Smoking History does not have Prognostic Significance in HPV Positive Oropharynx Cancer Patients Treated with Transoral Robotic Surgery

Presentation: AHNS-029
Topic: Mucosal - HPV Positive
Type: Oral
Date: Wednesday, May 1, 2019
Session: 4:05 PM - 5:00 PM Scientific Session 4 - HPV Positive
Authors: Dylan F Roden, MD, Kealan Hobelmann, Tony Richa, Swar Vimawala, Adam Luginbuhl, Joe Curry, Richard Goldman, David Cognetti
Institution(s): Thomas Jefferson University

Introduction:  HPV positive (+) oropharyngeal squamous cell carcinoma (OPSCC) has a favorable prognosis.  However, HPV+ patients with significant smoking histories treated with definitive chemoradiation have a worse prognosis compared to their nonsmoking counterparts.   Several studies demonstrate that HPV+ patients with >10 pack year (pk-yr) smoking history treated nonsurgically fall into an intermediate risk group, compared to HPV+ non-smokers.  The prognostic significance of smoking history is in surgically treated patients is not known. We sought to investigate whether smoking history is a prognostic factor in HPV+ patients treated with upfront transoral robotic surgery (TORS).

Methods: We reviewed our single institution database of patients treated with upfront TORS from 2010-2016.  Exclusion criteria was non-oropharyngeal primaries, histology other than SCC, and HPV negative tumors, previous head and neck cancer history, and/or previous head and neck radiotherapy.  We compared non-smokers (< 10 pk-yr) to smokers (>=10 pk-yr).  We also compared recent/current smokers to remote smokers (quit >5 years ago), each group having a >=10 pk-yr smoking history.  We compared continuous variables with t-test and categorical variables with X-square.  We compared recurrence free survival (RFS) using Kaplan-Meier method and log rank test.

Results: Our analysis included 160 patients, mean age 59, 88.8% male.  The median followup was 49 months and there were 8 recurrences (2 local, 0 regional, 6 distant).  There were 82 tonsil (51.2%), and 78 base of tongue (48.8%) tumors.  Adjuvant radiatiotherapy was delivered in 146 patients (91.3%), and adjuvant chemoradiation therapy was delivered in 83 patients (51.9%).  There were 93 non-smokers (58.1%%), and 67 smokers (41.9%).  Amongst the smokers, 24 patients (35.8%) were recent/current smokers and 43 patients (64.2%) were remote smokers.  By pathologic N staging (7th edition) there were 14 (8.8%) N0, 12 (7.5%) N1, 39 (24.4%) N2A, 83 (51.9%) N2B, 7 (4.4%) N2C, and 5 (3.1%) N3. By pathologic N staging (8th edition) there were 19 (11.9%) N0, 122 (76.3%) N1, 19 (11.9%) N2.   There were 67 (41.9%) T1, 80 (50%) T2, and 13 (8.1%) T3.  The smoker versus non-smoker comparison groups were not significantly different with respect to age, gender, T stage, or N stage.  When comparing adverse pathologic features between non-smokers and smokers, there were no significant differences in PNI (23% vs 20%, p=0.68), LVI (56% vs 43%, p=0.15), or ECE (42% vs 32%, p=0.18).  The 3 year RFS between non-smokers and smokers was not different (96.4% vs 96.9% respectively, p=0.285).  The 3 year RFS between remote smokers and recent/current smokers was not different (97.7% vs 95.5%, p=0.69).  When specifically comparing the 83 patients with N2b nodal disease (7th edition staging), 3 year RFS between non-smokers and smokers was not different (97.7% vs 94.2% respectively, p=0.82). 

Conclusions: Significant smoking history is common in HPV associated H&N cancer, seen in 40% of our cohort.  In this single institution experience HPV+ smokers treated with upfront TORS did not demonstrate decreased survival compared to non-smokers.  A history of smoking may be an additional factor to advocate for upfront TORS in select patients.