Reliability of sentinel lymph node biopsy with squamous cell carcinoma of the oral cavity

Although sentinel lymph node biopsy (SLNB) may reduce surgery-related complications related to unnecessary lymph node dissection and is now widely used for many patients with cutaneous melanoma and breast cancer, its use for oral cancer patients remains controversial. One of the main reasons for the reluctance to initiate SLNB for oral cancer is that the frequency of skip metastasis has not been clarified. The objectives of this study are to examine the frequency of skip metastasis and to evaluate SLNB for oral cancer.

To shed light on these concerns, we first conducted a retrospective study of 296 patients with squamous cell carcinoma of the oral cavity who underwent neck dissection. Next, the accuracy of lymph node biopsy with and without detecting sentinel lymph node was examined.

Ten patients showed skip neck metastasis in the level III-V region without level I-II involvement. Of these patients, 7 underwent neck dissection when their initially N0 neck progressed to N+, 2 underwent neck dissection when local recurrence occurred, and only 1 underwent surgery as an initial therapy. Most patients who underwent neck dissection as the initial therapy showed skip metastasis. Intraoperative lymph node biopsy without any attempt to detect sentinel lymph nodes by means of blue dye or lymphoscintigraphy was performed on 68 patients with oral cancer. Sixty-one (90%) were diagnosed correctly, whereas 7 diagnosed as N- actually had neck metastasis. SLNB with blue dye was performed on 21 patients. In 17 of them, sentinel lymph node was easily detected, resulting in a correct diagnosis for 16 patients (94%), while 1 with a false negative result actually had micrometastasis.

These findings seem to suggest that SLNB is useful and can be applied to patients with oral cancer who undergo surgery as the initial therapy.