HPV status
HPV genotyping was carried out using Real-Time PCR (RT-PCR) technique with HPV Low Risk (6,11) and High Risk (16,18) Typing Real-TM kit. From the histological samples of 44 patients, 15 patients were found to have at least one subtype of HPV. HPV was detected in 15 (34%) of cases (Table 1).
Four patients were found to have two subtypes present from the histological specimens. One of the patients had Type 6 and Type 11 HPV, another patient had Type 6 and Type 16 present while two more patients had type 16 and Type 18 HPV detected (Table 2). None of the patients had more than two subtypes present.
The most prevalent type of HPV detected in the samples was Type 11 which was detected in eight (18%) patients. There were five (11%) patients that were positive for HPV Type 6. Four patients had HPV Type 16 (9%) while only two (5%) patients had HPV type 18 detected.
Eleven out of 34 (32%) patients with IP had at least one positive HPV detected. Two out of seven (29%) patients with tumour recurrence had at least one type of HPV positivity. Two out of three (67%) patients with IP with SCC had at least one type of HPV detected.
Association of HPV with tumour recurrence
There were seven patients who had tumour recurrence and were classified as IP with recurrence (Table 1). From this study, we found that only two out of the seven (29%) patients with tumour recurrence were positive for HPV. One of the patients had HPV 16 while another patient had HPV 6 and 11. The recurrence rate of inverted papilloma positive for HPV infection was 15% compared to IPs with negative HPV infection (18%). The result was not statistically significant (p>0.05). (Table 3)