Temporal bone carcinoma: Treatment patterns and survival

Survival Outcomes of Temporal Bone Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVE

Temporal bone squamous cell carcinoma (TBSCC) is a rare malignancy with poor prognosis, and optimal treatment for advanced cases is uncertain. Our systematic literature review aimed to assess 5-year survival outcomes for advanced TBSCC across different treatment modalities.

DATA SOURCES

EMBASE, Medline, PubMed, and Web of Science.

REVIEW METHODS

A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for articles published between January 1989 and June 2023.

RESULTS

The review yielded 1229 citations of which 31 provided 5-year survival data for TBSCC. The final analysis included 1289 patients. T classification data was available for 1269 patients and overall stage for 1033 patients. Data for 5-year overall survival (OS) was 59.6%. Five-year OS was 81.9% for T1/2 and 47.5% for T3/4 (P < .0001). OS for T1/T2 cancers did not significantly differ between surgery and radiation (100% vs 81.3%, P  = .103). For advanced-stage disease (T3/T4), there was no statistical difference in OS when comparing surgery with postoperative chemoradiotherapy (CRT) (OS 50.0%) versus surgery with postoperative radiotherapy (XRT) (OS 53.3%) versus definitive CRT (OS 58.1%, P  = .767-1.000). There was not enough data to assess the role of neoadjuvant CRT.

CONCLUSION

Most patients will present with advanced-stage disease, and nodal metastasis is seen in nearly 22% of patients. This study confirms the prognostic correlation of the current T classification system. Our results suggest that OS did not differ significantly between surgery and XRT for early stage disease, and combined treatment modalities yield similar 5-year OS for advanced cancers.

Carcinomas of the external auditory canal: Management and results: A multicenter REFCOR propensity score matching study

OBJECTIVES

To analyse prognostic factors and survival outcomes of malignant tumors of the external auditory canal, to investigate the role of regional surgery, and adjuvant radiotherapy in early stages and to investigate the role of surgery in operable T4 stage.

SETTING

A retrospective analysis was conducted on all patients prospectively included in the national database of the French Expertize Network for Rare ENT Cancers (REFCOR) from January 2000 to December 2016.

PARTICIPANTS

103 patients from 19 reference centers were included. A propensity score matching analysis was applied to enable comparisons between treatments.

MAIN OUTCOMES AND MEASURES

Event-free survival, overall survival and factors of poor prognosis of the cohort were described. The interest of local and regional surgery and postoperative radiotherapy were evaluated.

RESULTS

The factors of poor prognosis on event-free survival were immunosuppression (p = 0.002), Karnofsky status less than 90% (p = 0.02), body mass index less than 19 Kg / m2 (p = 0.0009), peripheric facial palsy (p = 0.0016), and positive margin (p = 0.0006). In early stages, locoregional surgery was associated with an increase in event-free survival (p = 0.003, HR = 0.21) versus local surgery alone, while postoperative radiotherapy was not associated with an increase in event-free survival (p = 0.86, HR = 0.91) or overall (p = 0.86, HR = 0.91). In locally advanced stages, locoregional surgery followed by radiotherapy was associated with an increase in event-free survival (p = 0.03, HR = 0.39) and overall (p = 0.02, HR = 0.34) versus chemoradiotherapy alone.

CONCLUSION AND RELEVANCE

Regional surgery is recommended for early stages of cancers of the external auditory canal. In operable cases, locoregional surgery followed by radiotherapy is recommended.

Temporal bone management in external and middle ear carcinoma

PURPOSE OF REVIEW

The purpose of this review is to outline the temporal bone management of external and middle ear carcinoma. The review will outline the current evidence involved in deciding which surgical approach to take, as well as new advances in auditory rehabilitation and immunotherapy.

RECENT FINDINGS

Traditional surgical approaches include lateral temporal bone resection, subtotal temporal bone resection and total temporal bone resection. They can also involve parotidectomy and neck dissection depending on extension of disease into these areas. Options for auditory rehabilitation include osseointegrated hearing aids, transcutaneous bone-conduction implants, and active middle ear implants. Recent advances in immunotherapy have included the use of anti-PD-1 monoclonal antibodies.

SUMMARY

The mainstay of management of temporal bone disease involves surgical resection. Early-stage tumours classified according to the Pittsburgh staging tool can often be treated with lateral temporal bone resection, whereas late-stage tumours might need subtotal or total temporal bone resection. Parotidectomy and neck dissection might also be indicated if there is a risk of occult regional disease. Recent advances in immunotherapy have been promising, particularly around anti-PD-1 inhibitors. However, larger clinical trials will be required to test the extent of efficacy, particularly around combination use with surgery.

Treatment outcome and prognostic factors of external auditory canal squamous cell carcinoma: A retrospective study in a tertiary center

Objective

Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is a rare malignancy with various treatment strategies and outcomes. The purpose of this study was to evaluate the clinical characteristics and survival outcomes and identify prognostic factors in patients with SCC of EAC.

