Comparison between intensified neoadjuvant treatment and standard preoperative chemoradiation for rectal cancer.

Objectives: The aim of the current study was to compare a neoadjuvant regimen containing oxaliplatin with standard preoperative treatment for rectal cancer.

Methods: From December 2006 to December 2007, 20 patients with rectal cancer were treated at our Institution with the weekly addition of oxaliplatin (50 mg/m(2)) to radiotherapy (50.4-54.0 Gy in 28-30 daily fractions) and continuous infusion of 5-fluorouracil (200 mg/m(2)). The results of the regimen were compared with a historical control group including 21 consecutive patients previously treated with standard 5-fluorouracil treatment from December 2004 to October 2006.

Results: Both the rate of sphincter preservation in low rectal cancer (91.7% vs 36.4%, P = 0.009) and the rate of downstaging (84.2% vs 47.6%, P = 0.023) were higher in the oxaliplatin group than in the control group. Pathological complete response was achieved in 8 patients (42.1%) in the oxaliplatin group and in 4 patients (19.0%) in the control group (P = 0.172). When ypT0-pT1 stages were analyzed together, the P value was 0.051. Acute toxicity was increased in the oxaliplatin group, with a higher incidence of G3 diarrhea and pelvic pain than in the control group (30.0% vs 14.3%, P = NS).

Conclusions: Our data seem to correlate the addition of oxaliplatin to the standard treatment for rectal cancer with higher rates of sphincter preservation, down-staging and complete response. Toxicity is increased and requires careful monitoring. However, our results refer to a retrospective comparison of a small series of patients and need to be validated by the large, phase III randomized trial currently ongoing.