Published online Apr 21, 2014. doi: 10.3748/wjg.v20.i15.4256
Revised: November 11, 2013
Accepted: January 14, 2014
Published online: April 21, 2014
The current standard treatment of low-lying locally advanced rectal cancer consists of chemoradiation followed by radical surgery. The interval between chemoradiation and surgery varied for many years until the 1999 Lyon R90-01 trial which compared the effects of a short (2-wk) and long (6-wk) interval. Results showed a better clinical tumor response (71.7% vs 53.1%) and higher rate of positive and pathologic tumor regression (26% vs 10.3%) after the longer interval. Accordingly, a 6-wk interval between chemoradiation and surgery was set to balance the oncological results with the surgical complexity. However, several recent retrospective studies reported that prolonging the interval beyond 8 or even 12 wk may lead to significantly higher rates of tumor downstaging and pathologic complete response. This in turn, according to some reports, may improve overall and disease-free survival, without increasing the surgical difficulty or complications. This work reviews the data on the effect of different intervals, derived mostly from retrospective analyses using a wide variation of treatment protocols. Prospective randomized trials are currently ongoing.
Core tip: The traditional 6-wk interval between chemoradiation and surgery in the treatment of rectal cancer was based primarily on a single publication. There has been a trend in recent years to prolong this interval based on studies showing that it may be advantageous in terms of tumor downstaging and pathologic complete response, without increasing surgical difficulty or complications. The data so far are derived largely from retrospective studies using a wide variation of treatments. Further investigations with a higher level of evidence are required to definitively resolve this issue.