External Auditory Canal Squamous Cell Carcinoma with History of Nasopharyngeal Carcinoma – A Retrospective Review on Clinical Manifestation and Management in a Single Institute

By June 7, 2019

Chan, Po Ling1; Chang, Wai Tsz1; Tong, Michael Chi Fai1
1 Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Hong Kong, China.

Nasopharyngeal carcinoma(NPC) is not uncommon in southern Chinese population. Despite rarity, there is increasing trend of NPC post-irradiative induced squamous cell carcinoma of external auditory canal (EACSCC).

To describe and analyse the clinical characteristics, prognostic factors, treatment modalities and survival outcomes between post-irradiative EACSCC and primary EACSCC patients.

Thirty-two patients of EACSCC were analysed for clinical presentation, treatment modalities(open surgery, endoscopic assisted transcanal approaches (EATA), radiotherapy and chemotherapy) and survival rates. Pittsburgh Staging System was adopted.
Progression free survival(PFS) was estimated by Kaplan–Meier method with the use of Log rank test for assessment of prognostic factors on PFS.
p value of <0.05 was considered statistically significant.

Median age of presentation was 64 years(range:38-84 years). Male to female ratio was 25:7. Fifteen patients had history of NPC(46.9%). Twenty-nine patients underwent surgery(90%), in which five patients were using EATA(17%). Twenty patients received radiotherapy(15 had post-operative radiotherapy; 3 had palliative radiotherapy and 2 received radical radiotherapy and chemotherapy). Eleven patient (of 29 patients; 37.9%) had recurrent EACSCC, with median recurrent months as 10.9(range: 3-32 months). There was no evidence of recurrence in EATA group(follow-up 2-22 months). A median follow-up was 23 months. Median PFS was 49 months.

Advanced stage of history of NPC(p=0.01), advanced stage of EACSCC(p=0.013), facial nerve palsy at presentation(p=0.002), and margin involved after resection(p=0.039) were significant predictors of poor PFS.

A significant proportion of EACSCC patients had history of NPC with irradiation in our institute.  Advanced staging in EACSCC or NPC, and facial nerve palsy reflected poor survival outcomes. EATA surgery showed a promising disease-free survival in early follow-up.