, and 3 were 24, 30, and 36 Gy in 3 fractions, respectively. Enrolled patients with metastases from primary renal tumors and sarcoma histologies were to begin at dose level 1 and 2, respectively. Exclusion criteria included receipt of whole-lung/hemi-thorax irradiation >12 Gy within 6 months of consent. Primary endpoints were tolerability and safety per Common Terminology Criteria for Adverse Events grading and disease response at 6 weeks post-SBRT per response evaluation criteria in solid tumors (RECIST) 1.1 criteria. Secondary endpoints included rates of local control and distant failure within the lung, but outside of the treatment volume.

Results

Five patients with median age of 13 years (range, 7-21) received SBRT at dose level 2. Primary tumor histologies included Ewing sarcoma (n = 3), anaplastic chordoma (n = 1), and osteosarcoma (n = 1). No grade ≥3 adverse events were observed. At 6 weeks after SBRT, 7/8 (87.5%) lesions achieved partial response. With median follow-up of 2.1 years (range, 1.4-2.5), 2-year local control and distant failure-free survival were 60% (n = 8) and 40% (n = 5), respectively. One patient developed widespread metastases and succumbed to disease 1.4 years after SBRT.

Conclusions

SBRT for pulmonary metastases produces responses in pediatric patients with sarcoma at 6 weeks with acceptable toxicity; however, patients remain at risk of local and distant failure within the lung. Future prospective studies are needed to investigate whether higher doses of SBRT, possibly in combination with other therapies, are safe and provide more durable response.

Response and outcomes after anti-CTLA4 versus anti-PD1 combined with stereotactic body radiation therapy for metastatic non-small cell lung cancer: retrospective analysis of two single-institution prospective trials

BACKGROUND

This study compared response rates and outcomes of combined radiotherapy and immunotherapy (iRT) based on the type of checkpoint inhibitor (anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) vs antiprogrammed death-1 (PD1)) for metastatic non-small cell lung cancer (mNSCLC).

METHODS

We retrospectively reviewed two prospective trials of radiation combined with anti-CTLA4 or anti-PD1 for patients with mNSCLC. Patients undergoing non-salvage stereotactic body radiation therapy (SBRT) to lung sites were selected from both trials and grouped by the immunotherapeutic compound received. Endpoints included in-field and out-of-field response rates, and overall response rate (complete or partial response) (all by response evaluation criteria in solid tumors). Progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method.

RESULTS

Median follow-up times for the 33 patients (n=17 SBRT+anti-CTLA4, n=16 SBRT+anti-PD1) were 19.6 and 19.9 months. Response rates for out-of-field lesions were similar between anti-PD1 (37%) and anti-CTLA4 (24%) (p=0.054). However, global response rates for all lesions were 24% anti-CTLA4 vs 56% anti-PD1 (p=0.194). The PFS was 76% for anti-CTLA4 vs 94% anti-PD1 at 3 months, 52% vs 87% at 6 months, 31% vs 80% at 12 months, and 23% vs 63% at 18 months (p=0.02). Respective OS values were 76% vs 87% at 6 months, 47% vs 80% at 12 months, and 39% vs 66% at 18 months (p=0.08).

CONCLUSIONS

Both anti-CTLA4 and anti-PD1 agents prompt a similar degree of in-field and out-of-field responses after iRT, although the global response rate and PFS were statistically higher in the anti-PD1 cohort. Further dedicated study and biological mechanistic assessment is required.

TRIAL REGISTRATION NUMBERS

NCT02239900 and NCT02444741.

Low-dose radiation treatment enhances systemic antitumor immune responses by overcoming the inhibitory stroma

Background

Despite some successes with checkpoint inhibitors for treating cancer, most patients remain refractory to treatment, possibly due to the inhibitory nature of the tumor stroma that impedes the function and entry of effector cells. We devised a new technique of combining immunotherapy with radiotherapy (XRT), more specifically low-dose XRT, to overcome the stroma and maximize systemic outcomes.

Methods

We bilaterally established 344SQ lung adenocarcinoma tumors in 129Sv/Ev mice. Primary and secondary tumors were irradiated with either high-dose or low-dose of XRT with systemic anti-programmed cell death protein 1 and anti-cytotoxic T-lymphocyte associated protein 4 administration. Survival and tumor growth were monitored for the various groups, and secondary tumors were phenotyped by flow cytometry for immune populations. Tumor growth factor-beta (TGF-β) cytokine levels were assessed locally after low-dose XRT, and specific immune-cell depletion experiments were conducted to identify the major contributors to the observed systemic antitumor effect.

