Squamous cell carcinoma of the temporal bone: results and management

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 squamous cell carcinoma: Aggressive behavior coursing with cerebellar invasion and hydrocephalus

Background

Temporal bone squamous cell carcinoma (TBSCC) is a very rare condition. The prognosis is dismal for advanced tumors. Due to its rarity, information in the literature is scarce. Here, we report a unique case of TBSCC with cerebellar invasion and hydrocephalus.

Case Description

A 46-year-old reported right-sided hearing loss and a painful right retroauricular mass for 4 months. Magnetic resonance imaging revealed a 8.7 × 7.6 × 6.4 cm mass invading the right temporal and occipital bones. After a biopsy and 3 surgical procedures over 6 months, the diagnosis of TBSCC was obtained. Due to invasion of the cerebellar tissue and obstructive hydrocephalus, a ventriculoperitoneal shunt was performed. The patient was referred for adjuvant radiotherapy. However, palliative care was initiated due to tumor progression.

Conclusion

We report a case of advanced TBSCC with poor prognosis despite surgical treatment and radiotherapy. More data are necessary to provide new and better treatment to these patients.

Treatment outcomes of the external auditory canal and temporal bone malignancy with dura invasion

Objectives

This study aimed to evaluate the characteristics and surgical outcomes of patients with external auditory canal (EAC) and temporal bone (TB) malignancy with dura invasion.

Methods

The medical records of patients with EAC and TB malignancy with dura invasion were retrospectively reviewed. Survival outcomes (overall survival [OS], disease-specific survival [DSS], recurrence-free survival [RFS], and distant metastasis-free survival [DMFS]) were analyzed using the Kaplan-Meier method.

Results

A total of eight patients were included in this study. The median age at diagnosis was 49.5 years (range 12-74 years). The median follow-up periods were 46.5 months. Histologically, four out of eight patients were diagnosed with squamous cell carcinoma (SCC; 50%). The 2-year OS and DSS rates of all patients were 62.5%, and those of EAC SCC patients were 50% and 66.7%, respectively; while the 2-year RFS and DMFS rates of all patients were 37.5%. There was one local recurrence at the resection site (12.5%), two regional neck nodal recurrences (25%), and two distant metastases (25%). Dura resection and duroplasty areas were not involved in the local recurrence case.

Conclusion

In EAC and TB cancer with dura invasion, radical surgery with dura resection may show similar survival outcomes to previous studies without recurrence at the dura resection site.Level of evidence: IV.

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.

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.

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.

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.

Evaluation of subclasses for T4-classified squamous cell carcinoma of the external auditory canal

Background

T4‐classified squamous cell carcinoma (SCC) of external auditory canal (EAC) can potentially involve different anatomical structures, which could translate into different treatment strategies and survival outcomes within one classification. Our aim is to evaluate the clinical added value of T4‐subclasses proposed by Lavieille and by Zanoletti.

Methods

Retrospective data, including patients with primary operated cT4‐classified EAC SCC, was obtained from 12 international hospitals. We subclassified according to the T4‐subclasses. The treatment strategies, disease‐free survival (DFS) and overall survival per subclass were calculated.

Results

A total of 130 T4‐classified EAC SCC were included. We found commonly used treatment strategies per subclass according to Lavieille and the DFS seems also to differ per subclass. Subclass according to Zanoletti showed comparable treatment strategies and survival outcomes per subclass.

Conclusion

Our study suggests that the subclass according Lavieille might have added value in clinical practice to improve care of T4‐classified EAC SCC.

Treatment Strategies for Malignancies of the External Auditory Canal

Malignant tumors of the external auditory canal (EAC) are rare tumors in the head and neck. Delayed diagnosis is not uncommon because the symptoms of early tumors are nonspecific. Various surgical and oncological treatment modalities have been reported. Decision-making depends on pathological feature and stage of the lesions, patient’s general condition and preference, and physician’s experience and skill. Radical surgery is widely accepted as the primary treatment of choice. Postoperative radiotherapy is used more often to improve local and regional control of the disease. Chemotherapy is usually recommended for advanced disease, residual disease, and metastasis. Prognosis is affected by multiple factors such as TNM stage, surgical margin, pathological type and differentiation of tumor, involvement of facial nerve, and so on. Although the survival rate is improved significantly over the past several decades with the development of skull base surgery, neuroradiology, anesthesiology, and oncology, it remains challenging to diagnose and treat EAC malignancies due to the rarity, the local anatomical complexity of temporal bone, and the lack of standard TNM staging system.

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.

