Outcome and Salvage Surgery Following "Watch and Wait" for Rectal Cancer after Neoadjuvant Therapy: A Systematic Review.
BACKGROUND
Currently there is no reliable test to predict pathological complete response following neoadjuvant chemoradiotherapy for rectal cancer. However, there is increasing interest in using clinical complete response as a surrogate marker, allowing a subset of patients with locally advanced rectal cancer to be allocated into a "watch and wait" pathway. Little is known about the oncological safety of the "watch and wait" approach or the rate of salvage surgery in cases of tumor regrowth. This information is critical for the implementation of this approach.


OBJECTIVE
The aim of this study is to assess the rate of salvage surgery and associated oncological outcomes for patients who develop a tumor regrowth with the "watch and wait" approach.


METHODS
Relevant studies were identified through PubMed, Embase, and Google Scholar search.


METHODS
A systematic review was undertaken of studies assessing patients selected for the "watch and wait" approach according to PRISMA guidelines.


METHODS
The associated tumor regrowth, salvage surgery, and disease-free and overall survival rates were assessed.


RESULTS
Five retrospective and 4 prospective observational studies were included into the analysis, with a total of 370 patients in the "watch and wait" group, of which 256 (69.2%) had persistent clinical complete response. Of those who had tumor regrowth, salvage surgery was possible in 83.8%. There was no difference in overall survival and disease-free survival between patients who received immediate surgery and the "watch and wait" group.


CONCLUSIONS
The limitations of this study include its retrospective nature and small sample size. Furthermore, there is significant heterogeneity between study protocols, including the short median follow-up, given that tumor regrowth and distant metastasis may manifest at a later time point.


CONCLUSIONS
The majority of patients with tumor regrowth can be salvaged with definite surgery after "watch and wait." However, there is insufficient evidence to draw firm conclusions on the oncological safety of this approach; therefore, it is currently not the standard of care for locally advanced rectal cancer.
1 Division of Cancer Surgery, University of Melbourne, Melbourne, Victoria, Australia 2 Differentiation and Transcription Laboratory, University of Melbourne, Melbourne, Victoria, Australia 3 Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, Victoria, Australia.
Joseph C
JC
Kong
Glen R
GR
Guerra
Satish K
SK
Warrier
Robert G
RG
Ramsay
Alexander G
AG
Heriot
D003131:Combined Modality Therapy; D006801:Humans; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000401:mortality; D012004:Rectal Neoplasms / Q000401:mortality / Q000628:therapy*; D016879:Salvage Therapy; D016019:Survival Analysis; D057832:Watchful Waiting