Background: Pelvic oligo-recurrence is common in rectal cancer patients, and some could not achieve radical resection.
Objective: The study was to analyze long-term outcomes and prognostic factors associated with survival in patients treated with intensity-modulated radiation therapy (IMRT).
Methods: Study participants were identified from rectal patients with pelvic oligo-recurrence without distant metastases, who were not suitable for surgery (n=135). Patients were recommended to receive concurrent chemotherapy in the course of IMRT (median dose 64.5 Gy, range: 45-70 Gy). Additionally, 24.4% (33/135) of patients received radical surgery after preoperative radiotherapy. Median time to pelvic failure was 25.4 months (range: 1-144 months). With a median follow-up period of 45.5 months (range: 3-104 months), 5-year overall survival (OS) and disease-free survival (DFS) were 55.6% and 45.5%, respectively.
Results: In univariate survival analysis, OS stratified by subsites indicated that 5-year OS for anastomotic recurrence (80.5%) was better than for anterior recurrence (57.7%) and other pelvic oligo-recurrences (44.5%) (P=0.005). Five-year DFS in the three groups was 60.3%, 49% and 36.6%, respectively (P=0.037). In multivariate survival analysis, pelvic oligo-recurrence and symptomatic recurrence patterns were independently associated with OS in recurrent rectal cancer after pelvic radiotherapy (RT).
Conclusions: These results indicate that RT for rectal cancer patients with pelvic oligo-recurrence had favorable prognosis, especially for patients with anastomotic recurrence.
Keywords: Rectal cancer; intensity-modulated radiation therapy; pelvic oligo-recurrence.