Results

Through our preclinical and clinical studies, we observed that when tumor burden was high, there was a necessity of combining high-dose XRT to ‘prime’ T cells at the primary tumor site, with low-dose XRT directed to secondary (metastatic) tumors to ‘modulate the stroma’. Low-dose XRT improved the antitumor outcomes of checkpoint inhibitors by favoring M1 macrophage polarization, enhancing natural killer (NK) cell infiltration, and reducing TGF-β levels. Depletion of CD4⁺ T cells and NK cells abrogated the observed antitumor effect.

Conclusion

Our data extend the benefits of low-dose XRT to reprogram the tumor environment and improve the infiltration and function of effector immune cells into secondary tumors.

Consolidation radiotherapy for patients with extended disease small cell lung cancer in a single tertiary institution: impact of dose and perspectives in the era of immunotherapy

Background Consolidation radiotherapy (cRT) in extended disease small cell lung cancer (ED-SCLC) showed improved 2-year overall survival in patients who responded to chemotherapy (ChT) in CREST trial, however results of two meta - analysis were contradictive. Recently, immunotherapy was introduced to the treatment of ED-SCLC, making the role of cRT even more unclear. The aim of our study was to access if consolidation thoracic irradiation improves survival of ED-SCLC patients treated in a routine clinical practice and to study the impact of cRT dose on survival. We also discuss the future role of cRT in the era of immunotherapy. Patients and methods We retrospectively reviewed 704 consecutive medical records of patients with small cell lung cancer treated at the Institute of Oncology Ljubljana from January 2010 to December 2014 with median follow up of 65 months. We analyzed median overall survival (mOS) of patients with ED-SCLC treated with ChT only and those treated with ChT and cRT. We also compared mOS of patients treated with different consolidation doses and performed univariate and multivariate analysis of prognostic factors. Results Out of 412 patients with ED-SCLC, ChT with cRT was delivered to 74 patients and ChT only to 113 patients. Patients with cRT had significantly longer mOS compared to patients with ChT only, 11.1 months (CI 10.1-12.0) vs. 7.6 months (CI 6.9-8.5, p < 0.001) and longer 1-year OS (44% vs. 23%, p = 0.0025), while the difference in 2-year OS was not significantly different (10% vs. 5%, p = 0.19). The cRT dose was not uniform. Higher dose with 45 Gy (in 18 fractions) resulted in better mOS compared to lower doses 30-36 Gy (in 10-12 fractions), 17.2 months vs. 10.3 months (p = 0.03) and statistically significant difference was also seen for 1-year OS (68% vs. 30%, p = 0.01) but non significant for 2-year OS (18% vs. 5%, p = 0.11). Conclusions Consolidation RT improved mOS and 1-year OS in ED-SCLC as compared to ChT alone. Higher dose of cRT resulted in better mOS and 1-year OS compared to lower dose. Consolidation RT, higher number of ChT cycles and prophylactic cranial irradiation (PCI) were independent prognostic factors for better survival in our analysis. For patients who received cRT, only higher doses and PCI had impact on survival regardless of number of ChT cycles received. Role of cRT in the era of immunotherapy is unknown and should be exploited in further trials.

Combination of Ipilimumab and Nivolumab in Cancers: From Clinical Practice to Ongoing Clinical Trials

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) are inhibitory checkpoints that are commonly seen on activated T cells and have been offered as promising targets for the treatment of cancers. Immune checkpoint inhibitors (ICIs)targeting PD-1, including pembrolizumab and nivolumab, and those targeting its ligand PD-L1, including avelumab, atezolizumab, and durvalumab, and two drugs targeting CTLA-4, including ipilimumab and tremelimumab have been approved for the treatment of several cancers and many others are under investigating in advanced trial phases. ICIs increased antitumor T cells’ responses and showed a key role in reducing the acquired immune system tolerance which is overexpressed by cancer and tumor microenvironment. However, 50% of patients could not benefit from ICIs monotherapy. To overcome this, a combination of ipilimumab and nivolumab is frequently investigated as an approach to improve oncological outcomes. Despite promising results for the combination of ipilimumab and nivolumab, safety concerns slowed down the development of such strategies. Herein, we review data concerning the clinical activity and the adverse events of ipilimumab and nivolumab combination therapy, assessing ongoing clinical trials to identify clinical outlines that may support combination therapy as an effective treatment. To the best of our knowledge, this paper is one of the first studies to evaluate the efficacy and safety of ipilimumab and nivolumab combination therapy in several cancers.

