Frequent expression of somatostatin receptor 2a in olfactory neuroblastomas: a new and distinctive feature

Efficacy of anti-PD-1 monotherapy for recurrent or metastatic olfactory neuroblastoma

Background

Olfactory neuroblastoma (ONB) is a rare malignant tumor of the head and neck. Due to its rarity, standard systemic therapy for this condition has yet to be established. In particular, the use of immune checkpoint inhibitors (ICIs) for the recurrent or metastatic (R/M) ONB population remains unclear.

Methods

We retrospectively evaluated 11 patients with R/M ONB who received any systemic chemotherapy at two Japanese institutions (National Cancer Center Hospital East and Kyushu Medical Center) between January 2002 and March 2022 and analyzed outcomes by use of anti-PD-1 antibody (nivolumab or pembrolizumab) monotherapy.

Results

Of the 11 patients, 6 received ICI (ICI-containing treatment group) and the remaining 5 were treated with systemic therapy but not including ICI (ICI-non-containing treatment group). Overall survival (OS) was significantly longer in the ICI-containing group (median OS: not reached vs. 6.4 months, log-rank p-value: 0.035). The fraction of ICI systemic therapy in the entire treatment period of this group reached 85.9%. Four patients (66.7%) in the ICI-containing treatment group experienced immune-related adverse events (irAE), with grades of 1/2. No irAE of grade 3 or more was seen, and no patient required interruption or discontinuation of treatment due to toxicity.

Conclusion

ICI monotherapy appears to be effective and to contribute to prolonged survival in R/M ONB.

Update on olfactory neuroblastoma

Olfactory neuroblastomas are uncommon malignancies that arise from olfactory receptor cells located high in the nasal cavity. Accurate diagnosis plays a crucial role in determining clinical results and guiding treatment decisions. Diagnosis can be a major challenge for pathologists, especially when dealing with tumours with poor differentiation. The discovery of several molecular and immunohistochemical markers would help to overcome classification difficulties. Due to the paucity of large-scale studies, standardisation of diagnosis, treatment and prediction of outcome remains a challenge. Surgical resection by endoscopic techniques with the addition of postoperative irradiation is the treatment of choice. In addition, it is advisable to consider elective neck irradiation to minimise the risk of nodal recurrence. Molecular characterisation will help not only to make more accurate diagnoses but also to identify specific molecular targets that can be used to develop personalised treatment options tailored to each patient. The present review aims to summarise the current state of knowledge on histopathological diagnosis, the molecular biology and management of this disease.

Challenging differential diagnoses in small biopsies from the sinonasal tract

Sinonasal biopsy specimens are a challenging area in anatomic pathology. The small, often fragmented or crushed nature of these biopsies can hinder morphologic assessment. Additionally, many of the tumors in this area are rare and share morphologic, and sometime immunophenotypic similarities. In many cases, immunohistochemistry is helpful if not necessary to reach a specific diagnosis. In other cases, a specific diagnosis is not possible and a differential diagnosis must be given on a biopsy specimen despite access to a well-equipped immunohistochemistry laboratory. This review article groups some of the more challenging entities in the sinonasal region based on morphologic patterns. These include low grade squamoid lesions such as sinonasal (Schneiderian) papilloma and DEK::AFF2 rearranged carcinoma, glandular neoplasms such as intestinal and non-intestinal type sinonasal adenocarcinoma, high-grade carcinomas such as HPV-related multiphenotypic sinonasal carcinoma, NUT carcinoma and SWI/SNF deficient carcinomas, small round blue cell tumors such as teratocarcinosarcoma, neuroendocrine carcinoma and olfactory neuroblastoma, and finally, low grade spindle cell neoplasms such as glomangiopericytoma, biphenotypic sinonasal sarcoma and solitary fibrous tumor.

Tumors of the Nose and Paranasal Sinuses: Promoting Factors and Molecular Mechanisms-A Systematic Review

Sinonasal neoplasms are uncommon diseases, characterized by heterogeneous biological behavior, which frequently results in challenges in differential diagnosis and treatment choice. The aim of this review was to examine the pathogenesis and molecular mechanisms underlying the regulation of tumor initiation and growth, in order to better define diagnostic and therapeutic strategies as well as the prognostic impact of these rare neoplasms. A systematic review according to Preferred Reporting Items for Systematic Review and Meta-Analysis criteria was conducted between September and November 2022. The authors considered the three main histological patterns of sinonasal tumors, namely Squamous Cell Carcinoma, Intestinal-Type Adenocarcinoma, and Olfactory Neuroblastoma. In total, 246 articles were eventually included in the analysis. The genetic and epigenetic changes underlying the oncogenic process were discussed, through a qualitative synthesis of the included studies. The identification of a comprehensive model of carcinogenesis for each sinonasal cancer subtype is needed, in order to pave the way toward tailored treatment approaches and improve survival for this rare and challenging group of cancers.