Variations of en Bloc Resection for Advanced External Auditory Canal Squamous Cell Carcinoma: Detailed Anatomical Considerations

Currently, only lateral temporal bone resection (LTBR) and subtotal temporal bone resection (STBR) are widely utilized for the surgical treatment of advanced squamous cell carcinoma of the external auditory canal (EAC-SCC). However, there are few descriptions of variations on these surgical approaches. This study aimed to elucidate the variations of en bloc resection for advanced EAC-SCC. We dissected the four sides of cadaveric heads to reveal the anatomical structures related to temporal bone resection. From the viewpoint of surgical anatomy, surgical patterns of temporal bone cutting can be divided into four categories: conventional LTBR, extended LTBR, conventional STBR, and modified STBR. Extended LTBR is divided into four types: superior, inferior, anterior, and posterior extensions. Several extension procedures can be combined based on the extension of the tumor. Furthermore, en bloc resection with the temporomandibular joint or glenoid fossa increases the technical difficulty of a surgical procedure because the exposure and manipulation of the petrous segment of the internal carotid artery are limited from the middle cranial fossa. Surgical approaches for advanced SCC of the temporal bone are diverse. They require accurate preoperative evaluation of the tumor extension and preoperative consideration of the exact line of resection to achieve marginal negative resection.

Malignancies requiring temporal bone resection: An Australian single-institution experience

BACKGROUND

Malignancies in and around the temporal bone are aggressive and difficult to manage. In Queensland (Australia), where skin cancer rates are exceedingly high, tumours extending to the temporal bone from surrounding structures occur more commonly than primary cancers. Yet, a paucity of evidence exists as to their management and outcomes. This study aimed to review an Australian centre's experience of managing temporal and peritemporal bone malignancies, reporting on patient and tumour characteristics, treatment, and survival outcomes.

METHODS

Retrospective analysis of patients with primary temporal bone cancer and cancers extending to the temporal bone managed by the Queensland Skull Base Unit (Princess Alexandra Hospital) between 2000 and 2019.

RESULTS

A total of 222 patients were identified, of which 203 (91.4%) had cutaneous primaries, with 167 (75.2%) being squamous cell carcinoma (SCC). 73.9% presented with locoregionally recurrent or residual disease. Secondary tumours (92.8%) were 12 times more frequent than primary malignancies (7.2%), with the preauricular subsite the most common (45.5%). In the 201 patients (90.5%) who underwent curative intent surgery, 5-year overall survival, disease-free survival (DFS), and disease-specific survival was 46.6%, 52.2%, and 65.9%, respectively. The preauricular subsite (p = 0.004), melanoma (vs. SCC, p = 0.027), involved margins (p < 0.001), and pathologically involved nodes (p < 0.001) were associated with significantly worse DFS.

CONCLUSION

This is one of the largest studies of temporal bone malignancy in the literature, comprised primarily of secondary cutaneous malignancies. Although clear differences in epidemiological characteristics exist around the world, survival remains poor. Treatment should focus on achieving a clear margin of resection to optimize outcomes.

Occult parotid involvement in early-stage squamous cell carcinoma of the external auditory canal

BACKGROUND

The importance of elective parotidectomy in early-stage squamous cell carcinoma (SCC) of the external auditory canal (EAC) is not well established.

METHODS

A retrospective study of 43 patients with early-stage SCC of the EAC who underwent parotidectomy in conjunction with lateral temporal bone resection at three centers.

RESULTS

Overall occult parotid involvement (OPI) rate in early-stage SCC of the EAC was 13.9% (6/43). When considering both the anteroposterior position and the bony-cartilaginous position, patients with SCC in both the anterior wall and cartilaginous portion exhibited significantly higher OPI than other locations (37.5% vs. 0%, p = 0.001), with an increase in the OPI predictive value.

CONCLUSION

SCC located in either the anterior wall of the EAC or the cartilaginous portion of the EAC or both simultaneously showed a high prevalence of OPI, and elective parotidectomy should be considered in those patients.

Survival outcomes of lateral skull base tumors following temporal bone resection

BACKGROUND

Lateral skull base tumors often necessitate temporal bone resection (TBR), although clinical outcomes can be unfavorable. Factors influencing survival and recurrence after TBR for cutaneous and salivary malignancies were evaluated.

METHODS

Twenty-six TBR subjects were included. Survival and recurrence outcomes were estimated at 1, 2, and 5 years postresection. Prognostic factors were analyzed using univariate and multivariate Cox regression.

RESULTS

Two years postresection, the overall survival (OS), disease-specific survival (DSS) and recurrence-free survival (RFS) rates were 61%, 74%, and 49%, respectively, and 51%, 63%, and 45% at 5 years. On univariate analysis, preoperative facial nerve dysfunction and intraoperative nerve sacrifice worsened OS, DSS, and RFS. Prior surgery and adjuvant radiation independently predicted reduced OS, DSS, and RFS on multivariate analysis.

