HER2 status in sinonasal intestinal-type adenocarcinoma

Molecular Basis and Rationale for the Use of Targeted Agents and Immunotherapy in Sinonasal Cancers

Despite the progress of surgery, radiotherapy, and neoadjuvant chemotherapy, the prognosis for advanced sinonasal cancers (SNCs) remains poor. In the era of precision medicine, more research has been conducted on the molecular pathways and recurrent mutations of SNCs, with the aim of understanding carcinogenesis, helping with diagnosis, identifying prognostic factors, and finding potentially targetable mutations. In the treatment of SNC, immunotherapy is rarely used, and no targeted therapies have been approved, partly because these tumors are usually excluded from major clinical trials. Data on the efficacy of targeted agents and immune checkpoint inhibitors are scarce. Despite those issues, a tumor-agnostic treatment approach based on targeted drugs against a detected genetic mutation is growing in several settings and cancer subtypes, and could also be proposed for SNCs. Our work aims to provide an overview of the main molecular pathways altered in the different epithelial subtypes of sinonasal and skull base tumors, focusing on the possible actionable mutations for which potential target therapies are already approved in other cancer types.

Novel Biomarkers in Sinonasal Cancers: from Bench to Bedside

PURPOSE OF REVIEW

Sinonasal cancers are a heterogenous group of rare cancers for which histopathological diagnosis can be very challenging and treatment options are limited for advanced disease in particular. Here, we review the candidacy of novel diagnostic and prognostic biomarkers, and therapeutic targets for sinonasal cancers.

RECENT FINDINGS

Molecular multidimensional analyses of sinonasal cancers have been lagging behind other major cancers, but there are numerous publications describing the discovery of novel candidate biomarkers, e.g. the methylation classifier, originally developed for brain cancers, and gene expression panels for the prediction of response to induction chemotherapy in sinonasal undifferentiated carcinoma. The most promising biomarkers are summarized and discussed further with regard to their clinical applicability and future potential. Many of the described novel biomarkers for sinonasal cancers will eventually overcome the pitfalls associated with the frequently non-specific immunohistological tests. With comprehensive, multidimensional molecular testing of these tumours in collaborative consortia projects, our better understanding of the molecular mechanisms of sinonasal cancers and their carcinogenesis will determine the most useful diagnostic and prognostic biomarkers, allow stringent multi-institutional validation and guide trials on targeted therapies.

Tumor budding is an adverse prognostic marker in intestinal-type sinonasal adenocarcinoma and seems to be unrelated to epithelial-mesenchymal transition

Intestinal-type adenocarcinoma (ITAC) of sinonasal tract is a rare malignant tumor with strong morphological, immunophenotypical, and molecular similarities to colorectal adenocarcinoma (CRC). Tumor budding (TB) is a well-established adverse prognostic marker in CRC and some head and neck tumors, with features of epithelial-mesenchymal transition (EMT). The aim of this study was to assess TB in ITAC and to evaluate its possible association with EMT markers in this setting. We selected 32 surgically resected specimens of non-mucinous/non-signet ring ITAC and evaluated them for TB according to the international recommendations developed for CRC. The expression of the EMT markers E-cadherin, ZEB1, ZEB2, SLUG, and SNAIL was evaluated by immunohistochemistry (IHC). Results were stratified using clinical and follow-up data (2/32 patients had metastatic disease and 4/32 died of disease). We observed TB in 13/32 (40.6%) ITAC cases including the 7 patients with relapse (p = 0.0005) and the 4 patients dead of disease (p = 0.02). Lymphovascular invasion was associated with TB (p = 0.008). Absence of TB was associated with low ZEB2 expression (p = 0.003). No other association with EMT markers emerged. Occupational exposure to wood and leather dust was not related to the presence of TB. TB interobserver concordance was substantial (proportion of agreement = 87%; Cohen's kappa = 0.73). This work suggests that TB is associated with a worse prognosis in ITAC, but our findings do not seem to support the involvement of EMT in this specific setting. Further larger studies are needed to address this point.

Management of sinonasal adenocarcinomas with anterior skull base extension

INTRODUCTION

Sinonasal adenocarcinomas (SNAC) are rare and heterogeneous. Management of SNAC follows a rather standardized and internationally accepted paradigm. Several refinements have been introduced during the last decade.

METHODS

A narrative review of most updated literature on SNACs has been conducted.

RESULTS

SNACs are classified as intestinal-type and non-intestinal-type, which are further categorized according to grade. Preoperative work-up should include magnetic resonance imaging (or contrast-enhanced computed tomography as a secondary or complementary choice) and biopsy under general anesthesia, or under local anesthesia in case of a history of exposure to wood and/or leather dust. Positron emission tomography, neck ultrasound, and fine-needle aspiration cytology are indicated in selected cases. Surgery represents the most common upfront modality of treatment and is usually accomplished via a transnasal endoscopic approach. Adjuvant radiation therapy is indicated for high-grade, locally advanced tumors and/or in case of margins involvement. Neoadjuvant chemotherapy with cisplatin, 5-fluorouracil and leucovorin may offer high response rates and long-term control in a subgroup of patients affected by intestinal-type adenocarcinoma, and in particular in those whose tumors harbor a functional p53 protein. Most of the bio- and immune-therapeutic potentials on SNACs still remain theoretical, and no clinical data are currently available.

CONCLUSIONS

Management of SNAC consists of histological diagnosis, radiological staging, radical surgery, and adjuvant radiation therapy. Neoadjuvant chemotherapy can be indicated in selected cases. The role of biotherapy and immune therapy still needs to be elucidated.