Outcome of patients with rectal adenocarcinoma and localized pelvic non-nodal metastatic foci

PURPOSE: The aim of this study was to evaluate the outcome of patients with primary rectal adenocarcinoma and soft tissue metastatic foci restricted to the pelvis and to determine whether this entity, which is considered N1 disease in the American Joint Committee on Cancer staging system, behaves like completely replaced nodal disease or the first sign of M1 disease. The clinical course for patients with this finding is not well-described in the literature. METHODS: The authors retrospectively reviewed the medical records of 395 patients with rectal adenocarcinoma who received radiation treatment. Eighteen patients had pelvic soft tissue metastatic foci. Exclusions from this study included 1) cases without metastatic pelvic foci; 2) cases of recurrent cancer; 3) cases with known distant metastatic disease as defined by American Joint Committee on Cancer criteria; and 4) cases with extrapelvic metastatic foci. All patients received adjuvant radiotherapy. Thirteen cases received preoperative radiotherapy. Four cases received postoperative radiotherapy. One case received both preoperative and postoperative radiotherapy. Eight cases received chemotherapy. RESULTS: All eighteen patients had T3 or T4 lesions. Thirteen patients had lymph nodes that contained metastatic disease and would therefore have been scored N1 or N2 even without the pelvic tumor implants. Sixteen of 18 (89 percent) patients died of disease after a survival time of 12 to 37 (mean, 25) months. Only 1 of 18 (6 percent) patients was disease free at five years. The other remaining survivor was undergoing palliative therapy for metastatic disease to the lung. This is significantly worse than our institution's experience with T3,4N+ disease after preoperative radiation (5-year survival, 11 vs. 56 percent; P = 0.0002, Generalized Wilcoxon of Breslow). There was a high incidence of local (9/18) and distant (14/18) failure. No other factor, including radiation dose, margin status, chemotherapy, T stage, and number of involved nodes or soft tissue implants, correlated independently with outcome. CONCLUSIONS: Pelvic metastatic foci confer a significantly worse prognosis than other T3,4N + disease. Such cases should be excluded from prospective trials for localized disease. Although this entity probably represents M1 disease for most patients, survival can be long, and aggressive locoregional and systemic treatment is warranted.