The best timing for administering systemic chemotherapy in patients with locally advanced rectal cancer.

Over the past several decades, outcomes for patients with rectal cancer have improved considerably. However, several questions have emerged as survival times have lengthened and quality of life has improved for these patients. Currently patients with locally advanced rectal cancer (LARC) are often recommended multimodality therapy with fluoropyrimidine-based chemotherapy (CT) and radiation followed by total mesorectal excision (TME), with consideration given to FOLFOX before chemoradiotherapy (CRT). Recently, Garcia-Aguilar and colleagues reported in Lancet Oncology that the addition of mFOLFOX6 administered between CRT and surgery affected the number of patients achieving pathologic complete response (pathCR), which is of great interest from the standpoint of pursuit of optimal timing of systemic CT delivery. This was a multicenter phase II study consisting of 4 sequential treatment groups of patients with LARC, and they reported that patients given higher number CT cycles between CRT and surgery achieved higher rates of pathCR than those given standard treatment. There was no association between response improvement and tumor progression, increased technical difficulty, or surgical complications. Ongoing phase III clinical trial further assessing this strategy might result in a paradigm shift.