Curative chemoradiotherapy for isolated retroperitoneal lymph node recurrence of colorectal cancer

Purpose: To investigate the efficacy of curative chemoradiotherapy for isolated retroperitoneal lymph node recurrence of colorectal cancer.

Materials and methods: Twenty-two colorectal cancer patients who received three-dimensional conformal radiotherapy (n=20) or helical tomotherapy (n=2) for isolated retroperitoneal lymph node recurrence were analyzed retrospectively. Radiation dose was 55.8Gy in 31 fractions or 63Gy in 35 fractions, and 60Gy in 20 fractions by helical tomotherapy. All patients received concurrent chemotherapy and 16 (72.7%) received adjuvant chemotherapy.

Results: The treatment response was complete in 13 (59.1%), partial in 6 (27.3%), and stable in 3 (13.6%) patients. Median follow-up for 11 (50%) surviving patients was 32 months (range, 27-61). The 3- and 5-year overall survival rates were 64.7% and 36.4%, and median overall survival was 41 months. Recurrences developed in 15 (68.2%) patients; outside the retroperitoneum in 13. The 3- and 5-year recurrence-free survival rates were 34.1% and 25.6%, and median recurrence-free survival was 20 months. Response and adjuvant chemotherapy were significant prognostic factors for overall survival. Gastrointestinal toxicity ≥ Grade 3 was not observed.

Conclusions: Definitive chemoradiotherapy is an effective salvage treatment for isolated retroperitoneal lymph node recurrence of colorectal cancer without severe complications.