Other Less Prevalent Tumors of the Central Nervous System

The presented tumors in this chapter are somewhat very rare, and their management is still debated due to the scarcity of information about their cell of origin, behavior, and biology. Treatment options are still limited, but we are confident that in the near future by discovering the genetic and biological mechanisms that drive tumor growth we will be able to offer new target therapies that should be flanked by surgery, radiotherapy, and chemotherapeutic agents actually in use. The purpose of this chapter is to highlight the most important known characteristics of these tumors offering the chance to recognize the disease and then offer the best opportunity for treatment to patients. The 5th WHO Classification Central Nervous System features substantial changes by moving further to advance the role of molecular diagnostics in CNS tumor classification, but remaining rooted in other established approaches to tumor characterization, including histology and immunohistochemistry, and probably, the category of many tumors will change. Here, the most important characteristics of each neoplasm are summarized focusing on genetic mechanisms and molecular pathways, their histopathologic footprints, signs and symptoms, radiologic features, therapeutic approaches, and prognosis as well as follow-up protocols. Schematic classifications are also presented to offer a better understanding of the pathology.

Clinical outcomes, Kadish-INSICA staging and therapeutic targeting of somatostatin receptor 2 in olfactory neuroblastoma

INTRODUCTION

Olfactory neuroblastoma (ONB) is a rare cancer of the sinonasal region. We provide a comprehensive analysis of this malignancy with molecular and clinical trial data on a subset of our cohort to report on the potential efficacy of somatostatin receptor 2 (SSTR2)-targeting imaging and therapy.

METHODS

We conducted a retrospective analysis of 404 primary, locally recurrent, and metastatic olfactory neuroblastoma (ONB) patients from 12 institutions in the United States of America, United Kingdom and Europe. Clinicopathological characteristics and treatment approach were evaluated. SSTR2 expression, SSTR2-targeted imaging and the efficacy of peptide receptor radionuclide therapy [PRRT](177Lu-DOTATATE) were reported in a subset of our cohort (LUTHREE trial; NCT03454763).

RESULTS

Dural infiltration at presentation was a significant predictor of overall survival (OS) and disease-free survival (DFS) in primary cases (n = 278). Kadish-Morita staging and Dulguerov T-stage both had limitations regarding their prognostic value. Multivariable survival analysis demonstrated improved outcomes with lower stage and receipt of adjuvant radiotherapy. Prophylactic neck irradiation significantly reduces the rate of nodal recurrence. 82.4% of the cohort were positive for SSTR2; treatment of three metastatic cases with SSTR2-targeted peptide-radionuclide receptor therapy (PRRT) in the LUTHREE trial was well-tolerated and resulted in stable disease (SD).

CONCLUSIONS

This study presents pertinent clinical data from the largest dataset, to date, on ONB. We identify key prognostic markers and integrate these into an updated staging system, highlight the importance of adjuvant radiotherapy across all disease stages, the utility of prophylactic neck irradiation and the potential efficacy of targeting SSTR2 to manage disease.

Molecular Biomarkers in Sinonasal Cancers: New Frontiers in Diagnosis and Treatment

Purpose of Review

Sinonasal tumors are rare and heterogeneous diseases which pose challenges in diagnosis and treatment. Despite significant progress made in surgical, oncological, and radiotherapy fields, their prognosis still remains poor. Therefore, alternative strategies should be studied in order to refine diagnosis and improve patient care.

Recent Findings

In recent years, in-depth molecular studies have identified new biological markers, such as genetic abnormalities and epigenetic variations, which have allowed to refine diagnosis and predict prognosis. As a consequence, new histological entities have been described and specific subgroup stratifications within the well-known histotypes have been made possible. These discoveries have expanded indications for immunotherapy and targeted therapies in order to reduce tumor spread, thus representing a valuable implementation of standard treatments.

