Evaluating the prognostic potential of the Ki67 proliferation index and tumour-infiltrating lymphocytes in olfactory neuroblastoma

Hyams Grade and Ki-67 as Predictive Factors for Primary Treatment Failure in Olfactory Neuroblastoma

BACKGROUND/OBJECTIVE

Tumor progression and first recurrence (TPR) after curative treatment for olfactory neuroblastoma can be regarded as primary treatment failure. Prognostic parameters for TPR and primary tumor-progression-free and recurrence-free survival (TPRFS) have not been sufficiently investigated in the literature.

METHODS

Data for 43 patients were analyzed retrospectively to evaluate prognostic parameters for TPR after curative treatment for olfactory neuroblastoma: age, age < / ≥ 50 years, sex, tumor classifications, curative therapy (monotherapy vs. combined, R0 vs. R1/2/x resection), Hyams-grade (grades, grade I-II/III-IV), and Ki-67 labeling index (values, labeling index < / ≥ 10%). The primary endpoints were TPR and TPRFS. Parameters that were significant after univariate analysis and Kaplan-Meier survival analysis were included in multiple regression and Cox regression analysis.

RESULTS

After univariate analysis, younger age (p = 0.032) and higher Ki-67 values (p = 0.001) were significantly negatively associated with time to the development of TPR. TPRFS according to Kaplan-Meier was significantly poorer with Hyams-grade III-IV (p = 0.002) and Ki-67 ≥ 10% (p = 0.001). After Cox regression analysis, TPRFS according to Kaplan-Meier was weekly significantly poorer for younger age (p = 0.033) and highly significantly worse for Hyams-grade III-IV (p = 0.005) and a Ki-67 LI ≥ 10% (p = 0.009). Tumor-stage classifications and all therapeutical parameters were not significantly associated with TPRFS.

CONCLUSIONS

Out of a panel of parameters tested, younger age, Hyams-grade III-IV, and a Ki-67 LI ≥ 10% were significantly associated with a significantly worse TPRFS after multivariate Cox regression analysis. In particular, parameters such as Hyams-grade and the Ki-67 LI should be included in management considerations in olfactory neuroblastoma at an early stage.

LEVEL OF EVIDENCE: 3

Forty-Year Long-Term Outcome After Endoscopic and Open Surgery for Esthesioneuroblastoma in Consideration of Prognostic Factors

Background: The objective of this study was to compare results after endoscopic (ES) and open surgery (OpS) for esthesioneuroblastoma over a 40-year period. Methods: In a retrospective study, patients who had undergone ES and OpS for esthesioneuroblastoma with curative intent were included. The following outcome parameters were compared after ES and OpS: epidemiologic, clinical (including known tumor classifications), histopathologic, therapeutic (resection state, adjuvant therapy), and development of recurrences. Crude survival and Kaplan-Meier 10 y, 20 y, and 35 y actuarial survival were calculated. Results: Between 1981 and 2021, 15 patients were operated with ES and 28 with OpS. Advanced-stage tumors were significantly more often treated using OpS. For all other parameters, there were no other significant differences between ES and OpS. After ES, the 35 y OS, DSS, and DFS were 48.1%, 100%, and 55.9%, respectively. After OpS, they were 40.5%, 77.5%, and 35.3%. Conclusions: ES is an effective approach in esthesioneuroblastoma, even in the long-term course over decades, if the appropriate indication compared to OpS is respected.

The Prognostic Implications of Neutrophil-to-Lymphocyte Ratio in Olfactory Neuroblastoma

OBJECTIVE

Olfactory neuroblastoma is a rare sinonasal malignancy with comparatively positive prognosis and survival, but with a range of biological behaviors that can be difficult to prognosticate with current means of risk stratification. Neutrophil-to-lymphocyte ratio (NLR) has been found across a diverse range of malignancies to be associated with poorer outcomes. This paper aims to elucidate the relationship of NLR with olfactory neuroblastoma to assess its prognostic value in this setting.

STUDY DESIGN

Retrospective chart review.

SETTING

A single tertiary care academic hospital.