Methods

Twenty-one patients with SCC of EAC treated in a single tertiary center between 2009 and 2021 were retrospectively reviewed and analyzed. The modified Pittsburgh classification system was applied for staging. Factors associated with survival were identified by univariate survival analysis.

Results

The mean age at diagnosis was 61 years (range: 41-79 years). Early-stage (T1 + T2) accounts for 38.1% of the series and advanced-stage (T3 + T4) accounts for 61.9%. Eighteen (85.7%) patients underwent primary surgery with curative intent. The 5-year overall survival rate of the 21 patients was 67.4%. Tumor invasion to the otic capsule, eustachian tube, sigmoid sinus, and dura were associated with poor prognosis in univariate analysis (p = .046; .008; .027; and .08, respectively).

Conclusions

Factors predictive of less favorable survival include the history of COM, tumor invasion to the otic capsule, eustachian tube, sigmoid sinus, and dura. It is important to make a precise and systemic preoperative evaluation of disease extent.

Level of Evidence

4.

Algorithms of follow-up in patients with head and neck cancer in relation to primary location and advancement. Consensus of Polish ENT Society Board and Head Neck Experts

Summary

The algorithm of follow-up in patients with head and neck cancer (HNC) has been prepared by a board of Polish Head Neck and Oncology Experts. The aim of this research is to focus on the specificity of HNC monitoring, to review the current trends in follow-up, and to adapt the evidence-based medicine international standards to the capabilities of the local healthcare service.

Materials and methods

The first methodological step was to categorize HNCs according to the estimated risk of failure after the adequate first-line treatment and according to the possibility of effective salvage treatment, resulting in improved overall survival. The final method used in this work was to prepare an authors' original monitoring algorithm for HNC groups with a high, moderate, and low risk of recurrence in combination with a high or low probability of using an effective salvage.

Results

Four categories were established: Ia. low risk of recurrence + effective organ preservation feasible; Ib. low risk of recurrence + effective salvage feasible; II. moderate risk of recurrence + effective salvage feasible; III. high risk of recurrence + effective salvage feasible; and IV. high risk of recurrence + no effective salvage feasible. Follow-up visit consisting of 1. ENT examination + neck ultrasound, 2. imaging HN tests, 3. chest imaging, 4. blood tests, and 5. rehabilitation (speech and swallowing) was scheduled with a very different frequency, at the proposed monthly intervals, tailored to the needs of the group. The number of visits for individual groups varies from 1 to 8 in the first 2 years and from 1 to 17 in the entire 5-year monitoring period. Group IV has not been included in regular follow-up, visits on own initiative of the patient if symptomatic, or supportive care needs, having in mind that third-line therapy and immune checkpoint inhibitors are available.

Conclusion

Universal monitoring algorithm for HNC four groups with a high, moderate, and low risk of recurrence after the adequate treatment in combination with a high or low probability of using an effective salvage is an innovative approach to redeploying system resources and ensuring maximum benefit for patients with HNC.

Biological and genetic characterization of a newly established human external auditory canal carcinoma cell line, SCEACono2

Squamous cell carcinoma of the external auditory canal (EACSCC) is an extraordinarily rare and aggressive malignant disease. Establishment of EACSCC cell line with robust molecular characteristics is essential for the basic and translational research of EACSCC. Here, we show the newly established EACSCC cell line SCEACono2, derived from a patient with well-to-moderately differentiated EACSCC. We analyzed histologic and genetic features of SCEACono2 hiring multiple experiments, including next-generation sequencing (NGS). Immunocytochemical staining of SCEACono2 showed positivity of p53 and SCC1/2. Furthermore, SCEACono2 exhibited a unique characteristic that cytokeratin, vimentin as well as cancer stem cell markers (CD44, CD133, ALP and Oct3/4) were positive. SCEACono2 had an ability to form tumors at the temporal lesion xenograft nude mice model. NGS revealed that SCEACono2 harbored the somatic mutations of TP53 (p.G245S) and NOTCH1 (p.A465T). RNA-seq and downstream bioinformatics analysis revealed significant enrichment of genes involved in inflammation and cell adhesion in SCEACono2 compared to SCC-9 and HSC-4. STR profiling indicated no evidence of cross-contamination. In conclusion, SCEACono2 could serves as a promising and robust research resource of EACSCC in vitro and in vivo.

Analysis of Prognostic Factors For External Auditory Canal Carcinoma: A 22-Year Experience

OBJECTIVE

This study aimed to investigate the prognostic factors and treatment outcomes in patients with the external auditory canal (EAC) squamous cell carcinoma (SCC).

METHODS

All patients diagnosed with EAC SCC and treated with curative intent at a single tertiary institution were retrospectively reviewed over a 22-year period. Treatment modalities included surgery with adjuvant treatment or definitive radiotherapy. The primary endpoints were overall survival (OS) and disease-specific survival (DSS).