Summary

Recent findings in molecular biology have paved the way for better understanding and managing such rare and aggressive tumors. Although further efforts need to be made in this direction, expectations are promising.

p53-Mediated Radiosensitization of 177Lu-DOTATATE in Neuroblastoma Tumor Spheroids

p53 is involved in DNA damage response and is an exciting target for radiosensitization in cancer. Targeted radionuclide therapy against somatostatin receptors with 177Lu-DOTATATE is currently being explored as a treatment for neuroblastoma. The aim of this study was to investigate the novel p53-stabilizing peptide VIP116 in neuroblastoma, both as monotherapy and together with 177Lu-DOTATATE. Five neuroblastoma cell lines, including two patient-derived xenograft (PDX) lines, were characterized in monolayer cultures. Four out of five were positive for 177Lu-DOTATATE uptake. IC50 values after VIP116 treatments correlated with p53 status, ranging between 2.8-238.2 μM. IMR-32 and PDX lines LU-NB-1 and LU-NB-2 were then cultured as multicellular tumor spheroids and treated with 177Lu-DOTATATE and/or VIP116. Spheroid growth was inhibited in all spheroid models for all treatment modalities. The most pronounced effects were observed for combination treatments, mediating synergistic effects in the IMR-32 model. VIP116 and combination treatment increased p53 levels with subsequent induction of p21, Bax and cleaved caspase 3. Combination treatment resulted in a 14-fold and 1.6-fold induction of MDM2 in LU-NB-2 and IMR-32 spheroids, respectively. This, together with differential MYCN signaling, may explain the varying degree of synergy. In conclusion, VIP116 inhibited neuroblastoma cell growth, potentiated 177Lu-DOTATATE treatment and could, therefore, be a feasible treatment option for neuroblastoma.

Ectopic Primary Olfactory Neuroblastoma: Case Series and Literature Review

OBJECTIVE

Olfactory neuroblastoma (ONB) is a rare malignant tumor arising in the upper nasal cleft. Rarely, ONB may originate in ectopic sites and the impact of this on prognosis and treatment strategies continues to be debated.

METHODS

A retrospective analysis was undertaken of patients with ectopic ONB treated between 2000 and 2020 in a tertiary-care referral center for skull base tumors. Three patients were included in this analysis: a 37-year-old woman with ONB arising from the bulla ethmoidalis; a 28-year-old man with inappropriate secretion of antidiuretic hormone caused by a maxillary sinus ONB; and a 41-year-old man with lacrimal sac ONB. Preoperative workup, surgical approach, adjuvant treatments and postoperative surveillance were analyzed. Relevant literature published between 2000 and January 2021 was fully reviewed to investigate oncologic outcomes and delineate the standard of care for such rare tumors.

RESULTS

All patients were treated via endoscopic endonasal resection with radical intent, followed by adjuvant treatments when required. No recurrences of disease were observed after a mean follow-up time of 32 months (range, 12-60 months). Data emerging from the literature suggest that a multidisciplinary treatment approach, including free-margins surgical resection followed by adjuvant radiotherapy or radiochemotherapy, is recommended. Olfactory bulb and dura preservation should be attempted whenever feasible.

CONCLUSIONS

Endoscopic endonasal surgery should be preferred, when possible, to achieve complete excision to minimize patients' morbidity. The ectopic site of origin affects prognosis and should be considered when selecting the appropriate multimodal treatment strategy.

Somatostatin receptor 2 is highly sensitive and specific for Epstein-Barr virus-associated nasopharyngeal carcinoma

Viruses are known drivers of head and neck squamous cell carcinomas (HNSCC), particularly Epstein-Barr virus (EBV) and human papillomavirus (HPV). Both EBV-positive nasopharyngeal carcinoma (EBVNPC) and HPV-positive oropharyngeal SCC (OPSCC) can have overlapping histomorphology and molecular signatures, including nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB) pathway mutations. A recent study showed that NFKB activation in EBVNPC drives somatostatin receptor 2 (SSTR2) expression that is detectable by immunohistochemistry and by imaging with 68-Gadolinium-DOTA-peptide radioconjugate. However, whether a similar NFKB-SSTR2 signaling mechanism exists for other virus-positive HNSCC, namely HPV-positive sinonasal carcinomas and OPSCC, remains unclear. Here we examined SSTR2 expression in a cohort of EBV-positive, HPV-positive, and virus-negative HNSCC with immunohistochemistry. SSTR2 immunohistochemistry was performed on our cohort of primary and/or metastatic EBVNPC, HPV-positive sinonasal SCC, OPSCC, HPV-negative sinonasal and oral cavity SCC, and benign tonsil and adenoid tissue. For SSTR2 staining, the extent was categorized as focal, multifocal, or diffuse, and the intensity was categorized as weak, moderate, or strong. Multifocal/diffuse SSTR2 staining of any intensity was considered positive. Among primary, recurrent, and/or undifferentiated NPC, 90% showed multifocal to diffuse strong SSTR2 expression. One HPV-positive sinonasal carcinoma showed patchy SSTR2 staining. None of the remaining HPV-positive sinonasal carcinomas, OPSCC, or oral cavity HNSCC showed significant SSTR2 staining. Overall, SSTR2 is highly sensitive and specific for EBVNPC and could represent a surrogate biomarker. Among HNSCC assessed here, we recommend testing primary NPC for SSTR2 because of its relevance for diagnosis, associated imaging modalities, and its therapeutic implications for patient care.

