Temporal bone carcinoma: a first glance beyond the conventional clinical and pathological prognostic factors

Temporal Bone Squamous Cell Carcinoma: Molecular Markers Involved in Carcinogenesis, Behavior, and Prognosis: A Systematic Review

Temporal bone squamous cell carcinoma (TBSCC) is an uncommon malignancy with a poor prognosis in advanced cases. The dismal outcome of advanced TBSSC cases is largely due to the cancer’s local aggressiveness and the complex anatomy of this region, as well as to persistent pitfalls in diagnosis and treatment. Molecular changes occur in malignancies before any morphological changes become visible, and are responsible for the disease’s clinical behavior. The main purpose of this critical systematic review is to assess the level of knowledge on the molecular markers involved in the biology, behavior, and prognosis of TBSCC. A search (updated to March 2022) was run in PubMed, Scopus, and Web of Science electronic databases without publication date limits for studies investigating molecular markers in cohorts of patients with primary TBSCC. The search terms used were: “temporal bone” OR “external auditory canal” OR “ear”, AND “cancer” OR “carcinoma” OR “malignancy”. We preliminarily decided not to consider series with less than five cases. Twenty-four case series of TBSCC were found in which different analytical techniques had been used to study the role of several biomarkers. In conclusion, only very limited information on the prognostic role of molecular markers in TBSCC are currently available; prospective, multi-institutional, international prognostic studies should be planned to identify the molecular markers involved in the clinical behavior and prognosis of TBSCC. A further, more ambitious goal would be to find targets for therapeutic agents able to improve disease-specific survival in patients with advanced TBSCC.

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.

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.

Temporal bone carcinoma: testing the prognostic value of a novel clinical and histological scoring system

PURPOSE

Our group recently proposed the novel Padova prognostic scoring system for temporal bone carcinoma (TBSCC) that considers: the revised Pittsburgh staging system; radiological dura mater involvement; non-anterior spread (medial, inferior or posterior into the temporal bone and skull base) of T4 tumors; and histological grade. The aim of the present study was to validate this prognostic TBSCC scoring system in a case series selected from the literature.

METHODS

A search was run to identify studies on TBSCC reporting the variables included in our score for each patient. Then our system was applied to the data extracted.

RESULTS

Only two published investigations reported all the clinical and pathological data required for our scoring system. In one series from the Gruppo Otologico in Piacenza (Italy), a significantly higher recurrence rate (p = 0.008), shorter disease-free survival (DFS) (p = 0.001), higher disease-specific mortality (DSM) (p = 0.006), and shorter disease-specific survival (DSS) (p = 0.004) were associated with scores ≥ 5. Receiver operating curve (ROC) analysis showed an AUC of 0.804 for TBSCC recurrence, and 0.832 for DSM. In a series from Kyushu University Hospital (Japan), a significantly higher DSM (p = 0.018) and shorter DSS (p = 0.021) were associated with scores ≥ 5. ROC analysis showed an AUC of 0.812 for tumor relapse and 0.790 for DSM.

CONCLUSION

Our TBSCC Padova scoring system confirmed its validity when applied to the only two international TBSCC series providing the required data. These preliminary results need to be confirmed in a multi-center prospective setting.

Temporal bone carcinoma: Novel prognostic score based on clinical and histological features

BACKGROUND

This study aimed to develop a novel temporal bone squamous cell carcinoma (TBSCC) prognosis scoring system and compare it with the revised Pittsburgh staging system.

METHODS

Forty-four consecutive TBSCC patients were assessed to identify predictors of recurrence. Each predictor's hazard ratio for recurrence was used to develop our novel scoring system.

RESULTS

Based on variables with P < .10 in Cox's regression model, our score included: revised Pittsburgh stage; non-anterior spread of T4 carcinoma; dural involvement; and histological grade. A higher recurrence rate (P = .000) and shorter disease-free survival (P = .000) were associated with scores of ≥5. The area under the curve of our score was larger than that of the revised Pittsburgh stage for both recurrence and disease-specific mortality (P = .0178 and P = .0193, respectively).

CONCLUSION

Our TBSCC scoring system is based on variables that are obtainable preoperatively from clinical and radiological data and biopsies. Its prognostic value should be validated for published TBSCC series and then in prospective settings.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

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.

Dramatic response of CTNNB1 and VEGFR-2 mutant temporal bone squamous cell carcinoma to bevacizumab in combination with pemetrexed

High recurrence rates and poor survival rates for late stage/advanced temporal bone squamous cell carcinoma with the standard treatments continues to be a significant challenge to otolaryngologists. Targeted therapy for temporal bone squamous cell carcinoma after relapse has not been reported. Here we present a 58-year-old man who was diagnosed with recurrent temporal bone squamous cell carcinoma and treated with a regimen developed using whole exome sequencing. Somatic mutations in genes encoding catenin beta 1 and vascular endothelial growth factor receptor 2 were identified in the patient’s tumor sample compared to the normal tissue. The patient was then treated with Bevacizumab in combination with pemetrexed. After two weeks of treatment, tumor volume was reduced by 95% measured by MRI, and the Visual Analogue Scale headache scores went down from 10/10 to 2/10. Our results reveal novel gene mutations of temporal bone squamous cell carcinoma and demonstrate, for the first time, an effective targeted therapy for temporal bone squamous cell carcinoma. The successful treatment regimen of bevacizumab and pemetrexed may provide a new treatment option for treating recurrent temporal bone squamous cell carcinoma that fails to respond to conventional tumor resection, radiotherapy, and/or chemotherapy.

Cortactin and phosphorylated cortactin tyr466 expression in temporal bone carcinoma

PURPOSE

Cortactin is a multidomain protein engaged in several cellular mechanisms involving actin assembly and cytoskeletal arrangement. Cortactin overexpression in several malignancies has been associated with increased cell migration, invasion, and metastatic potential. Cortactin needs to be activated by tyrosine or serine/threonine phosphorylation. The role of cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) was investigated in temporal bone squamous cell carcinoma (TBSCC).

MATERIALS AND METHODS

Immunohistochemical expression of cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) was assessed in 27 consecutively-operated TBSCCs.

RESULTS

Several clinicopathological variables correlated with recurrence (pT stage, dura mater involvement), and disease-free survival (DFS) (cT stage, pT stage, pN status, dura mater involvement). Twenty-three of 24 immunohistochemically evaluable TBSCCs were cortactin-positive. Median cortactin expression was 75.0%. Cortactin reaction in the cytoplasm was more intense in carcinoma cells than in normal adjacent tissue. Recurrence and DFS rates did not correlate with cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) expression in TBSCC specimens.

CONCLUSIONS

Cortactin upregulation in TBSCC supports the conviction that inhibiting cortactin functions could have selective effects on this malignancy. Multi-institutional studies should further investigate the role of cortactin and phosphorylated cortactin in TBSCC, and their potential clinical application in integrated treatment modalities.