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Objective  Surgical resection is widely accepted as a critical component for definitive treatment of sinonasal mucosal melanoma. Systemic immunotherapy, including multiple newer agents, has been used to treat metastatic or unresectable disease. In this study, we examine its efficacy in locoregional control when used in conjunction with surgical resection for primary mucosal lesions. Design  Present study is a retrospective review of all patients at a tertiary academic medical center with primary sinonasal mucosal melanoma and distant metastatic disease. Results  A total of four patients were identified. In all cases, patients were treated with a combination of surgical resection of the primary tumor and systemic immunotherapy. Three patients were initially treated with surgery at the primary site followed by immunotherapy for distant metastases. Response to immunotherapy at the sites of primary and metastatic disease was seen in two patients. All four patients developed progression or recurrence at the primary site following initiation of immunotherapy for which they underwent surgical resection. One patient remains in follow-up without evidence of disease 20 months after initial treatment; three succumbed to the disease at 135, 37, and 16 months after initial treatment. Conclusion  Surgical resection for local control plays a critically important role in the treatment of sinonasal mucosal melanoma regardless of the presence of metastases and whether immunotherapy will be given. This case series suggests that, though immunotherapy may demonstrate efficacy in managing distant disease, surgery should remain the first-line treatment for the primary site.

Akt is an important kinase in metabolism. Akt also phosphorylates and activates endothelial and neuronal nitric oxide (NO) synthases (eNOS and nNOS, respectively) expressed in M0 (unpolarized) macrophages. We showed that e/nNOS NO production downstream of bitter taste receptors enhances macrophage phagocytosis. In airway epithelial cells, we also showed that the activation of Akt by a small molecule (SC79) enhances NO production and increases levels of nuclear Nrf2, which reduces IL-8 transcription during concomitant stimulation with Toll-like receptor (TLR) 5 agonist flagellin. We hypothesized that SC79's production of NO in macrophages might likewise enhance phagocytosis and reduce the transcription of some pro-inflammatory cytokines. Using live cell imaging of fluorescent biosensors and indicator dyes, we found that SC79 induces Akt activation, NO production, and downstream cGMP production in primary human M0 macrophages. This was accompanied by a reduction in IL-6, IL-8, and IL-12 production during concomitant stimulation with bacterial lipopolysaccharide, an agonist of pattern recognition receptors including TLR4. Pharmacological inhibitors suggested that this effect was dependent on Akt and Nrf2. Together, these data suggest that several macrophage immune pathways are regulated by SC79 via Akt. A small-molecule Akt activator may be useful in some infection settings, warranting future in vivo studies. [ABSTRACT FROM AUTHOR]

Objectives Although adjuvant radiotherapy may be indicated in patients with sinonasal squamous cell carcinoma (SNSCC) following primary surgery, some patients choose to forgo recommended postoperative radiation therapy (PORT). This study aimed to elucidate factors associated with patient refusal of recommended PORT in SNSCC and examine overall survival. Methods Retrospective analysis of patients with SNSCC treated with primary surgery from the National Cancer Database diagnosed between 2004 and 2016. A multivariable logistic regression model was created to determine the association between clinical or demographic covariates and likelihood of PORT refusal. Unadjusted Kaplan–Meier estimates, log-rank tests, and a multivariable Cox proportional hazard model were used to assess overall survival. Results A total of 2,231 patients were included in the final analysis, of which 1,456 (65.3%) were males and 73 (3.3%) refused recommended PORT. Patients older than 74 years old were more likely to refuse PORT than those younger than 54 (odds ratio [OR] 3.43, 95% confidence interval [CI]: 1.84–6.62). Median survival among the entire cohort, those who received recommended PORT, and those who refused PORT was 83.0 months (95% CI: 74.6–97.1), 83.0 months (95% CI: 74.9–98.2), and 63.6 months (95% CI: 37.3–101.4), respectively. Refusal of PORT was not associated with overall survival (hazard ratio: 0.99, 95% CI: 0.69–1.42). Conclusions PORT refusal in patients with SNSCC is rare and was found to be associated with several patient factors. The decision to forgo PORT is not independently associated with overall survival in this cohort. Further study is required to determine the clinical implications of these findings as the treatment decisions are complex. [ABSTRACT FROM AUTHOR]

