Radiotherapy-induced anti-tumor immune response and immune-related adverse events in a case of recurrent nasopharyngeal carcinoma undergoing anti-PD-1 immunotherapy

Major and durable responses to photon and electron-beam palliative radiotherapies after immune-checkpoint inhibitors in head and neck cancer

BACKGROUND

The immuno-modulatory effects of ionizing radiation are well-known and preclinical studies suggest a synergistic effect of combining radiotherapy (RT) and IO. However, data regarding the clinical activity and safety of this approach are limited.

METHODS

We present the cases of two patients with SCCHN primary progressing to PDL1-based IO within a clinical trial (NCT03383094), that received subsequent but not concurrent palliative RT using two different modalities (electron beam and photon beam therapies).

RESULTS

Both patients achieved major and durable responses at 4 irradiated sites, with excellent tolerance and no grade ≥ 3 toxicities. Complete response occurred in 3 of the disease areas (all locoregional) and partial response in 1 metastatic lesion.

CONCLUSION

Palliative radiotherapy after progression to IO was safe and demonstrated profound and durable responses in the cases presented.

Radiation combined with ultrasound and microbubbles: A potential novel strategy for cancer treatment

Cancer is one of the leading causes of death worldwide. Several emerging technologies are helping to battle cancer. Cancer therapies have been effective at killing cancer cells, but a large portion of patients still die to this disease every year. As such, more aggressive treatments of primary cancers are employed and have been shown to be capable of saving a greater number of lives. Recent research advances the field of cancer therapy by employing the use of physical methods to alter tumor biology. It uses microbubbles to enhance radiation effect by damaging tumor vasculature followed by tumor cell death. The technique can specifically target tumor volumes by conforming ultrasound fields capable of microbubbles stimulation and localizing it to avoid vascular damage in surrounding tissues. Thus, this new application of ultrasound-stimulated microbubbles (USMB) can be utilized as a novel approach to cancer therapy by inducing vascular disruption resulting in tumor cell death. Using USMB alongside radiation has showed to augment the anti-vascular effect of radiation, resulting in enhanced tumor response. Recent work with nanobubbles has shown vascular permeation into intracellular space, extending the use of this new treatment method to potentially further improve the therapeutic effect of the ultrasound-based therapy. The significant enhancement of localized tumor cell kill means that radiation-based treatments can be made more potent with lower doses of radiation. This technique can manifest a greater impact on radiation oncology practice by increasing treatment effectiveness significantly while reducing normal tissue toxicity. This review article summarizes the past and recent advances in USMB enhancement of radiation treatments. The review mainly focuses on preclinical findings but also highlights some clinical findings that use USMB as a therapeutic modality in cancer therapy.

Irradiation combined with PD-L1-/- and autophagy inhibition enhances the antitumor effect of lung cancer via cGAS-STING-mediated T cell activation

Radiotherapy combined with immune checkpoint blockade has gradually revealed the superiority in the antitumor therapy; however, the contribution of host PD-L1 remains elusive. In this study, we found that the activation of CD8⁺ T cells was strikingly increased in both irradiated PD-L1-expressing primary tumor and distant non-irradiated syngeneic tumor in PD-L1-deficient mouse host, and thus enhanced radiation-induced antitumor abscopal effect (ATAE) by activating cGAS-STING pathway. Notably, the autophagy inhibitors distinctively promoted dsDNA aggregation in the cytoplasm and increased the release of cGAS-STING-regulated IFN-β from irradiated cells, which further activated bystander CD8⁺ T cells to release IFN-γ and contributed to ATAE. These findings revealed a signaling cascade loop that the cytokines released from irradiated tumor recruit CD8⁺ T cells that in turn act on the tumor cells with amplified immune responses in PD-L1-deficient host, indicating a potential sandwich therapy strategy of RT combined with PD-L1 blockage and autophagy inhibition.

Immunotherapy and Radiotherapy for Older Cancer Patients during the COVID-19 Era: Proposed Paradigm by the International Geriatric Radiotherapy Group

BACKGROUND

Older cancer patients with locally advanced or metastatic disease may benefit from chemotherapy alone or combined with radiotherapy. However, chemotherapy is often omitted either because of physician bias or because of its underlying comorbidity, thus compromising their survival. The coronavirus disease 19 (COVID-19) pandemic is compounding this issue because of the fear of immunosuppression induced by chemotherapy on the elderly which makes them more vulnerable to the virus.

SUMMARY

Immunotherapy has less effect on the patient bone marrow compared to chemotherapy. The potential synergy between radiotherapy and immunotherapy may improve local control and survival for older patients with selected cancer. Preliminary data are encouraging because of better survival and local control in diseases which are traditionally resistant to radiotherapy and chemotherapy such as melanoma and renal cell carcinoma. Key Message: We propose a new paradigm combining immunotherapy at a reduced dose and/or extended dosing intervals and hypofractionated radiotherapy for older patients with selected cancer which needs to be tested in future clinical trials.

Re-irradiation with concurrent and maintenance nivolumab in locally recurrent and inoperable squamous cell carcinoma of the head and neck: A single-center cohort study

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Combination of in-field ReRT and nivolumab for locally recurrent HNSCC is feasible.