METHODS

The study cohort included all patients treated for initial presentation of olfactory neuroblastoma from 2004 to 2020. NLR was calculated from preoperative labs, and each patient was evaluated for Kadish staging, Hyams grade, intraoperative positive margin, use of adjuvant therapy, posttreatment recurrence, and death. All statistical analysis was conducted using R and relationship between NLR and variables was assessed via binomial logistic regression.

RESULTS

Forty-four patients were included, 24 were male. Average age 52.8, average length of follow-up was 9.6 years. Patients were grouped by low (Kadish A/B) and advanced (Kadish C/D) stage, n = 23 and n = 21, respectively, and low (Hyams I/II) and high (Hyams III/IV) risk, n = 15 and n = 11, respectively. Advanced Kadish stage was associated with elevated NLR, odds ratio 5.69 [2.30, 20.7], P = .001. No other variables were associated with elevated NLR including Hyams grade, margin status, recurrence, and mortality.

CONCLUSION

Higher Kadish grade is associated with elevated NLR which may provide novel prognostic value to current risk-stratifying systems.

Development of an evaluation and treatment strategy for olfactory neuroblastoma: a review of evidence from large-scale studies, including population-based and multicenter studies, and meta-analyses

Olfactory neuroblastoma is a rare sinonasal malignancy arising from the olfactory epithelium that is characterized by skull base involvement and a modest natural history. Because of its rarity and long course, identification of independent prognostic factors is dependent on multivariate analysis of large, long-term data. In this review, we outline evidence for the evaluation and treatment of olfactory neuroblastoma obtained from recent large-scale population-based studies, meta-analyses and multicenter studies. Hyams grade is currently the only pathological grade system for olfactory neuroblastoma. The modified Kadish staging and Dulguerov classification are available for clinical staging. The results of large-scale studies have confirmed Hyams, the modified Kadish and Dulguerov as independent prognostic factors. Surgery followed by radiotherapy provides the best overall survival and recurrence-free survival for resectable disease. The question of whether postoperative radiotherapy should be administered for all cases or only for those at risk of recurrence remains unanswered. Exclusively endoscopic resection is indicated for modified Kadish A/B cases without any increase in the risk of death or recurrence, and is also indicated for modified Kadish C cases if a negative surgical margin is ensured. For more advanced cases, such as those with extensive brain infiltration, the open approach is indicated. Elective nodal irradiation prevents late nodal recurrence of N0 patients. Chemotherapy has failed to show a benefit in survival or disease control. Current needs for olfactory neuroblastoma include the development and validation of refined staging systems suitable for current practice; expansion of indications for endoscopic surgery; less invasive surgery; definitive radiotherapy and novel systemic therapy.

Augmentation of tumor expression of HLA-DR, CXCL9, and CXCL10 may improve olfactory neuroblastoma immunotherapeutic responses

BACKGROUND

Olfactory neuroblastoma is a rare malignancy of the anterior skull base typically treated with surgery and adjuvant radiation. Although outcomes are fair for low-grade disease, patients with high-grade, recurrent, or metastatic disease oftentimes respond poorly to standard treatment methods. We hypothesized that an in-depth evaluation of the olfactory neuroblastoma tumor immune microenvironment would identify mechanisms of immune evasion in high-grade olfactory neuroblastoma as well as rational targetable mechanisms for future translational immunotherapeutic approaches.

METHODS

Multispectral immunofluorescence and RNAScope evaluation of the tumor immune microenvironment was performed on forty-seven clinically annotated olfactory neuroblastoma samples. A retrospective chart review was performed and clinical correlations assessed.

RESULTS

A significant T cell infiltration was noted in olfactory neuroblastoma samples with a stromal predilection, presence of myeloid-derived suppressor cells, and sparse natural killer cells. A striking decrease was observed in MHC-I expression in high-grade olfactory neuroblastoma compared to low-grade disease, representing a mechanism of immune evasion in high-grade disease. Mechanistically, the immune effector stromal predilection appears driven by low tumor cell MHC class II (HLA-DR), CXCL9, and CXCL10 expression as those tumors with increased tumor cell expression of each of these mediators correlated with significant increases in T cell infiltration.

CONCLUSION

These data suggest that immunotherapeutic strategies that augment tumor cell expression of MHC class II, CXCL9, and CXCL10 may improve parenchymal trafficking of immune effector cells in olfactory neuroblastoma and augment immunotherapeutic responses.