RESULTS

There were 51 patients in our cohort. The 5-year OS and DSS were 64.0% ± 7.0% and 72.0% ± 7.0% respectively. Patients in the surgical arm and RT arm showed no significant difference in OS, DSS, and LRFS (p = 0.075, 0.062, 0.058 respectively). Compared to other routes of spread within the temporal bone, pattern of posterior disease invasion (involving mastoid/sigmoid sinus) showed poorer OS and DSS on multivariate analysis (hazard ratio, HR4.34 and 5.88; p = 0.006 and 0.009). On multivariate analysis, the following factors were independently prognostic of poorer OS and DSS: Previous radiotherapy (HR 3.29 and 4.81, p = 0.021 and p = 0.029); Presence of facial nerve palsy (HR 3.80 and 7.63, p = 0.013 and p = 0.003); Posterior pattern of invasion (HR4.05 and 3.59, p = 0.013 and p = 0.043). Advanced modified Pittsburgh stage was not predictive of poor OS and DSS (HR1.17 and 1.17 E+5, p = 0.786 and p = 0.961).

CONCLUSION

Presence of previous radiotherapy, facial nerve palsy and posterior pattern of disease invasion were independent prognostic factors of poorer survival in patients with EAC SCC.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2203-2210, 2023.

A Novel External Auditory Canal Squamous Cell Carcinoma Cell Line Sensitive to CDK4/6 Inhibition

OBJECTIVE

To characterize cell line CAE606 derived from a squamous cell carcinoma (SCC) of the external auditory canal (EAC) and to show its usefulness as a model for testing candidate therapeutic agents.

STUDY DESIGN

Preclinical translational research.

SETTING

Biomedical research institute.

METHODS

The cell line was initiated from a moderately differentiated T2N0M0 EAC SCC. We studied its histologic and genetic features as well as growth and invasion parameters. Sensitivity to cell CDK4/6 cell cycle inhibitor palbociclib was analyzed.

RESULTS

CAE606 cells expressed heavy molecular weight cytokeratin, p63, and vimentin. The population doubling time was 25.8 hours, and the cells showed fast collective cell migration in a wound-healing assay. Short tandem repeat analysis confirmed it to be derived from the primary tumor of the patient. Next-generation sequencing revealed alterations in cell cycle regulation genes, including inactivating mutations in CDKN2A and TP53 and high-level amplification of CCND1 and EGFR. CAE606 showed a strong decrease of phospo-Rb expression upon exposure to the CDK4/6 inhibitor palbociclib, causing significant growth inhibition with an IC₅₀ of 0.46 µM.

CONCLUSION

This is the first report of a stable EAC SCC cell line. Its genetic features make it a useful tool for preclinical testing of new therapeutic agents for EAC SCC, particularly those targeting cell cycle regulation in combination with radio- and chemotherapy or other specific signaling pathway inhibitors.

Neoadjuvant Immunotherapy for Head and Neck Squamous Cell Carcinoma: Expecting Its Application in Temporal Bone Squamous Cell Carcinoma

Temporal bone malignant tumors are characterized by atypical clinical symptoms, and easy recurrence and metastasis. They account for 0.2% of head and neck tumors, and the most common pathological type is squamous cell carcinoma. Patients with squamous cell carcinoma of the temporal bone are often at advanced stages when diagnosed, and lose the chance for surgery. Neoadjuvant immunotherapy has recently been approved as the first-line treatment for refractory recurrent/metastatic squamous cell carcinoma of the head and neck. However, it remains to be determined whether neoadjuvant immunotherapy can be used as the first-line treatment for temporal bone squamous cell carcinoma to reduce the tumor stage before surgery, or as a palliative treatment for patients with unresectable advanced stage carcinoma. The present study reviews the development of immunotherapy and its clinical application in head and neck squamous cell carcinoma, summarizes the treatment of temporal bone squamous cell carcinoma, and prospects the neoadjuvant immunotherapy as the first-line treatment for temporal bone squamous cell carcinoma.

Survival Outcomes in Squamous Cell Carcinoma of the External Auditory Canal: A Systematic Review and Meta-Analysis

Squamous cell carcinomas (SCC) of the external auditory canal (EAC) are rare tumors representing a surgical challenge. Current knowledge is based largely on case series; thus, the level of evidence is weak. This study sought to systematically review the available SCC of the EAC literature and to identify risk factors for overall survival (OS) and disease-specific survival (DSS). A systematic review and meta-analysis of papers searched up to December 2022 through PubMed, Scopus, Web of Science, and Cochrane Library databases was conducted. Quality assessment of the eligible studies was done according to the Newcastle-Ottawa Scale. Pooled univariate and multivariable analyses and meta-analysis using a random-effects or fixed-effects Mantel-Haenszel model were performed. Fifteen articles (282 patients) met the inclusion criteria and were included in the quantitative analysis. The pooled multivariable analysis revealed cT3 and cT4 as independent prognostic factors for OS (p = 0.005, and p < 0.001, respectively) and DSS (p = 0.002, and p < 0.001, respectively). Local recurrence rate was 32.3%. The meta-analysis estimated significantly higher odds ratios for advanced T categories, than cT1-T2 tumors for OS and DSS (OR = 3.55; 95% CI, 1.93–6.52, and OR = 3.73; 95% CI, 2.00–6.97, respectively). In conclusion, locally advanced tumors were associated with poor prognosis. Poor outcomes mostly occurred due to local recurrence.