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No unexpected radiation-related toxicity occurred.

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CRP-, hemoglobin-levels, and neutrophil/lymphocyte ratio were associated with LPFS.

Background

The rate of loco-regional recurrences for locally advanced head and neck squamous cell carcinoma (HNSCC) following standard treatment reaches up to 50%, accompanied by a probability of 20% to develop a second primary tumor in the head and neck region.

Methods

Ten patients with inoperable, in-field recurrence of HNSCC following previous primary or adjuvant radiotherapy (RT) in combination with concurrent platinum-based chemotherapy were re-irradiated with 60 Gray in 30 fractions between December 2017 and January 2020 with concurrent and maintenance nivolumab administration. Data were retrospectively collected and compared with patients who underwent re-irradiation (ReRT) with concurrent cisplatin following propensity score matching (PSM). Local progression-free survival (LPFS) and overall survival (OS) were visualized using Kaplan-Meier method (log-rank test).

Results

All patients completed ReRT. Median number of applied courses of nivolumab was 12 (range, 3–38). OS rate was 50% at 12 months and the median OS was 11 (range, 2–23) months. Six and 12 month LPFS rates were 60% and 30%, respectively. Median LPFS was 8 (range, 2–19) months. OS and LPFS rates were not inferior to those of patients treated with concurrent cisplatin. No unexpected radiation-related toxicity occurred. A total of four patients developed any-grade immune-related adverse events of which two presented with grade 3 toxicities. One patient died within 3 weeks after ReRT. Higher blood levels of CRP (p = 0.004), lower levels of hemoglobin (p = 0.029) and higher neutrophil/lymphocyte ratio (p = 0.004) were associated with impaired LPFS. Higher recursive portioning analysis (RPA) class was associated with impaired LPFS (p = 0.022) and OS (p = 0.024).

Conclusion

The combination of ReRT and nivolumab for locally recurrent HNSCC was feasible without occurrence of unexpected toxicities. Combined radioimmunotherapy might offer an effective treatment option for carefully selected pre-irradiated patients ineligible for salvage surgery.

Challenges in Combining Immunotherapy with Radiotherapy in Recurrent/Metastatic Head and Neck Cancer

Immunotherapy with immune checkpoint inhibitors (ICI) has recently become a standard part of the treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), although the response rates are low. Numerous preclinical and clinical studies have now illuminated several mechanisms by which radiotherapy (RT) enhances the effect of ICI. From RT-induced immunogenic cancer cell death to its effect on the tumor microenvironment and vasculature, the involved mechanisms are diverse and intertwined. Moreover, the research of these interactions is challenging because of the thin line between immunostimulatory and the immunosuppressive effect of RT. In the era of active research of immunoradiotherapy combinations, the significance of treatment and host-related factors that were previously seen as being less important is being revealed. The impact of dose and fractionation of RT is now well established, whereas selection of the number and location of the lesions to be irradiated in a multi-metastatic setting is something that is only now beginning to be understood. In addition to spatial factors, the timing of irradiation is as equally important and is heavily dependent on the type of ICI used. Interestingly, using smaller-than-conventional RT fields or even partial tumor volume RT could be beneficial in this setting. Among host-related factors, the role of the microbiome on immunotherapy efficacy must not be overlooked nor can we neglect the role of gut irradiation in a combined RT and ICI setting. In this review we elaborate on synergistic mechanisms of immunoradiotherapy combinations, in addition to important factors to consider in future immunoradiotherapy trial designs in R/M HNSCC.

Radiotherapy-Mediated Immunomodulation and Anti-Tumor Abscopal Effect Combining Immune Checkpoint Blockade

Radiotherapy (RT) is a conventional method for clinical treatment of local tumors, which can induce tumor-specific immune response and cause the shrinkage of primary tumor and distal metastases via mediating tumor infiltration of CD8+ T cells. Ionizing radiation (IR) induced tumor regression outside the radiation field is termed as abscopal effect. However, due to the mobilization of immunosuppressive signals by IR, the activated CD8+T cells are not sufficient to maintain a long-term positive feedback to make the tumors regress completely. Eventually, the "hot" tumors gradually turn to "cold". With the advent of emerging immunotherapy, the combination of immune checkpoint blockade (ICB) and local RT has produced welcome changes in stubborn metastases, especially anti-PD-1/PD-L1 and anti-CTLA-4 which have been approved in clinical cancer treatment. However, the detailed mechanism of the abscopal effect induced by combined therapy is still unclear. Therefore, how to formulate a therapeutic schedule to maximize the efficacy should be took into consideration according to specific circumstance. This paper reviewed the recent research progresses in immunomodulatory effects of local radiotherapy on the tumor microenvironment, as well as the unique advantage for abscopal effect when combined with ICB, with a view to exploring the potential application value of radioimmunotherapy in clinic.

Re-irradiation for oligoprogression under Nivolumab in recurrent head and neck squamous cell carcinoma: A case report

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Immunotherapy is a new option for head and neck squamous cell carcinoma.

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Very limited data are available for concurrent radio-immunotherapy in recurrent disease.

