[Squamous cell carcinoma of cervical lymph nodes from an unknown primary site: a retrospective analysis of treatment strategies and prognosis].

Objective: To analyze the treatment strategies and prognosis of squamous cell carcinoma of cervical lymph nodes from an unknown primary site (SCCUP).

Methods: A total of 125 cases with SCCUP was retrospectively analyzed from January 2001 to December 2011. Ninety-seven of the cases were treated with neck dissection (ND), including 24 with classic radical ND, 62 with modified ND and 11 with extended radical ND. Of 125 cases with SCCUP, 72 cases were supplemented with radiotherapy and 52 cases with chemotherapy. Radiotherapy was applied with extensive field in 36 cases, bilateral neck in 15 cases, and ipsilateral neck in 21 cases. The patients were followed up and the Kaplan-Meier method was used to calculate survival curves. Cox's analysis and logistic regression were used to evaluate the prognosis factors for SCCUP.

Results: The 5-year overall survival rate and disease free survival rate of the cohort were 66.2% and 60.0%, respectively. The median survival time was 70 months. Cox's analysis showed N-stage, extracapsular spread, bilateral neck metastasis and ND were independent prognostic factors for SCCUP. Logistic regression suggested that N-stage was the main factor for nodal recurrence or uncontrolled. The primary tumor sites emerged in 27 patients (21.6%) within 3 - 96 months after treatment (median time was 15 months), but only 4 patients (11.1%) existed in 36 cases underwent radiotherapy with extensive field.

Conclusions: N-stage and extracapsular spread are two major factors influencing the prognosis of SCCUP. ND may improve the locoregional control and long-term survival.