Short-course radiotherapy followed by delayed surgery in rectal cancer

Short-course radiotherapy followed by delayed surgery becomes a validated alternative to treat intermediate-risk localised rectal cancer

The full publication in Lancet Oncology of the Stockholm III trial helps us to understand that short-course radiotherapy in patients with localised rectal cancer could also be followed by delayed surgery.1
During more than 14 years, more than 800 patients with rectal cancer not showing unresectable features were randomised in a two-arm versus three-arm study with a non-inferiority design.
Patients could be randomised to short-course radiotherapy (5×5 Gy) and immediate (within a week) versus delayed (4–8 weeks) surgery.
In the three-arm randomisation patients could also be allocated to a long course of concurrent chemoradiation (25×2 Gy), with surgery performed 6–8 weeks thereafter.
Time to local recurrence was established as the primary endpoint.
Interestingly, short-course radiotherapy followed by delayed surgery was proven to have less acute toxicity and a lower postoperative complication rate compared with immediate surgery.Oncological results were similar among the three arms.
The authors conclude that short-course radiotherapy with surgery delayed for 4–8 weeks might have certain advantages over immediate surgery in rectal cancer treatment.
Another interesting fact observed in this study is that tumour regression and downstaging is seen in the delayed surgery arm, achieving a pathological complete response rate of 11.8%, while tumour regression is rarely appreciated in the immediate surgery group.2 Moreover, delayed surgery allows the integration of chemotherapy after short-course radiation in patients with locally advanced tumours. This strategy has been further developed in the RAPIDO trial, which already completed accrual and whose results are to be reported in about 3 years from now.