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.