[Comparison of cutaneous squamous cell carcinomas of the face and ear with and without external auditory canal...

In cutaneous squamous cell carcinoma (cSCC) of the auricle or external auditory canal entrance, involvement of the external auditory meatus (EAM) is associated with an unfavorable prognosis. The aim of this study was to evaluate oncologic outcomes as well as immunosuppressive comorbidities as potential risk factors.

A total of 137 patients treated between 2007 and 2017 were included (31 cSCCs of the auricle or external auditory canal entrance with EAM involvement, 60 auricular cSCCs, 9 lip cSCCs, and 37 nasal cSCCs). Oncologic characteristics and immunosuppressive comorbidities were analyzed retrospectively.

The cSCCs with EAM involvement presented with significantly more advanced T and N stages than all other subgroups. Whereas EAM involvement was associated with a 1.2-fold increased risk of tumor recurrence (p = 0.016), advanced T and N stage were associated with a 1.8- and 2.5-fold increased risk of tumor-related death, respectively. After adjustment for T and N stage, the overall survival of patients with EAM involvement was comparable to that of patients with other tumor locations. Immunosuppressive comorbidities were identified in 25% of patients, most commonly diabetes mellitus, hematologic disorders, and a history of heart or kidney transplantation. However, Cox regression analysis revealed no significant association between immunosuppressive comorbidities and either recurrence-free or overall survival.

Patients with cSCC of the auricle or external auditory canal entrance involving the EAM presented with significantly more advanced T and N stages at diagnosis, underscoring the need for more aggressive treatment strategies, including consideration of adjuvant therapy. After adjustment for T and N stage, overall survival was comparable to that of other tumor locations, suggesting that the poorer prognosis associated with EAM involvement is primarily attributable to more advanced disease at presentation rather than to distinct tumor biology.