CONCLUSIONS

Mortality is highest in the first 2 years following resection. Preoperative facial nerve dysfunction, facial nerve sacrifice, and prior radiation are negative predictors of survival and recurrence.

A systematic review of the primary squamous cell carcinoma of the external auditory canal: survival outcome based on T-staging and proposal of a new classification

OBJECTIVE

This study aimed to provide a systematic review on survival outcome based on Pittsburgh T-staging for patients with primary external auditory canal squamous cell carcinoma.

METHOD

This study was a systematic review in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines performed until January 2018; pertinent studies were screened. Quality of evidence was assessed using the grading of recommendation, assessment, development and evaluation working group system.

RESULTS

Eight articles were chosen that reported on 437 patients with external auditory carcinoma. The 5-year overall survival rate was 53.0 per cent. The pooled proportion of survivors at 5 years for T1 tumours was 88.4 per cent and for T2 tumours was 88.6 per cent. For the combined population of T1 and T2 cancer patients, it was 84.5 per cent. For T3 and T4 tumours, it was 53.3 per cent and 26.8 per cent, respectively, whereas for T3 and T4 tumours combined, it was 40.4 per cent. Individual analysis of 61 patients with presence of cervical nodes showed a poor survival rate.

CONCLUSION

From this review, there was not any significant difference found in the survival outcome between T1 and T2 tumours. A practical classification incorporating nodal status that accurately stratifies patients was proposed.

Management of squamous cell carcinoma of the temporal bone: long-term results and factors influencing outcomes

OBJECTIVE

Temporal bone squamous cell carcinoma (TBSCC) is a rare, aggressive tumor. Surgery, alone or combined with radiotherapy, represent the mainstay of treatment. To report our experience in the treatment of TBSCC and evaluate the disease-specific survival, identifying the factors influencing this outcome.

MATERIALS AND METHODS

A retrospective study was performed on 66 patients between 1993 and 2018. Patients were staged according to the University of Pittsburgh-modified TNM staging system. Nine cases (13.6%) were Stage I, 7 cases (10.6%) Stage II, 20 cases (30.3%) Stage III and 30 cases (45.5%) Stage IV. Twenty-four patients underwent lateral temporal bone resection (LTBR) and 42 patients underwent subtotal temporal bone resection (STBR).

RESULTS

One hundred percent of Stage I and II patients showed no evidence of disease (NED) after a median follow-up of 101 months (range 1-289 months). NED resulted in 88.2% of Stage III (mean follow-up 80.3 months; range 8-257) and 46.4% of stage IV (mean follow-up 50.6 months; range 3-217). Pittsburgh Stage or involvement of mastoid, facial nerve, medial wall of the middle ear, temporomandibular joint and middle fossa dura emerged as negative prognostic factors. The highest mortality rate occurred in the first 2 years after treatment, due to local recurrence.

CONCLUSIONS

Prognosis of TBSCC can be excellent in early stage tumors, employing a LTBR. In more advanced cases, prognosis is poor. STBR with adjuvant radiotherapy represents the treatment of choice, offering acceptable survival rates. Given the rarity of the pathology, many controversies still exist concerning optimal management.

Evaluation of the modified Pittsburgh classification for predicting the disease-free survival outcome of squamous cell carcinoma of the external auditory canal

Background

Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is a rare disease, which is commonly classified with the modified Pittsburgh classification. Our aim was to evaluate the predictive performance of this classification in relation to disease‐free survival (DFS).

Methods

We examined retrospective data from a nationwide Dutch cohort study including patients with primary EAC SCC. These data were combined with individual patient data from the literature. Using the combined data, the predictive performances were calculated using the c‐index.

Results

A total of 381 patients were included, 294 for clinical and 281 for the pathological classification analyses. The c‐indices of the clinical and the pathological modified Pittsburgh classification predicting DFS were 0.725 (0.668‐0.782) and 0.729 (0.672‐0.786), respectively.

Conclusion

The predictive performance of the modified Pittsburgh classification system as such appears to be acceptable to predict the DFS of EAC SCC. Other factors need to be added to a future model to improve the predicted performance.

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.

Temporal bone resection for lateral skull-base malignancies

INTRODUCTION

Malignancies involving the temporal bone are increasingly common and require specialized multi-disciplinary care. Given this complex location, involvement of the lateral skull base and local neurovascular structures is common. In this review we discuss general principles for temporal bone resection, as well as alternative and complementary surgical approaches that should be considered in the management of patients with temporal bone cancer.

METHODS

A comprehensive review on literature pertaining to temporal bone resection was performed.

