D. S. Swords1, C. Zhang2, A. P. Presson2, M. A. Firpo1, S. J. Mulvihill1, C. L. Scaife1 1University Of Utah,Department Of Surgery,Salt Lake City, UT, USA 2University Of Utah,Study Design And Biostatistics Center,Salt Lake City, UT, USA
Introduction: Timeliness is a domain of healthcare quality, and wait times for cancer surgery have increased in recent years. Time to surgery (TTS) from diagnosis in pancreatic adenocarcinoma (PDAC) may be delayed due to the need for biliary decompression, multi-disciplinary review, or medical optimization. Existing data on the clinical impact of TTS have been conflicting.
Methods: The National Cancer Database was reviewed from 2004-2012 for patients undergoing upfront resection of clinical Stage I-II PDAC with data on TTS. TTS was defined as time from diagnosis to resection. Patients with TTS of 0 or > 120 days and those that received neoadjuvant therapy were excluded. Patients with unknown clinical stage were excluded if pathologic stage was III-IV. Overall survival (OS) began at time of surgery and was the primary outcome. Multivariable Cox regression with TTS modeled as a restricted cubic spline was used to evaluate the relationship between TTS and mortality in order to define TTS groups. OS was evaluated with unadjusted Kaplan-Meier analysis and multivariate Cox regression analysis. Secondary outcomes were rates of positive margins, nodal positivity, and upstaging from clinical to pathologic stage; they were examined using logistic regression models adjusted for demographic and clinical characteristics.
Results: There were 15,945 patients available for analysis. Patients with TTS ≤ 2 weeks had the highest risk of mortality with a gradual decrease to 40 days, and then a gradual increase to 120 days. We thus defined TTS as: short (1-14 days, N=5,465), medium (15-42 days, N=8,241), and long (43-120 days, N=2,239). Adjusted odds of positive margins, nodal positivity, and upstaging were not significantly different between TTS groups. On unadjusted survival analysis, short TTS patients had slightly worse survival than medium and long (P<0.001, Log-rank). Survival differences between TTS groups were most pronounced in Stage I patients; long TTS had superior survival to medium TTS, which was superior to short TTS (P<0.001 for both, Log-rank, Figure). On multivariate Cox proportional hazard analysis, short vs. medium TTS was associated with modestly increased hazards of mortality (Hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.02-1.11, P=0.003) but long vs. medium was not (HR 0.95, 95% CI 0.9-1.01, P=0.12).
Conclusion: Moderately longer TTS was not associated with worse outcomes and short TTS was associated with higher mortality, especially in Stage I disease. These findings should reassure patients and providers that reasonable delays are likely safe. However, we could not account for patients who initially were planned for resection but progressed on repeat imaging or who were unresectable on exploration.