Ga-68 DOTATATE Positron Emission Tomography/Computed Tomography in a Rare Case of Esthesioneuroblastoma

We describe the Ga-68 DOTATATE positron emission tomography/computed tomography (PET/CT) findings of a 51-year-old man, operated for right esthesioneuroblastoma. Postoperative Ga-68 DOTATATE PET/CT revealed focal uptake anterior to sphenoid ostium on the right paramedian side, suspicious for residual disease. Magnetic resonance imaging showed an enhancing lesion in posterosuperior nasal cavity on the right side extending into the right sphenoid sinus. He underwent re-surgery and adjuvant chemoradiotherapy. The histopathology revealed residual olfactory neuroblastoma. The follow-up Ga-68 DOTATATE PET/CT was negative. This case emphasizes the role of Ga-68 DOTATATE PET/CT in the management, especially in residual or recurrent disease and potential radiotheranostics for these rare tumors.

SSTR2 Expression in Olfactory Neuroblastoma: Clinical and Therapeutic Implications

Somatostatin receptor 2 (SSTR2) expression has previously been documented in olfactory neuroblastoma (ONB). Here, we fully characterize SSTR2 expression in ONB and correlate staining results with clinicopathologic parameters including Hyams grade. We also assess SSTR2 immunohistochemistry expression in various histologic mimics of ONB to assess its diagnostic functionality. 78 ONBs (51 primary biopsies/excisions and 27 recurrences/metastases) from 58 patients were stained for SSTR2. H-scores based on intensity (0-3 +) and percentage of tumor cells staining were assigned to all cases. 51 histologic mimics were stained and scored in an identical fashion. 77/78 (99%) ONB cases demonstrated SSTR2 staining (mean H-score: 189, range: 0-290). There were no significant differences in staining between primary tumors and recurrences/metastases (mean H-score: 185 vs 198). Primary low-grade ONB had somewhat stronger staining than high-grade tumors (mean H-score: 200 vs 174). SSTR2 expression had no prognostic value when considering disease-free or disease-specific survival. SSTR2 staining is significantly higher in ONB than its histologic mimics (mean H-score: 189 vs 12.9, p < 0.001) suggesting a potential use of the marker in diagnosis of ONB. In conclusion, SSTR2 is consistently expressed in ONB suggesting a role for somatostatin-analog based imaging and therapy in this disease. More generally, SSTR2 may be another marker of neuroendocrine differentiation in ONB.

Pediatric applications of Dotatate: early diagnostic and therapeutic experience

In recent years, new somatostatin receptor agents (SSTRs) have become available for diagnostic imaging and therapy in neuroendocrine tumors. The novel SSTR ligand DOTA-DPhel-Tyr3-octreotate (Dotatate) in particular can be linked with ⁶⁸Gallium for diagnostic imaging purposes, and with the β-emitter ¹⁷⁷Lutetium for radiotherapy in the setting of neuroendocrine tumors. Dotatate imaging offers distinct advantages in the evaluation of neuroendocrine tumors compared to standard techniques, including greater target-to-background ratio and lesion conspicuity, high sensitivity/specificity, improved spatial resolution with positron emission tomography (PET)/CT or PET/MR, and decreased radiation exposure. Although currently off-label in pediatrics, Dotatate theranostics in children are being explored, most notably in the setting of neuroblastoma and hereditary neuroendocrine syndromes. This article provides a multicenter case series of Dotatate imaging and therapy in pediatric patients in order to highlight the spectrum of potential clinical applications.