Intratumoral and Peritumoral Multiparametric MRI-Based Radiomics Signature for Preoperative Prediction of Ki-67 Proliferation Status in Glioblastoma: A Two-Center Study

RATIONALE AND OBJECTIVES

To assess the predictive ability of intratumoral and peritumoral multiparametric magnetic resonance imaging (MRI)-based radiomics signature (RS) for preoperative prediction of Ki-67 proliferation status in glioblastoma. MATERIALS AND METHODS: A total of 205 patients with glioblastoma at two institutions were retrospectively analyzed. Data from institution 1 (n = 158) were used to develop the predictive model, and as an internal test dataset, data from institution 2 (n = 47) constitute the external test dataset. Feature selection was performed using spearman correlation coefficient, univariate ranking method, and the least absolute shrinkage and selection operator algorithm. RSs were established using a logistic regression algorithm. The predictive performance of the RSs was assessed using calibration curve, decision curve analysis (DCA), and area under the curve (AUC).

RESULTS

In the RSs based on single-parametric (contrast-enhanced T1-weighted image, T2-weighted image, or apparent diffusion coefficient maps), the AUCs of intratumoral, peritumoral, and combined area (intratumoral and peritumoral) were 0.60-0.67, with no significant difference among them. The RSs that using multiparametric features (integrating the previously mentioned three sequences) showed improved AUC compared to the single-parametric RSs; AUC reached 0.75-0.89. Among them, the multiparametric RS based on radiomics features of the combined area (Multi-Com) exhibited the highest performance, with an internal test dataset AUC of 0.89 (95% confidence interval (CI) 0.75-1.00) and an external test dataset AUC of 0.88 (95% CI 0.78-0.97). The calibration curve and DCA display RS (Multi-Com) have good calibration ability and clinical applicability.

CONCLUSION

The multiparametric MRI-based RS combining intratumoral and peritumoral features can serve as a noninvasive and effective tool for preoperative assessment of Ki-67 proliferation status in glioblastoma.

Survival Analysis and Prognostic Factors After Endonasal Resection of Advanced Olfactory Neuroblastomas: A Single Institution Experience

OBJECTIVES

To explore the prognostic factors in patients with advanced olfactory neuroblastoma (ONB) underwent endoscopic surgery.

MATERIALS AND METHODS

Retrospective medical records were reviewed of patients with pathologically proven ONB who underwent endoscopic surgical resection. Clinicopathological characteristics including patient demographics, treatment, complications, follow-up, and outcomes were analyzed. Kaplan-Meier overall survival (OS) and disease-free survival (DFS) curves were plotted. Univariate and multivariate Cox regression models were used to determine prognostic factors.

RESULTS

Eighty-five patients with Kadish stage C ONB were examined. According to the various staging systems used, most patients harbored modified Kadish stage C (78.8%). Twenty-six patients (30.6%) underwent bony skull base resection, 11 (12.9%) underwent dura resection, and 24 (28.2%) underwent additional intracranial resection that included the olfactory bulb and duct. Median follow-up was 39 months. Five-year OS and DFS rates were 83.7% and 74.9%, respectively. Five-year OS was 100% in patients treated with bony skull base resection and 77.5% in those who were not (P = .052). Dura resection did not improve OS. Multivariate Cox regression analysis identified perioperative complications (P = .009), gross total resection (P = .004), orbital invasion (P = .014), postoperative radiotherapy (P = .030), and bony skull base resection (P = .019) as independent prognostic predictors.

CONCLUSION

For patients with advanced ONB, endoscopic surgery in conjunction with radiotherapy and chemotherapy is effective and safe. Dura resection should be performed with caution in selected patients to balance survival and complications. Postoperative radiotherapy is important to improve OS and DFS.

Genomic profiling and immune landscape of olfactory neuroblastoma in China

Background

Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of the olfactory mucosa. The paucity of genomic data has prevented the development of individualized ONB treatments. Here, we investigated the genomic and immune landscape of ONB in Chinese patients.

Methods

Whole exome sequencing (WES) and multiplex immunofluorescence (MIF) analysis were performed on tissue samples from 19 Chinese ONB patients. Patients were divided into low- and high-grade groups.

