Cancer of unknown primary: does treatment modality make a difference?

Abstract

Objectives/hypothesis: We systematically reviewed the published experience on the treatment outcomes of patients with head and neck cancer of unknown primary (CUP) to determine if treatment modality affects survival outcomes.

Study design: Meta-analysis.

Methods: A comprehensive literature search was performed for articles reporting survival outcomes for CUP in the head and neck published within the last 12 years.

Results: Eighteen studies with 1,726 patients met the inclusion criteria. All studies reported at least 5-year survival outcomes. Thirteen of the 18 studies also reported 5-year survival based on N stage, and six reported 5-year survival based on presence of extracapsular extension (EC). Overall 5-year survival in the entire group was 48.6%. Five-year survival based on N stage was as follows: N1 = 60.8%, all N2 = 51.1%, N2a = 63.6%, N2b = 42.5%, N2c = 37.5%, and N3 = 26.3%, with P < .001 on multivariate analysis. Patients who underwent surgical treatment with either postoperative radiation or chemoradiation had a 5-year survival of 52.4% compared to 46.6% for those treated with chemoradiation alone; however, this difference was not statistically significant. Patients with EC had a 5-year disease-specific survival of 56.9% compared to 81.5% for those without EC (P = .01).

Conclusions: In patients with CUP, survival outcomes are most significantly influenced by clinical stage at time of diagnosis. No significant 5-year survival difference was seen between patients treated with radiation or chemoradiation alone when compared to patients who also received surgical treatment.