Comparison of the University of Pittsburgh staging system and the eighth edition of the American Joint Committee on Cancer TNM classification for the prognostic evaluation of external auditory canal cancer

Risk Factors for Locoregional Recurrence and Distant Metastasis in 143 Patients with Adenoid Cystic Carcinoma of the External Auditory Canal

AIMS

Adenoid cystic carcinoma (ACC) grows slowly and is characterised by potential recurrence and metastasis to distant organs. This study aimed to evaluate the risk factors for locoregional recurrence (LRR) and distant metastasis in patients with ACC of the external auditory canal (EAC).

MATERIALS AND METHODS

Demographic, pathological, therapeutic and survival data of 143 patients with EAC ACC were reviewed in this study. Univariate and multivariate Cox proportional hazard regression analyses were carried out to determine the risk factors for LRR and distant metastasis. Factors associated with overall survival after LRR and distant metastasis were also analysed.

RESULTS

During a median follow-up of 49 months, 31 of 143 patients were observed with LRR and 34 developed distant metastasis. Bone invasion and histological subtype were independent risk factors for locoregional recurrence-free survival. T stage and LRR were independent risk factors for distant metastasis-free survival. Salvage surgery and adjuvant radiotherapy or chemoradiotherapy for LRR resulted in better survival, whereas extrapulmonary metastasis and LRR were associated with a higher risk of poor survival after distant metastasis.

CONCLUSION

Patients with distant metastases, especially those with LRR, are at significant risk of poor prognosis. Our findings emphasise the importance of long-term regular follow-up and recommend surgical intervention with radiotherapy for recurrent EAC ACC.

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.

[Rare cancers of the head and neck on behalf of the REFCOR, part 1]

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology, which determines their local invasiveness, and their hematogenous/nodal spread. Their diagnosis can be difficult and often requires comprehensive immunohistochemistry and genomic techniques. Expert pathology review is recommended in the cases of undifferentiated tumors, sarcomas and at the slightest diagnostic doubt. These rare cancers can also be rare by their anatomical location when arising from the paranasal sinuses, salivary glands and ear. Their location requires knowledge of their specific extension routes, and may call for a specific surgical technique (skull base endoscopic sinus surgery, extended total parotidectomy, etc.) and adapted radiotherapy to spare healthy organs surrounding the tumor. This article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the French ENT Cancer Expertise Network (REFCOR) concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. A second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

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.

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.

Clinical outcome and prognostic factors in adenoid cystic carcinoma of the external auditory canal: proposal for a refined T-stage classification system

PURPOSE

Although adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) has a different pathophysiology from squamous cell carcinoma, the same staging system is used. The aim of this study was to propose a refined staging system, which is more suitable for ACC of the EAC.

METHODS

A total of 25 patients who were diagnosed with ACC of the EAC were reviewed. The modified Pittsburgh staging system (mPSS) that is universally used for temporal bone malignancy was refined for ACC (rPSS). The limited (< 0.5 cm) lateral soft tissue involvement was classified as T1 and extensive (≥ 0.5 cm) lateral soft tissue involvement as T2. The disease-free survival rate (DFSR) was assessed in the patients who underwent surgical treatment according to two staging systems; mPSS and rPSS.

RESULTS

When staging using mPSS, most patients (96.0%, n = 24) were classified as T4. However, when rPSS was used, T1, T2, T3, and T4 stage occupied 36.0% (n = 9), 40.0% (n = 10), 12.0% (n = 3), 12.0% (n = 3), respectively. There was no difference in DFSR according to the T stage using mPSS (p = 0.466). However, when rPSS was used, the DFSR showed significant correlation with the T stage (p = 0.032).

CONCLUSIONS

Clinical T stage of mPSS was not sufficient to predict survival rate in ACC of the EAC, and we propose that the information on the lateral soft tissue involvement needs to be added to the existing staging system.

