Influence of postoperative radiotherapy target volumes in unilateral head and neck carcinoma of unknown primary: A multicentric study using propensity score.

OBJECTIVE: To compare the impact of two radiation modalities on loco-regional control, survival and tumour emergence, after node dissection for an unilateral head and neck carcinoma of unknown primary (HNCUP). MATERIALS AND METHODS: This is a multicentric retrospective study of 138 patients with unilateral HNCUP treated between 2002 and 2017. The absence of primary tumour was assessed by a systematic panendoscopy and positron emission tomography. Neck dissection was initially performed for all patients. Radiation Therapy was delivered on ipsilateral lymph node areas in 62 cases (44%: UL-RT group) and on bilateral lymph node areas and the entire pharyngeal mucosa in 77 cases (56%: COMP-RT group). Impact of radiation modalities on locoregional control and overall survival was assessed using propensity score matching method in order to balance baseline characteristics between the two groups. RESULTS: The population included 80.4% men, 80.4% smokers, 32.6% P16 positive tumours and 71.0% extracapsular extension. After a median follow-up of 5 years, the locoregional control rate was 80.3% in the UL-RT group and 75.3% in the COMP-RT group (p = 0.688). The corresponding rate of contralateral lymph node recurrence was 0% versus 2.6% (p = 0.503) and the rate of tumour emergence was 11.5% versus 9.1% (p = 0.778). No significant difference was observed between the UL-RT and the COMP-RT groups for overall survival (p = 0.9516), specific survival (p = 0.4837) or tumour emergence (p = 0.9034). CONCLUSION: UL-RT seems to provide similar outcomes as COMP-RT in unilateral HNCUP post-operative management.

Management of unilateral head and neck carcinoma of unknown primary: Retrospective analysis of the impact of postoperative radiotherapy target volumes.

BACKGROUND: We compared the outcome of postoperative unilateral cervical nodes radiotherapy (UL-RT) vs bilateral cervical nodes plus total mucosal irradiation (COMP-RT) in the management of head and neck carcinoma of unknown primary (HNCUP). METHODS: HNCUP, defined by the absence of primary despite a PET-CT combined with a panendoscopy, were treated with curative intent by initial ipsilateral neck dissection. Sixty-nine patients with unilateral HNCUP were included: 23 received UL-RT while 46 received COMP-RT. Carcinologic outcomes and long-term quality of life (QOL) according to the QOL Questionnaire for Head and Neck 35 were assessed. RESULTS: Within 6.3 years of median follow-up, there was no significant difference in primary tumor emergence rate (P = .68), cervical node recurrence rate (P = .34), or overall survival (P = .33) between UL-RT and COMP-RT groups. A trend toward QOL improvement was observed in the UL-RT group. CONCLUSION: UL-RT seems to provide similar outcomes as COMP-RT in unilateral HNCUP management.