CHICAGO–The mFOLFOX6 regimen administered concurrently with radiation therapy resulted in a higher pathological complete response, while neoadjuvant mFOLFOX6 alone achieved a similar down staging rate with less toxicity and fewer postoperative complications, compared with preoperative fluorouracil (5-FU) with radiotherapy, a research presented at the 2015 American Society of Clinical Oncology (ASCO) 2015 annual meeting in Chicago, IL, has shown.
The trial enrolled 495 patients with stage II-III rectal cancer within 12 cm from the anal verge and randomly assigned them to receive either five cycles of 5-FU with radiation (control arm), five cycles of mFOLFOX6 with radiation (FOLFOX-RT arm), or four to six cycles of mFOLFOX6 alone (FOLFOX arm).
Within the FOLFOX arm, 5% of patients received post-operative radiation, which was available to patients if needed.
Results showed that the pathological complete response rate was 14.3%, 28.0%, and 6.1% in the control arm, FOLFOX-RT arm, and FOLFOX arm, respectively (P=0.001). In addition, good down staging was achieved in 37.8%, 57.4%, and 35.8% of patients, respectively (P=0.001).
Subgroup analyses showed a pathological complete response rate of 15.6%, 29.2%, and 6.6% in the control arm, FOLFOX-RT arm, and FOLFOX arm, respectively, in patients whose tumor was located within 5 cm from the anal verge.
In regard to safety, greater toxicity and more postoperative complications were observed in patients who received radiation.
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Concluding the presentation, Yanhoung Deng, MD, PhD, from the department of medical oncology at Gastrointestinal Hospital and Sun Yat-sen University in China said, “mFOLFOX6 with concurrent radiation as neoadjuvant treatment for locally advanced rectal cancer compared to 5-FU single agent led to increased pathological complete response, increased good response, and slightly increased toxicity, but not decreased compliance.”
“mFOLFOX6 alone as neoadjuvant treatment for locally advanced rectal cancer compared to 5-FU based chemoradiation had similar R0 resection rates, similar good response rates, lower surgical complication rates, and similar efficacy in the low rectal cancer subgroup.”
The findings suggest that mFOLFOX6 with radiation may replace 5-FU as standard treatment in this setting.
Follow-up is ongoing and researchers plan to report the recurrence and survival outcomes in the future.
- Deng Y, Chi P, Lan P, et al. A multi-center randomized controlled trial of mFOLFOX6 with or without radiation in neoadjuvant treatment of local advanced rectal cancer (FOWARC study): Preliminary results. J Clin Oncol. 2015;33:(suppl; abstr 3500).