Human airway sweet (T1R2 + T1R3), umami (T1R1 + T1R3), and bitter taste receptors (T2Rs) are critical components of the innate immune system, acting as sensors to monitor pathogenic growth. T2Rs detect bacterial products or bitter compounds to drive nitric oxide (NO) production in both healthy and diseased epithelial cell models. The NO enhances ciliary beating and also directly kills pathogens. Both sweet and umami receptors have been characterized to repress bitter taste receptor signaling in healthy and disease models. We hypothesized that the sweet/umami T1R3 antagonist lactisole may be used to alleviate bitter taste receptor repression in airway basal epithelial cells and enhance NO production. Here, we show that lactisole activates cAMP generation, though this occurs through a pathway independent of T1R3. This cAMP most likely signals through EPAC to increase ER Ca2+ efflux. Stimulation with denatonium benzoate, a bitter taste receptor agonist which activates largely nuclear and mitochondrial Ca2+ responses, resulted in a dramatically increased cytosolic Ca2+ response in cells treated with lactisole. This cytosolic Ca2+ signaling activated NO production in the presence of lactisole. Thus, lactisole may be useful coupled with bitter compounds as a therapeutic nasal rinse or spray to enhance beneficial antibacterial NO production in patients suffering from chronic inflammatory diseases such as chronic rhinosinusitis. [ABSTRACT FROM AUTHOR]

T1Rs are expressed in solitary chemosensory cells of the upper airway where they detect apical glucose levels and repress bitter taste receptor Ca2+ signaling pathways. Microbial growth leads to a decrease in apical glucose levels. T1Rs detect this change and liberate bitter taste receptor signaling, initiating an innate immune response to both kill and expel pathogens through releasing antimicrobial peptides and increasing nitric oxide production and ciliary beat frequency. However, chronic inflammation due to disease, smoking, or viral infections causes a remodeling of the epithelial airway. The resulting squamous metaplasia causes a loss of multi-ciliated cells and solitary chemosensory cells, replaced by basal epithelial cells. To understand how T1R function is altered during disease, we used basal epithelial cells as a model to study the function of T1R3 on Ca2+ signaling dynamics. We found that both T1R1 and T1R3 detect amino acids and signal via cAMP, increasing the responsiveness of the cells to Ca2+ signaling stimuli. Either knocking down T1R1/3 or treating wild-type cells with MEM amino acids caused a reduction in ER Ca2+ content through a non-cAMP signaled pathway. Treatment with amino acids led to a reduction in downstream denatonium-induced Ca2+-signaled caspase activity. Thus, amino acids may be used to reduce unwanted apoptosis signaling in treatments containing bitter compounds. [ABSTRACT FROM AUTHOR]

Introduction: Bitter taste receptors (T2Rs) are G protein-coupled receptors identified on the tongue but expressed all over the body, including in airway cilia and macrophages, where T2Rs serve an immune role. T2R isoforms detect bitter metabolites (quinolones and acyl-homoserine lactones) secreted by gram negative bacteria, including Pseudomonas aeruginosa, a major pathogen in cystic fibrosis (CF). T2R activation by bitter bacterial products triggers calcium-dependent nitric oxide (NO) production. In airway cells, the NO increases mucociliary clearance and has direct antibacterial properties. In macrophages, the same pathway enhances phagocytosis. Because prior studies linked CF with reduced NO, we hypothesized that CF cells may have reduced T2R/NO responses, possibly contributing to reduced innate immunity in CF. Methods: Immunofluorescence, qPCR, and live cell imaging were used to measure T2R localization, calcium and NO signaling, ciliary beating, and antimicrobial responses in air-liquid interface cultures of primary human nasal epithelial cells and immortalized bronchial cell lines. Immunofluorescence and live cell imaging was used to measure T2R signaling and phagocytosis in primary human monocyte-derived macrophages. Results: Primary nasal epithelial cells from both CF and non-CF patients exhibited similar T2R expression, localization, and calcium signals. However, CF cells exhibited reduced NO production also observed in immortalized CFBE41o-CF cells and non-CF 16HBE cells CRISPR modified with CF-causing mutations in the CF transmembrane conductance regulator (CFTR). NO was restored by VX-770/VX-809 corrector/potentiator pre-treatment, suggesting reduced NO in CF cells is due to loss of CFTR function. In nasal cells, reduced NO correlated with reduced ciliary and antibacterial responses. In primary human macrophages, inhibition of CFTR reduced NO production and phagocytosis during T2R stimulation. Conclusions: Together, these data suggest an intrinsic deficiency in T2R/NO signaling caused by loss of CFTR function that may contribute to intrinsic susceptibilities of CF patients to P. aeruginosa and other gram-negative bacteria that activate T2Rs. [ABSTRACT FROM AUTHOR]

