Expression of Ki-67 and P16 are related with HPV in squamous cell carcinoma of the external auditory canal.

Abstract

Background: Squamous cell carcinoma of the external auditory canal (EACSCC) is an uncommon tumor and responsible for no more than 0.2% of all the head and neck malignancies. Although there is remarkable research evidence exhibiting that high-risk human papillomavirus (HPV) accounts for considerable head and neck malignancies, its role in the pathogenesis of EACSCC is yet to be determined.

Methods: We evaluated 16 patients with EACSCC treated at our department. We employed PCR to assay for high-risk subtypes of HPV. Two pathologists reviewed the histopathological staining via hematoxylin and eosin along with immunohistochemical staining of p16^INK4a and Ki‑67.

Results: Detection of HPV DNA was done via PCR in 3 (18.75%) patients, and 8 (50%) positive (+) cases were determined via p16^INK4a immunostaining. Besides, 3 (37.5%) individuals were HPV positive as per p16^INK4a PCR results. In addition, all of the p16^INK4a-positive specimens were diagnosed as moderately differentiated carcinomas.

Conclusions: Expression of Ki-67 was related to HPV status. This is the first report implicating high-risk HPV in squamous cell carcinoma of the external auditory canal. However, p16^INK4a immunostaining is a suspectable approach for diagnosing HPV for EACSCC. In addition, HPV might enhance an elevated proliferation rate in EACSCC, illustrated via expression of Ki-67.