The survival impact of surgical waiting time in patients with resectable pancreatic head cancer.

Backgrounds/aims: After centralization policy, clinical outcomes have been improved in patients underwent pancreaticoduodenectomy for pancreatic cancer. However, centralization could exacerbate the prolongation of surgical waiting time. This study aims to investigate whether the shorter waiting time correlates with the better survival and to identify the major confounders that influence the association between those.

Methods: In this retrospective cohort study, a total 554 patients with pathologically confirmed pancreatic ductal adenocarcinoma were assessed the eligibility from 2014 through 2015. Patients with neoadjuvant chemotherapy, body-tail resection, total pancreatectomy and combined adjacent organ resection were excluded. All patients were divided into two groups by median waiting time, 21 days, defined as the date difference between initial imaging diagnosis and operation.

Results: Median overall survival did not differ between long and short waiting group (30.4 vs 24.8 months, =0.35; HR=0.84, 95% CI=0.58-1.21). The proportion of cancer stage shifting, the difference between clinical and pathologic staging, did not differ depending on waiting time group (=0.811 and 0.255, each of reviewers). Short waiting time was highly correlated with high initial clinical stage (Spearman correlation coefficients -0.201 (=0.006) and -0.100 (=0.175), each of reviewers).

Conclusions: Initial clinical stage had confounding effect on the association between waiting time and overall survival. Therefore, in evaluating centralization policy at the national level, evidence for maximum acceptable waiting time should be investigated in the near future with considering that surgical waiting time could be affected by initial clinical stage.