RESULTS

The primary surgical strategy for malignancies of the temporal bone is temporal bone resection. This may be limited to the ear canal and tympanic membrane (lateral temporal bone resection) or may include the otic capsule and its contents (subtotal temporal bone resection), and/or the petrous apex (total temporal bone resection). Management of adjacent neurovascular structures including the facial nerve, the carotid artery, and the jugular bulb/sigmoid sinus should be considered during surgical planning. Finally, adjunctive procedures such as parotidectomy and neck dissection may be required based on tumor stage.

CONCLUSIONS

Temporal bone resection is an important technique in the treatment of lateral skull-base malignancies. This strategy should be incorporated into a multi-disciplinary approach to cancer.

Squamous cell carcinoma of the temporal bone: A current review

OBJECTIVES

The rarity of temporal bone squamous cell carcinoma (TBSCC) precludes a clear understanding of the disease and approach to its management. This review provides general background on the disease and discusses the current and emerging oncologic and rehabilitative management options.

DATA SOURCES

PubMed literature review.

METHODS

A review of the current literature was conducted to assess and collate up-to-date information regarding TBSCC management.

RESULTS

TBSCC is a rare and aggressive disease arising in the ear canal, temporal bone, or extratemporal sites. Prior radiation, chronic ear disease, or habitual ear picking may contribute to primary disease development. Because the symptoms of TBSCC and benign otologic disease are similar, TBSCC diagnosis may be delayed, allowing the tumor time to spread throughout the anatomically intricate temporal bone. The extent of the disease is determined based on imaging and is usually staged with the Pittsburgh Staging System. Temporal bone resection with parotidectomy and neck dissection is the current standard of care. Survival is generally good for early disease and poor for advanced disease, but chemotherapy is emerging as a promising treatment option. Auditory rehabilitation with osseointegrated hearing aids is recommended at initial oncologic resection.

CONCLUSIONS

The knowledge of and outcomes for TBSCC have improved with time, but because of the aggressive nature of the disease and the anatomic intricacy of the temporal bone, TBSCC treatment is complex and should be delivered by a multidisciplinary team. Inter-institutional collaboration may accelerate research for this rare disease.

LEVEL OF EVIDENCE

5.

Temporal bone carcinoma: Treatment patterns and survival

OBJECTIVES/HYPOTHESIS

Carcinomas of the temporal bone are rare, and appropriate treatment, staging, and survival data are limited. This study evaluates clinical characteristics and survival rates for patients with temporal bone carcinoma treated with resection at a single tertiary-care institution, with a focus on the outcomes of patients with locally advanced disease including skull base and/or dural invasion.

STUDY DESIGN

Retrospective chart review.

METHODS

Demographic, tumor-specific, and survival data were collected for patients with primary carcinomas of the external auditory canal with involvement of the temporal bone from 2003 to 2015. All patients were staged according to the modified Pittsburgh system. Kaplan-Meier and logistic regression analysis were used to calculate factor-specific survival outcomes.

RESULTS

Sixty-seven patients met inclusion criteria; 85% were male. There were 43 squamous cell carcinomas (64%) and 24 basal cell carcinomas (BCCs) (36%). Tumor stage was 24 (36%) T2, 12 (18%) T3, and 31 (46%) T4 tumors; 53% had recurrent disease. Surgical management included 49 lateral temporal bone resections and 18 subtotal temporal bone resections. Kaplan-Meier analyses revealed more favorable 5-year survival rates associated with BCC histology (P = .01), lateral temporal bone resection compared to subtotal temporal bone resection (P < .01), lack of immunocompromise (P = .04), and absence of perineural/lymphovascular invasion (P = .01). Multivariate regression analysis did not yield statistically significant results.

CONCLUSIONS

Factors predictive of more favorable survival include lack of immunocompromise, BCC histology, absence of perineural/lymphovascular invasion, and disease extent amenable to lateral temporal bone resection. Dural invasion is not an absolute contraindication to surgery, with a subset of patients surviving >5 years.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:E11-E20, 2020.

Evidence Based Tailored Parotidectomy in Treating External Auditory Canal Carcinoma

Carcinoma of the external auditory canal (EAC) is a rare tumor and little information is available regarding parotid gland in surgically treating EAC carcinomas. This study aimed to investigate the mode of parotid involvement in EAC carcinoma through staging and histopathological analysis, and to establish surgical guidelines for the parotid gland management when there is no clinical evidence of parotid involvement. Sixty-five patients with EAC carcinoma who underwent temporal bone resection and any type of parotidectomy simultaneously were retrospectively reviewed. The rate of direct parotid invasion and parotid nodal involvement was analyzed according to the stage and histopathological findings. Among the 65 patients, 39 were confirmed to have squamous cell carcinoma (SCC) and 26 were confirmed to have adenoid cystic carcinoma (ACC). Direct parotid invasion occurred in 7 of 39 patients with SCC, only in the advanced stages, and in 15 of 26 patients with ACC, regardless of stage. Metastasis to the parotid node was noted in 6 patients with advanced-stage SCC, whereas no patient with ACC showed parotid nodal metastasis. For adequate tumor control with low risk of surgical complications, evidence based tailored parotidectomy should be applied. With no evidence of parotid involvement, an elective parotidectomy can be excluded in early SCC, whereas a total parotidectomy is recommended for advanced SCC. In ACC, basal resection of the parotid gland rather than a superficial or total parotidectomy should be performed at all disease stages.

