Limited Value of Staging Squamous Cell Carcinoma of the Anal Margin and Canal Using the Sentinel Lymph Node Procedure: A Prospective Study with Long-Term Follow-Up

Abstract

BackgroundSelection of patients with anal cancer for groin irradiation is based on tumor size, palpation, ultrasound, and fine needle cytology. Current staging of anal cancer may result in undertreatment in small tumors and overtreatment of large tumors. This study reports the feasibility of the sentinel lymph node biopsy (SLNB) in patients with anal cancer and whether this improves the selection for inguinal radiotherapy.MethodsA total of 50 patients with squamous anal cancer were evaluated prospectively. Patients without a SLNB (n = 29) received irradiation of the inguinal lymph nodes based on lymph node status, tumor size, and location of the primary tumor. Inguinal irradiation treatment in patients with a SLNB was based on the presence of metastases in the SLN.ResultsSLNs were found in all 21 patients who underwent a SLNB. There were 5 patients (24%) who had complications after SLNB and 7 patients (33%) who had a positive SLN and received inguinal irradiation. However, 2 patients with a tumor-free SLN and no inguinal irradiation developed lymph node metastases after 12 and 24 months, respectively.ConclusionsWe conclude that SLNB in anal cancer is technically feasible. SLNB can identify those patients who would benefit from refrain of inguinal irradiation treatment and thereby reducing the incidence of unnecessary inguinal radiotherapy. However, because of the occurrence of inguinal lymph node metastases after a tumor-negative SLNB, introduction of this procedure as standard of care in all patients with anal carcinoma should be done with caution to avoid undertreatment of patient who otherwise would benefit from inguinal radiotherapy.

Value of staging squamous cell carcinoma of the anal margin and canal using the sentinel lymph node procedure: an update of the series and a review of the literature

“…To better diagnose inguinal MTS, in recent years, SLNB has proven to be a safe and an effective technique (Spratt, 2000; Keshtgar et al , 2001; Vajda et al , 2001; Mistrangelo et al , 2002; Peley et al , 2002; Rabbit et al , 2002; Bobin et al , 2003; Damin et al , 2003; Ulmer et al , 2003; Castro et al , 2005; Damin et al , 2006; Gretschel et al , 2008; Mariani et al , 2008; Mistrangelo et al , 2009a; De Jong et al , 2010; Hirche et al , 2010; De Nardi et al , 2011). …”

“…Therefore, in 2010, De Jong et al (2010) reported a limited value of staging squamous cell carcinoma of the anal margin and canal using the sentinel node procedure in a prospective study with long-term follow up. The authors conclude that, because of the occurrence of inguinal lymph node MTS after a tumour-negative SLNB, the introduction of this procedure as a standard of care in all patients with anal carcinoma should be done with caution to avoid undertreatment of patients who otherwise would benefit from inguinal radiotherapy.…”

Cancers of the Anal Canal: Diagnosis, Treatment and Future Strategies

“…The draining sentinel nodes have been detectable in 66-100% of cases [57]. Lymph node metastases are found in 7.1-42% of patients [57,58] with false-negative rates of 3.7% [58,59].…”

Le ganglion sentinelle dans la prise en charge du carcinome du canal anal. Où en sommes-nous en 2011 ?

“…En effet, à ce jour, un nombre limité de séries comportant de faibles effectifs de malades a été publié (193 cas au total) alors que la technique a commencé à se développer en 2002 [1][2][3][4][5][6][7][8][9]. Les résultats de ces séries sont résumés dans le tableau 1.…”