High-risk HPV-related squamous cell carcinoma in the temporal bone: a rare but noteworthy subtype

High-risk human papillomavirus (HPV) is a risk factor for the development of several head and neck squamous cell carcinomas (SCCs). However, there have been few reports of high-risk HPV infection in temporal bone squamous cell carcinomas (TBSCCs), and thus the prevalence and clinicopathologic significance of high-risk HPV in TBSCCs are still unclear. We retrospectively collected 131 TBSCCs and analyzed them for transcriptionally active high-risk HPV infection using messenger RNA in situ hybridization; we also assessed the utility of p16-immunohistochemistry (IHC) and Rb-IHC to predict HPV infection. Eighteen (13.7%) of the 131 TBSCCs were positive for p16-IHC, and five of them were positive for high-risk HPV infection (the estimated high-risk HPV positivity rate was 3.8% [5/131]). Interestingly, all five HPV-positive patients were male and had TBSCC on the right side. In the p16-IHC⁺/HPV⁺ cases (n = 5), the Rb-IHC showed a partial loss pattern (n = 4) or complete loss pattern (n = 1). In contrast, all p16-IHC-negative cases (n = 113) showed an Rb-IHC preserved pattern. The positive predictive value (PPV) of p16-IHC positivity for high-risk HPV infection was low at 27.8%, while the combination of p16-IHC⁺/Rb-IHC partial loss pattern showed excellent reliability with a PPV of 100%. The prognostic significance of high-risk HPV infection remained unclear. High-risk HPV-related TBSCC is an extremely rare but noteworthy subtype.

Clinical outcomes of temporal bone squamous cell carcinoma: A single-institution experience

OBJECTIVES

This study aimed to investigate the survival outcomes and potential prognostic factors of patients with temporal bone squamous cell carcinoma (TBSCC) treated at our institution.

METHODS

We retrospectively included patients who were diagnosed with TBSCC between 2008 and 2019. The Kaplan-Meier (KM) method was used to describe overall survival (OS), and the association between baseline characteristics and prognoses was examined using Cox proportional hazards models.

RESULTS

Fifty consecutive patients with TBSCC were included in this study. The results showed that patients with advanced modified Pittsburgh (MPB)- T classifications had a poorer prognosis (T3 vs. T1-2: HR: 2.81, 95% CI: 0.34-23.43; T4 vs. T1-2: HR: 7.25, 95% CI: 0.95-55.41; p = 0.041). Meanwhile, middle ear squamous cell carcinoma (MESCC) showed a significantly worse prognosis than external auditory canal squamous cell carcinoma (EACSCC, HR: 2.65, 95% CI: 1.04-6.76, p = 0.04).

CONCLUSIONS

MESCC and advanced MPB-T classifications might be considered predictors of unfavorable outcomes in patients with TBSCC, indicating that special attention should be paid to the original tumor subsite and tumor extension in the management of patients with TBSCC.

Temporal Bone Resection for Squamous Cell Carcinoma of the Lateral Skull Base: Systematic Review and Meta-analysis

OBJECTIVE

Temporal bone squamous cell carcinoma (TBSCC) is rare and often confers a poor prognosis. The aim of this study was to synthesize survival and recurrence outcomes data reported in the literature for patients who underwent temporal bone resection (TBR) for curative management of TBSCC. We considered TBSCC listed as originating from multiple subsites, including the external ear, parotid, and external auditory canal (EAC), or nonspecifically from the temporal bone.

DATA SOURCES

PubMed, Cochrane Library, Embase, and manual search of bibliographies.

REVIEW METHOD

A systematic literature review conducted in December 2020 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Survival data were collected from 51 retrospective studies, resulting in a pooled cohort of 501 patients with TBSCC. Compared to patients undergoing lateral TBR (LTBR), patients undergoing subtotal (SBTR) or total (TTBR) TBR exhibited significantly higher rates of stage IV disease (P < .001), positive surgical margins (P < .001), facial nerve involvement (P < .001), and recurrent disease (P < .001). A meta-analysis of 15 studies revealed a statistically significant 97% increase in mortality in patients who underwent STBR or TTBR. On multivariate analysis, recurrent disease was independently associated with worse overall survival (P < .001). On univariate analysis, facial nerve involvement was also associated with decreased overall survival (P < .001).

