Checkpoint inhibition in combination with an immunoboost of external beam radiotherapy in solid tumors (CHEERS): study protocol for a phase 2, open-label, randomized controlled trial.

BACKGROUND: While the introduction of checkpoint inhibitors (CPIs) as standard of care treatment for various tumor types has led to considerable improvements in clinical outcome, the majority of patients still fail to respond. Preclinical data suggest that stereotactic body radiotherapy (SBRT) could work synergistically with CPIs by acting as an in situ cancer vaccine, thus potentially increasing response rates and prolonging disease control. Though SBRT administered concurrently with CPIs has been shown to be safe, evidence of its efficacy from large randomized trials is still lacking. The aim of this multicenter randomized phase II trial is to assess whether SBRT administered concurrently with CPIs could prolong progression-free survival as compared to standard of care in patients with advanced solid tumors. METHODS/DESIGN: Ninety-eight patients with locally advanced or metastatic disease will be randomized in a 1:1 fashion to receive CPI treatment combined with SBRT (Arm A) or CPI monotherapy (Arm B). Randomization will be stratified according to tumor histology (melanoma, renal, urothelial, head and neck squamous cell or non-small cell lung carcinoma) and disease burden (≤ or > 3 cancer lesions). The recommended SBRT dose is 24Gy in 3 fractions, which will be administered to a maximum of 3 lesions and is to be completed prior to the second or third CPI cycle (depending on CPI treatment schedule). The study's primary endpoint is progression-free survival as per iRECIST. Secondary endpoints include overall survival, objective response, local control, quality of life and toxicity. Translational analyses will be performed using blood, fecal and tissue samples. DISCUSSION: The CHEERS trial will provide further insights into the clinical and immunological impact of SBRT when combined with CPIs in patients with advanced solid tumors. Furthermore, study results will inform the design of future immuno-radiotherapy trials. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03511391 . Registered 17 April 2018.

Microbiome and metabolome dynamics during radiotherapy for prostate cancer.

BACKGROUND: Prostate cancer patients treated with radiotherapy are susceptible to acute gastrointestinal (GI) toxicity due to substantial overlap of the intestines with the radiation volume. Due to their intimate relationship with GI toxicity, faecal microbiome and metabolome dynamics during radiotherapy were investigated. MATERIAL & METHODS: This prospective study included 50 prostate cancer patients treated with prostate (bed) only radiotherapy (PBRT) (n = 28) or whole pelvis radiotherapy (WPRT) (n = 22) (NCT04638049). Longitudinal sampling was performed prior to radiotherapy, after 10 fractions, near the end of radiotherapy and at follow-up. Patient symptoms were dichotomized into a single toxicity score. Microbiome and metabolome fingerprints were analyzed by 16S rRNA gene sequencing and ultra-high-performance liquid chromatography hybrid high-resolution mass spectrometry, respectively. RESULTS: The individual α-diversity did not significantly change over time. Microbiota composition (ß-diversity) changed significantly over treatment (PERMANOVA p-value = 0.03), but there was no significant difference in stability when comparing PBRT versus WPRT. Levels of various metabolites were significantly altered during radiotherapy. Baseline α-diversity was not associated with any toxicity outcome. Based on the metabolic fingerprint, no natural clustering according to toxicity profile could be achieved. CONCLUSIONS: Radiation dose and treatment volume demonstrated limited effects on microbiome and metabolome fingerprints. In addition, no distinctive signature for toxicity status could be established. There is an ongoing need for toxicity risk stratification tools for diagnostic and therapeutic purposes, but the current evidence implies that the translation of metabolic and microbial biomarkers into routine clinical practice remains challenging.

Checkpoint Inhibitors in Combination With Stereotactic Body Radiotherapy in Patients With Advanced Solid Tumors: The CHEERS Phase 2 Randomized Clinical Trial.