Results

Overall, 929 nonsynonymous alterations were identified in 18 (94.74%) ONB cases. The most prevalent altered cancer-related genes were CTNNB1 (16%) and ZNRF3 (16%). The most mutated oncogenic pathways were the WNT and RAS pathways. The median tumor mutation burden (TMB) was 0.45, ranging from 0 to 3.25. Only one case expressed PD-L1 (> 1%) in the tumor region. The percentage of CD8+ tumor-infiltrating lymphocytes (TILs) in the tumor region ranged from 0.03% to 84.9%, with a median of 1.08%. No significant differences were observed between the low- and high-grade groups for clinicopathological features, mutant genes, mutant pathways, TMB, tumor neoantigen burden (TNB), mutant-allele tumor heterogeneity (MATH), PD-L1 expression levels, or CD8+ TIL percentage. However, the low-grade group showed significantly more CD68+ macrophages in both the tumor and total region than the high-grade group. Notably, CD68+CD163- macrophages accounted for an average of 80.5% of CD68+ macrophages.

Conclusion

This study presents data on the genomic and immune landscape of ONB cases in China. CTNNB1 and ZNRF3 were the most prevalent altered cancer-related genes. The results of TMB, PD-L1, and CD8+ Tils suggest that ONB may be insensitive to immunotherapy. M1 macrophages may be positively associated with the prognosis of ONB.

Implications for Practice

In this study, the most prevalent altered cancer-related genes were CTNNB1 (16%) and ZNRF3 (16%). The most mutated oncogenic pathways were the WNT and RAS pathways. The median tumor mutation burden (TMB) was 0.45, ranging from 0 to 3.25. Only one (1/15) case expressed PD-L1 (> 1%) in the tumor region. However, the low-grade group showed significantly more CD68+ macrophages in both the tumor and total region than the high-grade group. The higher level of CD68-related macrophages indicates that M1 macrophages potentially play an important role in ONB development that is possibly associated with prognosis.

Sox2 and βIII-Tubulin as Biomarkers of Drug Resistance in Poorly Differentiated Sinonasal Carcinomas

Poorly differentiated sinonasal carcinomas (PDCs) are tumors that have a poor prognosis despite advances in classical treatment. Predictive and prognostic markers and new personalized treatments could improve the oncological outcomes of patients. In this study, we analyzed SOX2 and βIII-tubulin as biomarkers that could have prognostic and therapeutic impacts on these tumors. The cohort included 57 cases of PDCs: 36 sinonasal undifferentiated carcinoma (SNUC) cases, 13 olfactory neuroblastoma (ONB) cases, and 8 sinonasal neuroendocrine carcinoma (SNEC) cases. Clinical follow-up data were available for 26 of these cases. Sox2 expression was detected using immunohistochemistry in 6 (75%) SNEC cases, 19 (53%) SNUC cases, and 6 (46%) ONB cases. The absence of Sox2 staining correlated with a higher rate of recurrence (p = 0.015), especially distant recurrence. The majority of cases showed βIII-tubulin expression, with strong positivity in 85%, 75%, and 64% of SNEC, ONB, and SNUC cases, respectively. Tumors with stronger βIII-tubulin expression demonstrated longer disease-free survival than those with no expression or low expression (p = 0.049). Sox2 and βIII-tubulin expression is common in poorly differentiated sinonasal tumors and has prognostic and therapeutic utility.

Sinonasal Cancer: Improving Classification, Stratification and Therapeutic Options

The nasal cavities and paranasal sinuses are the site of origin of a wide spectrum of histologically and clinically distinct disease entities [...].

Diagnostic, Prognostic, and Predictive Role of Ki67 Proliferative Index in Neuroendocrine and Endocrine Neoplasms: Past, Present, and Future

