eP241 - How Fast Is Too Fast: Time to Treatment and Positive Margin in Rectal Cancer

Purpose/Background: As rectal cancer care has rapidly advanced in recent years, the question of time to treatment initiation remains. While historically both patients and providers have sought to have their patients initiated on treatment as soon as feasible, there has been no evaluation of outcomes related to time to treatment initiation. In this study we look at the effect of time to treatment and surgery on surgical outcomes, namely rate of margin positivity.Methods/Interventions: This study is a retrospective analysis of the National Cancer Database 2020 release. Patients with Stage 2 or 3 rectal adenocarcinoma were evaluated based on age, Charlson-Deyo Score (CDS), days to first treatment, days to any surgery, days to definitive surgery, and pathologic margin status. A two-sample, two-tail t-test was used to analyze significance; unequal variance was assumed for all tests. Z scores were used to calculate significance for comparison of proportions.Results/Outcomes: There was a significant difference noted in average time to treatment and positive pathologic margin in all groups. This was noted in time to any treatment (37.1 days for negative margin vs 32.66 days for positive margin, p=0.005), time to any surgery (123.4 vs 111.5, p=0.048), and time to definitive surgery (128.0 vs 117.4, p=0.048). When evaluating early-onset rectal cancer (age 18-50), the same association was only significant for days to all treatment (33.6 vs 30.2, p=0.014). Margin status and days to surgical intervention were not significantly associated. However, for patients over age 50, there was an association with positive margin and days to any treatment (38.0 vs 33.3, p=0.002), days to any surgery (122.7 vs 109.0, p=0.022), and days to definitive surgery (127.2 vs 114.6, p=0.023).While there was no difference in time to any treatment and positive margin rate, there was a decrease in positive margin rate with any surgery >90 days from diagnosis (5.92% vs 7.11%, p=0.020) and with definitive surgery >90 days from diagnosis (6.00% vs 7.14%, p=0.023). In contrast, there was an increase in positive margin rate for surgery >180 days from diagnosis, both for all surgery (12.72% vs 7.11%, p < 0.001) and definitive surgery (14.08% vs 7.14%, p < 0.001).There was no difference in positive margin rates based upon comorbidities. Patients with a CDS ≥ 2 were noted to have a significant increase in time to treatment >45 days (p=0.005), time to any surgery >90 days (p < 0.001), and time to definitive surgery >90 days (p < 0.001). This association did not remain when extended to >180 days from diagnosis.Conclusion/

Discussion: While effort has historically been made to get patients to treatment for rectal cancer as efficiently as possible, recent literature has shown no significant effect on survival. This retrospective analysis shows that some delay in time to treatment and surgery could actually be beneficial to patients’ surgical outcomes in regard to margin status. More analysis is necessary to further elucidate more appropriate treatment time-frames as well as possible confounding factors within this data. However, these findings do raise concern as to the push for rapidity of treatment initiation.