Objective  This study aimed to provide information regarding the prognosis of patients presenting with metastatic anterior skull base malignancies based upon histology and site of distant metastasis (DM). Patients and Methods  The National Cancer Database was queried for patients with anterior skull base malignant neoplasms with DM. Outcomes  Prognosis was compared between site of DM and tumor histologies. A multivariable Cox proportional hazards model was used to identify prognostic factors for overall survival (OS). Results  A total of 481 patients were identified. Lung was the most common site of DM (24.9%), followed by bone (22.2%), liver (5.6%), and brain (2.5%). Lung was the most common site for squamous cell carcinoma (SCCa) (28.3%), melanoma (37.7%), and adenoid cystic carcinoma (ACC; 31.4%). The median survival for patients presenting with metastatic disease regardless of tumor histology was 9.0 months (95% confidence interval [CI]: 8.2–10.3), and patients with metastasis to the liver had the best median survival at 15.5 months (95% CI: 10.5–25.6). The median survivals for the most common histologies, SCCa, melanoma, and ACC were 8.2 months (95% CI: 5.5–10.2), 10.5 months (95% CI: 8.7–14.1), and 15.0 months (95% CI: 11.1–61.1), respectively. Multivariable analysis demonstrated worse overall survival (OS) for older patients, higher Charlson-Deyo comorbidity scores, and tumors with higher grade and T stage. Compared with metastasis to bone, lung metastasis had better OS on multivariable analysis (hazard ratio [HR]: 0.70, 95% CI: 0.51–97). Adenoid cystic carcinoma had improved OS compared with SCCa (HR: 0.62, 95% CI: 0.39–99). Conclusion  Tumor histology, metastatic sites, and several disease factors affected prognosis in anterior skull base malignancies with DM. [ABSTRACT FROM AUTHOR]

Bitter taste receptors (T2Rs) are G protein-coupled receptors (GPCRs) expressed in various cell types including ciliated airway epithelial cells and macrophages. T2Rs in these two innate immune cell types are activated by bitter products, including those secreted by Pseudomonas aeruginosa, leading to Ca2+-dependent activation of endothelial nitric oxide (NO) synthase (eNOS). NO enhances mucociliary clearance and has direct antibacterial effects in ciliated epithelial cells. NO also increases phagocytosis by macrophages. Using biochemistry and live-cell imaging, we explored the role of heat shock protein 90 (HSP90) in regulating T2R-dependent NO pathways in primary sinonasal epithelial cells, primary monocyte-derived macrophages, and a human bronchiolar cell line (H441). Immunofluorescence showed that H441 cells express eNOS and T2Rs and that the bitter agonist denatonium benzoate activates NO production in a Ca2+- and HSP90-dependent manner in cells grown either as submerged cultures or at the air–liquid interface. In primary sinonasal epithelial cells, we determined that HSP90 inhibition reduces T2R-stimulated NO production and ciliary beating, which likely limits pathogen clearance. In primary monocyte-derived macrophages, we found that HSP-90 is integral to T2R-stimulated NO production and phagocytosis of FITC-labeled Escherichia coli and pHrodo-Staphylococcus aureus. Our study demonstrates that HSP90 serves as an innate immune modulator by regulating NO production downstream of T2R signaling by augmenting eNOS activation without impairing upstream Ca2+ signaling. These findings suggest that HSP90 plays an important role in airway antibacterial innate immunity and may be an important target in airway diseases such as chronic rhinosinusitis, asthma, or cystic fibrosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Inverted papillomas are benign sinonasal tumors that can recur or become cancerous. The mainstay of treatment is surgical resection. We summarize the biology of inverted papillomas and review surgical outcomes in an effort to define the current treatment strategy. Inverted papillomas (IP) are the most common sinonasal tumor with a tendency for recurrence, potential attachment to the orbit and skull base, and risk of malignant degeneration into squamous cell carcinoma (SCC). While the overall rate of recurrence has decreased with the widespread adoption of high-definition endoscopic optics and advanced surgical tools, there remain challenges in managing tumors that are multiply recurrent or involve vital neurovascular structures. Here, we review the state-of-the-art diagnostic tools for IP and IP-degenerated SCC, contemporary surgical management, and propose a surveillance protocol. [ABSTRACT FROM AUTHOR]

