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Reprinted by permission of Laryngoscope. 2016; 126(1):9-10.

The Laryngoscope V C 2015 The American Laryngological, Rhinological and Otological Society, Inc.

What is the Role of Sentinel Lymph Node Biopsy in Early-Stage Oral Cavity Carcinoma?

Vikas Mehta, MD, MPH, FACS; Cherie-Ann Nathan, MD, FACS

BACKGROUND Lymphatic spread in oral cavity squamous cell car- cinoma (OSCC) remains a critical factor for staging, treatment, and prognosis. Involvement of the regional lymphatics portends approximately 50% decrease in sur- vival. OSCC–cervical metastases remain common. Due to the inaccuracy of the physical exam and imaging to reliably detect occult disease, elective neck dissections (ENDs) have become the standard of care for the major- ity of clinically node-negative (cN0) patients. However, many patients (55%–76%) 1–3 with T1/2 cN0 OSCC dis- ease will not have pathologically positive cervical metas- tases, and are being subjected to overtreatment with unnecessary morbidity by an END. Sentinel lymph node biopsy (SLNB) has emerged as a powerful tool for advancing minimally invasive surgical management of many cancers. SLNB has been proven to be highly sensi- tive, cost-effective, and beneficial to patient quality of life. The data supporting the use of SLNB in early-stage OSCC, a brief description of the SLNB method, and recent technical advances are the focus of this article. LITERATURE REVIEW A prospective multi-institutional trial was con- ducted with 25 institutions and 34 surgeons. 1 The study enrolled patients with newly diagnosed T1/T2 cN0 OSCC over 3 years. All patients underwent SLNB dur- ing the primary resection followed by END. Of the 140 eligible patients, there were 52 T1 (37.1%) and 88 T2 lesions (62.9%). Forty-one patients (29%) had positive nodes after sentinel lymph node (SLN) sectioning and From the Department of Otolaryngology/Head and Neck Surgery, Louisiana State University Health–Shreveport, Shreveport, Louisiana, U.S.A. Editor’s Note: This Manuscript was accepted for publication July 6, 2015. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Vikas Mehta, MD, Co-Director of Head and Neck Surgical Oncology, Feist-Weiller Cancer Center, 1501 Kings Highway, Rm 9-203, Shreveport, LA 71130. E-mail: dr.vikasmehta@gmail.com

immunohistochemistry (IHC), with 21 having the SLN as the sole positive node. Of the 106 negative SLNBs, 100 were classified as truly negative on final pathology of the neck dissection (ND) specimen, which corre- sponded to a 0.94 negative predictive value (NPV) (95% confidence interval [CI]: 0.88-0.98). Step-sectioning and IHC increased the NPV to 0.96, with T1 and T2 lesions having an NPV of 1.0 and 0.94, respectively. The false- negative rate (FNR) was 9.8% overall (four false nega- tives out of 41 positives, Table I). With an overall NPV of 0.96 in a population of 30% with metastatic disease, a negative SLNB would thus demonstrate a regional recurrence in only 4% of patients. Of the 140 patients, 100 could have been spared END. A recent meta-analysis of 26 studies looking at SLNB for head and neck cancer combined 593 early- stage (T1/2) OSCC patients who had undergone SLNB and a concurrent END. 3 The SLNB was positive in 177 patients (29.8%) and true negative in 408 patients (68.8%). The overall sensitivity and NPV of SLNB in the OSCC cohort were 94% (95% CI: 89–98%) and 96% (95% CI: 93–99%), respectively (Table I). This included an additional 38 OSCC patients with T3/4 patients (n 5 631). There were only 12 patients ( < 2%) misclassi- fied as N0 on SLNB who had a positive concurrent END, with eight patients having early T1/T2 oral cavity tumors and four patients with T3/T4 OSCC. A separate analysis was done that included five studies, which examined regional recurrence in oral cavity and oropha- ryngeal SCC patients who did not receive END following negative SLNB. There were 11 documented regional recurrences from 200 total patients (5.5%) with a follow- up of 2 years. Once a positive SLN is identified, the finding has both therapeutic and prognostic implications. A retro- spective study of 109 cT1/T2 N0 OSCC patients with positive SLNB from 15 centers was conducted. 4 All patients had subsequently undergone ND at the time of the SLNB or within 3 weeks (I–III, 13%; I–IV, 23%; I–V, 64%) for a total of 122 ND specimens with additional ( 1 non-SLN) metastases in 42/122 (34.4%). In those patients with 1 non-SLN, 18/42 patients (42.9%) had

DOI: 10.1002/lary.25541

Laryngoscope 126: January 2016

Mehta and Nathan: SNLB in Early-Stage Oral Cavity Carcinoma

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