Background: Sentinel lymph node biopsy (SLNB) is well-established in breast cancer and melanoma surgery for staging and prognostication. However, data supporting the use of SLNB for non-melanoma skin cancers is sparse. Squamous cell carcinoma (SCC) of the lip is the most common head and neck cancer, with a considerable reduction in survival for patients who have regional nodal metastases.
History: Neck dissection is generally not performed in the absence of clinically suspicious cervical nodes for lip SCC. Primary lymphatic drainage for the lower lip is to submental and submandibular nodes, which has been thought to be associated with technical difficulties in performing SLNB.
Current Evidence: Current literature does include a few small (<50 patient) prospective trials of SLNB for T1-T2 N0 lip SCC, with results generally indicating sentinel node identification in ≥80% patients, with 7-26% SLNB positive rate. False negative rates and complications were reported to be low. However, a systematic review1 in 2014 concluded that current evidence was insufficient to justify elective treatment of the neck in clinically N0 lip SCC patients and that close observation is viable.
Conclusion: There is a small amount of emerging evidence which suggests considering SLNB for T1/T2 clinically node-negative lip SCC. Robust literature to support such a practice is currently lacking. However, it seems reasonable that SLNB may provide useful staging and prognostic information in such cases of lip SCC to better guide patient and clinician decision-making. Technical difficulties and resource availability may prove barriers to widespread implementation of the practice.