Salvage neck dissection after primary radiochemotherapy in HPV-positive and HPV-negative oropharyngeal cancer

Introduction:

Human papillomavirus (HPV)-positive and -negative oropharyngeal cancers (OPC) are separate tumor entities. The aim of this study was to examine if the occurrence of malignant nodes varies for HPV-positive and -negative carcinomas after salvage neck dissection (SND), if that leads to different therapeutical options and if a salvage neck dissection is generally justified for OPC after primary radiochemotherapy (pRCT).

Methods:

Retrospective study of 175 patients who underwent pRCT for OPC between 2009 and 2016. 46 patients were HPV-positive (26.3%), 87 patients HPV-negative (49.7%) and for 42 patients the HPV-status was unknown (24%). A SND was performed for 13 (28.3%) HPV-positive carcinomas, 16 (18.4%) HPV-negative carcinomas and 5 (11.9%) carcinomas with unknown HPV-status. The clinical nodal status was assessed using ultrasound and in most cases an additional computed tomography of the neck with contrast.

Results:

No significant association between the HPV-status and the indication for SND could be found (p = 0.13). Additionally, no significant association between the HPV-status and the occurrence of malignant nodes could be shown (p = 0.45). The probability for the persistence of the ypN+ nodal status independent of the HPV-status was 29.4%.

Conclusions:

Although HPV-positive cancer generally shows a higher radiosensibility, a significant association between the HPV-status and the indication for a SND as well as for persistent malignant nodes after pRCT could not be found. Consequently, a positive HPV-status does not justify a de-escalation regarding the SND. The performance of a SND is generally recommended for patients with OPC as the probability for malignancy is 29.4%.