Importance: Although immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1) and PD-1 ligand 1 have improved the outcome for many cancer types, the majority of patients fails to respond to ICI monotherapy. Hypofractionated radiotherapy has the potential to improve the therapeutic ratio of ICIs. Objective: To assess the addition of radiotherapy to ICIs compared with ICI monotherapy in patients with advanced solid tumors. Design, Setting, and Participants: This open-label, multicenter, randomized phase 2 trial was conducted in 5 Belgian hospitals and enrolled participants between March 2018 and October 2020. Patients 18 years or older with locally advanced or metastatic melanoma, renal cell carcinoma, urothelial carcinoma, head and neck squamous cell carcinoma, or non-small cell lung carcinoma were eligible. A total of 99 patients were randomly assigned to either the control arm (n = 52) or the experimental arm (n = 47). Of those, 3 patients (1 in the control arm vs 2 in the experimental arm) withdrew consent and thus were not included in the analysis. Data analyses were performed between April 2022 and March 2023. Interventions: Patients were randomized (1:1) to receive anti-PD-1/PD-1 ligand 1 ICIs alone as per standard of care (control arm) or combined with stereotactic body radiotherapy 3 × 8 gray to a maximum of 3 lesions prior to the second or third ICI cycle, depending on the frequency of administration (experimental arm). Randomization was stratified according to tumor histologic findings and disease burden (3 and fewer or more than 3 cancer lesions). Main Outcomes and Measures: The primary end point was progression-free survival (PFS) as per immune Response Evaluation Criteria in Solid Tumors. Key secondary end points included overall survival (OS), objective response rate, local control rate, and toxic effects. Efficacy was assessed in the intention-to-treat population, while safety was evaluated in the as-treated population. Results: Among 96 patients included in the analysis (mean age, 66 years; 76 [79%] female), 72 (75%) had more than 3 tumor lesions and 65 (68%) had received at least 1 previous line of systemic treatment at time of inclusion. Seven patients allocated to the experimental arm did not complete the study-prescribed radiotherapy course due to early disease progression (n = 5) or intercurrent illness (n = 2). With a median (range) follow-up of 12.5 (0.7-46.2) months, median PFS was 2.8 months in the control arm compared with 4.4 months in the experimental arm (hazard ratio, 0.95; 95% CI, 0.58-1.53; P = .82). Between the control and experimental arms, no improvement in median OS was observed (11.0 vs 14.3 months; hazard ratio, 0.82; 95% CI, 0.48-1.41; P = .47), and objective response rate was not statistically significantly different (22% vs 27%; P = .56), despite a local control rate of 75% in irradiated patients. Acute treatment-related toxic effects of any grade and grade 3 or higher occurred in 79% and 18% of patients in the control arm vs 78% and 18% in the experimental arm, respectively. No grade 5 adverse events occurred. Conclusions and Relevance: This phase 2 randomized clinical trial demonstrated that while safe, adding subablative stereotactic radiotherapy of a limited number of metastatic lesions to ICI monotherapy failed to show improvement in PFS or OS. Trial Registration: ClinicalTrials.gov Identifier: NCT03511391.

Impact of radiotherapy parameters on the risk of lymphopenia in urological tumors: A systematic review of the literature.

BACKGROUND: We investigated how radiotherapy (RT) parameters may contribute to the risk of lymphopenia in urological tumors and we discussed how this may impact clinical outcomes. MATERIAL & METHODS: A systematic review was performed according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. The PubMed, Embase and ISI Web Of Knowledge databases were searched. Study quality was assessed according to the Newcastle-Ottawa Scale. RESULTS: Overall, 8 articles reporting on a total of 549 urological cancer patients met the inclusion criteria. The pooled mean incidence of acute severe lymphopenia (absolute lymphocyte count < 500 cells/µL) was 17.1%. Extended radiation volumes may lead to an increased risk of developing lymphopenia. Medium-high doses (≥ 40 Gy) to the whole pelvic (odds ratio (OR) = 1.01; 95% confidence interval (CI) 1.00-1.01; p = 0.025) and iliac (OR = 1.04; 95% CI 1.01-1.08; p = 0.009) bone marrow (BM) were associated with acute grade 3 and late grade 2 lymphopenia, respectively. CONCLUSION: Multiple studies reported high and severe incidences of lymphopenia. Minimizing radiation volumes and unintentional irradiation of pelvic BM may reduce the incidence of lymphopenia, potentially improving clinical outcomes. More research is needed to further elucidate these findings and effectively implement recently developed new risk assessment tools.

