EP833 - Does early versus delayed time to surgery affect post-operative outcomes among older patients with colon cancer and malignant obstructions?

Purpose/Background: Recent studies have outlined the preferred "time to surgery" associated with improved outcomes for common diseases surgeons face. However, there is paucity of data guiding the management of older patients who present with a large bowel obstruction presumed to be secondary to colon cancer. The clinician must weigh the benefits of further workup vs. urgent surgery. We sought to determine whether early vs. delayed time to surgery (TTS) impacts outcomes in older patients with colon cancer who present with malignant bowel obstructions.

Methods/Interventions: We conducted a retrospective analysis with the American College of Surgeons National Surgery Quality Improvement Program Colectomy Participant Use Data File (2018-2023). Patients age >= 65 who were diagnosed with colon cancer and underwent inpatient procedures with obstruction as the emergent operative indication were included. Participants were excluded if they had septic shock at time of admission or stage 4 colon cancer. Key co-variates included age, race, sex, frailty (modified 5-item frailty index, with frailty defined as score >= 2), American Society of Anesthesiologists (ASA) classification, operative approach, and cancer stage. TTS was defined in days from hospital admission to surgery. We conducted sensitivity analyses with different TTS cut-offs utilizing the Akaike Information Criterion (AIC). Based on the lowest AIC, TTS < 3 days was considered early, and TTS >= 3 days was delayed. Length of stay (LOS), the primary outcome, was defined as days from surgery to discharge. Thirty-day major complications, defined by the Clavien-Dindo Classification, was the secondary outcome. We used descriptive statistics and multivariate regression models to assess whether early vs. delayed TTS was associated with LOS and complications. We also investigated the role of frailty on TTS and post-operative outcomes using the chi-square test and multivariate regression models.

Results/Outcomes: A total of 2,418 patients were included in the study. The median age was 78 years (IQR: 71-85), 52% (n=1,249) female, 61% (n=1,475) non-white, 25% (n=602) frail, and 84% (n=2,024) had an ASA >=3. In terms of colon cancer stage, 47% (n=624) were characterized as stage <= 2 and 53% (n=693) as stage 3. For operative approach, 23% (n=509) had a minimally invasive procedure, 73% (n=1,625) an open procedure, and 4% (n=96) a procedure converted to open. The median LOS was 8 days (IQR: 5-12). In terms of delayed TTS, 24% (n=590) had surgery >= 3 days, and delayed TTS was more common among frail patients (p = 0.036). Those who had delayed TTS had an increased risk of longer LOS (IRR: 3.54, 95% CI: 3.00, 4.20) compared to those with early TTS. Delayed TTS was associated with increased odds of major complications (OR: 1.27, 95% CI: 1.03, 1.56). Frailty was also independently associated with increased risk of longer LOS (IRR: 1.14, 95% CI: 1.06,1.22) and higher odds of complications (OR: 1.37, 95% CI: 1.04, 1.80) compared to non-frail patients.

Conclusion/Discussion: This study stresses the importance of early TTS for malignant bowel obstruction in older patients with colon cancer, particularly in mitigating the detrimental impacts of longer LOS and complications. Next steps include investigating the role of frailty on delays in TTS among older colon cancer patients with malignant obstructions. These findings should also prompt clinicians to be mindful of TTS among the older population and may aid in development of clinical guidelines for this patient population.