TP1.2.3Oncological Outcomes of Organ Preservation Strategies - Local Excision Procedures and ‘Watchful Waiting’ In Management of Low Rectal Cancers – A Systematic Review And Meta-Analysis

Objective To evaluate local recurrence, metastases, and survival outcomes of `wait and watch’ (WW) strategy and local excision (LE) of tumours, in comparison to the present standard practice of total mesorectal excision (TME) for locally advanced rectal cancers. Data Sources MEDLINE, EMBASE, PubMed databases, and sources of Grey literature. Study Selection Randomised and non-randomised prospective studies, retrospective studies with propensity-score-matched analyses. Data Extraction and Synthesis These were carried out independently by two reviewers. A random-effects methodology was used for meta-analyses. Data was presented keeping with the 27-item PRISMA checklist. Main Outcomes The primary outcomes of interest were local recurrence, distant metastases, disease-free-survival and overall-survival, which were assessed in comparison to those associated with radical surgeries (TME). Results 7 of the 16 studies in the systematic review were included for the quantitative synthesis and meta-analysis. Local recurrence rates were comparable amongst patients in WW group and LE group to those undergoing TME. [Risk ratio (RR) 3.07/1.41; 95% Confidence Interval (CI) 0.86-10.95/0.66-3.01; P = 0.08/P=0.89 respectively]. Rates of distant metastases in the WW group and LE group were comparable to those undergoing TME [RR = 0.71/0.94; 95% CI 0.22-2.30/0.55-1.61; P = 0.56/ P = 0.83 respectively]. The median 3-year disease-free survival among patients undergoing WW, LE procedure, and TME were 88%, 80%, and 78.2% respectively; and the median 3-year overall survival among the three groups were 96%, 93%, and 89.5% respectively. Conclusions and Relevance Organ-preservation strategies appear to be a viable treatment option in the management of rectal-cancers. Further research is warranted to provide stronger levels of evidence on organ-preservation strategies.