Protocol for a national audit of the watch-and-wait approach in patients with rectal cancer in Aotearoa New Zealand: The ACCORD study

AimThe watch-and-wait approach is increasingly being used in the management of rectal cancer as many patients achieve a clinical complete response after neoadjuvant treatment This national, multicentre, retrospective cohort study aims to understand the use of the watch-and-wait approach in the management of rectal cancer in Aotearoa New Zealand and its associated outcomes.MethodThis retrospective cohort study will include patients aged 18 years and over with biopsy proven rectal adenocarcinoma diagnosed between January 2015 and December 2022 who have a clinical complete response following neoadjuvant treatment (including short-course radiotherapy, long-course chemoradiotherapy or total neoadjuvant treatment) and have been managed with a watch-and-wait approach. Data will be collected from centres that manage rectal cancer in Aotearoa New Zealand with the eligible population being identified using data linkage with the National Cancer Registry.ConclusionThis multicentre, national cohort study will investigate the use of the watch-and-wait strategy for rectal cancer in Aotearoa New Zealand. Through novel data linkage approaches, these data and methods will lay the foundation for a future prospective registry and outcome-tracking initiative.