Relationship between the tumor microenvironment and the efficacy of the combination of radiotherapy and immunotherapy

Radiotherapeutic Treatment of an Epidermoid Tumor in a Patient With Zanubrutinib-Treated Mantle Cell Lymphoma: The First Report of Concomitant Treatment

Mantle cell lymphoma (MCL) is a challenging B-cell non-Hodgkin lymphoma with a poor prognosis and frequent relapses. While treatment advancements such as rituximab and Bruton tyrosine kinase inhibitors (BTKi) like ibrutinib have improved outcomes, novel treatments are continually sought. Zanubrutinib, a second-generation BTKi, promises reduced side effects due to its high selectivity and reduced off-target inhibition. This paper presents a novel case of simultaneous radiotherapy and zanubrutinib treatment in a patient with MCL. We describe a 76-year-old female with a history of MCL treated with zanubrutinib. The patient presented with a metastatic lesion in the parotid gland, which emerged from a previously treated spinocellular carcinoma. She underwent parotidectomy followed by adjuvant radiotherapy while continuing zanubrutinib. The combination was well-tolerated with minimal side effects, including grade 1 dermatitis and grade 2 mucositis, neither of which progressed significantly. Hematological parameters monitored during treatment showed delayed, transient lymphopenia and neutropenia, which resolved post-therapy. No dose adjustment was necessary. The safety and efficacy of concurrent radiotherapy and zanubrutinib treatment in MCL patients are largely unexplored in clinical literature. This case represents the first documented instance of concurrent radiotherapy and zanubrutinib treatment. Our case suggests a favorable safety profile with manageable adverse effects, contrasting with concerns about increased toxicity with other tyrosine kinase inhibitors and radiotherapy combinations. These results indicate the feasibility of this approach with minimal adverse effects. Future studies should explore the broader applicability and efficacy of this treatment strategy, focusing on long-term outcomes and the interplay between BTKi therapy and radiotherapy response.

Radiotherapy Combined with Intralesional Immunostimulatory Agents for Soft Tissue Sarcomas

Immunotherapy has shifted the treatment paradigm for many types of cancer. Unfortunately, the most commonly used immunotherapies, such as immune checkpoint inhibitors (ICI), have yielded limited benefit for most types of soft tissue sarcoma (STS). Radiotherapy (RT) is a mainstay of sarcoma therapy and can induce immune modulatory effects. Combining immunotherapy and RT in STS may be a promising strategy to improve sarcoma response to RT and increase the efficacy of immunotherapy. Most combination strategies have employed immunotherapies, such as ICI, that derepress immune suppressive networks. These have yielded only modest results, possibly due to the limited immune stimulatory effects of RT. Combining RT with immune stimulatory agents has yielded promising preclinical and clinical results but can be limited by the toxic nature of systemic administration of immune stimulants. Using intralesional immune stimulants may generate stronger RT immune modulation and less systemic toxicity, which may be a feasible strategy in accessible tumors such as STS. In this review, we summarize the immune modulatory effects of RT, the mechanism of action of various immune stimulants, including toll-like receptor agonists, and data for combinatorial strategies utilizing these agents.