T2R bitter taste receptors in airway motile cilia increase ciliary beat frequency (CBF) and nitric oxide (NO) production. Polymorphisms in some T2Rs are linked to disease outcomes in chronic rhinosinusitis (CRS) and cystic fibrosis (CF). We examined the expression of cilia T2Rs during the differentiation of human nasal epithelial cells grown at air–liquid interface (ALI). The T2R expression increased with differentiation but did not vary between CF and non-CF cultures. Treatment with Pseudomonas aeruginosa flagellin decreased the expression of diphenhydramine-responsive T2R14 and 40, among others. Diphenhydramine increased both NO production, measured by fluorescent dye DAF-FM, and CBF, measured via high-speed imaging. Increases in CBF were disrupted after flagellin treatment. Diphenhydramine impaired the growth of lab and clinical strains of P. aeruginosa, a major pathogen in CF and CF-related CRS. Diphenhydramine impaired biofilm formation of P. aeruginosa, measured via crystal violet staining, as well as the surface attachment of P. aeruginosa to CF airway epithelial cells, measured using colony-forming unit counting. Because the T2R agonist diphenhydramine increases NO production and CBF while also decreasing bacterial growth and biofilm production, diphenhydramine-derived compounds may have potential clinical usefulness in CF-related CRS as a topical therapy. However, utilizing T2R agonists as therapeutics within the context of P. aeruginosa infection may require co-treatment with anti-inflammatories to enhance T2R expression. [ABSTRACT FROM AUTHOR]

Bitter taste receptors (T2Rs) are G-protein-coupled receptors (GPCRs) expressed on the tongue but also in various locations throughout the body, including on motile cilia within the upper and lower airways. Within the nasal airway, T2Rs detect secreted bacterial ligands and initiate bactericidal nitric oxide (NO) responses, which also increase ciliary beat frequency (CBF) and mucociliary clearance of pathogens. Various neuropeptides, including neuropeptide tyrosine (neuropeptide Y or NPY), control physiological processes in the airway including cytokine release, fluid secretion, and ciliary beating. NPY levels and/or density of NPYergic neurons may be increased in some sinonasal diseases. We hypothesized that NPY modulates cilia-localized T2R responses in nasal epithelia. Using primary sinonasal epithelial cells cultured at air–liquid interface (ALI), we demonstrate that NPY reduces CBF through NPY2R activation of protein kinase C (PKC) and attenuates responses to T2R14 agonist apigenin. We find that NPY does not alter T2R-induced calcium elevation but does reduce T2R-stimulated NO production via a PKC-dependent process. This study extends our understanding of how T2R responses are modulated within the inflammatory environment of sinonasal diseases, which may improve our ability to effectively treat these disorders. [ABSTRACT FROM AUTHOR]

Objectives: The use of topical corticosteroids to manage postoperative sinonasal symptoms after endoscopic skull base surgery (ESBS) has not been well studied. We quantified long-term impact of postoperative steroid irrigations (SIs) on quality of life of patients after ESBS., Methods: Retrospective review of patients at the University of Pennsylvania undergoing ESBS from 2010 to 2019. Data on patient demographics and postoperative treatment with nasal saline irrigation twice daily with and without dissolved steroids (mometasone or budesonide) was collected. Preoperative, and 1-, 3-, 6-, 12-, 18-, and 24-month postoperative Sino-Nasal Outcome Test (SNOT-22) scores were assessed., Results: A total of 727 patients were assessed (53.4% males), with 479 patients in the no SI group and 248 patients in the SI group. Preoperative SNOT-22 scores did not differ significantly ( P  = 0.19). 1-, 3-, 6-, 12-, 18-, and 24-month post-op SNOT-22 scores did not significantly differ between groups. However, mometasone irrigations resulted in significantly lower postoperative 2-year SNOT-22 scores compared to budesonide ( P  < 0.01) and saline ( P  = 0.03)., Conclusions: Though corticosteroid irrigations are routine in managing inflammatory sinus disease, their role in postoperative management after ESBS for tumors is unclear. Our findings suggest that mometasone irrigation may be effective at improving postoperative quality of life in patients after ESBS., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. World Journal of Otorhinolaryngology ‐ Head and Neck Surgery published by John Wiley & Sons Ltd on behalf of Chinese Medical Association.)