Surgical Strategy for Squamous Cell Carcinoma of the External Auditory Canal: Management of Locally Advanced Cases with Skull Base Involvement

Objective  Surgical indications for advanced-stage squamous cell carcinoma (SCC) of the external auditory canal (EAC) are highly dependent on the skull base surgery team. The aim of this study was to evaluate the surgical outcomes in patients with SCC of the EAC and to clarify the surgical indication of far advanced cases using the T4 subclassification. Methods  Patients with SCC of the EAC who underwent curative treatment from 2002 to 2021 at our hospital were retrospectively reviewed. Clinical and surgical results, including operative data, overall survival (OS), and disease-specific survival (DSS), were analyzed. To clarify the surgical indication for advanced-stage tumors, we proposed the T4 subclassification. Results  In the 46 patients included in the study, 8 patients had T1 tumors, 10 had T2 tumor, 5 had T3 tumors, and 23 had T4 tumors. The 5-year DSS with T1, T2, T3, and T4 tumors were 100, 85.7, 100, and 61.7%, respectively. No prognostic impacts for margin status were found between the 5-year OS and DSS ( p  = 0.23 and 0.13, respectively). Patients with far-advanced-stage (T4b) tumors were significantly associated with shorter DSS than those with early-stage (T1/T2) and advanced-stage (T3/T4a) tumors ( p  = 0.007 and 0.03, respectively). Conclusion  The present study focused on patients with SCC of the EAC at a university hospital over a period of 20 years, especially with skull base involvement, and a T4 subclassification was proposed. Complete tumor resection in an en bloc fashion could help achieve a good survival rate even in patients with locally advanced tumors.

Primary temporal bone squamous cell carcinoma: Comparing the prognostic value of the American Joint Committee on Cancer TNM classification (8th edition) with the revised Pittsburgh staging system

BACKGROUND

Retrospectively considering a temporal bone squamous cell carcinomas (TBSCCs) series, our aim was to compare the predictive power of the American Joint Committee on Cancer (AJCC) staging system (8th edition) with the revised Pittsburgh staging system (rPSS) in terms of disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS).

METHODS

Forty-three TBSCCs consecutively treated surgically were reviewed. The prognostic performance of AJCC and rPSS was compared.

RESULTS

The areas under the curves for the prediction of DFS, DSS, and OS did not differ significantly between both staging systems (p = 0.518, p = 0.940, and p = 0.910, respectively). Harrel's C-indexes for respectively the AJCC and rPSS were 0.76 and 0.70 for DFS, 0.73 and 0.76 for DSS, 0.66 and 0.63 for OS.

CONCLUSION

Comparable prognostic accuracy was observed between AJCC and rPSS. Levels of prognostic performance were only acceptable for both systems, according to Hosmer-Lemeshow scale. Further efforts are needed to define new TBSCC staging modalities with higher prognostic reliability.

Evaluating the prognostic contributions of TNM classifications and building novel staging schemes for middle ear squamous cell carcinoma

Background

A universally acknowledged cancer staging system considering all aspects of the T‐, N‐, and M‐classifications for middle ear squamous cell carcinoma (MESCC) remains absent, limiting the clinical management of MESCC patients.

Materials and Methods

A total of 214 MESCC patients were extracted from the SEER (the Surveillance, Epidemiology, and End Results) database between 1973 and 2016. The relationships between patient’s characteristics and prognoses were analyzed by Kaplan–Meier and Cox proportional hazards regression models. Novel staging schemes for MESCC were designed by adjusted hazard ratio (AHR) modeling method according to the combinations of Stell’s T‐classification and the eighth AJCC N‐ and M‐classifications, of which performances were evaluated based on five criteria: hazard consistency, hazard discrimination, explained variation, likelihood difference, and balance.

Results

T‐classification was the most significant prognostic factor for MESCC patients in multivariable analysis (p = 0.021). The N‐ and M‐classifications also had obvious prognostic effect but were not statistically significant by multivariate analysis due to the limited metastasis events. Three novel staging schemes (AHR‐Ⅰ–Ⅲ models, different combination of T‐ and N‐classifications) and ST (solely derived from Stell’s T‐classification) were developed, among which the AHR‐Ⅰ staging scheme performed best.

Conclusions

Tumor extension, quantified by Stell’s T‐classification, is the most significant prognostic factor for MESCC patients. However, our AHR‐Ⅰ staging scheme, a comprehensive staging scheme that integrating T‐, N‐, and M‐classifications, might be an optimal option for clinical practitioners to predict MESCC patients’ prognosis and make proper clinical decisions.

