Squamous Cell Carcinoma Extending to the Temporal Bone

Patterns of spread and anatomical prognostic factors of pre-auricular cutaneous squamous cell carcinoma extending to the temporal bone

BACKGROUND

Improvements can be made in the management and staging of advanced pre-auricular cutaneous squamous cell carcinoma (cSCC). We aimed to analyze radiological patterns of spread and clinico-anatomical prognostic factors.

METHODS

Retrospective review of 54 patients with pre-auricular cSCC (cutaneous/nodal) who underwent temporal bone resection with curative intent.

RESULTS

Involvement of the cartilaginous external auditory canal (EAC) (79.6%) and retromandibular space (63.0%) was common. Styloid process/anterior carotid sheath (ACS) (11.1%) and bony EAC (7.4%) involvement were rare. ACS involvement resulted in high rates of involved surgical margins (100%) and poor outcomes on univariable analysis. Negative prognostic factors on multivariable analysis included salvage surgery and invasion of the bony EAC, mandible, pterygoid muscle(s), and dura.

CONCLUSION

The bony EAC and ACS can form temporary barriers to tumor spread, with the latter representing a potential limit of resectability. Prognostic factors revealed can lead to the development of a more appropriate staging tool.

Epidemiology and treatment outcomes of cutaneous squamous cell carcinoma extending to the temporal bone

BACKGROUND

Accurate epidemiological and outcomes data regarding cutaneous squamous cell carcinoma (cSCC) extending to the temporal bone is lacking.

METHODS

Retrospective analysis of 167 Australian patients with primary and peri-temporal bone cSCC.

RESULTS

cSCC extending from secondary subsites (93.4%) was 14 times more frequent than primary temporal bone SCC (6.6%). For patients who underwent curative surgery ± post-operative radiotherapy (n = 146, 87.4%), 5-year disease-free survival, locoregional recurrence-free survival, disease-specific survival, and overall survival was 53.0%, 59.4%, 67.9%, and 44.7%, respectively. External ear and pre-auricular tumors, salvage surgery, tumor size (≥40 mm medial-lateral), nodal disease, and involved margins were negative predictors of survival in multivariable analysis.

CONCLUSION

In regions of high sun exposure, cSCCs extending to the temporal bone are more common than primary cancers. Outcomes are improved with clear margins, justifying the need for radical resection. Further research regarding pre-auricular cancers is required given poorer associated survival outcomes.

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.