Viable tumor in salvage neck dissections in head and neck cancer: Relation with initial treatment, change of lymph node size and human papillomavirus

Objectives: To identify predictive factors for the presence of viable tumor and outcome in head and neck cancer patients who undergo therapeutic salvage neck dissections.

Materials and Methods: Retrospective analysis of 76 salvage neck dissections after radiotherapy alone (n = 22), radiotherapy in combination with carboplatin/5-fluorouracil (n = 42) or with cetuximab (n = 12).

Results: Viable tumor was detected in 41% of all neck dissections. Univariate analysis revealed initial treatment with radiotherapy without systemic therapy (OR 6.93, 95%CI: 2.28-21.07, p <.001), increased lymph node size after initial treatment compared to pretreatment CT scan (OR 20.48, 95%CI: 2.46-170.73, p =. 005), more extensive neck dissections (OR 8.40, 95%CI: 2.94-23.98, p <.001), and human papillomavirus negative cancer (OR 4.22, 95%CI: 1.10-16.22, p =. 036) as predictors of viable tumor. Patients with decreased or stable, but persistently enlarged lymph node size after chemoradiation had a significantly lower chance of viable tumor (OR 0.15, 95%CI: 0.05-0.41, p <.001). Disease-specific 5-year survival was 34% in case of viable tumor, and 78% when no viable tumor was found (p <.001).

Conclusions: Viable tumor in salvage neck dissections is associated with reduced survival. Radiotherapy alone, human papillomavirus negative cancer and increase in lymph node size, are associated with viable tumor in salvage neck dissections. In case of decreased or stable lymph node size after chemoradiation, watchful waiting could be considered.