Sentinel node navigation surgery for lower rectal cancer.

BACKGROUND: Lateral pelvic lymph node metastasis is generally present in 17% of patients with T3 lower rectal cancer. However, such lymph node metastases cannot be accurately detected before surgery. Since 2001, we have performed sentinel node navigation surgery for patients with T3 lower rectal cancer considering the lymph nodes located between the vesicohypogastric fascia and the pelvic nerve plexus as the lateral sentinel lymph node (LSN).

PATIENTS AND METHODS: Between 2001 and 2010, 101 patients with T3 lower rectal cancer without distant metastasis or peritoneal dissemination were prospectively enrolled in the study. Patients with negative lymph nodes in the mesorectum underwent only LSN dissection in the lateral pelvic space. Patients with metastatic lymph nodes detected in the mesorectum underwent lateral pelvic lymph node dissection (LPLD).

RESULTS: Fifty-three out of the 101 patients with pathologically-negative lymph nodes in the mesorectum and a negative LSN were clinically judged as having stage II disease because no recurrence was detected in the lateral pelvic space during the three years following surgery. The other 48 patients underwent LPLD because of a positive lymph node in the mesorectum, and were further divided into two sub-groups, 40 with a negative and 8 with a positive LSN. Only the eight patients with a positive LSN also had positive lymph nodes in the lateral pelvic space.

CONCLUSION: Patients with T3 lower rectal cancer in stage III may not require LPLD. LSN may be very useful to determine stage II disease during surgery.