Interaction between lymphopenia, radiotherapy technique, dosimetry, and survival outcomes in lung cancer patients receiving combined immunotherapy and radiotherapy

AIM

Immune function (e.g. absolute lymphocyte count (ALC)) and modifiable predictors thereof (e.g. volume of the heart/lungs receiving low-dose radiation) impact outcomes of cancer patients, but this has not been well-studied in the immunotherapy era. This investigation of metastatic lung cancer assessed the interaction of dosimetric parameters (e.g. lung/heart V5), radiotherapy technique (e.g. stereotactic (SBRT) or traditional radiotherapy), lymphopenia, and survival outcomes.

METHODS

Patients were collected from three institutional phase I/II trials of combined immunotherapy and lung irradiation. SBRT referred to 50 Gy/4 fractions or 60 Gy/10 fractions, and traditional RT as 45 Gy/15 fractions. Blood collections were standardized on the first and last day of radiotherapy and each cycle of immunotherapy. Statistics included multivariable linear regression to identify variables associated with ALC decline, Kaplan-Meier analysis of overall and progression-free survival (PFS), and Cox multivariate analysis.

RESULTS

The median follow-up of the 165 patients was 21 months. The only factor independently predictive of ALC decline was traditional RT (p < 0.001). Therefore, the analysis was repeated for traditional RT and SBRT separately; lung V5 was associated with lymphopenia for traditional RT (p < 0.001) but not SBRT (p = 0.12). Pre-radiotherapy ALC was independently associated with PFS in both cohorts (p < 0.05 for both); post-RT ALC predicted for PFS in the traditional RT (p = 0.048) but not the SBRT (p = 0.90) group. Neither heart nor lung V5 was independently associated with PFS.

CONCLUSIONS

When combined with immunotherapy, SBRT may better preserve lymphocytes (and hence improve outcomes) than traditional RT. When administering traditional RT, constraining the lung V5 may indirectly impact outcomes by means of ALC preservation.

Impact of Lung Parenchymal-Only Failure on Overall Survival in Early-Stage Lung Cancer Patients Treated With Stereotactic Ablative Radiotherapy

INTRODUCTION

The impact of lung parenchymal-only failure on patient survival after stereotactic ablative body radiotherapy (SABR) for early-stage non-small-cell lung cancer (NSCLC) remains unclear.

PATIENTS AND METHODS

The study population included 481 patients with early-stage NSCLC who were treated with 3- to 5-fraction SABR between 2000 and 2016. The primary study objective was to assess the impact of out-of-field lung parenchymal-only failure (OLPF) on overall survival (OS).

RESULTS

At a median follow-up of 5.9 years, the median OS was 2.7 years for all patients. Patients with OLPF did not have a significantly different OS compared to patients without failure (P = .0952, median OS 4.1 years with failure vs. 2.6 years never failure). Analysis in a 1:1 propensity score-matched cohort for Karnofsky performance status, comorbidity score, and smoking status showed no differences in OS between patients without failure and those with OLPF (P = .8). In subgroup analyses exploring the impact of time of failure on OS, patients with OLPF 6 months or more after diagnosis did not have significantly different OS compared to those without failure, when accounting for immortal time bias (P = .3, median OS 4.3 years vs. 3.5 years never failure). Only 7 patients in our data set experienced failure within 6 months of treatment, of which only 4 were confirmed to be true failures; therefore, limited data are available in our cohort on the impact of OLPF for ≤ 6 months on OS.

CONCLUSION

OLPF after SABR for early-stage NSCLC does not appear to adversely affect OS, especially if occurring at least 6 months after SABR. More studies are needed to understand if OLPF within 6 months of SABR is associated with adverse OS. These data are useful when discussing prognosis of lung parenchymal failures after initial SABR.

Oligometastasis and local ablation in the era of systemic targeted and immunotherapy

Background

During these last years, new agents have dramatically improved the survival of the metastatic patients. Oligometastases represent a continuous field of interest in which the integration of metastases-directed therapy and drugs could further improve the oncologic outcomes.

Herein a narrative review is performed regarding the main rationale in combining immunotherapy and target therapies with SBRT looking at the available clinical data in case of oligometastatic NSCLC, Melanoma and Kidney cancer.

Material and method

Narrative Review regarding retrospective and prospective studies published between January 2009 to November 2019 with at least 20 patients analyzed.