Spatiotemporal Evolution of Radiation Myositis on 18F-FDG PET/CT Following Hypofractionated Radiotherapy of Intramuscular Melanoma Metastases.

ABSTRACT: Radiation myositis is an infrequent late adverse effect of radiotherapy (RT), more commonly seen after hypofractionated regimens. We present the case of a 52-year-old woman with oligorecurrent metastatic melanoma who, several months after receiving local hypofractionated RT, developed a painful swelling at the irradiated site. As an integral part of routine oncologic follow-up, 18F-FDG PET/CT allowed accurate visualization of the affected region and when matched with RT treatment plans clearly illustrated their apparent overlap. This case demonstrates the utility of 18F-FDG PET/CT in the early detection and monitoring of radiation myositis and highlights the importance of a multidisciplinary approach in melanoma care.

Clinical Relevance of Serum Kyn/Trp Ratio and Basal and IFNγ-Upregulated IDO1 Expression in Peripheral Monocytes in Early Stage Melanoma.

Immune escape is an early phenomenon in cancer development/progression. Indoleamine 2,3-dioxygenase 1 (IDO1) is a normal endogenous mechanism of acquired peripheral immune tolerance and may therefore be tumor-promoting. This study investigated the clinical relevance of IDO1 expression by immune cells in the lymph nodes and blood and of the serum kynurenine/tryptophan (Kyn/Trp) ratio in 65 systemic treatment naïve stage I-III melanoma patients. Blood samples were collected within the first year of diagnosis. Patients had a median follow-up of 61 months. High basal IDO1 expression in peripheral monocytes and low IFNγ-induced IDO1 upregulation correlated with worse outcome independent from disease stage. Interestingly studied factors were not interrelated. During follow-up, the risk of relapse was 9% (2/22) in the subgroup with high IFNγ-induced IDO1 upregulation in monocytes. In contrast, if IDO1 upregulation was low, relapse occurred in 30% (3/10) of patients with low basal IDO1 expression in monocytes and in 61.5% (8/13) in the subgroup with high basal IDO1 expression in monocytes (Log-Rank test, p=0.008). This study reveals some immune features in the blood of early stage melanoma that may be of relevance for disease outcome. These may offer a target for sub-stratification and early intervention.

A fatal wound complication following sequential anti-angiogenesis, immune checkpoint inhibition and ultra-hypofractionated radiotherapy.

PURPOSE: Multimodality treatments combining radiotherapy, immune therapy and/or targeted therapy are under heavy investigation. Promising data from clinical trials are emerging, nevertheless unexpected interactions and adverse events should not be overlooked. CASE PRESENTATION: Here we present a case study of a patient with metastatic colon adenocarcinoma treated sequentially with a chemotherapy/targeted therapy combination, immune checkpoint inhibitors and ultra-hypofractionated radiotherapy. After radiation treatment, the patient developed extensive posterior abdominal wall wounds coinciding with regression of the irradiated metastatic tumour mass and marked elevation of the inflammation parameters. CONCLUSION: This case represents an unusual fatal wound complication after palliative ultra-hypofractionated radiotherapy. Further research into synergistic effects of sequential radiotherapy and anti-angiogenesis therapy may provide an advantage in anticipating severe sequelae.

Immune Monitoring in Melanoma and Urothelial Cancer Patients Treated with Anti-PD-1 Immunotherapy and SBRT Discloses Tumor Specific Immune Signatures.

