The authors performed a specific analysis of the clinical significance of inguinal lymph nodes metastases in patients with anal canal carcinoma (ACC).

A retrospective analysis was conducted of 270 patients who were treated in Lyon between 1980 and 1996 with radiotherapy with curative intent for ACC: No elective irradiation of clinically normal inguinal areas was performed. Patients with metastatic inguinal lymph nodes were treated with inguinal dissection and postoperative irradiation with a dose of 50 grays over 5 weeks. Concomitant chemoradiation, usually with a regimen of fluorouracil and cisplatinum, was given to 159 patients.

The median follow-up for the whole series was 72 months. Synchronous inguinal metastases were observed in 10% of patients (n = 27; the rate was 16% for patients with T3--T4 lesions), and the 5-year overall survival rate was 54.4%. Metachronous inguinal metastases were seen in 19 patients (7.8%), and the 5-year overall survival rate of these patients was 41.4%. An original finding was that, when the primary tumor clearly was located on a single lateral side of the anal canal, the inguinal lymphatic metastases was always homolateral to it (36 of 36 synchronous plus metachronous tumors).

The data from this series of patients and a review of the literature are in favor of a selective approach in the management of inguinal lymph node involvement for patients with ACC, depending on the disease stage and the location of the primary tumors.