Clinical outcomes in relapsed oropharyngeal cancer after definitive (chemo)radiotherapy

Objectives: To report clinical outcomes of relapsed oropharyngeal squamous cell carcinoma (OPSCC) after definitive intensity-modulated (chemo)radiotherapy [(C)RT]. Materials and methods: Data for all relapsed patients treated for OPSCC with definitive (C)RT between 2010-2016 was collected. Primary end-point was post-failure survival (PFS). Results: Overall, 273 OPSCC patients completed definitive (C)RT. Of these, 42 cases (n = 26 human papilloma virus (HPV)-negative; n = 16 HPV-positive) had relapsed (n = 23 persistent disease; n = 19 recurrent disease) and were included in the final analysis. Two-year PFS for the entire population was 30.6%; 20.5% for HPV-negative and 43.8% for HPV-positive patients. Salvage curative surgery was associated with a significantly higher 2-year PFS rate (56.2%) compared to palliative treatment (22.9%) and best supportive care (0%) (p < 0.001). A positive trend in 2-year PFS was recorded in the early complete response cases (49.5%) versus patients who did not achieve a complete response within 3 months of the end of (C)RT (23.0%) (p = 0.11). Conclusion: A higher PFS rate is achieved when relapsed OPSCC cases are treated with salvage curative intent. HPV-positive disease and early complete response within 3 months from the end of (C)RT may be related to better PFS.