HPV status is not associated with better survival rates in low-prevalence HPV infection geografic regions

Presentation: C045
Topic: Pharynx / Larynx Cancer
Type: Poster
Date: Thursday, April 19, 2018
Session: 9:00 AM - 7:00 PM
Authors: Rafael De Cicco, MD1, Rosilene M Menezes, MD, PhD2, Ulisses R Nicolau, MD, PhD1, Clovis A Pinto, Md, PhD1, Luiza L Villa, PhD3, Luiz P Kowalski, MD, PhD1
Institution(s): 1AC Camargo Cancer Center, 2Hospital do Servidor Publico Municipal, 3Instituto do Cancer do Estado de São Paulo

Background: HPV positive oropharyngeal squamous cell carcinoma (OSCC) has been associated with better response rates and survival outcomes and it was the basis for the significant modifications on TNM classification. However, in some geographic regions with lower prevalence of this association, the role of HPV infection on prognosis is still unclear.

Objective: to describe patterns of recurrence and survival analysis in a series of OSCC treated in a geographic region with reported low prevalence of HPV infection.

Methods: We retrospectively collected data from 215 patients treated for OSCC in a tertiary center in Brazil. The collected data included demographic information, HPV status, tobacco and alcohol consumption, TNM stage, pathologic and treatment variables. The patterns of recurrence were recorded according to HPV status. Disease specific survival and recurrence free survival were calculated using Kaplan Meier method and finally, multivariate Cox’s regression analysis was performed.

Results: 127 (59.1%) patients had HPV-positive OSCC. Median age was 56 years (CI 55- 58). Tonsil was the most frequent site for both HPV-positive (61.2%) and HPV-negative (60.9%) groups. Most patients had locally advanced disease (T3-T4). According to AJCC 7th edition staging system, there was 9 (4.2%) stage I; 17 (7.9%) stage II; 40 (18.6%) stage III and 146 (67.9%) stage IV patients. Moreover, restaging patients according to AJCC 8th edition, there was 34 (15.8%) stage I; 71 (33%) stage II; 47 (21.9%) and 60 (27.9%) stage IV patients. There was no difference between treatment among groups. Surgery was initially performed in 50.7% of the cases, and chemoradiation regimens were the initial treatment option in 48.4% (p=0.686). Median follow-up time was 47 months (IQR – 43.53). Amongst the HPV-negative group, 8 patients (9.3%) had local recurrences, while 12 (14%) had regional recurrences and 12 cases (14.0%) presented with distant metastasis. In the HPV-positive group, 8 patients (6.5%) had local recurrences, 13 (10.5%) had regional recurrences, while 16 patients (12.9%) presented distant metastasis. HPV status was not associated with differences in recurrence rates (p=0.680), however we observed unusual sites of distant metastasis in the HPV-positive group, as 5 patients presented liver metastasis, 4 had bone metastasis, one had skin implants, and one presented CNS disease. 5-year disease specific survival rate was of 71.5% and 5-year recurrence free survival rate was of 63.7%. HPV positivity was not significant associated with higher rates of disease specific survival and recurrence free survival. However, tobacco and alcohol exposure were significant associated with lower rates of both disease specific and recurrence free survival, regardless of the HPV status.

Conclusion: HPV status was not associated with higher survival rates in the studied group. However, patients with HPV-positive tumors were more likely to have unusual distant metastasis.