Sentinel lymph node biopsy in high-risk cutaneous squamous cell carcinoma of the head and neck

Cutaneous squamous cell carcinoma (cSCC) shows malignant behaviour in 3-4% of patients with locoregional metastases and a poor prognosis, metastases that are difficult to predict clinically. Therefore, sentinel lymph node biopsy (SLNB) has been assessed, with contradictory findings thus far. We aimed to clarify the prognostic value of SLNB in high-risk cSCC patients.

We completed a retrospective clinical study amongst 63 patients, preoperatively classified as N0 with a high-risk primary cSCC of the head and neck who underwent SLNB between 2001 and 2014 at Helsinki University Hospital (Finland). Considered high risk, the inclusion criteria comprised at least two of the following characteristics: tumour diameter ≥10 mm and/or thickness ≥4 mm and a specific tumour location, such as the lips, ear, scalp and central face. Patients were followed-up postoperatively for a median of 4.1 years (0.2-13.8 years).

Only four (6.3%) patients had positive sentinel nodes. One of these patients died of cSCC, while the other three ultimately survived their disease. Five (7.9%) patients showed a negative SLNB, but developed recurrence within one year postoperatively. Recurrence appeared in the neck lymph nodes concurrently with locoregional soft-tissue invasion in all patients. Amongst these patients, three died for cSCC and the remaining two from other causes. Comparing the SLNB-positive and SLNB-negative groups with recurrence, we identified no significant differences in terms of patient or tumour characteristics.

SLNB appears to carry no prognostic value for identifying recurrent disease amongst high-risk cSCC in the head and neck area.