Prognostic Factors Affecting Surgical Outcomes in Squamous Cell Carcinoma of External Auditory Canal

Objectives

Carcinomas of the external auditory canal (EAC) are rare, and management remains challenging. Previous studies seeking prognostic factors for EAC cancers included cancers other than carcinomas. In this study, we analyzed the treatment outcomes of, prognostic factors for, and survival rates associated with specifically squamous cell carcinoma (SCC) of the EAC.

Methods

A retrospective review of 26 consecutive patients diagnosed with SCCs of the EAC in a 10-year period was performed in terms of clinical presentation, stage, choice of surgical procedure, and adjunct therapy. Overall survival (OS) and recurrence-free survival (RFS) were calculated and univariate analysis of prognostic factors was performed.

Results

The median age of the 26 patients with SCCs of the EAC was 63 years (range, 40 to 72 years), and 16 males and 10 females were included. According to the modified University of Pittsburgh staging system, the T stages were T1 in 11, T2 in six, T3 in four, and T4 in five cases. The surgical procedures employed were wide excision in three cases, lateral temporal bone resection (LTBR) in 17, and extended LTBR in four, and subtotal temporal bone resection in two. Two patients underwent neoadjuvant chemotherapy, and two underwent adjuvant chemotherapy. One patient received preoperative radiation therapy, and eleven received postoperative radiation therapy. Of the possibly prognostic factors examined, advanced preoperative T stage and advanced overall stage were significant predictors of RFS, but not of OS.

Conclusion

The advanced T stage and overall stage were associated with decreased survival after surgical treatment in patients with SCC of the EAC, highlighting the importance of clinical vigilance and early detection.

Effect of Piecemeal vs En Bloc Approaches to the Lateral Temporal Bone on Survival Outcomes

Objectives

Lateral temporal bone resection (LTBR) has traditionally been performed en bloc in accordance with oncologic principles. Occasionally, this is not possible due to a low tegmen or lateralized vasculature. We sought to determine if outcomes of piecemeal and en bloc LTBR are comparable.

Study Design

Retrospective review.

Setting

Two academic medical centers.

Subjects and Methods

Multi-institutional retrospective cohort study. Current Procedural Terminology codes were used to identify patients with T1 to T3 squamous cell carcinoma of the external auditory canal (EAC) who underwent LTBR from 2005 to 2015. Kaplan-Meier curves were constructed to compare total survival between the 2 treatment approaches. Pairwise comparisons were performed using χ2 and Fisher exact tests (significance at P = .05), as appropriate.

Results

Twenty-five patients were identified. Ten patients underwent en bloc LTBR; 15 underwent piecemeal LTBR. Median follow-up time was 11 months (range, 1-60 months). There was not a significant difference in overall survival between en bloc (38.9 months; 95% confidence interval [CI], 22.7-55.2) compared to piecemeal (37.5 months; 95% CI, 21.1-53.9) procedures ( P = .519). Estimates of disease-free survival also did not reveal statistically significant differences: estimated mean disease-free survival was 48.1 months (95% CI, 33.7-62.6) in en bloc patients and 32.5 months (95% CI, 17.1-47.8) in piecemeal patients ( P = .246).

Conclusion

These data suggest that piecemeal resection can be considered for cases of squamous cell carcinoma involving the external auditory canal where anatomic constraints preclude a safe en bloc resection. Larger studies or studies with a longer follow-up time may provide improved insight into survival comparisons.

The Outcomes of Surgery and Chemoradiotherapy for Temporal Bone Cancer

OBJECTIVE

We aimed to evaluate the prognostic factors and efficacy of treatment modalities for patients with temporal bone cancer, and to determine if definitive chemoradiotherapy (CRT) for advanced-stage disease can provide a substitute for highly invasive surgeries.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

Sixty-six patients with previously untreated squamous cell carcinoma of the temporal bone treated with curative intent between April 1997 and March 2015.

INTERVENTION

Surgery alone, radiotherapy (RT) alone, surgery followed by RT or definitive CRT.

