Abstract 251P
Background
Total mesorectal excision is a highly effective treatment for RC but is associated with significant morbidity and mortality. OP approach for locally advanced RC has been successful but not well studied for NN low RC. The objective of this investigator-initiated trial (IIT) is to determine the feasibility of performing successful LE after neoadjuvant Ctx in NN low RC.
Methods
With IRB approval, patients (pts) with clinical stage T1-3, N0 low rectal adenocarcinomas (<6 cm from anal verge) were included in this single arm phase II IIT. Pts received 6 cycles of FOLFOX (5- FU bolus 400 mg/m2 and infusion 2400 mg/m2, Leucovorin 400 mg/m2 and Oxaliplatin 85 mg/m2) and those with evidence of a response underwent LE (trans anal excision) 6-12 weeks later. To target occult nodal metastases and reduce in-bowel recurrences, LE was followed by chemoradiotherapy (Capecitabine 825 mg/m2 and long course RT to 54 Gy). The primary endpoint was the proportion of pts who had successful LE after neoadjuvant Ctx (NCT03548961).
Results
Nineteen pts with low RC were enrolled, of which 9 were female and the mean age at diagnosis was 65 years. T stage was as follows: T1- 1(5%), T2 - 11(58%), T3 - 7(36%). Eighteen (95%) pts completed at least 5 cycles of neoadjuvant Ctx and 15/18 (83%) underwent LE (one pt yet to reach time point for LE). Negative margins and downstaging were achieved in 78% (14/18) and 50% (9/18) of pts, respectively. Complete pathological response was achieved in 4/15 (27%) of pts who underwent LE. Three pts (16%) didn’t have response to allow for LE and 1 pt (5%) had LE with positive margins, all of these were T2 stage. All 14 pts who had successful LE completed adjuvant chemoradiotherapy. Complete organ preservation, margin status, recurrence rates and quality of life data will be presented.
Conclusions
Neoadjuvant Ctx and LE allows for OP in NN low RC and results in a margin negative LE in over two thirds of pts. Ongoing trials are investigating OP approach in NN RC (NCT03259035). Our approach adds to the mounting evidence and will also provide early data around the benefit of adjuvant chemoradiation to target occult nodes in this setting and needs further investigation.
Clinical trial identification
NCT03548961.
Legal entity responsible for the study
N. Vijayvergia.
Funding
Colon Cancer Coalition and Fox Chase Cancer Center.
Disclosure
All authors have declared no conflicts of interest.