The introduction of Ki67 immunohistochemistry in the work-up of neuroendocrine neoplasms (NENs) has opened a new approach for their diagnosis and prognostic evaluation. Since the first demonstration of the prognostic role of Ki67 proliferative index in pancreatic NENs in 1996, several studies have been performed to explore its prognostic, diagnostic, and predictive role in other neuroendocrine and endocrine neoplasms. A large amount of information is now available and published results globally indicate that Ki67 proliferative index is useful to this scope, although some differences exist in relation to tumor site and type. In gut and pancreatic NENs, the Ki67 proliferative index has a well-documented and accepted diagnostic and prognostic role and its evaluation is mandatory in their diagnostic work-up. In the lung, the Ki67 index is recommended for the diagnosis of NENs on biopsy specimens, but its diagnostic role in surgical specimens still remains to be officially accepted, although its prognostic role is now well documented. In other organs, such as the pituitary, parathyroid, thyroid (follicular cell-derived neoplasms), and adrenal medulla, the Ki67 index does not play a diagnostic role and its prognostic value still remains a controversial issue. In medullary thyroid carcinoma, the Ki67 labelling index is used to define the tumor grade together with other morphological parameters, while in the adrenal cortical carcinoma, it is useful to select patients to treated with mitotane therapy. In the present review, the most important information on the diagnostic, prognostic, and predictive role of Ki67 proliferative index is presented discussing the current knowledge. In addition, technical issues related to the evaluation of Ki67 proliferative index and the future perspectives of the application of Ki67 immunostaining in endocrine and neuroendocrine neoplasms is discussed.

Olfactory Neuroblastoma: Morphological Reappraisal and Molecular Insights with Quantum Leap in Clinical Perspectives

PURPOSE OF REVIEW

The purpose of review is to provide a comprehensive review of the literature focusing on the recent advances in the diagnosis, molecular underpinning, and targeted therapy of olfactory neuroblastoma (ONB).

RECENT FINDINGS

Studies focused on the molecular fingerprinting of ONB are critical to engage new promising treatment strategies. Molecular-based subtype classifications have been proposed (basal-like ONB and neural-like ONB) but are not widely used. The rationale for implementation of DNA methylation analysis and IDH2 sequencing in routine work-up for ONB is gaining recognition. Expression of somatostatin receptors (SSTR) in ONB open new avenues for both, diagnostic (especially metastatic disease) and new treatment protocols with somatostatin analogs. Olfactory carcinoma is proposed as a unifying diagnostic terminology pertinent to epithelial divergent differentiation in olfactory neuroblastoma. Molecular (genetic and epigenetic) efforts on olfactory neuroblastoma are promising; however further refinement is needed for employment of these biomarkers as clinical standard of care. Ongoing and future multi-institutional collaborative studies will contribute to further understanding of ONB biology and aid the development of targeted treatments for this disease.

Biomarkers for Immunotherapy in Poorly Differentiated Sinonasal Tumors

The sinonasal cavities harbor a wide variety of rare cancer types. Histopathological classification can be challenging, especially for poorly differentiated tumors. Despite advances in surgery and radio-chemotherapy, the 5-year survival rate is still very low. Thus, there is an unmet clinical need for new therapeutic options. We retrospectively evaluated poorly differentiated tumors of 9 different histological subtypes from 69 patients who had received conventional treatments for the presence of CD8+ tumor-infiltrating lymphocytes (TILs), as well as the expression of PD-L1 and microsatellite instability (MSI) markers MLH1, MSH2, MSH6 and PMS2, as biomarkers for immunotherapy. CD8+ TILs were present in 23/69 (33%) cases, PD-L1 expression was observed in 23/69 (33%), and markers for MSI positivity in 5/69 (7%) cases. CD8+ TILs correlated with PD-L1 positivity, while both were mutually exclusive with MSI markers. None of the biomarkers were associated with clinical features as age, gender or tumor stage. Cases with CD8+ TILs and PD-L1 positivity showed a tendency toward worse disease-specific survival. Immune checkpoint inhibitors are emerging as new options for treatment of many tumor types. Our results indicate that also a substantial subset of patients with poorly differentiated sinonasal tumors may be a candidate to be treated with this promising new therapy.

The prognostic value of S-100 protein and Ki-67 index in olfactory neuroblastoma

OBJECTIVE

To evaluate the prognostic value of S-100 protein and Ki-67 labeling index in olfactory neuroblastomas.

METHODS

A retrospective study was conducted on a cohort of 85 patients with olfactory neuroblastomas. The immunohistochemical expression of S-100 and Ki-67 was assessed, and the predictive value of S-100 and Ki-67 was further evaluated. The optimal cutoff value of Ki-67 labeling index was determined using time-dependent receiver operating characteristic curve analysis. Overall survival and progression-free survival were assessed using the Kaplan-Meier method.

