IMPACT OF TIME TO SURGERY ON OUTCOMES FOLLOWING LOW ANTERIOR RESECTION FOR RECTAL CANCER

BACKGROUND: The objective of this study was to assess the impact of time to surgery (TTS) on outcomes following low anterior resection (LAR) among patients with non-metastatic rectal cancer. Initial treatment approaches were defined as having received upfront surgery (UFS), neoadjuvant chemo-radiation (XRT) or total-neoadjuvant therapy (TNT).

METHODS: The 2004-2017 National Cancer Database was queried for patients with non-metastatic rectal cancer who underwent LAR. TTS was categorized based on the study population’s median TTS from time of diagnosis. We scrutinized the TTS amongst the initial treatment approaches. Kaplan-Meier Method with log-rank test was used to compare and estimate overall survival (OS) rates between patients based on TTS, as well as initial clinical approach. A p-value of < 0.05 was considered statistically significant.

RESULTS: A total of 19,937 patients were identified, of which 44% underwent XRT, 40% UFS, and 16% TNT. For the UFS cohort almost 96% had a TTS ≤ 119 days. Conversely, approximately 77% of both the XRT and TNT cohort has a TTS > 119 days. Data stratified by initial clinical approach and TTS revealed that patients in the UFS + TTS ≤ 119 days cohort experienced a longer median OS compared to their UFS + TTS > 119 days counterparts (151.9 vs. 112.6 months; p = 0.022). Additionally, the UFS + TTS ≤ 119 days cohort was less likely to be lymph node positive (9.9% vs 13.8%; p = 0.025). Among patients who received XRT, the TTS > 119 days cohort was more likely to die within 90-days (2.9% vs 2.0%, p = 0.047) and less likely to achieve 5-year survival (41.7% vs 50.5%, p < 0.001) when compared to their TTS > 119 days counterparts. Furthermore, patients in the TTS > 119 days group were more likely to have pathologic stage IV disease (1.3% vs 1.2%; p = 0.001). Patients in the TNT + TTS ≤ 119 days cohort were more likely to have a small tumor size (0 - 2 cm) on final pathology than their TTS > 119 days counterparts (25.3% vs. 21.3%; p = 0.034). Likewise, the TNT + TTS ≤ 119 days cohort experienced a higher 5-year survival rate (57.6% vs. 49.2%; p > 0.001).

DISCUSSION: Our study demonstrated that across all three clinical approaches TTS > 119 days is associated with poorer outcomes. Consequently, time to surgery may be an important factor to consider in the treatment of patients with non-metastatic rectal cancer who are undergoing LAR.