Sentinel event.

Top Line: Does sentinel node biopsy for early stage oral cavity cancer maintain disease control outcomes while reducing post-op toxicity?

The Study: Elective neck dissection (ND) improves survival for patients with clinically node negative oral cavity squamous cell carcinoma - 30% of patients have occult nodal disease and 45% fail in the neck without dissection. But could sentinel node biopsy (SNB) provide the same benefit with less toxicity? In 2020, the Senti-MERORL trial showed that SNB-guided neck dissection (i.e. neck dissection if SNB positive) was non-inferior to full neck dissection for both detection of occult mets and neck recurrence rate. This randomized, multicenter Japanese trial asks the same question in 271 patients with T1-2 N0 oral squamous cell carcinoma (>80% tongue, >80% T2). They were randomized to up-front supraomohyoid ND or SNB-directed ND. The latter was performed with radiotracer and lymphoscintigraphy. Immediate frozen sections were obtained, and if positive an immediate ND was performed. Of note, isolated tumor cells were considered positive. Adjuvant radiation was delivered for extranodal extension or positive margins. There was no significant difference in the rate of nodal mets, however positive nodes were identified in 25% of those who had neck dissection compared to 34% of those who had SNB. In the SNB group, 24% had nodal mets identified on frozen section while another 10% had mets (mostly ITCs and micromets) identified on final path. There was no significant difference in 3-year disease-free or overall survival. There was also no difference in the rate or distribution of disease recurrence. Neck symptoms and functionality were better in the SNB group than the ND group. NRG HN006 remains open in this space to further answer this question.

TBL: Disease and survival outcomes appear similar and neck toxicity is less when sentinel node biopsy is used to guide neck dissection for early stage oral cavity cancer. | Hasegawa, J Clin Oncol 2021