(1) Background: Blockade of the PD-1/PD-L1 pathway has revolutionized the oncology field in the last decade. However, the proportion of patients experiencing a durable response is still limited. In the current study, we performed an extensive immune monitoring in patients with stage III/IV melanoma and stage IV UC who received anti-PD-1 immunotherapy with SBRT. (2) Methods: In total 145 blood samples from 38 patients, collected at fixed time points before and during treatment, were phenotyped via high-parameter flow cytometry, luminex assay and UPLC-MS/MS. (3) Results: Baseline systemic immunity in melanoma and UC patients was different with a more prominent myeloid compartment and a higher neutrophil to lymphocyte ratio in UC. Proliferation (Ki67+) of CD8+ T-cells and of the PD-1+/PD-L1+ CD8+ subset at baseline correlated with progression free survival in melanoma. In contrast a higher frequency of PD-1/PD-L1 expressing non-proliferating (Ki67-) CD8+ and CD4+ T-cells before treatment was associated with worse outcome in melanoma. In UC, the expansion of Ki67+ CD8+ T-cells and of the PD-L1+ subset relative to tumor burden correlated with clinical outcome. (4) Conclusion: This study reveals a clearly different immune landscape in melanoma and UC at baseline, which may impact immunotherapy response. Signatures of proliferation in the CD8+ T-cell compartment prior to and early after anti-PD-1 initiation were positively correlated with clinical outcome in both cohorts. PD-1/PD-L1 expression on circulating immune cell subsets seems of clinical relevance in the melanoma cohort.

Is the Combination of Immunotherapy and Radiotherapy in Non-small Cell Lung Cancer a Feasible and Effective Approach?

For many years, conventional oncologic treatments such as surgery, chemotherapy, and radiotherapy (RT) have dominated the field of non-small-cell lung cancer (NSCLC). The recent introduction of immunotherapy (IT) in clinical practice, especially strategies targeting negative regulators of the immune system, so-called immune checkpoint inhibitors, has led to a paradigm shift in lung cancer as in many other solid tumors. Although antibodies against programmed death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) are currently on the forefront of the immuno-oncology field, the first efforts to eradicate cancer by exploiting the host's immune system date back to several decades ago. Even then, researchers aimed to explore the addition of RT to IT strategies in NSCLC patients, attributing its potential benefit to local control of target lesions through direct and indirect DNA damage in cancer cells. However, recent pre-clinical and clinical data have shown RT may also modify antitumor immune responses through induction of immunogenic cell death and reprogramming of the tumor microenvironment. This has led many to reexamine RT as a partner therapy to immuno-oncology treatments and investigate their potential synergy in an exponentially growing number of clinical trials. Herein, the authors review the rationale of combining IT and RT across all NSCLC disease stages and summarize both historical and current clinical evidence surrounding these combination strategies. Furthermore, an overview is provided of active clinical trials exploring the IT-RT concept in different settings of NSCLC.

Prognostic Value of Stimulated Thyroglobulin Levels at the Time of Radioiodine Administration in Differentiated Thyroid Cancer.

OBJECTIVE: The prognostic value of stimulated thyroglobulin (sTg) and Tg-related parameters prior to and immediately after radioactive iodine (RAI) administration was assessed in a cohort of patients presenting with differentiated thyroid cancer (DTC) as a predictor of recurrent or progressive structural disease. METHODS: Clinical records of 180 DTC patients were retrospectively reviewed, and serum TSH, Tg, and Tg antibodies were recorded just before RAI administration (pre-) and at the time of whole body scanning (post-). Based on the results of initial staging and RAI scintigraphy, patients were divided into two groups: those who were considered to be structurally disease-free after thyroidectomy and RAI (group 1) and those who were not (group 2). Univariate analyses were performed for pre-Tg, ratioTg (post-Tg/pre-Tg), and other clinical and pathological markers for long-term outcome, as well as separate bivariate analyses focusing on pre-Tg to correct for possible confounders. Different pre-Tg cut-off values for predicting structural disease recurrence were assessed in a subgroup of patients in group 1 prepared with thyroid hormone withdrawal. RESULTS: In group 1, (n = 166) male gender, higher T-stage and both Tg-related parameters proved to be significant risk factors for structural disease relapse. Of all candidate variables, only higher T-stage served to predict progressive structural disease in group 2 (n = 14). Subgroup analysis showed a negative predictive value of 91.67$ for pre-Tg < 10 µg/L. CONCLUSION: The sTg value at the time of RAI administration may be helpful in predicting structural disease recurrence in patients with DTC.