RESULTS

A cut-off Ki-67 labeling index value of 67.5% was determined for prognosis in patients with olfactory neuroblastomas. There was a significant correlation between Ki-67 expression and cervical lymph node metastasis (P = 0.049). Compared with S-100 (+), S-100 (-) was associated with a higher rate of lymph node metastasis and a higher level of Ki-67 (P = 0.007, < 0.001, respectively), as well as an advanced Kadish stage (P = 0.037). Survival analyses showed that patients with S-100 (+) had better 5-year overall survival than those with S-100 (-) (P = 0.028), and patients with both S-100 (+) and Ki-67 (<67.5%) had superior 5-year overall survival compared with all the other patients (P = 0.0225).

CONCLUSION

Our findings suggest that S-100 combined with Ki-67 labeling index are reliable prognostic factors in patients with olfactory neuroblastomas.

Multi-parametric MRI-based radiomics signature for preoperative prediction of Ki-67 proliferation status in sinonasal malignancies: a two-centre study

OBJECTIVE

To assess the predictive ability of a multi-parametric MRI-based radiomics signature (RS) for the preoperative evaluation of Ki-67 proliferation status in sinonasal malignancies.

METHODS

A total of 128 patients with sinonasal malignancies that underwent multi-parametric MRIs at two medical centres were retrospectively analysed. Data from one medical centre (n = 77) were used to develop the predictive models and data from the other medical centre (n = 51) constitute the test dataset. Clinical data and conventional MRI findings were reviewed to identify significant predictors. Radiomics features were determined using maximum relevance minimum redundancy and least absolute shrinkage and selection operator algorithms. Subsequently, RSs were established using a logistic regression (LR) algorithm. The predictive performance of RSs was assessed using calibration, decision curve analysis (DCA), accuracy, and AUC.

RESULTS

No independent predictors of high Ki-67 proliferation were observed based on clinical data and conventional MRI findings. RS-T1, RS-T2, and RS-T1c (contrast enhancement T1WI) were established based on a single-parametric MRI. RS-Combined (combining T1WI, FS-T2WI, and T1c features) was developed based on multi-parametric MRI and achieved an AUC and accuracy of 0.852 (0.733-0.971) and 86.3%, respectively, on the test dataset. The calibration curve and DCA demonstrated an improved fitness and benefits in clinical practice.

CONCLUSIONS

A multi-parametric MRI-based RS may be used as a non-invasive, dependable, and accurate tool for preoperative evaluation of the Ki-67 proliferation status to overcome the sampling bias in sinonasal malignancies.

KEY POINTS

• Multi-parametric MRI-based radiomics signatures (RSs) are used to preoperatively evaluate the proliferation status of Ki-67 in sinonasal malignancies. • Radiomics features are determined using maximum relevance minimum redundancy (mRMR) and least absolute shrinkage and selection operator (LASSO) algorithms. • RSs are established using a logistic regression (LR) algorithm.

Emerging concepts in sinonasal tumor research

PURPOSE OF REVIEW

Sinonasal malignancies are rare and understudied, often diagnosed at late stages, and may behave aggressively. This review explores investigative diagnostic, therapeutic, and scientific advances specific to sinonasal undifferentiated carcinoma (SNUC), intestinal-type adenocarcinoma (ITAC), and olfactory neuroblastoma (ONB).

RECENT FINDINGS

A number of studies have recently contributed more robust knowledge of the genetic and molecular landscapes of SNUC, ITAC, and ONB. These analyses have identified SMARCB1 and IDH2 mutations in SNUC, potentially allowing for the tumor's subdivision. Recent studies have also defined a role for induction chemotherapy in SNUC. Somatic mutations for ITAC have been identified and may be potentially targetable with FDA approved therapies. Studies defining the tumor microenvironment for ITAC and ONB have introduced the possibility of immune checkpoint inhibition for these tumor types.

SUMMARY

Studies reviewed here detail promising results of the most current and novel characterization of SNUC, ITAC, and ONB genetic and molecular landscapes, which have informed ongoing therapeutic discovery. With continued multi-institutional efforts, the field of sinonasal tumor research will achieve higher disease control and improved treatment outcomes for patients afflicted with these rare cancers.