Associations Between Clinical Outcomes and a Recently Proposed Adult Congenital Heart Disease Anatomic and Physiological Classification System

Background

American Heart Association and American College of Cardiology consensus guidelines introduce an adult congenital heart disease anatomic and physiological (AP) classification system. We assessed the association between AP classification and clinical outcomes.

Methods and Results

Data were collected for 1000 outpatients with ACHD prospectively enrolled between 2012 and 2019. AP classification was assigned based on consensus definitions. Primary outcomes were (1) all‐cause mortality and (2) a composite of all‐cause mortality or nonelective cardiovascular hospitalization. Cox regression models were developed for AP classification, each component variable, and additional clinical models. Discrimination was assessed using the Harrell C statistic. Over a median follow‐up of 2.5 years (1.4–3.9 years), the composite outcome occurred in 185 participants, including 49 deaths. Moderately or severely complex anatomic class (class II/III) and severe physiological stage (stage D) had increased risk of the composite outcome (AP class IID and IIID hazard ratio, 4.46 and 3.73, respectively, versus IIC). AP classification discriminated moderately between patients who did and did not suffer the composite outcome (C statistic, 0.69 [95% CI, 0.67–0.71]), similar to New York Heart Association functional class and NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide); it was more strongly associated with mortality (C statistic, 0.81 [95% CI, 0.78–0.84]), as were NT‐proBNP and functional class. A model with AP class and NT‐proBNP provided the strongest discrimination for the composite outcome (C statistic, 0.73 [95% CI, 0.71–0.75]) and mortality (C statistic, 0.85 [95% CI, 0.82–0.88]).

Conclusions

The addition of physiological stage modestly improves the discriminative ability of a purely anatomic classification, but simpler approaches offer equivalent prognostic information. The AP system may be improved by addition of key variables, such as circulating biomarkers, and by avoiding categorization of continuous variables.

Treatment Outcome of External Auditory Canal Carcinoma: The Utility of Lateral Temporal Bone Resection

We examined the role of lateral temporal bone resection (LTBR) in the treatment of external ear canal (EAC) carcinoma between 2007 and 2018. The estimated 3-year disease-free survival (DFS) and disease-specific survival (DSS) according to the tumor stage and treatments were investigated in 36 patients with EAC squamous cell carcinoma. T stage classification according to the University of Pittsburgh staging system was as follows: 14 patients in T1, four patients in T2, nine patients in T3, and nine patients in T4. The 3-year DFS rate was 77.4% for T1 tumors, 100% for T2, 44.4% for T3 tumors, and 11.1% for T4 tumors (p < 001). The 3-year DSS rate was 100% for T1/T2 tumors, 87.5% for T3 tumors, and 11.1% for T4 tumors (p < 0.01). T1/T2 patients received mostly LTBR. Among nine T3 tumors, five patients (56%) received LTBR combined with preoperative chemotherapy and/or postoperative radiation (RT). Four of them had negative surgical margin and survived with no evidence of disease. The DFS of T3 patients who underwent concurrent chemoradiotherapy and LTBR was 0 and 80%, respectively (p = 0.048). For T1/T2 tumors, surgery achieved an excellent outcome. For T3 tumors, LTBR achieved negative surgical margin and showed good survival when combined with preoperative chemotherapy and/or postoperative RT. In contrast, the prognosis of T3 patients who could not undergo surgery was as poor as that of T4 patients. Therefore, in addition to subtotal temporal bone resection, LTBR-based treatment strategy may be a treatment option for limited cases of T3 patients.

The importance of flaps in reconstruction of locoregionally advanced lateral skull-base cancer defects: a tertiary otorhinolaryngology referral centre experience

BACKGROUND

The aim of the study was to identify the value of extensive resection and reconstruction with flaps in the treatment of locoregionally advanced lateral skull-base cancer.

PATIENTS AND METHODS

The retrospective case review of patients with lateral skull-base cancer treated surgically with curative intent between 2011 and 2019 at a tertiary otorhinolaryngology referral centre was made.