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Our case report adds to this very limited series, focusing on oligopression under immunotherapy.

Immune checkpoint inhibitors (ICIs) represent a recently introduced class of agents active in head and neck squamous cell carcinoma (HNSCC). For a subgroup of patients with recurrent or metastatic disease, long-term benefit can be achieved: maintaining a sustained response to immunotherapy is therefore a critical factor for its efficacy at an individual level. In analogy to targeted agents, a limited pattern of progression, or “oligoprogression”, can occur. For locally recurrent HNSCC, the potential biologic interplay between the efficacy of ICIs and the design of radiation fields chosen for primary treatment is currently unknown. Here, we report on a patient who presented two subsequent oligoprogressions successfully treated with re-irradiation without interrupting Nivolumab. Both oligoprogressive lesions developed in previously unirradiated areas. We hypothesize the existence of a synergistic effect with optimal spatial cooperation between ICIs and re-irradiation for oligoprogressive disease under immunotherapy.

The value of moderate dose escalation for re-irradiation of recurrent or second primary head-and-neck cancer

Background

Treatment for local and locoregional recurrence or second head-and-neck (H&N) cancers after previous radiotherapy is challenging, and re-irradiation carries a significantly increased risk for radiotherapy-related normal tissue toxicities and treatment failure due to a radioresistant tumor phenotype. Here, we analyzed re-irradiation management and outcomes in patients with recurrent or second primary H&N carcinoma using state-of-the-art diagnostic procedures and radiotherapy techniques.

Methods

Between 2010 and 2019, 48 patients with recurrent or second primary H&N carcinoma received re-radiotherapy at the University of Freiburg Medical Center and were included in this study. Overall survival (OS) and progression-free survival (PFS) were calculated with the Kaplan-Meier method, and univariate Cox-regression analyses were performed to assess the effects of clinico-pathological factors on treatment outcomes. Acute and chronic treatment-related toxicities were quantified using the Common Terminology Criteria for Adverse Events (CTCAE v4.03).

Results

Thirty-one patients (64.6%) received definitive and 17 (35.4%) adjuvant radiotherapy. Simultaneous chemotherapy was administered in 28 patients (58.3%) with cetuximab as the most commonly used systemic agent (n = 17, 60.7%). After a median time of 17 months (range 4 months to 176 months) between first and second radiotherapy, patients were re-irradiated with a median of 58.4 Gy and a treatment completion rate of 87.5% (n = 42). Median OS was 25 months with a 1-year OS amounting to 62.4%, and median PFS was 9 months with a 1-year PFS of 37.6%. Univariate analyses demonstrated that both a lower rT-status and a radiotherapy boost were associated with improved OS (p < 0.05). There was a trend towards superior OS for patients who received > 50 Gy (p = 0.091) and who completed the prescribed radiotherapy (p = 0.055). Five patients (10.4%) suffered from at least one grade 3 toxicities, while 9 patients (27.3%) experienced chronic higher-grade toxicities (≥ grade 3) with one (3.0%) grade 4 carotid blowout and one (3.0%) grade 4 osteoradionecrosis.

Conclusion

Re-irradiation of recurrent or second primary H&N cancer with modern radiation techniques such as intensity-modulated radiotherapy resulted in promising survival rates with acceptable toxicities compared to historical cohorts. Increased re-irradiation doses, utilization of a radiotherapy boost and completion of the re-irradiation treatment were found to result in improved survival.

Predictive biomarkers and mechanisms underlying resistance to PD1/PD-L1 blockade cancer immunotherapy

Immune checkpoint blockade targeting PD-1/PD-L1 has promising therapeutic efficacy in a variety of tumors, but resistance during treatment is a major issue. In this review, we describe the utility of PD-L1 expression levels, mutation burden, immune cell infiltration, and immune cell function for predicting the efficacy of PD-1/PD-L1 blockade therapy. Furthermore, we explore the mechanisms underlying immunotherapy resistance caused by PD-L1 expression on tumor cells, T cell dysfunction, and T cell exhaustion. Based on these mechanisms, we propose combination therapeutic strategies. We emphasize the importance of patient-specific treatment plans to reduce the economic burden and prolong the life of patients. The predictive indicators, resistance mechanisms, and combination therapies described in this review provide a basis for improved precision medicine.

Current Immune-Related Molecular Approach in Combating Nasopharyngeal Cancer

Nasopharyngeal cancer is a cancer closely related to Epstein-Barr virus (EBV) infection. EBV protein has been shown to be related to various oncogenic development. Suppression of tumor suppressor genes, upregulating molecules to prevent immune attack, downregulating pro-apoptotic proteins, and stimulating local immune suppressive environment are among some roles that EBV proteins can exert on host cells. All those factors combined together with underlying genetic susceptibility of host cells further increase the chance of nasopharyngeal cancer development. Approach targeting those carcinogenesis pathways has been tested with marginal benefit. A newer approach boosting immune cells to increase recognition of tumor antigen and promoting cytotoxic T cell attack has shown promising clinical benefit. Further combination of those immunotherapies with other modality, in particular radiotherapy, has resulted in amplification of cancer killing.