CONCLUSION

Recurrent disease was associated with risk of death in patients undergoing TBR. Larger prospective multi-institutional studies are needed to ascertain prognostic factors for a wider array of postoperative outcomes, including histology-specific survival and recurrence outcomes.

Necrotizing Otitis Concealing Carcinomas of the External Auditory Canal

External auditory canal Carcinomas are rare and aggressive tumors and their prognosis depends on early diagnosis. Their clinical similarity to necrotizing otitis is a source of error and therefore of diagnostic delay. Hence the interest of our study which consists in providing ENT specialists and all practitioners with the necessary clinical, evolutionary, radiological, biological and histological elements to avoid diagnostic errors. This is a retrospective study of all patients who were hospitalized for necrotizing otitis in the department of otolaryngology of the hospital of specialties of Rabat spread over a period of 5 years. All patients received an admission CT scan, biological tests, bacteriological sampling and biopsy. As well as initial parenteral antibiotic therapy and surgery for incidentally discovered EAC carcinomas. Clinically, all patients had otalgia and granulation tissue on otoscopic examination under the microscope. 50% had otorrhea. Pseudomonas aeruginosa was isolated in 50% of the cases, staphylococcus aureus in 25% and sterile culture in 25%. From the first biopsy, the diagnosis of tumor was retained in 6/10 patients. A second biopsy was performed in patients who did not show improvement and had a sterile culture. This one allowed the diagnosis in 4 other patients. All our patients had a surgical indication and were operated and then irradiated. The survival at 5 years was 50%. Biopsy must be systematic for every patient hospitalize for necrotizing otitis. Without hesitating to do it again each time the evolution is not good and the culture is sterile.

[Current status of the diagnosis and treatment of temporal bone squamous cell carcinoma]

Temporal bone squamous cell carcinoma, which is rare in the clinical setting, is the most common type of temporal bone malignancy. Its rarity makes the staging, the way of temporal bone resection, the management of parotid gland and cervical lymph node, and the application of radiotherapy and chemotherapy still controversial.There is no unanimous consensus and guideline about it to date at home and abroad.This paper reviewed the recent advance in the diagnosis and treatment of temporal bone squamous cell carcinoma in the hope of providing some help and reference for the management of the disease.

Treatment of advanced squamous cell carcinoma of the external auditory canal: Critical analysis of persistent failures in diagnosis and surgery with a competing-risk model

BACKGROUND

A series of temporal bone squamous cell carcinomas (TBSCCs) was analyzed with the aim of (i) better understanding the causes for the persistent high failure rate in advanced SCCs and (ii) discussing a possible way out from this stalemate in treatment.

METHODS

Forty-five TBSCCs consecutively treated surgically were reviewed.

RESULTS

The 5-year cumulative incidence for postoperative local recurrence was 41.8%. At multivariable analysis, pT3-4 stages were associated with eightfold relative incidence of developing local recurrence during follow-up (sHR = 9.06, 95% confidence interval [CI] = 1.18-69.46, p = 0.034) and cause-specific death (sHR = 7.95, 95%CI = 1.01-62.27, p = 0.048).

CONCLUSIONS

The poor outcome in advanced TBSCC occurred because of local recurrence due to defective resection. The fundamental pitfall of surgery on advanced TBSCC appeared to be the insufficient knowledge of microscopic tumor growth in the different sites and subsites of the temporal bone. The serial histopathological study of the en bloc surgical specimen and autopsy temporal bones seems to represent a way to enhance our understanding of these tumors.

Ear canal and middle-ear tumors: a single-institution series of 87 patients

BACKGROUND

Ear canal and middle ear tumors are rare and exhibit variability in histology and clinical manifestation. Surgical resection remains the treatment of choice, but individualized approach is needed to preserve function when possible.

AIMS/OBJECTIVES

To review the management and outcome of ear canal and middle ear tumors at an academic referral center.

MATERIALS AND METHODS

Helsinki University Hospital (HUS) patient files were searched for clinically and histologically confirmed ear canal and middle ear tumors over a 14-year period. The minimum follow-up time was 2 years.

RESULTS

Eighty-seven patients with 88 tumors were identified. There were 20 (23%) benign external auditory canal (EAC), 36 (41%) benign middle ear space (MES), 29 (33%) malignant EAC, and 3 (3%) malignant MES tumors. Most (92%) tumors were managed with primary resection. Thirty-five percent of the operatively managed patients had a residual or a recurrent tumor.

CONCLUSIONS AND SIGNIFICANCE

EAC and MES tumors show great diagnostic and histologic heterogeneity with need for individualized investigative and treatment approaches. In benign tumors, we advocate aggressive local surgical control without sacrificing vital structures. In malignant tumors, we recommend local surgical control with or without adjunct RT.

Prevalence of occult nodal metastases in squamous cell carcinoma of the temporal bone: a systematic review and meta-analysis

PURPOSE

Primary: To determine the rate of occult cervical metastases in primary temporal bone squamous cell carcinomas (TBSSC). Secondary: to perform a subgroup meta-analysis of the risk of occult metastases based on the clinical stage of the tumour and its risk based on corresponding levels of the neck.

