[The technique of sentinel lymph nodes in patients with anus neoplasm]

Anal cancer is a rare neoplasm, representing 1-2% of all large bowel cancers. Surgical excision by abdominoperineal resection has been the standard treatment. In the 1920s and 1930s inguinal node dissection was included in the surgical management of these patients. In the 1950s it was evident that the morbidity associated with lymphnode dissection was much greater than any survival benefit and this procedure was abandoned. Since 1974 "multimodality treatment" with a combination of radiation and chemotherapy has become the standard treatment. Synchronous inguinal lymph node metastases occur in 10-25% of patients and metachronous metastases have been reported in 5-25% of cases. Inguinal lymph node metastases are an independent prognostic factor for local failure and overall mortality by a multivariate analysis of EORTC. In order to assess inguinal lymph node status we applied the sentinel node technique to patients affected by anal cancer. Fifteen patients were studied with a lymphoscintigraphy after peritumoral injection of 37 MBq of Tc-99m colloid. A surgical biopsy of sentinel node was performed in all patients with a detection rate of 100%. Inguinal metastases occurred in 4 patients (26.6%), and in 2 cases metastases were located bilaterally. Twelve patients (80%) were treated in local anesthesia and they were dismissed the same day of surgical procedure. No major complication occurred. Considering the strong correlation between prognosis and node involvement, we consider this technique an important and simple method for evaluating the lymph node status and for an adequate pre-treatment staging of anal carcinoma. fundamental in the choice of radiation plane. In particular inguinal radiotherapy could be reserved for N1 patients only. avoiding the morbidity related to this procedure in N0 patients. Further studies are required to confirm these results and a consistent follow-up will be necessary to evaluate long-term results particularly in those patients (N0) who have not been treated with prophylactic inguinal radiotherapy.