Sentinel lymph node biopsy and risk factors for predicting metastasis in cutaneous squamous cell carcinoma

Background Cutaneous squamous cell carcinoma (cSCC) is a common cancer capable of metastasis. Sentinel lymph node biopsy (SLNB) may be a valuable adjunct for patients with cSCC at high risk for metastasis. However, data on risk factors for metastasis and results of SLNB from patients with cSCC are limited. Objectives To evaluate risk factors for metastasis in patients with cSCC in a large cohort study with long-term follow-up and to determine the value of SLNB. Methods We retrospectively analysed all records of patients who underwent excision of cSCC between January 2005 and August 2009 at a tertiary referral centre. In total, 143 patients were included in the cohort, including 17 patients with SLNB and a follow-up time of >= 24 months. Results Tumour thickness > 4 mm and recurrent cSCC were strongly associated with metastatic disease. All metastases in this cohort occurred within 24 months of follow-up. SLNB showed a low sensitivity with regard to the development of metastasis. Six of 17 patients developed metastatic disease despite a negative SLNB. Conclusions Patients with risk factors (cSCC with a tumour thickness > 4 mm or recurrent disease) may develop metastases within the first 2 years despite a negative SLNB. Therefore these patients should be closely monitored during the follow-up. Based on our data SLNB does not provide diagnostic value for patients with cSCC.