METHODS

A systematic review and meta-analysis of papers searched through Medline, Cochrane, Embase, Scopus and Web of Science up to November 2021 to determine the pooled rate of occult lymph node/parotid metastases. Quality assessment of the included studies was assessed through the Newcastle-Ottawa scale.

RESULTS

Overall, 13 out of 3301 screened studies met the inclusion criteria, for a total of 1120 patients of which 550 had TBSCC. Out of the 267 patients who underwent a neck dissection, 33 had positive lymph nodes giving a pooled rate of occult metastases of 14% (95% CI 10-19%). Occult metastases rate varied according to Modified Pittsburg staging system, being 0% (0-16%) among 12 pT1, 7% (2-20%) among 43 pT2 cases, 21% (11-38%) among 45 pT3, and 18% (11-27%) among 102 pT4 cases. Data available showed that most of the positive nodes were in Level II.

CONCLUSION

The rate of occult cervical metastases in TBSCC increases with pathological T category with majority of nodal disease found in level II of the neck.

Lateral temporal bone resection for cutaneous carcinomas of the external auditory canal and peri-auricular region

OBJECTIVES

To evaluate the outcomes for patients after lateral temporal bone resection surgery for cutaneous squamous cell carcinoma and basal cell carcinoma, and to ascertain predictors of survival and treatment failure.

METHODS

A retrospective review was conducted of the medical records for all patients who underwent lateral temporal bone resection for cutaneous squamous cell carcinoma or basal cell carcinoma between 2007 and 2019 in Western Australia.

RESULTS

Thirty-seven patients underwent lateral temporal bone resection surgery. Median follow-up duration was 22 months. Twenty-five patients had squamous cell carcinoma and 12 had basal cell carcinoma. The overall survival rate at two years for patients with squamous cell carcinoma was 68.5 per cent. Pre-operative facial nerve involvement (determined via clinical or radiological evidence) was identified as a predictor of mortality (hazard ratio = 3.411, p = 0.006), with all patients dying before two years post-operatively. Locoregional tumour control was achieved in 81 per cent of cases (n = 30).

CONCLUSION

Lateral temporal bone resection offers acceptable local control rates and survival outcomes. Caution should be used in offering this surgery to patients with clinical or radiological evidence of facial nerve involvement because of the relatively poorer survival outcomes in this subgroup.

Surgical treatment for squamous cell carcinoma of the temporal bone: predictors of survival

Objective

Evaluation of the management and survival in patients treated for temporal bone squamous cell carcinoma (TBSCC) in a tertiary referral centre.

Methods

Forty-nine patients underwent primary treatment for TBSCC. Thirty-six patients underwent a lateral temporal bone resection (LTBR) or subtotal temporal bone resection (STBR). Overall survival (OS) and disease-specific survival (DSS) analysis were assessed.

Results

Five-year OS of the 49 patients was 39%. Five-year OS of the 36 patients who underwent LTBR or STBR was 46%. Tumour-free margins were achieved in all patients with T1 and T2 disease, in 59% patients with T3 tumours and 0% patients with T4 disease. Five-year DSS was 85% for all T1/T2 tumours, 53% for T3 tumours and 0% for T4 tumours. Clear resection margins was the only significant predictor of DSS in our cohort.

Conclusions

The mainstay of treatment for TBSCC is temporal bone resection with tumour free resection margins, with or without adjuvant radiotherapy. Survival is negatively influenced by non-radical resection. T1 and T2 tumours can be managed safely with LTBR. More advanced disease requires a more extensive resection, with a higher likelihood of non-radical resections and decreased survival rates.

Programmed Death-Ligand 1 Expression and Tumor-Infiltrating Lymphocytes in Temporal Bone Squamous Cell Carcinoma

OBJECTIVES/HYPOTHESIS

The tumor immune microenvironment in temporal bone squamous cell carcinoma (TBSCC), including the programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs), has not been established.

STUDY DESIGN

Retrospective cohort study.

METHODS

We performed immunohistochemistry analyses to retrospectively analyze 123 TBSCC cases for PD-L1 expression and TILs and their prognostic significance. We also evaluated the prognostic correlations between these immunomarkers and the therapeutic responses to chemoradiotherapy (CRT).

RESULTS

PD-L1 expression (≥1%) was detected in 62 (50.4%) TBSCC cases and was significantly associated with worse prognosis: progression-free survival (PFS), P < .0001; overall survival (OS), P = .0009. A high density of CD8⁺ TILs was significantly associated with better prognosis (PFS, P = .0012; OS, P = .0120). In contrast, a high density of Foxp3⁺ TILs tended to be associated with an unfavorable prognosis (PFS, P = .0148; OS, P = .0850). With regard to the tumor microenvironment subtypes defined by CD8⁺ TILs and PD-L1 expression, the CD8^low /PD-L1⁺ group showed significantly worse prognosis. Among the 36 neoadjuvant CRT-treated cases, PD-L1 expression was significantly associated with worse OS (P = .0132). Among the 32 CRT-treated cases without surgery, a high density of CD8⁺ TILs tended to be more highly associated with complete response to CRT compared to a low density of CD8⁺ TILs (P = .0702).