MAIN OUTCOME MEASURE

The overall survival (OS) rate.

RESULTS

The 5-year OS rate for each T classification was 100% for T1, 76.2% for T2, 55.6% for T3, and 36.7% for T4. Univariable and multivariable analysis showed that T classification was an independent predictor of the OS rate (hazard ratio 5.66; 95% confidence interval 1.51-27.0; p = 0.015). Analysis by treatment modality revealed that the 5-year OS rate for patients with T1-2 was 100% for surgery and 81.3% for RT alone. The rate for patients with T3-4 was 52.1% for definitive CRT and 55.6% for surgery followed by RT with or without chemotherapy.

CONCLUSIONS

Patients with T1-2 benefited from surgical intervention without significant morbidity or mortality. Our findings also suggested that definitive CRT might be appropriate as the first-line treatment for T3-4, especially in cases with unresectable tumors.

Multicenter experiences in temporal bone cancer surgery based on 89 cases

OBJECTIVE

To present outcomes of extensive surgery: lateral, subtotal, total petrosectomies in patients with temporal bone invasion resulting from specific primary cancers.

STUDY DESIGN

Retrospective case review.

SETTING

Four tertiary referral centers.

MATERIAL

89 patients with cancer of the temporal bone treated between January 2006 and December 2010.

INTERVENTION

Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy.

MAIN OUTCOME MEASURE

Disease-specific survival, overall survival.

RESULTS

In 27.0% of the patients, relapse was reported, with an average of 6.3 months after surgery; 31 patients (34.8%) died during the follow-up. The average mortality was 22.1 months. Fifty-four patients (58.7%) stayed alive during the time of observation. The average survival time was 42.0 months. The median time of survival with relapse was 12 months (range: 1-51 months). The three-year disease-free rate was 38.0% and the overall survival rate was 58.7%.

CONCLUSIONS

Petrosectomy is an effective treatment for malignant temporal bone invasion. The probability of a good outcome was statistically decreased with a high T grade, positive margins, and salvage surgery. Younger age is connected with better prognosis. One of the major tasks remains to improve detection and to shorten the time to diagnosis, keeping in mind that symptoms are insidious and in younger people, the time before diagnosis was longer.

The contribution of CT and MRI in staging, treatment planning and prognosis prediction of malignant tumors of external auditory canal

Carcinomas of external auditory canal (EAC) are rare. Radiological imaging particular in computed tomography (CT) and magnetic resonance imaging (MRI) plays an important role in the staging, treatment planning and follow up of the patients with malignant EAC tumor. This article aims to review the role of CT and MRI in the describing different tumor growth pattern, tumor staging, treatment planning, follow up and predicting the prognosis of malignant tumors of EAC.

Hearing loss due to metastasis of gastric cancer to temporal bone: A case report

Metastatic temporal bone tumors are rare, and tend to be asymptomatic. The clinical symptoms consist of aural discharge, bleeding, hearing loss and facial nerve paresis. The most common origin of the metastasis is breast cancer, and other sites of the primary tumor include the thyroid gland, brain, lungs, prostate and blood. Clinical reports of hearing loss due to gastric cancer metastatic to temporal bone are rare. In the present study, a case of gastric cancer metastasis to temporal bone without other organ involvement is described. The patient presented with the symptom of hearing loss, and the metastatic tumor was diagnosed by radiological imaging, including magnetic resonance imaging, computed tomography and bone scan.

Squamous cell carcinoma of the temporal bone

Temporal bone malignancy presents a significant clinical challenge for the otolaryngologist. This article provides an overview of squamous cell carcinoma of the temporal bone, including clinical presentation, diagnosis, staging, treatment, and prognosis. As demonstrated in this case study, the prognosis for patients with advanced-stage temporal bone malignancy is poor, even with maximal therapy.

Comparison of hearing outcomes after treatment for early-stage external auditory canal cancer

BACKGROUND

The purpose of this study was to compare the hearing outcomes after surgery with reconstruction of the external auditory canal in combination with tympanoplasty, radiotherapy (RT) alone, and surgery followed by postoperative RT for T1 to 2N0M0 external auditory canal cancer.

METHODS

We performed a retrospective, single-institution review of consecutive patients with early-stage external auditory canal cancer treated with surgery and/or RT between April 1997 and August 2013. Audiological data included the pretreatment hearing thresholds and those obtained at 12 months after the completion of therapy.

RESULTS

When we compared the functional gains for air-conduction pure-tone average thresholds and mean air-bone gaps, those in the surgery group (n = 10) were significantly higher than those in the RT (n = 13) and surgery + RT (n = 5) groups.

CONCLUSION

Adequate techniques for reconstruction of the external auditory canal in combination with tympanoplasty after complete surgical resection is useful for hearing preservation in addition to good survival outcomes. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1110-E1116, 2016.