Results

Concerning the combination between SBRT and Immunotherapy, the correct sequence of remains uncertain, and seems to be drug-dependent. The optimal patients’ selection is crucial to expect substantial benefits to SBRT/Immunotherapy combination and, among several factors. A potential field of interest is represented by the so-called oligoprogressed disease, in which SBRT could improve the long-term efficacy of the existing target therapy.

Conclusions

A low tumor burden seems to be the most relevant, thus making the oligometastatic disease represent the ideal setting for the use of combination therapies with immunological drugs.

Relationship between pneumonitis induced by immune checkpoint inhibitors and the underlying parenchymal status: a retrospective study

In patients with primary or secondary lung tumour treated with immune checkpoint inhibitors, immune-related pneumonitis is a rare adverse event but may evolve to respiratory failure. Prompt management is required and usually consists of treatment interruption and immunosuppressive drug administration. The aim of this study was to evaluate relationships between immune-related pneumonitis and pre-existing parenchymal status, especially tumour location and history of chest radiotherapy.

Computed tomography (CT) scans of patients with immune-related pneumonitis were retrospectively reviewed. Pattern, distribution and extent of pneumonitis were assessed in six lung regions. In patients who received radiotherapy, the extent of pneumonitis was evaluated according to the radiation field.

Among 253 patients treated with immunotherapy, 15 cases of immune-related pneumonitis were identified. 10 had previous or concomitant chest radiotherapy in addition to immunotherapy. At CT scan, 29 (33%) out of 88 regions encompassed the primary tumour (n=4), a lung metastasis (n=4) and/or radiation fields (n=21). A significantly higher prevalence of parenchymal involvement by immune-related pneumonitis occurred within areas of primary or metastatic malignancy and/or radiation field (97%) as compared to other areas (3%, p=0.009). Lung regions affected by the primary tumour, metastasis or radiotherapy had a higher probability of immune-related pneumonitis than others (OR 10.8, p=0.024). An organising pneumonia (OP) pattern was more frequent after radiotherapy (70% versus 0%, p=0.024), whereas nonspecific interstitial pneumonia features were more commonly seen in radiotherapy-naive patients (100% versus 10%, p=0.002).

In patients with primary or secondary lung tumour treated with immune checkpoint inhibitors, immune-related pneumonitis is preferentially located within lung areas involved by tumour and/or radiation fields.

In patients with primary or secondary lung tumour treated by immune checkpoint inhibitors, immune-related pneumonitis induced by these agents is preferentially located within lung areas involved by tumour and/or radiation fieldshttp://bit.ly/2NJZmGx

Synergizing systemic responses by combining immunotherapy with radiotherapy in metastatic non-small cell lung cancer: The potential of the abscopal effect

Immunotherapy has obtained a secure place in the treatment of metastatic non-small cell lung cancer (NSCLC) and has made a great impact on prognosis of responders. Unfortunately, not all NSCLC patients derive benefit from this treatment. Several immune escape mechanisms have been postulated, explaining failure of tumor immune attack. A better understanding of these mechanisms helps us to seek treatment strategies to overcome resistance to immunotherapy. Radiotherapy has immunomodulatory qualities capable of enhancing the anti-cancer immune response by tackling a number of these tumor escape mechanisms. In this review, we focus on mechanisms of off-target effects of radiotherapy, the so-called abscopal effect, by describing the current role of immune checkpoint inhibitors (ICIs) in NSCLC, the possible reasons for its failures and evidence on how radiotherapy may be able to counteract these mechanisms. An oversight of pre-clinical and clinical data supporting augmentation of abscopal events by radiotherapy when combined with ICIs is presented. As much remains unclear regarding optimal dose, fractionation, target volume or timing of radiation therapy, future research will need to focus on implementing data from pre-clinical and translational findings in the development of new clinical trials in order to help optimizing the potential of the combination of immunotherapy with radiotherapy.

Phase I Trial of Pembrolizumab and Radiation Therapy after Induction Chemotherapy for Extensive-Stage Small Cell Lung Cancer

INTRUDUCTION

Radiation and immunotherapy have separately been shown to confer survival advantages to patients with extensive-stage small cell lung cancer (ESCLC), but failure rates remain high and combination therapy has been understudied. In this single-arm phase I trial (NCT02402920), we assessed the safety of combining pembrolizumab with thoracic radiotherapy (TRT) after induction chemotherapy for SCLC.