CONCLUSIONS

These results indicate that the evaluation of the tumor immune microenvironment may contribute to the prediction of prognoses and the selection of an individualized therapeutic strategy for patients with TBSCC.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Indications for and extent of elective neck dissection for lymph node metastasis from external auditory canal carcinoma

OBJECTIVES

We aim to clarify the frequency of lymph node metastasis of external auditory canal (EAC) carcinoma, including susceptible locations, adequate extent of elective neck dissection, and the relationship between the tumor infiltration site and lymph node metastasis.

PATIENTS AND METHODS

From 2003 to 2018, 63 patients with EAC carcinoma at Tokyo Medical and Dental University Hospital were enrolled in this study. The T and N stages, locations of clinically positive lymph nodes, prognoses, and anatomic site of tumor infiltration were analyzed after treatment.

RESULTS

Clinically positive lymph node metastasis (cN+) was detected in 18 patients (28.6%), consisting of T1, T2, T3, and T4 disease in 1 (6%), 2 (22%), 8 (38%), and 7 (41%) patients, respectively. The metastatic locations were at level II in 10 patients, parotid gland nodes in 7, preauricular nodes in 5, level Ib in 3, level Va in 3, level III in 1, and superficial cervical nodes in 1. Neck recurrence was determined in two of 45 patients with clinically negative lymph nodes (cN0), with the metastatic locations being levels II, Ib, and III. Among 18 cN+ cases, neck recurrence was noted in 2 of 9 patients who underwent neck dissection. Neck lesions were found to be manageable in all five patients who underwent docetaxel, cisplatin, 5-fluorouracil, and radiation therapy (TPF-RT). No relationship was noted between the tumor infiltration site and lymph node metastasis among T3/4 canrcinoma patients.

CONCLUSIONS

Elective neck dissection could be indicated only in T3/4 patients with free flap reconstruction. Levels Ib to III are considered appropriate for elective neck dissection in cN0 cases. Levels Ib to III and Va indicated favorable sites, even in cases with metastasis in the parotid gland or preauricular area. Furthermore, TPF-RT could be a useful option even in cN+ cases.

Middle Ear and Temporal Bone Nonkeratinizing Squamous Cell Carcinomas With DEK-AFF2 Fusion: An Emerging Entity

Primary squamous cell carcinomas (SCCs) of the middle ear and temporal bone are rare and usually keratinizing by morphology. Nonkeratinizing, basaloid SCCs arising in this area are exceedingly rare, and, due to the anatomic proximity to the skull base, nasopharynx, and nasal sinuses, the differential diagnosis is broad. Most tumors with squamous differentiation arising in these subsites are either viral-induced (human papillomavirus/Epstein-Barr virus) or rarely may have specific molecular alterations (BRD4-NUT, EWSR1-FLI translocations). Occasional tumors are negative for these findings, and their pathogenesis is unknown. A recently discovered DEK-AFF2 fusion was clinically detected in a series of 2 cases known to the authors. This fusion has been previously reported in the literature in a patient with a base of skull tumor who was an exceptional responder to programmed cell death protein 1 inhibitor therapy. We examine here the histomorphologic and molecular findings of 2 additional cases of an emerging entity. Two male patients were identified. Each had a primary middle ear/temporal bone mass with locally advanced disease. The histology was reviewed, and immunohistochemistry was performed. RNA-based next-generation sequencing was performed for clinical detection of diagnostic or actionable fusions. Both patients had basaloid/nonkeratinizing tumors on biopsy. They were positive for markers of squamous differentiation (HMWK, CK5, and p40). By RNA sequencing, they demonstrated the presence of a DEK-AFF2 fusion and were negative for EWSR1 and NUT translocations. The DEK-AFF2 fusion may define a novel diagnostic category of middle ear and temporal bone nonkeratinizing/basaloid SCCs. This fusion also may represent a potential avenue for immunotherapy in these patients. Further studies are needed to fully explore whether this fusion defines a location-specific clinicopathologic entity.

Prognostic Impact of Tumor Extension in Patients With Advanced Temporal Bone Squamous Cell Carcinoma

Objective: The extreme rarity of temporal bone squamous cell carcinoma (TB-SCC) has delayed the accumulation of high-quality clinical evidence. Our objective here was to explore anatomical factors associated with the prognosis of T4 TB-SCC cases.

Study Design: Case series with chart review.

Setting: Two academic tertiary care medical centers.