Background  Sinonasal debridement is typically performed in the weeks following endonasal skull base surgery (ESBS). In the pediatric population, this second-look procedure may require general anesthesia; however, there is currently little evidence assessing the benefit of this practice. Methods  This was a multicenter retrospective study of pediatric patients (age <18 years) undergoing a planned second-look debridement under general anesthesia following ESBS. Intraoperative findings, interventions performed, and perioperative complications were reviewed. Multivariate regression analysis was performed to identify associations between intraoperative findings and clinical factors. Results  We reviewed 69 cases of second-look debridements (age mean 8.6 ± 4.2 years, range: 2-18 years), occurring a mean of 18.3 ± 10.3 days following ESBS. All abnormal findings were noted in patients age ≤12 years. Synechiae were noted in 8.7% of cases, bacterial rhinosinusitis in 2.9%, and failed reconstruction with cerebrospinal fluid leak in 4.5% (two cases of flap malposition and one case of flap necrosis). All failed reconstructions were noted following expanded endonasal cases for craniopharyngioma, and in each case, a revision reconstruction was performed during the second-look surgery. Synechiae were not significantly associated with younger age, revision cases, or cases with reconstructive flaps. There were no perioperative complications. Conclusion  Second-look debridement under general anesthesia may be useful in the identification and intervention of sinonasal pathology following endoscopic skull base surgery, particularly in children ≤12 years old or those with pedicled flap reconstructions. Larger controlled studies are warranted to validate this practice and refine indications and timing of this second procedure., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objective: Functional endoscopic sinus surgery is a commonly performed otolaryngologic procedure that often uses the microdebrider device for tissue removal. Given the ubiquitous nature of the instrument, we sought to better define the patterns of device failure using the postmarket surveillance openFDA database., Methods: The openFDA database was queried for all microdebrider-related adverse events from January 1, 2000 to November 1, 2020. Descriptive information on the nature of device failure and any associated patient injury was compiled. Reports not directly related to device failure were excluded from the analysis., Results: A total of 641 events were included in the analysis. The most common device failure was overheating ( n  = 348, 54.3%), followed by material separation ( n  = 173, 27%), and inconsistent device activation ( n  = 52, 8.1%). Of the reported events, the vast majority did not result in patient harm ( n  = 579, 90.3%). On review of the remaining cases, only 24 events (3.7%) resulted in true harm to the patient, defined as a temporary or permanent injury or >30 min of additional anesthesia time. Of these cases, the need to reschedule surgical cases ( n  = 5, 0.8%), retained foreign body ( n  = 5, 0.8%), and thermal tissue injury ( n  = 3,0.5%) were the most common. Five patients suffered an injury due to surgeon error unrelated to device malfunction ( n  = 5, 0.8%)., Conclusions: Microdebrider device failures are extremely rare. When they do occur, less than 10% result in patient harm. In cases of patient harm related to microdebrider failure, preoperative testing of the device before use could prevent many of the reported malfunctions., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. World Journal of Otorhinolaryngology ‐ Head and Neck Surgery published by John Wiley & Sons Ltd on behalf of Chinese Medical Association.)