Radiological Findings of Malignant Tumors of External Auditory Canal: A Cross-Sectional Study Between Squamous Cell Carcinoma and Adenocarcinoma

The primary malignant tumors of external auditory canal (EAC) are rare. The purpose of this study is to compare the imaging features of growth and recurrence pattern between 2 most common carcinomas namely squamous cell carcinoma (SCC) and adenocarcinoma of the EAC.This is a retrospective study involving 41 patients with primary EAC carcinomas of which 22 are SCC and 19 are adenocarcinoma. They were all scanned with high resolution computer tomography (HRCT) and magnetic resonance imaging. Follow-up clinical and imaging studies have also been collected and compared with a median follow-up time of 43 months (range 5-192 months). Necrosis was presented as hypodensity on computed tomography images, hyper-intense on T2WI and heterogeneous enhancement.Eighteen patients were diagnosed to be in T1 and T2 stage, it was found that SCC involved both the cartilaginous part and the bony part of the EAC (11/12), whereas adenocarcinoma involved only the cartilaginous part (6/6) (P < 0.01). Twenty-three patients were diagnosed to be in T3 and T4 stage showed bony involvement and adjacent tissue involvement for both SCC and adenocarcinoma. Parapharyngeal space involvement is much more common in recurrent SCC (P = 0.02). Lymph node metastasis was seen in 6 out of 22 patients with SCC, while 5 out of 19 patients of adenocarcinoma had lung metastasis, even at early stage (1/6; 1/5). Necrosis is more likely to occur in the patients with SCC (9/10) than that of adenocarcinoma (3/13) (P = 0.02).SCC and adenocarcinoma is seen to have different growth pattern at early stage but share similar patterns in the advanced stage. Lymph node metastasis is commonly seen in patients with SCC while adenocarcinoma shows lung metastasis even at early stage.

Squamous cell carcinoma of the temporal bone: clinical outcomes from radical surgery and postoperative radiotherapy

OBJECTIVE

To review the treatment of squamous carcinoma of the temporal bone at a regional skull base unit for the period 1982-2012.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Sixty patients with primary squamous carcinoma of the temporal bone.

INTERVENTIONS

Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy.

MAIN OUTCOME MEASURES

Disease-specific survival, overall survival.

RESULTS

The 5-year disease-specific survival for the whole cohort was 44% (CI, 37%-51%). Multivariable analysis revealed nodal status, poorly differentiated squamous cell histology, and carotid involvement to be poor prognostic indicators.

CONCLUSION

Although the survival figures in this series are comparable with the best outcomes from other units, our experience would suggest improvements can still be achieved by reconsidering the selection of patients for neck dissection and temperomandibular joint excision in early stage disease. We also conclude that postoperative radiotherapy should be delivered to all patients, including surgical salvage cases who may have received previous irradiation. Finally, the minority of patients with poor prognostic features should be offered a more palliative therapeutic approach.

Prognostic models to predict overall and cause-specific survival for patients with middle ear cancer: a population-based analysis

Background

The purpose of this study was to evaluate the survival outcome for middle ear cancer and to construct prognostic models to provide patients and clinicians with more accurate estimates of individual survival probability.

Methods

Patients diagnosed with middle ear cancer between 1983 and 2011 were selected for the study from the Surveillance Epidemiology and End Results Program. We used the Kaplan-Meier product limit method to describe overall survival and cause-specific survival. Cox proportional hazards models were fitted to model the relationships between patient characteristics and prognosis. Nomograms for predicting overall survival and cause-specific survival were built using the Cox models established.

Results

The entire cohort comprised 247 patients with malignant middle ear cancer. Median duration of follow-up until censoring or death was 25 months (range, 1–319 months). Five-year overall survival and cause-specific survival were 47.4% (95% Confidence Interval (CI), 41.2% to 54.6%) and 58.0% (95% CI, 51.6% to 65.3%), respectively. In multivariable analysis, age, histological subtype, stage, surgery and radiotherapy were predictive of survival. The bootstrap corrected c-index for model predicting overall and cause-specific survival was 0.73 and 0.74, respectively. Calibration plots showed that the predicted survival reasonably approximated observed outcomes.

Conclusion

The models represent an objective analysis of all currently available data. The resulting models demonstrated good accuracy in predicting overall survival and cause-specific survival. Nomograms should thus be considered as a useful tool for predicting clinical prognosis.

Rare case study of a primary carcinoma of the petrous bone and a brief literature review

BACKGROUND

Temporal bone carcinoma is an aggressive tumor with multiple unconfirmed risk factors.

