Abstract 245P
Background
Standard therapy for locally advanced rectal cancer includes concurrent chemoradiotherapy (CRT) followed by surgery and adjuvant chemotherapy. An alternative strategy - neoadjuvant intensified chemotherapy (NIC) involves administration of neoadjuvant chemotherapy (FOLFOX4) before surgery plus concomitant chemoradiation (in those only who did not achieve MRF (neg.)) with the goal of delivering optimized systemic therapy to eradicate micrometastases. A comparison of these 2 approaches was the aim of study.
Methods
This is a prospective single institution clinical trial. The study included patients with locally advanced stage II-III rectal cancer. Patients were randomized 1:1 for neoadjuvant concomitant CRT or NIC (FOLFOX4 regimen, a total of 8 cycles).
Results
142 patients (pts.) were included into the study. The median follow-up is 24 months. Both groups are well balanced. At baseline, MRF was involved in 40/65 pts. (62%) in the NIC arm and in 49/77 pts. (64%) in CRT arm (p=0.862). Radiologically, MRF remained involved after initial treatment in 17/40 pts (42.5%) NIC group and 22/49 pts. (44.9%) in the CRT group. Surgery was not performed in 11/65 pts. (16,9%) from NIC arm due to disease progression or early deaths during neoadjuvant treatment. In the CRT arm surgery was not performed in 15/77 pts. (19,5%). After surgery, circumferential resection margin (CRM) was involved in 2/44 pts. (5%) in NIC and in 1/55 pts. (2%). pCR was achieved in 3/44 pts (7%) NIC group and in 9/55 pts. (16%) CRT group (not sig). After treatment in NIC arm, a reduction in the tumor stage (evaluated by radiologist) was observed in 13/50 (26%) pts, and in pathologist’s report – in 27/44 pts (61%). In CRT arm, radiological downstaging was achieved in 28/69 pts. (41%) and pathologically in 39/55 (71%) ((not sig).). Three-year DFS was 86,4% and 92,7% in NIC and CRT groups, respectively (p = 0.6). Three-year overall survival (OS) did not differ statistically significantly between groups.
Conclusions
The preliminary findings of this ongoing prospective clinical trial did not show statistically significant difference in 3 year DFS and OS between neoadjuvant intensified chemotherapy and neoadjuvant concomitant chemoradiation arms but numerically chemoradiation arm was more benefitial.
Clinical trial identification
NCT05378919.
Legal entity responsible for the study
R. Ambraziene, R. Janciauskiene.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.