Background: Carcinosarcomas are rare, aggressive malignancies that can arise in the nasal cavity and paranasal sinuses. There are limited outcome data available. Accordingly, we sought to use the National Cancer Database (NCDB) to characterize patient demographics and outcomes., Method: A retrospective analysis of the NCDB from 2004 to 2016 for patients with sinonasal carcinosarcoma was conducted., Results: Thirty patients were included. The patients were predominantly male ( n  = 20), white ( n  = 23), and privately insured ( n  = 15), with an average age of 62.4 years. The nasal cavity was the most common subsite ( n  = 14), followed by the maxillary sinus ( n  = 8). Most patient were treated with surgery followed by radiation ( n  = 23), with the remaining undergoing surgery alone ( n  = 4), radiation alone ( n  = 2), or no treatment ( n  = 1). One-third ( n  = 10) received adjuvant chemotherapy. The 1- and 5-year overall survival (OS) in the cohort were 79.2% and 43.3%, respectively. Univariate log-rank testing showed OS varied based on intervention ( P  < 0.029), sex ( P  < 0.042), and age ( P  < 0.025), while on multivariate analysis none of these factors independently predicted OS., Conclusions: We describe the demographics and presenting features of a national cohort of sinonasal carcinosarcoma patients. Future research is needed to identify predictors of overall survival, and to assess the optimal roles for radiation and systemic chemotherapy., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors. World Journal of Otorhinolaryngology ‐ Head and Neck Surgery published by John Wiley & Sons Ltd on behalf of Chinese Medical Association.)

Background  Sinonasal undifferentiated carcinoma (SNUC) is a rare, aggressive malignancy with a poor prognosis, and multimodal therapy is the standard of care. We sought to characterize treatment delays in SNUC managed with surgery and adjuvant radiation and to determine the impact on survival using the National Cancer Database (NCDB). Methods  This was a retrospective, population-based cohort study of patients with SNUC between 2004 and 2016 in the NCDB. The intervals of diagnosis to surgery (DTS), surgery to radiation (SRT), and radiation duration (RTD) were examined. Recursive partitioning analysis (RPA) was performed to identify the variables with the greatest impact on survival. The association between treatment delay and overall survival (OS) was then assessed using multivariate Cox proportional hazards regression. Results  Of 173 patients who met inclusion criteria, 65.9% were male, average age at diagnosis was 56.6 years, and 5-year OS was 48.1%. Median durations of DTS, SRT, and RTD were 18, 43, and 46 days, respectively. Predictors of treatment delay included Black race, government insurance excluding Medicare/Medicaid, and positive margins. RPA-derived optimal thresholds were 29, 28, and 38 days for DTS, SRT and RTD, respectively. On multivariate analysis, positive margins (hazard ratio [HR]: 4.82; 95% confidence interval [CI]: 2.28-10.2) and DTS less than 29 days (HR: 2.41; 95% CI: 1.23-4.73) were associated with worse OS. Conclusion  Our results likely reflect the aggressive nature of the disease with surgeons taking more invasive disease to the operating room more quickly. Median treatment intervals described may serve as relevant national benchmarks., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objectives  Although adjuvant radiotherapy may be indicated in patients with sinonasal squamous cell carcinoma (SNSCC) following primary surgery, some patients choose to forgo recommended postoperative radiation therapy (PORT). This study aimed to elucidate factors associated with patient refusal of recommended PORT in SNSCC and examine overall survival. Methods  Retrospective analysis of patients with SNSCC treated with primary surgery from the National Cancer Database diagnosed between 2004 and 2016. A multivariable logistic regression model was created to determine the association between clinical or demographic covariates and likelihood of PORT refusal. Unadjusted Kaplan-Meier estimates, log-rank tests, and a multivariable Cox proportional hazard model were used to assess overall survival. Results  A total of 2,231 patients were included in the final analysis, of which 1,456 (65.3%) were males and 73 (3.3%) refused recommended PORT. Patients older than 74 years old were more likely to refuse PORT than those younger than 54 (odds ratio [OR] 3.43, 95% confidence interval [CI]: 1.84-6.62). Median survival among the entire cohort, those who received recommended PORT, and those who refused PORT was 83.0 months (95% CI: 74.6-97.1), 83.0 months (95% CI: 74.9-98.2), and 63.6 months (95% CI: 37.3-101.4), respectively. Refusal of PORT was not associated with overall survival (hazard ratio: 0.99, 95% CI: 0.69-1.42). Conclusions  PORT refusal in patients with SNSCC is rare and was found to be associated with several patient factors. The decision to forgo PORT is not independently associated with overall survival in this cohort. Further study is required to determine the clinical implications of these findings as the treatment decisions are complex., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)