OP128: Differences in management of neck metastases of unknown primary origin in two european centres: Consequences for future strategies

Abstract

Purpose Analysis of diagnostic and therapeutic management of neck metastasis of unknown primary origin (“true”-CUP) in two European tertiary referral centers (University Medical Centers of Maastricht and Cologne), and the presence of human papillomavirus (HPV) in this population. Materials and methods Retrospective analysis of 29 (Maastricht) and 22 (Cologne) “true”-CUP-patients (squamous cell carcinoma) for which an intended curative neck dissection was performed. The diagnostic and therapeutic approach were correlated with clinical follow-up data and HPV-status. Results In Maastricht, PET-CT (whole body) was performed since 2002, whereas in Cologne FDG-PET without CT was routinely performed since 2006 next to CT and ultrasound of the abdomen and skeletal scintigraphy, however with no additional information regarding tumor spreading. Oncogenic HPV was found exclusively in 18% of CUPs from Cologne (18 vs. 0%, p = 0.017). However, no differences were noted for recurrent disease or survival compared to HPV-negative CUPs. In Maastricht, unilateral adjuvant radiotherapy of the neck without involvement of the pharyngeal axis was performed more often ( n = 22/29) compared to bilateral radiotherapy including the pharyngeal axis ( n = 20/22) and combined with chemotherapy in Cologne ( n = 8/22). No primary tumors arose during five years of follow-up in Maastricht or Cologne. CUPs from Maastricht more frequently developed contralateral regional recurrences (5 vs. 0 patients: log rank p p = 0.099). The five-year-overall survival did not differ significantly. Conclusions The more extensive diagnostic approach (ultrasound/CT abdomen and skeletal scintigraphy) was not of additional value, neither did HPV-status contribute on primary tumor location or survival. De-escalation of therapy by abandoning irradiation of the pharyngeal axis did not lead to diminished local control. Contralateral irradiation offers potential advantages for regional control, particularly in the pN2b- and pN3-group.