Subjects and Methods: The medical records of all TB-SCC cases were retrospectively reviewed in two institutions. The resulting data set contained 30 cases of primary T4 cancer eligible for initial definitive (curative) treatment. Disease-specific survival was calculated according to the Kaplan–Meier method. Cox proportional hazards model was used to identify anatomical prognosis factors.

Results: The disease-specific 5-years survival rate of 30 cases of T4 TB-SCC was 53.9%. The tumor invasion to the pterygoid muscle, posterior fossa dura, and sigmoid sinus and destruction of the ossicles were associated with poor prognosis in univariate analysis. The multivariate analysis reveals that the invasion of the ossicles, posterior fossa dura, and sigmoid sinus is an independent prognostic factor [hazard ratio (HR): 4.528 (95% CI: 1.161–17.658), p = 0.030; HR: 5.135 (95% CI: 1.616–16.315), p = 0.006; HR: 4.292 (95% CI: 1.385–13.303), p = 0.012]. The invasion of the carotid canal, petrous apex, middle fossa dura, otic capsule, pterygoid muscle, and middle ear had a high HR (HR > 2). The more invaded anatomical factors present in patients resulted in a poorer patient disease-specific prognosis, with a statistically significant difference.

Conclusions: Assessing which anatomical structures are susceptible to invasion by tumors may be important for predicting TB-SCC patient prognosis and selecting appropriate treatment planning, especially surgical intervention. In addition to previously reported factors, the destruction of the ossicles in the middle ear cavity can be an anatomical prognosis factor.

Genetic landscape of external auditory canal squamous cell carcinoma

External auditory canal squamous cell carcinoma (EACSCC) is an extremely rare and aggressive malignancy. Due to its rarity, the molecular and genetic characteristics of EACSCC have not yet been elucidated. To reveal the genetic alterations of EACSCC, we performed whole exome sequencing (WES) on 11 primary tumors, 1 relapsed tumor and 10 noncancerous tissues from 10 patients with EACSCC, including 1 with a rare case of synchronous bilateral EACSCC of both ears. WES of the primary tumor samples showed that the most frequently mutated gene is TP53 (63.6%). In addition, recurrent mutations in CDKN2A, NOTCH1, NOTCH2, FAT1 and FAT3 were detected in multiple samples. The mutational signature analysis of primary tumors indicated that the mutational processes associated with the activation of apolipoprotein B mRNA‐editing enzyme catalytic polypeptide‐like (APOBEC) deaminases are the most common in EACSCC, suggesting its similarity to SCC from other primary sites. Analysis of arm‐level copy number alterations detected notable amplification of chromosomes 3q, 5p and 8q as well as deletion of 3p across multiple samples. Focal chromosomal aberrations included amplifications of 5p15.33 (ZDHHC11B) and 7p14.1 (TARP) as well as deletion of 9p21.3 (CDKN2A/B). The protein expression levels of ZDHHC11B and TARP in EACSCC tissues were validated by immunohistochemistry. Moreover, WES of the primary and relapsed tumors from a case of synchronous bilateral EACSCC showed the intrapatient genetic heterogeneity of EACSCC. In summary, this study provides the first evidence for genetic alterations of EACSCC. Our findings suggest that EACSCC mostly resembles other SCC.

External auditory canal carcinoma: clinical characteristics and long-term treatment outcomes

PURPOSE

Evidence-based treatment recommendations for external auditory canal (EAC) carcinoma are lacking in available literature. This study aims to evaluate the clinical characteristics and long-term outcomes of EAC carcinoma in a tertiary referral centre in a period of 15 years and identify independent prognostic factors.

METHODS

Retrospective observational study enrolling all patients with primary EAC carcinoma who underwent primary surgical treatment at the Portuguese Institute of Oncology (Lisbon) between 2004 and 2018. Epidemiological, clinical, histopathological and surgical data were retrieved from clinical records and analysed.

RESULTS

Twenty-seven patients were identified, with a median age of 77 years (range 29-92 years) and a slight female predominance (59.3%). Squamous cell carcinoma (55.6%) was the most common histological type, followed by basal cell carcinoma (40.7%) and ceruminous adenocarcinoma (3.7%). Pittsburgh tumour staging was distributed as early stage in 51.9% (I: 40.7%; II: 11.1%) and advanced stage in 48.1% (III: 29.6%; IV: 18.5%). Median follow-up period was 21 months (interquartile-range: 47). Four patients (14.8%) showed recurrence; recurrence rate was significantly higher in individuals aged < 60 years (p = 0.025) and with lymphovascular invasion (p = 0.049). Median overall survival was 88 months and estimated 2-year and 5-year overall survival rates were both 66%. Survival rates were higher in early stage patients (p = 0.021) and in those without facial palsy (p = 0.032).

CONCLUSION

Based on the available evidence in this review, individuals aged < 60, facial nerve impairment, advanced stage lesions, presence of lymphovascular invasion and squamous cell carcinoma histology are all associated with poor outcome and may be considered when discussing optimal treatment strategies in patients with EAC carcinoma.