Management of inguinal lymph node metastases from adenocarcinoma of the rectum

Forty patients with inguinal lymph node metastases from rectal adenocarcinoma were reviewed. Patients were divided into three groups based on the extent of their disease: (1) patients with unresectable primary tumors; (2) patients with recurrent disease after abdominoperineal resection; and (3) patients with isolated inguinal lymph node metastases after abdominoperineal resection. Patients in Groups 1 and 2 underwent biopsy of their nodal metastases. Patients in Group 3 were treated by inguinal node dissection. Survival data were examined for each group, and four clinical and pathologic features were analyzed to determine their impact on prognosis: depth of invasion of the primary tumor (T1-2 vs. T3-4), number of positive lymph nodes in the rectal specimen (0-2vs. > 2), extent of the inguinal lymph node metastases (unilateral vs. bilateral), and timing of the inguinal lymph node metastases (<1 vs. >1 year after abdominoperineal resection). There were no five-year survivors in any group. Median survival was highest in those with isolated lymph node metastases, with 2 patients remaining free of disease, and was lowest in those with unresectable primary disease (7 months). Median survival was increased when inguinal LNM were unilateral (17 vs. 6 months; P < 0.01) and when they occurred more than 1 year after abdominoperineal resection (21 vs. 7 months; P=0.02). Stage of the primary lesion (depth of invasion and number of positive lymph nodes) did not affect survival. Of the 32 patients who underwent biopsy alone, only 1 developed a tumor-related groin complication. For patients with isolated inguinal lymph node metastases, inguinal node dissection is recommended for the purposes of local control and possible cure. For patients with extranodal disease, prophylactic excision of inguinal lymph node metastases is not warranted.