SP 3.11 Opportunistic Complete Clinical Response After Neo-Adjuvant Chemoradiotherapy in Patients with Locally Advance Rectal Cancers – An Opportunity for Rectal Preservation
Afifa Naseer, Mahmoud Abdelreheem, Amit Dalip, Aftab KhanAbstract
Aim
To investigate the outcomes of patients with locally advance rectal adenocarcinoma (LARC) who had opportunistic complete clinical response (cCR) after neo-adjuvant chemoradiotherapy (NCRT) and opted for wait and watch approach.
Methods
A retrospective review of cases treated at a single Unit in United Kingdom for last 11 years (2014-2025). Patients with excised rectal polyp cancers followed by radiotherapy were excluded. All patients met criteria for NCRT as per index staging. Analysis of their outcomes and survival was undertaken.
Results
Thirty-one patients were included with median age of 72 years (IQR 63–80, M:F 1:1). About 74% and 16% were moderately and poorly differentiated adenocarcinoma, respectively. The pre-treatment tumour staging included T2=27%, T3=73%, N0=30%, N1=37%, N2=33%, M0=93.5%, M1=6.4%. The median follow-up period was 47 months (IQR 28 – 71). After cCR, patients were assessed every 3-4 months. Cancer regrowth within rectum occurred in 16 (52%) patients, 2 (6.4%) had concurrent liver metastasis. Fourteen patients (45%) underwent salvage radical surgery. The histopathology staging was ypT2=21%, ypT3=43%, ypT4=36%, ypN0=71%, ypN1=28.5%, R0=71%, R1=21%, R2=7%. About 6 (19%;) patient died during the follow-up period, 4 (13%) after salvage surgery. The median disease free and overall survivals were 22 months and 109 months, respectively.
Conclusions
Patients with LARC who achieve opportunistic complete clinical response can be considered for rectal preservation. Frequent monitoring is key for successful wait and watch approach. Patients should be made aware of the risks which include tumour re-growth (50%) within first two years and high frequency of positive resection margins.