RESULTS

Twelve patients with locoregionally advanced cancer were analysed. Lateral temporal bone resection was performed in nine (75.0%), partial parotidectomy in six (50.0%), total parotidectomy in one (8.3%), ipsilateral selective neck dissection in eight (66.7%) and ipsilateral modified radical neck dissection in one patient (8.3%). The defect was reconstructed with anterolateral thigh free flap, radial forearm free flap or pectoralis major myocutaneous flap in two patients (17.0%) each. Mean overall survival was 3.1 years (SD = 2.5) and cancer-free survival rate 100%. At the data collection cut-off, 83% of analysed patients and 100% of patients with flap reconstruction were alive.

CONCLUSIONS

Favourable local control in lateral skull-base cancer, which mainly involves temporal bone is achieved with an extensive locoregional resection followed by free or regional flap reconstruction. Universal cancer registry should be considered in centres treating this rare disease to alleviate analysis and multicentric research.

Exploration of High-Grade Transformation and Postoperative Radiotherapy on Prognostic Analysis for Primary Adenoid Cystic Carcinoma of the Head and Neck

Background

Despite Adenoid cystic carcinoma (ACC) with cribriform or tubular components being recognized as a potentially indolent malignancy, ACC displaying solid or, more rarely, high-grade transformation (HGT) components is considered a more aggressive variant of the disease. As it is difficult to measure the proportion of the solid component objectively, and the role of HGT in the current grading system remains unclear, the prognostic influence of tumor grading remains controversial. In addition, postoperative radiotherapy (PORT) has been proven to be effective in local control of ACC of the head and neck (ACCHN) with a high rate of nerve invasion and close surgical margin. However it remains to be explored that whether PORT could improve the survival of patients with ACC, particularly those with HGT.

Methods

A series of 73 surgically treated primary ACCHN cases were retrospectively accessed. Immunohistochemical staining was performed to observe the biphasic ductal-myoepithelial differentiation and to identify the HGT components of ACC for tumor grading. The correlation between tumor grading and clinicopathological characteristics was analyzed. Univariate and multivariate prognostic analysis were performed for progression-free survival (PFS) and overall survival (OS).

Results

Of the 73 included cases, 47 were grade I-II ACC and 26 were grade III ACC. Among the grade III cases, 14 with loss of biphasic ductal-myoepithelial differentiation identified by immunostaining were classified as HGT, and could be distinguished from conventional grade III cases. These HGT cases were correlated with a high propensity of lymph node metastases and more advanced stage. Univariate analysis demonstrated that tumor grading, perineural invasion, T stage, stage groups, and PORT were predictors for PFS, whereas tumor grading, margin status, and PORT were predictors for OS. However, only tumor grading and PORT were independent predictors for PFS and OS. The patients with HGT had significantly worse prognosis than those with conventional ACC. Moreover, disease progression tended to occur more frequently in younger patients. Among the patients with HGT, those who received PORT had a longer median survival time than those who did not.

Conclusion

HGT ACC identified by loss of biphasic differentiation should be considered in tumor grading. Tumor grading and PORT were independent predictors for disease progression and OS in surgically treated ACCHN patients.

Management of the temporal bone defect after resection of external auditory canal cancer

OBJECTIVE

To evaluate the surgical procedures used to treat external auditory canal cancer with respect to avoiding postoperative infection of the temporal bone defect.

METHODS

Enrolled in the study were 52 patients with external auditory canal cancer surgically treated between July 2015 and October 2020 (38 lateral temporal bone resections, 12 subtotal temporal bone resections and 2 partial resections, accompanied by various combined procedures). Retrospective chart review was conducted taking into consideration postoperative infection, and univariate analysis of prognostic factors was performed.

RESULTS

In cases managed with subtotal temporal bone resection, no postoperative infections occurred. Cases managed with subtotal temporal bone resection demonstrated increased use of free-flap reconstruction, and longer antibiotic infusion period. On the other hand, analysis of cases managed with lateral temporal bone resection revealed 10 out of 38 patients with postoperative infection (26.3%). However, we couldn't find out any factors that contributed significantly to the prevention of postoperative infection, including the surgical procedures used to manage the defected space, which included free-flap implantation, obliteration with fat tissue, muscular flap rotation, and leaving the space empty without obliteration or reconstruction.