Clinicopathologic features and prognosis of olfactory neuroblastoma with isocitrate dehydrogenase 2(IDH2) mutations

OBJECTIVE

Because of their rarity, it is not known whether isocitrate dehydrogenase 2 (IDH2) mutations are related to olfactory neuroblastoma. We investigated relationships between IDH2 mutations, clinicopathological parameters, and prognosis for olfactory neuroblastoma to establish a molecular classification based on IDH2 mutations.

MATERIALS AND METHODS

An 82-patient cohort was retrospectively screened by immunohistochemistry using a mutation-specific IDH2 antibody and by real-time PCR for IDH2 mutations. We also determined immunohistochemically the expression of chromogranin A, synaptophysin, neuron-specific enolase, CD56, S100, and Ki67.

RESULTS

The two methods for detection of IDH2 mutations had high consistency. Mutation of IDH2 detected by real-time PCR was correlated with higher Kadish stage, Hyams grade, and Ki67 proliferation index. Mutation of IDH2 was negatively correlated with expression of chromogranin A, synaptophysin, CD56, and S100. Kaplan-Meier analysis showed that an IDH2 mutation, high Hyams grade, and Ki67 index were associated with poor overall survival. Hyams grade and IDH2 mutation were independent prognostic factors in multivariable analysis.

CONCLUSIONS

Immunohistochemistry was a reliable method to assess the mutation status of IDH2. Tumors with IDH2 mutations represented a distinct subset with aggressive behavior and poor prognosis. The gene status of IDH2 can be a major molecular classification criterion in olfactory neuroblastoma.

Prognostic and Therapeutic Implications of Immune Classification by CD8+ Tumor-Infiltrating Lymphocytes and PD-L1 Expression in Sinonasal Squamous Cell Carcinoma

Sinonasal squamous cell carcinoma (SNSCC) is an aggressive tumor predominantly arising in the maxillary sinus and nasal cavities. Advances in imaging, surgical and radiotherapeutic techniques have reduced complications and morbidity; however, the prognosis generally remains poor, with an overall 5-year survival rate of 30-50%. As immunotherapy may be a new therapeutic option, we analyzed CD8⁺ tumor-infiltrating lymphocytes (TILs) and the tumor microenvironment immune type (TMIT, combining CD8⁺ TILs and PD-L1) in a series of 57 SNSCCs. Using immunohistochemistry, tissue samples of 57 SNSCCs were analyzed for expression of CD8 on TILs and of PD-L1 on tumor cells. The results were correlated to the clinical and survival data. In total, 88% (50/57) of the tumors had intratumoral CD8⁺ TILs; 19% (11/57)-CD8^high (>10%); and 39/57 (68%)-CD8^low (1-10%). PD-L1 positivity (>5%) was observed in 46% (26/57) of the SNSCCs and significantly co-occurred with CD8⁺ TILs (p = 0.000). Using univariate analysis, high intratumoral CD8⁺ TILs and TMIT I (CD8^high/PD-L1^pos) correlated with a worse survival rate. These results indicate that SNSCCs are immunogenic tumors, similar to head and neck squamous cell carcinomas. Nineteen percent of the cases were both CD8^high and PD-L1^pos and this subgroup may benefit from therapy with immune checkpoint inhibitors.

CRTC1-SS18 Fusion Sarcoma With Aberrant Anaplastic Lymphoma Kinase Expression

Undifferentiated small round cell sarcoma (USRCS) represents a highly heterogeneous group of tumors. A variety of specific gene fusions of USRCS have been reported, including CIC-FOXO4, CIC-NUTM1, BCOR-MAML3, and ZC3H7B-BCOR. Here we report a case of sarcoma harboring a rare recurrent CRTC1-SS18 gene fusion, which was considered as USRCS previously. This sarcoma was composed of nests of small round cells encapsulated in a fibrous stroma. Foci of necrosis and hemorrhage were observed in the tumor. Immunohistochemistry for anaplastic lymphoma kinase showed diffuse positivity. RNA-seq results revealed a chromosomal translocation of CRTC1 gene exon 1 on chromosome 19 with SS18 gene exon 2 on chromosome 18. Thereafter, fluorescence in-situ hybridization confirmed the presence of SS18 gene and CRTC1 gene break-apart, which manifested as the splitting of red and green signals into 2 parts. A previous study showed that CRTC1-SS18 fusion sarcoma and EWSR1-CREB1 fusion angiomatoid fibrous histiocytoma were clustered close in the expression profile. However, whether CRTC1-SS18 fusion sarcomas represent a high malignancy has been a matter of debate. Our study is a worthy addition to the series of rare rearrangements associated with sarcomas and may be of therapeutic relevance.