METHODS

Patients with ESCLC who had completed chemotherapy received TRT with pembrolizumab. The maximum tolerated dose of pembrolizumab was assessed by 3+3 dose-escalation; doses began at 100 mg and increased in 50 mg increments to 200 mg. Pembrolizumab was given every 3 weeks for up to 16 cycles; TRT was prescribed as 45 Gy in 15 daily fractions. Toxicity was evaluated with the Common Terminology Criteria for Adverse Events v4.0. The primary endpoint was safety of the combined therapy based on the incidence of dose-limiting toxicity in the 35 days following initiation of treatment.

RESULTS

Thirty-eight patients with ESCLC (median age 65 years, range: 37-79 years) were enrolled from September 2015 through September 2017; 33 received per-protocol treatment, and all tolerated pembrolizumab at 100 to 200 mg with no dose-limiting toxicity in the 35-day window. There were no grade 4-5 toxicities; 2 (6%) patients experienced grade 3 events (n = 1 rash, n = 1 asthenia/paresthesia/autoimmune disorder) that were unlikely/doubtfully related to protocol therapy. The median follow-up time was 7.3 months (range: 1-13 months); median progression-free and overall survival times were 6.1 months (95% confidence interval: 4.1-8.1) and 8.4 months (95% confidence interval: 6.7-10.1).

CONCLUSIONS

Concurrent pembrolizumab-TRT was tolerated well with few high-grade adverse events in the short-term; progression-free and overall survival rates are difficult to interpret due to heterogeneity in eligibility criteria (e.g., enrolling progressors on induction chemotherapy). Although randomized studies have shown benefits to TRT alone and immunotherapy alone, the safety of the combined regimen supports further investigation as a foundational approach for future prospective studies.

Lung Stereotactic Body Radiation Therapy and Concurrent Immunotherapy: A Multicenter Safety and Toxicity Analysis

PURPOSE

Radical treatment of metastases with stereotactic body radiation therapy (SBRT) is commonly implemented in patients receiving concurrent immune checkpoint inhibition (ICI), despite limited safety and toxicity data. The purpose of this study was to evaluate the safety and tolerability of lung SBRT with concurrent ICI.

METHODS AND MATERIALS

Records from a single academic institution were reviewed to identify patients treated with lung SBRT and concurrent (within 30 days) ICI; a contemporaneous cohort receiving lung SBRT alone was included for reference. Treatment-related adverse effects occurring within 30 days (acute) and 180 days (subacute) of SBRT were evaluated.

RESULTS

Our study included 117 patients; 54 received SBRT with concurrent ICI (56 courses, 69 target lesions), and 63 received SBRT alone (68 courses, 79 lesions). Median follow-up was 9.2 months in the SBRT + ICI cohort. Among the patients, 67.9% received ICI monotherapy, 17.9% ICI/chemotherapy, and 14.3% ICI/ICI combinations; 25% received ICI between SBRT fractions, and 42.9% received ICI both before and after SBRT. The risk of grade 3 pneumonitis was higher in the SBRT + ICI versus SBRT alone cohort (10.7% vs 0%, P < .01) and any-grade pneumonitis was similar (33.9% vs 27.9%, SBRT + ICI vs SBRT, P = .47). The risk of any-grade pneumonitis appeared elevated with ICI/ICI combinations (62.5% vs 29.2%). Receipt of ICI, planning treatment volume, and lobes involved in SBRT were linked to high-grade pneumonitis. Subacute grade 3+ adverse effects occurred in 26.8% of SBRT + ICI and 2.9% of SBRT-alone patients.

CONCLUSIONS

Overall, concurrent lung SBRT + ICI is safe. Given the clinically meaningful risk of pneumonitis, closer monitoring should be considered for SBRT + ICI patients, especially those receiving radiation therapy with ICI/ICI combinations.

Prognostic Role Of Computed Tomography Textural Features In Early-Stage Non-Small Cell Lung Cancer Patients Receiving Stereotactic Body Radiotherapy

Purpose

The imaging features of patients with early-stage non-small cell lung cancer (NSCLC) receiving stereotactic body radiotherapy (SBRT) are crucial for the decision-making process to establish a treatment plan. The purpose of this study was to predict the clinical outcomes of SBRT from the textural features of pretreatment computed tomography (CT) images.

Patients and methods

Forty-one early-stage NSCLC patients who received SBRT were included in this retrospective study. In total, 72 textural features were extracted from the pretreatment contrast-enhanced CT images. Survival analysis was used to identify high-risk groups for progression-free survival (PFS) and disease-specific survival (DSS). Receiver operating characteristic (ROC) curve analysis was utilized to estimate the diagnostic abilities of the textural parameters. Univariable and multivariable Cox regression analyses were performed to evaluate the predictors of PFS and DSS.

