Preoperative versus postoperative chemoradiotherapy in stage T3, N0 rectal cancer

The study populations of previous preoperative chemoradiotherapy (pre-CRT) studies have consisted of mixed clinical stages, such as cT3-cT4 and/or cN positive. For this reason, it has not been possible to demonstrate whether pre-CRT is of benefit for individual subgroups.

The medical records of 137 rectal cancer patients with clinical stage T3, N0 disease who received either pre-CRT or postoperative chemoradiotherapy (post-CRT) between 2002 and 2011 were retrospectively analyzed. The regimen of pre-CRT consisted of slow fluorouracil (5FU) infusion and that of post-CRT consisted of bolus 5FU and leucovorin concurrent with radiation.

Following pre-CRT, significant downstaging was achieved. However, administration of pre-CRT did not influence the type of surgical resection in tumours ≤5 cm distant from the anal verge (p = 0.14). Pathological complete response was achieved in 16 % of the patients in the pre-CRT group. The local recurrence rate (LRR) at 5 years was 5.7 % in the pre-CRT and 11.1 % in the post-CRT groups (p = 0.04). The distant recurrence rate (DRR) at 5 years was 76 % and 77 % in the pre-CRT and post-CRT groups, respectively (p = 0.1). Overall survival was similar in two groups (74.8 % vs. 75.3 %, p = 0.3).

The treatment of stage T3, N0 rectal cancer patients with pre-CRT followed by surgery decreased LRR, but did not improve DRR or OS as compared with surgery followed by post-CRT in our patient cohort.