OBJECTIVETo study the patterns and prognostic value of resection margin involvement and lateral pelvic metastases, providing surgeons with pathologic proofs of tumor spread within the studied areas.

METHODSLarge tissue slices of 62 specimens from patients with rectal cancer were used in the pathologic study and the outcomes were followed.

RESULTSCompared with patients without margin involvement, patients with circumferential margin involvement (CMI), seen in 8 cases (12.9%), had poorer postoperative survival (P=0.003). The 12 patients (19.4%) with lateral pelvic metastases suffered poorer survival, compared with those without lateral pelvic metastases (P=0.026). Eight patients (66.7%) were diagnosed to have single lateral pelvic region involved, while the other 4 had multiple regions involved. The incidence of lateral metastases differed among regions, with higher occurrence in the root of middle rectal artery (6/12, 50.0%), area of the internal iliac artery (4/12, 33.3%) and the obturator region (3/12, 25.0%).

CONCLUSIONOccurrence of CMI or lateral metastases in rectal cancer patients predispose poor survival, thus a more radical clearance and postoperative adjuvant therapy are recommended.