CONCLUSION

In cases managed with lateral temporal bone resection, leaving the resected space empty did not increase the risk of infection. On the other hand, in cases with subtotal temporal bone resection, filling the surgical defect with an autologous bulk, including the free-flap reconstruction and fat obliteration, seems to prevent the infection. Moreover, prolonged antibiotic infusion may suppress postoperative infection of the temporal bone defect.

A retrospective analysis of radiotherapy in the treatment of external auditory canal carcinoma

External auditory canal carcinoma (EACC) is a rare disease. The current study aimed to evaluate the clinical outcomes of patients treated with external beam radiotherapy (EBRT) for EACC. The present study retrospectively reviewed 34 consecutive patients treated for EACC with EBRT between February 2001 and January 2019 at the University of Tokyo Hospital. Clinical staging was performed according to the modified Pittsburgh classification. Of all the included patients, seven patients were in the early stages (I or II) and 27 in the advanced stages (III or IV) of EACC. A total of 16 patients underwent EBRT and surgery (S+RT) pre- and/or postoperatively, while 18 patients underwent definitive radiotherapy (dRT). The median prescribed doses for the S+RT and dRT groups were 66 and 70 Gy, respectively. The median follow-up period for all patients was 22.4 months (range, 2-205 months). The 5-year overall survival rates of the S+RT and dRT groups were 66.7 and 45.1%, respectively. The progression-free survival rate at 5-year was 55.6% (95% confidence interval: 36.5-71.1%) for the entire cohort. A total of 14 patients experienced disease relapse after treatment, consisting of 11 locoregional recurrences and three distant metastases. The current study revealed the clinical outcomes of EBRT for EACC.

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.

A Case of External Auditory Canal Sebaceous Carcinoma: Literature Review and Treatment Discussion

Sebaceous neoplasms are a rare type of skin cancer that may occur in any area with sebaceous glands, including the outer third of the external auditory canal. However, documentation of the tumor originating in this location is limited to scarce case reports. In this location, malignancies can invade the temporal bone, typically requiring en bloc resection and radiation therapy. We describe a case managed with limited surgical excision based on criteria for primary squamous cell carcinoma of the external auditory canal with only close observation following surgery. Margins were free of disease following excision and histology demonstrated a favorable prognosis. The patient was disease free after a follow-up period of over 3 years postoperatively. A review of relevant literature is utilized to discuss clinical characteristics, staging, treatment, and prognosis to assist in clinical decision making for these patients.

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.

Primary Advanced Squamous Cell Carcinoma of the Temporal Bone: A Single-Center Clinical Study

OBJECTIVES/HYPOTHESIS

The extreme rarity of temporal bone squamous cell carcinoma (TB-SCC) has delayed the accumulation of high-quality clinical evidence. For the purposes of retrospective meta-analysis in the future, a large dataset with information from various institutions would be ideal. Our objective here was to retrospectively review cases of TB-SCC encountered at a single tertiary referral center and explore survival outcomes and prognostic factors.

STUDY DESIGN

Retrospective chart review.

METHODS

The medical records of all TB-SCC cases were retrospectively reviewed. The resulting dataset contained 71 cases of primary cancer eligible for initial definitive (curative) treatment.

RESULTS

T4 status was associated with lower disease-specific 5-year survival than T1 to T3 staging (T1: 100%, T2: 92%, T3: 86%, T4: 51%). Survival was significantly higher in operable than in inoperable cases, even when restricted to advanced (T3/T4) cancers. The tumor extension to the middle ear cavity was observed in 13/17 of T3 cases, but it was not associated with poor survival. In addition, among operable cases, negative surgical margins were associated with significantly higher survival than positive margins.

CONCLUSIONS

Definitive treatments can offer disease-specific 5-year survival of over 85% in T1 to T3 cases of TB-SCC. The tumor extension to the middle ear cavity is not associated with poor survival. T4 status, inoperability, nodal invasion, and positive surgical margin are identified as a predictor of poor prognosis. Still, the matter of how to deal with unresectable tumors remains an outstanding issue in the treatment of TB-SCC.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E583-E589, 2021.