Results

Four parameters, including entropy (P=0.003), second angular moment (SAM) (P=0.04), high-intensity long-run emphasis (HILRE) (P=0.046) and long-run emphasis (LRE) (P=0.042), were significant prognostic features for PFS. In addition, contrast (P=0.008), coarseness (P=0.017), low-intensity zone emphasis (LIZE) (P=0.01) and large number emphasis (LNE) (P=0.046) were significant prognostic factors for DSS. In the ROC analysis, the area under the curve (AUC) of coarseness for local recurrence (LR) was 0.722 (0.528–0.916), and the AUC of entropy for lymph node metastasis (LNM) was 0.771 (0.556–0.987). The four highest AUCs for distant metastasis (DM) were 0.885 (0.784–0.985) for LNE, 0.846 (0.733–0.959) for SAM, 0.731 (0.500–0.961) for LRE and 0.731 (0.585–0.876) for contrast. In the multivariable analysis, smoking and entropy were independent prognostic factors for PFS.

Conclusion

This exploratory study reveals that textual features derived from pretreatment CT scans have prognostic value in early-stage NSCLC patients treated with SBRT.

Prior or concurrent radiotherapy and nivolumab immunotherapy in non-small cell lung cancer

BACKGROUND

Studies suggest that combining radiotherapy (RT) with programmed cell death protein 1 (PD-1) blockade may elicit a synergistic antitumor response. We aimed to assess whether prior or concurrent RT was associated with improved disease control in patients with metastatic non-small cell lung cancer (NSCLC) treated with nivolumab.

METHODS

We conducted a retrospective study of patients receiving nivolumab as second or subsequent line therapy for metastatic NSCLC. Patients were categorized into those who received any RT for NSCLC prior to or during nivolumab therapy, and those with no history of RT for NSCLC.

RESULTS

A total of 85 patients received nivolumab between July 2015 and December 2016 and were followed up for a median of 15 months. Sixty-five patients (76.4%) received RT prior to or during nivolumab and 20 patients (23.6%) received nivolumab alone. Baseline characteristics of age, performance status, histology, smoking status and previous therapy were similar between the two groups. Prior or concurrent RT was associated with a superior PFS, median 2.8 months with RT versus 1.3 months without RT (Hazard Ratio (HR) = 0.494; 95% Confidence Interval (CI), 0.279-0.873; P = 0.02). The median OS of the group receiving RT was 6.4 months versus 4.2 months for the no RT group (P = 0.20). RT was not associated with an increase in toxicity.

CONCLUSION

RT prior to or concurrent with nivolumab for metastatic NSCLC was associated with a modest improvement in PFS over nivolumab alone with no evidence of increase in adverse effects. RT may potentiate the effect of anti-PD-1 immunotherapy in NSCLC.

Phase II Trial of Ipilimumab with Stereotactic Radiation Therapy for Metastatic Disease: Outcomes, Toxicities, and Low-Dose Radiation-Related Abscopal Responses

Ipilimumab is effective for patients with melanoma, but not for those with less immunogenic tumors. We report a phase II trial of ipilimumab with concurrent or sequential stereotactic ablative radiotherapy to metastatic lesions in the liver or lung (NCT02239900). Ipilimumab (every 3 weeks for 4 doses) was given with radiotherapy begun during the first dose (concurrent) or 1 week after the second dose (sequential) and delivered as 50 Gy in 4 fractions or 60 Gy in 10 fractions to metastatic liver or lung lesions. In total, 106 patients received ≥1 cycle of ipilimumab with radiation. Median follow-up was 10.5 months. Median progression-free survival time was 2.9 months (95% confidence interval, 2.45-3.40), and median overall survival time was not reached. Rates of clinical benefit of nonirradiated tumor volume were 26% overall, 28% for sequential versus 20% for concurrent therapy (P = 0.250), and 31% for lung versus 14% for liver metastases (P = 0.061). The sequential lung group had the highest rate of clinical benefit at 42%. There were no differences in treatment-related adverse events between groups. Exploratory analysis of nontargeted lesions revealed that lesions receiving low-dose radiation were more likely to respond than those that received no radiation (31% vs. 5%, P = 0.0091). This phase II trial of ipilimumab with stereotactic radiotherapy describes satisfactory outcomes and low toxicities, lending support to further investigation of combined-modality therapy for metastatic cancers.

