Objective: To study lateral pelvic metastasis and micrometastasis of low rectal cancer and elucidate their prognostic value.
Methods: Whole-mount slice and tissue microarray of dissected lateral pelvic specimen from 67 cases of low rectal cancer were examined, and the included cases were followed up.
Results: Twelve specimens were diagnosed as lateral metastasis, while another 10 were proved to bear micrometastasis. Most of the involved metastatic lymph nodes (82.9%) were smaller than 5 mm in diameter. Internal iliac, obturator regions and middle rectal root were more likely to be involved by tumors. Patients with lateral metastasis suffered more recurrence and poorer survival.
Conclusions: Lateral pelvic metastasis could be observed in low rectal cancer and its incidence differed among lateral pelvic regions. Patients with lateral spread predisposed poor prognosis, thus underlies the value of pre/postoperative adjuvant therapy.