Clinical Outcomes and Multidisciplinary Patterns of Failure for Olfactory Neuroblastoma: The Ohio State Experience

Purpose  Olfactory neuroblastoma (ONB) is a rare head and neck cancer believed to be originated from neural crest cells of the olfactory membrane located in the roof of the nasal fossa. This study evaluates clinical outcomes and failure patterns in ONB patients of those patients treated with surgical resection at a high-volume tertiary cancer center. Methods and Materials  Thirty-nine ONB patients who underwent surgical resection at our institution from 1996 to 2017 were retrospectively identified. Univariate, multivariate, and survival analysis were calculated using Cox regression analysis and Kaplan-Meier log-rank. Results  Median follow-up time was 59 months (range: 5.2-236 months). The median overall survival (OS) and disease-free survival (DFS) for the entire cohort were 15 and 7.6 years, respectively. The 5-year cumulative OS and DFS were 83 and 72%, respectively. The 5-year OS for low Hyams grade (LHG) versus high Hyams grade (HHG) was 95 versus 61% ( p  = 0.041). LHG was found in 66% of the early Kadish stage patients compared with 28% in the advanced Kadish stage patients ( p  = 0.057). On multivariate analysis, HHG and positive node status predicted for worse OS and only HHG predicted for worse DFS. Of note, five patients (all Kadish stage A) who received surgical resection alone had no observed deaths or recurrences with a median follow-up of 44 months (range: 5-235 months). Conclusion  In this retrospective cohort, patients with positive nodes or HHG have significantly worse clinical outcomes. Future studies should explore treatment intensification for HHG or positive nodes.

Esthesioneuroblastoma: A Comprehensive Review of Diagnosis, Management, and Current Treatment Options

INTRODUCTION

Many controversies exist in the diagnosis and management of this aggressively malignant condition, mainly because of limited literature and lack of randomized control trials, resulting in nonstandardized treatment methods. We performed a comprehensive review of the literature to identify management approach and treatment options for esthesioneuroblastoma.

METHODS

An extensive review of the published literature was conducted in PubMed, OVID Medline, and EMBASE journals for studies of esthesioneuroblastoma. Terms for search included esthesioneuroblastoma (ENB) and olfactory neuroblastoma (ONB). No date restrictions were used.

RESULTS

The search yielded 3876 related articles. Cross-checking of articles led to exclusion of duplicate articles. The remaining 1170 articles were screened for their full text and English language availability. Of 609 full-text articles available, animal studies, irrelevant articles, and studies with mixed/confusing data were excluded. We finalized 149 articles pertaining to the topic, including 119 original research articles, 3 book chapters, 11 reviews, 9 case reports, and 7 case series.

CONCLUSIONS

Surgical resection followed by radiotherapy is the standard for treatment for higher-grade lesions. The endoscopic endonasal approach is gaining further recognition with more favorable outcomes and better survival than for open surgery. Postoperative radiotherapy is associated with the highest overall survival and shows benefit for patients with higher-stage disease and those who receive chemotherapy. Recurrence rates after treatment vary drastically in the literature and, therefore, prolonged follow-up with repeated imaging is recommended. Lifelong surveillance is recommended because of late recurrences associated with this tumor.

Endoscopic management of Esthesioneuroblastoma: Our experience and review of the literature

During the last two decades evolution of the endoscopic endonasal approaches (EEA) has offered the option of minimally invasive techniques in the management of esthesioneuroblastomas (ENB), either as endoscope assisted cranial resection or as pure endoscopic procedures. This study presents the use of pure EEA in the management of ENB in our center, along with a literature review. We retrospectively reviewed the clinical, radiology and pathology records of patients with ENB treated during the period July 2006 to January 2016. During the above period, ten patients with ENB were treated using pure EEA. The mean age was 47.5 years. The gender distribution was: eight males, two females. The most common presenting symptoms were nasal obstruction and discharge or epistaxis (8/10). The mean duration of symptoms was 1.5 years. All patients had preoperative confirmation of ENB by biopsy. Five patients received neoadjuvant radiation and four underwent postoperative radiation. One patient did not receive any radiotherapy and no patient received chemotherapy. Gross total resection was achieved in all patients and intraoperative microscopically negative surgical margins achieved in 9/10 (90%). No major intraoperative complications occurred. The most common postoperative complication was nasal infection. Cerebrospinal fluid leak was noted in one patient. During the follow-up period of 6-120 months (mean 74.8) two cases of neck lymph node recurrence were observed. No deaths due to the disease occurred during the follow-up period. Pure EEA offer excellent results in the management of ENB. Neoadjuvant radiation treatment is promising although more studies need to establish its role.