A Cochrane review [Abstract] 1 included 19 studies. Overall (OA) mortality was marginally improved by PRT, HR 0.93 [95% CI -0.87-1](absolute difference is 2% if the expected survival rate is 60%). Local recurrence (LR) was improved but the magnitude of benefit was heterogeneous across trials. Sensitivity analyses suggested greater benefits in patients treated with BED>30Gy10 and multiple field RT techniques. There was significantly more pelvic or perineal wound infection, late rectal and sexual dysfunction.
Nine trials compared PRT vs. other NA/A. Available evidence did not support an OA mortality or sphincter preserving benefit with the use of combined chemoradiotherapy (CRT) or selective postoperative RT. CRT provides incremental benefit for local control compared with PRT, which was independent of the timing of the CT. There was no significant difference in outcome for different intervals between RT and surgery (2 vs. 8 wk). Dose escalation with endocavitary boost showed significant effect on sphincter preservation.
Comment: The study quality is downgraded by indirectness; differences in studied interventions in time and in techniques.
Primary/Secondary Keywords