Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Background: Between 20-40% of patients with head and neck cancer with recur. Many of these patients are unable to undergo additional rounds of radiation due to patient preference, medical comorbidities, or cumulative radiation dose. Patients who recur and undergo salvage surgery and meet indications for adjuvant treatment based on pathology, currently have limited options if they are not a candidate for additional radiation. Pembrolizumab improves survival in non-operative and metastatic head and neck cancer, and some providers have used it off label in this patient population.
Methods: 11 patients with recurrent squamous cell carcinoma who underwent salvage surgery with pathological indications for radiation (positive margins, lymphovascular invasion, perineural invasion, extranodal extension) but did not undergo radiation (due to patient preference, medical comorbidities or cumulative radiation dose) were matched on age, sex, primary location and HPV status to 11 patients who underwent salvage surgery with pathological indications for radiation who received no further treatment. Disease free survival and overall survival were calculated between the two groups.
Results: Cases and controls were similar based on age, sex, gender, primary location, HPV status, smoking status and stage at recurrence. The hazard ratio for time to recurrence in the pembrolizumab group was 0.30 (0.10, 0.88), p=0.021. The hazard ratio for overall survival in the pembrolizumab group was 0.34 (0.10, 1.13), p=0.065.
Conclusions: Pembrolizumab improves recurrence free survival in patients after salvage surgery for recurrent head and neck cancer compared to observation alone. Overall survival is also increased in the pembrolizumab group, but this does not achieve significance. Larger scale studies are needed to determine the true relationship between adjuvant pembrolizumab and recurrence free survival in high-risk recurrent head and neck cancer after salvage surgery.