Influence of low-dose radiation on abscopal responses in patients receiving high-dose radiation and immunotherapy

Background

Preclinical evidence suggests that low-dose radiation may overcome the inhibitory effects of the tumor stroma and improve a tumor’s response to immunotherapy, when combined with high-dose radiation to another tumor. The aim of this study was to evaluate tumor responses to this combination in a clinical setting.

Methods

A post-hoc analysis of 3 ongoing immunoradiation trials was performed. Twenty-six (of 155) patients received low-dose radiation (1–20 Gy total), either as scatter from high-dose radiation or from intentional treatment of a second isocenter with low-dose radiation, were evaluated for response. The low-dose lesions were compared to lesions that received no radiation (< 1 Gy total). Response rates, both defined as complete and partial responses as defined by RECIST criteria were used to compare lesion types.

Results

The 26 patients had a total of 83 lesions for comparison (38 receiving low-dose, 45 receiving no-dose). The average dose given to low-dose lesions was 7.3 Gy (1.1–19.4 Gy), and the average time to response was 56 days. Twenty-two out of 38 (58%) low-dose lesions met the PR/CR criteria for RECIST compared with 8 out of 45 (18%) no-dose lesions (P = 0.0001). The median change for longest diameter size for low-dose lesions was − 38.5% compared to 8% in no-dose lesions (P < 0.0001). Among the low-dose lesions that had at least one no-dose lesion within the same patient as a control (33 and 45 lesions respectively), 12 low-dose lesions (36%) responded without a corresponding response in their no-dose lesions; Conversely, two (4%) of the no-dose lesions responded without a corresponding response in their low-dose lesion (P = 0.0004).

Conclusions

Low-dose radiation may increase systemic response rates of metastatic disease treated with high-dose radiation and immunotherapy.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0718-6) contains supplementary material, which is available to authorized users.

What is the role of radiotherapy for extensive-stage small cell lung cancer in the immunotherapy era?

Small cell lung cancer has been a difficult disease to treat with poor survival and few significant improvements in outcomes in the last three decades. Most recently the addition of atezolizumab to chemotherapy in the first-line treatment of extensive-stage small cell lung cancer (ES-SCLC) resulted in improved overall survival and progression-free survival compared to chemotherapy alone. Recent randomized studies examining both consolidative thoracic radiotherapy and prophylactic cranial irradiation (PCI) in ES-SCLC have impacted the utilization of these interventions. The approval of immune checkpoint inhibitors (ICIs) to platinum/etoposide chemotherapy for the treatment of ES-SCLC in the front-line setting may also further impact the role of radiotherapy in this disease. In this article, we review the current evidence supporting thoracic radiotherapy in ES-SCLC and discuss the promising therapeutic implications of thoracic radiation in light of the inclusion of ICIs. We also address how the increasing routine use of surveillance brain magnetic resonance imaging (MRI) and ICIs may diminish the use of PCI in ES-SCLC.

Early-Stage NSCLC: Advances in Thoracic Oncology 2018

2018 was a banner year for all thoracic oncology, but especially for early-stage NSCLC. Three seminal events occurred in the approximately 18 months from mid-2017 to the end of 2018: in June 2017 at the American Society of Clinical Oncology Annual Meeting a small, relatively unheralded study from Max Diehn's group at Stanford University reported on the use of a novel "cancer personalized profiling by deep sequencing" circulating tumor-DNA technology to identify minimal residual disease in patients after curative-intent radiation or surgery for NSCLC; in April 2018 at the American Association for Cancer Research Annual Meeting, Drew Pardoll presented a small pilot study of 21 patients who had received two doses of preoperative nivolumab; in September 2018, at the 19th World Conference on Lung Cancer, Harry J. De Koning presented the long-awaited results of the Dutch-Belgian Lung Cancer Screening Trial (NELSON). These three seminal studies, along with others which are reviewed in this paper, promise to accelerate our progress towards a world in which lung cancer is identified early, more patients undergo curative-intent treatment that achieves the promised cure, and those at risk for failure after treatment are identified early, when the cancer remains most vulnerable. The day is around the corner when lung cancer is defanged and no longer the worldwide terror it currently is. We herein present an overview of the most recent body of work that moves us inexorably towards that day.

