Abscopal Effect Following Immunotherapy and Combined Stereotactic Body Radiation Therapy in Recurrent Metastatic Head and Neck Squamous Cell Carcinoma: A Report of Two Cases and Literature Review.

OBJECTIVE: We present two patients with recurrent, metastatic head and neck squamous cell carcinoma (R/M HNSCC) after platinum-based chemotherapy and radiotherapy (RT) with complete response via abscopal effect following combined immunotherapy (IT) and stereotactic body radiation therapy (SBRT). We review the literature for patients undergoing combined treatment with IT and RT to identify potential cases of abscopal response. STUDY DESIGN: This is a case series with a contemporary review of the literature. METHODS: Retrospective chart review identified two patients with potential abscopal responses after IT and RT for R/M HNSCC. The MEDLINE database was queried using the search terms "abscopal AND head and neck squamous cell carcinoma" and "immunotherapy AND stereotactic body radiation therapy." RESULTS: Two patients with metastatic HNSCC developed complete responses via a possible abscopal effect following combined SBRT and IT. Interim follow-up of both patients revealed a sustained, complete response. We examine the immunogenic effects of RT and report the first cases of potential abscopal effect for R/M HNSCC. We also review several preclinical studies demonstrating the synergistic efficacy of combined RT and IT with a discussion of possible mechanism. CONCLUSION: Observation of abscopal effect with combined IT and RT is currently under investigation through several preclinical studies and trials. To the best of our knowledge, these are the first two reported cases of abscopal effect for patients with HNSCC. We report two patients with R/M HNSCC with sustained, complete response after systemic IT and local RT.

Increased presence of dendritic cells and dendritic cell chemokines in the sinus mucosa of chronic rhinosinusitis with nasal polyps and allergic fungal rhinosinusitis.

BACKGROUND: The aim of this study was to determine if there is a link between local dendritic cells (DCs) and various subtypes of chronic rhinosinusitis (CRS): CRS with nasal polyposis (CRSwNP), CRS without nasal polyposis (CRSsNP), and allergic fungal rhinosinusitis (AFRS). Once DC presence was established we considered possible mechanisms for DC recruitment to the sinuses. METHODS: Biopsy specimens were taken from the osteomeatal complex during endoscopic sinus surgery in patients with AFRS (n ≥ 5), CRSsNP (n ≥ 6), and CRSwNP (n ≥ 6). Control patients (n ≥ 5) were undergoing either tumor resection or repair of cerebrospinal fluid leak and had no radiographic or endoscopic evidence of inflammatory sinus disease. Tissue samples were immunohistochemically stained for DC marker, CD209, costimulatory molecules, CD80 and CD86, and chemokine receptors, CCR2 and CCR6. Sinus tissue lysates were examined for levels of the DC chemoattractants, chemokine ligand 2 (CCL2) and CCL20. RESULTS: Analysis of sinus tissue from AFRS and CRSwNP revealed elevated numbers of cells staining positive for CD209, CD80, CD86, CCR2, and CCR6 compared to controls. CCL2 and CCL20 levels were elevated in AFRS and CRSwNP compared to controls, similar to increases in their receptors, CCR2 and CCR6, respectively. While there were trends toward increases in all markers in CRSsNP, none was statistically significant compared to control. CONCLUSION: AFRS and CRSwNP have increased numbers of DCs displaying costimulatory molecules, DC chemoattractants, and their corresponding receptors in the sinus mucosa compared to controls. These differences represent a possible mechanism for increased numbers of DCs with a T helper 2 (Th2)-skewed profile seen in CRSwNP and AFRS.