CD8+ Tumour-Infiltrating Lymphocytes and Tumour Microenvironment Immune Types as Biomarkers for Immunotherapy in Sinonasal Intestinal-Type Adenocarcinoma

BACKGROUND

Intestinal-type adenocarcinoma (ITAC) is a rare tumour occurring in the ethmoid sinus. Recent years have brought advances in endoscopic surgery and precision radiotherapy; however, five-year overall survival has not improved and remains at 35-80%, depending on tumour stage and histology. Therefore, there is a need for new therapeutic options.

METHODS

We evaluated CD8⁺ tumour-infiltrating lymphocytes (TILs) and tumour microenvironment immune type (TMIT, combining CD8⁺ TILs and PD-L1) as predictive biomarkers for immunotherapy in a series of 133 ITAC. All results were correlated to clinical and follow-up data.

RESULTS

The presence of intratumoural CD8⁺ TILs was low in 57% of cases and high in 8% of cases. Tumoural PD-L1 positivity was observed in 26% of cases. CD8⁺ TILs and TMIT correlated with the histological subtype of ITAC and with better overall survival. The presence of stromal PD-L1-positive macrophages was related to intratumoural CD8⁺ TILs. PD-L1 expression on tumour cells or macrophages did not show prognostic value.

CONCLUSIONS

TMIT classification did not have additional prognostic value over CD8⁺ TILs alone. The modest percentage of CD8^high/PD-L1^pos cases indicates that ITAC is a lowly immunogenic tumour type. Nevertheless, a proportion of ITAC, especially the papillary and colonic subtypes, could benefit from therapy with immune checkpoint inhibitors.

Expression of Programmed Cell Death Ligand 1 and Associated Lymphocyte Infiltration in Olfactory Neuroblastoma

BACKGROUND

Programmed cell death ligand 1 (PD-L1) is a transmembrane glycoprotein that interacts with the receptor programmed cell death 1 (PD-1) to suppress T-cell activation, reduce adjacent tissue damage, and promote tolerance to self-antigens. Tumors may express PD-L1 as a mechanism to evade immune detection. Recent clinical trials have demonstrated the efficacy of PD-L1/PD-1 antagonists through activation of tumor-infiltrated CD8⁺ T cells. The aim of this study was to determine the expression pattern of PD-L1 and PD-1 in olfactory neuroblastoma (ONB) tumor cells and to determine the presence of PD-1⁺ and CD8⁺ lymphocytes in the ONB immune microenvironment.

METHODS

Immunohistochemistry for expression of PD-L1, PD-1, and CD8 was performed on paraffin-embedded ONB tissue.

RESULTS

Of the 10 primary site ONB samples, 4 demonstrated positive PD-L1 expression. Of PD-L1⁺ tumors, the 2 highest expressing samples were found to contain PD-1⁺ tumor cells. Of the 4 available metastatic samples, all of which arose from PD-L1^- primary site ONB, 3 were positive for PD-L1 and contained PD-1⁺ tumor cells. PD-L1⁺ primary and metastatic tumors also demonstrated increased PD-1⁺ infiltrating lymphocytes in the tumor and stroma (11.6- and 4.62-fold increase) compared with PD-L1^- samples (P < 0.05 and P = 0.068 respectively). PD-L1⁺ specimens demonstrated increased CD8⁺ lymphocytes in the tumor and stroma (7.46- and 2.14-fold increase) compared with PD-L1^- tumors (P < 0.05 for both).

CONCLUSIONS

These data demonstrate that a proportion of ONB primary and metastatic tumors express PD-L1 and possess an associated tumor and stromal infiltrate of PD-1⁺ and CD8⁺ lymphocytes.