Stereotactic Ablative Radiotherapy Combined with Immune Checkpoint Inhibitors Reboots the Immune Response Assisted by Immunotherapy in Metastatic Lung Cancer: A Systematic Review

Background: Immune checkpoint inhibitors (ICI) have represented a revolution in the treatment of non-small-cell lung cancer (NSCLC). To improve these results, combined approaches are being tested. The addition of stereotactic ablative radiotherapy (SABR) to ICI seems promising. A systematic review was performed in order to assess the safety and efficacy of SABR-ICI combination. Material and Methods: MEDLINE databases from 2009 to March 3, 2019 were reviewed to obtain English language studies reporting clinical outcomes of the combination of ICI-SABR in NSCLC. 18 out of the 429 initial results fulfilled the inclusion criteria and were selected for review. Results: Eighteen articles, including six prospective studies, describing 1736 patients treated with an ICI-SABR combination fulfilled the selection criteria. The reported mean rates for local control and distant/abscopal response rates were 71% and 41%, respectively. Eleven studies reported progression-free survival and overall survival, with a mean of 4.6 and 12.4 months, respectively. Toxicity rates were consistent with the ones attributable to ICI treatment alone. Conclusions: The ICI-SABR combination has a good safety profile and achieves high rates of local control and greater chances of obtaining abscopal responses than SABR alone, with a relevant impact on PFS. More studies are needed to improve patient selection for an optimal benefit from this approach.

Role of Radiation Therapy in Modulation of the Tumor Stroma and Microenvironment

In recent decades, there has been substantial growth in our understanding of the immune system and its role in tumor growth and overall survival. A central finding has been the cross-talk between tumor cells and the surrounding environment or stroma. This tumor stroma, comprised of various cells, and extracellular matrix (ECM), has been shown to aid in suppressing host immune responses against tumor cells. Through immunosuppressive cytokine secretion, metabolic alterations, and other mechanisms, the tumor stroma provides a complex network of safeguards for tumor proliferation. With recent advances in more effective, localized treatment, radiation therapy (XRT) has allowed for strategies that can effectively alter and ablate tumor stromal tissue. This includes promoting immunogenic cell death through tumor antigen release to increasing immune cell trafficking, XRT has a unique advantage against the tumoral immune evasion mechanisms that are orchestrated by stromal cells. Current studies are underway to elucidate pathways within the tumor stroma as potential targets for immunotherapy and chemoradiation. This review summarizes the effects of tumor stroma in tumor immune evasion, explains how XRT may help overcome these effects, with potential combinatorial approaches for future treatment modalities.

Overall survival according to immunotherapy and radiation treatment for metastatic non-small-cell lung cancer: a National Cancer Database analysis

Background

Preclinical studies suggest enhanced anti-tumor activity with combined radioimmunotherapy. We hypothesized that radiation (RT) + immunotherapy would associate with improved overall survival (OS) compared to immunotherapy or chemotherapy alone for patients with newly diagnosed metastatic non-small-cell lung cancer (NSCLC).

Methods

The National Cancer Database was queried for patients with stage IV NSCLC receiving chemotherapy or immunotherapy from 2013 to 2014. RT modality was classified as stereotactic radiotherapy (SRT) to intra- and/or extracranial sites or non-SRT external beam RT (EBRT). OS was analyzed using the Kaplan-Meier method and Cox proportional hazards models.

Results

In total, 44,498 patients were included (13% immunotherapy, 46.8% EBRT, and 4.7% SRT). On multivariate analysis, immunotherapy (hazard ratio [HR]:0.81, 95% confidence interval [CI]:0.78–0.83) and SRT (HR:0.78, 95%CI:0.70–0.78) independently associated with improved OS; however, the interaction term for SRT + immunotherapy was insignificant (p = 0.89). For immunotherapy patients, the median OS for no RT, EBRT, and SRT was 14.5, 10.9, and 18.2 months, respectively (p < 0.0001), and EBRT (HR:1.37, 95%CI:1.29–1.46) and SRT (HR:0.78, 95%CI:0.66–0.93) associated with OS on multivariate analysis. In the SRT subset, median OS for immunotherapy and chemotherapy was 18.2 and 14.3 months, respectively (p = 0.004), with immunotherapy (HR:0.82, 95%CI:0.69–0.98) associating with OS on multivariate analysis. Furthermore, for patients receiving SRT, biologically effective dose (BED) > 60 Gy was independently associated with improved OS (HR:0.79, 95%CI:0.70–0.90, p < 0.0001) on multivariate analysis with a significant interaction between BED and systemic treatment (p = 0.008).

Conclusions

Treatment with SRT associated with improved OS for patients with metastatic NSCLC irrespective of systemic treatment. The high survival for patients receiving SRT + immunotherapy strongly argues for evaluation in randomized trials.