METHODS AND RESULTS

Herein, we present a rare case of a primary petrous bone carcinoma in a female patient (65 years old) with an irrelevant medical history. She presented a postauricular swelling that revealed a multilocular osteolytic cystic lesion of the mastoid portion of the temporal bone on the CT scan. The patient underwent resection of the lesion and pathological analysis revealed moderately to well-differentiated squamous cell carcinoma. Postoperative radiotherapy was carried out. Until the present time, the patient shows complete remission on regular clinical and radiological follow-up.

CONCLUSION

Although no widely accepted strategy for managing temporal bone tumors exists, a review of the literature showed that surgery with or without radiotherapy is the treatment of choice. Preoperative assessment and accurate staging are vital in ensuring that the treatment is adequate for each disease stage.

Chemoradiation therapy for squamous cell carcinoma of the external auditory canal: A meta-analysis

BACKGROUND

The standard treatment for advanced external auditory canal squamous cell carcinoma (SCC) is subtotal temporal bone resection and postoperative radiation therapy (RT), whereas chemoradiation therapy (CRT) is used in some institutions to improve patient prognosis. The purpose of this study was to evaluate the efficacy of CRT in external auditory canal SCC treatment.

METHODS

Meta-analyses of external auditory canal SCC studies were performed. We extracted 5-year overall survival rates and number of patients for aggregate patient data, and types of treatment and outcomes for individual patient data.

RESULTS

The 5-year overall survival rate of 752 patients was 57%. In the individual patient data meta-analysis, the 5-year overall survival rates of patients who received surgery ± RT, preoperative CRT, definitive CRT, and postoperative CRT were 53.5%, 85.7%, 43.6%, and 0%, respectively.

CONCLUSION

Our data suggest that preoperative CRT may improve the survival of surgically treated patients with external auditory canal SCC and that definitive CRT may be equivalent to surgical resection.

Survival outcomes of patients with temporal bone squamous cell carcinoma with different invasion patterns

BACKGROUND

The correlation between the survival rate and various invasion patterns of patients with temporal bone squamous cell carcinoma (SCC) is unclear. This study was performed to compare the survival outcomes of these patients to disclose the correlation.

METHODS

The cases of 39 patients with temporal bone SCC who underwent surgery between January 2004 and December 2012 were reviewed.

RESULTS

The 2-year overall survival rate was 56.9%, and it was 22.3% for patients with stage IV disease, and 100% for patients with stage I-III disease. Patients with parotid invasion (n = 11), temporomandibular joint (TMJ) involvement (n = 8), and middle ear surgery (n = 7) before temporal bone malignancies were diagnosed had poor survival with statistical difference.

CONCLUSION

Patients with parotid gland, TMJ involvement, and previous middle ear surgery for chronic otitis media had poor outcomes.

Temporal bone malignancies

Primary temporal bone tumors are rare. Suspicious lesions of the ear canal should be biopsied for diagnosis. Surgical resection to achieve negative margins is the mainstay of treatment. Small tumors can be treated with lateral temporal bone resection. Parotidectomy and neck dissection are added for disease extension and proper staging. Higher staged tumors generally require subtotal temporal bone resection or total temporal bone resection. Adjuvant postoperative radiotherapy has shown improved survival for some patients. Chemotherapy has an emerging role for advanced stage disease. Evaluation and management by a multidisciplinary team are the best approach for patients with these tumors.

Lateral temporal bone resection in advanced cutaneous squamous cell carcinoma: report of 35 patients

Objective To evaluate lateral temporal bone resection (LTBR) in the management of advanced cutaneous squamous cell carcinoma (SCC) with temporal bone invasion and patterns of failure. Methods This is a retrospective study of 35 patients undergoing lateral temporal bone resection for advanced cutaneous SCC at a tertiary care center between 1995 and 2006. Results The Pittsburgh tumor stage was T4 in 18 patients (51%), T3 in 5 (14%), T2 in 9 (26%), and T1 in 3 (9%). Clear margins were reported in 22 (63%) patients. Resection of the mandible and/or temporomandibular joint (TMJ) was required in 11 (31%) patients. Facial nerve involvement was seen in 10 (29%) patients. Survival outcomes at 2 and 5 years for overall survival were 72% and 49%; disease-free survival, 68% and 59%; and disease-specific survival, 79% and 62%, respectively. Pittsburgh T stage correlated significantly with disease-specific survival (p = 0.015) and margin status was significant for both disease-free survival (p = 0.0015) and disease-specific survival (p < 0.001). Conclusions Surgery with curative intent is justified for cutaneous SCC invading the temporal bone with extended LTBR. Margin status was a significant predictor of outcome. Surgeons should plan preoperatively to achieve clear margins by extending the LTBR with possible nerve resection.