Neck restaging with sentinel node biopsy in T1-T2N0 oral and oropharyngeal cancer: Why and how?

Objective: To evaluate the lack of accuracy in neck staging with the classical technique (i.e., neck dissection and routine histopathology) with the sentinel node (SN) biopsy in oral and oropharyngeal T1-T2N0 cancer.

Study Design: Cross-sectional study with planned data collection.

Setting: Tertiary center care.

Subjects And Methods: In 50 consecutive patients, the pathological stage of sentinel node (pSN) was established after analyzing SN biopsies (n = 148) using serial sectioning and immunohistochemistry. Systematic selective neck dissection was performed. The pN stage was established with routine histopathologic analysis of both the non-SN (n = 1075) and the 148 SN biopsies.

Results: The sensitivity and negative predictive value of pSN staging were 100 percent. Conversely, if one considers pSN staging procedure as the reference test for micro- and macro-metastasis diagnosis, the sensitivity of the classical pN staging procedure was 50 percent (9/1; 95% CI 26.9-73.1) and its negative predictive value was 78 percent (95% CI 61.9-88.8). Fifteen patients (30%) were upstaged, including nine cases from pN0 to pSN >or= 1 and six cases from pN1 to pSN2. Two of the pN0-pSN1 upstaged patients died with relapsed neck disease.

Conclusion: The SN biopsy technique appeared to be the best staging method in cN0 patients and provided evidence that routinely undiagnosed lymph node invasion may have clinical significance.