title: Negative oncologic impact of poor postoperative pain control in left-sided pancreatic cancer.
abstract: OBJECTIVE
  To investigate the association between postoperative pain control and oncologic outcomes in resected pancreatic ductal adenocarcinoma (PDAC).
  
  
  METHODS
  From January 2009 to December 2014, 221 patients were diagnosed with PDAC and underwent resection with curative intent. Retrospective review of the patients was performed based on electronic medical records system. One patient without records of numerical rating scale (NRS) pain intensity scores was excluded and eight patients who underwent total pancreatectomy were also excluded. NRS scores during 7 postoperative days following resection of PDAC were reviewed along with clinicopathologic characteristics. Patients were stratified into a good pain control group and a poor pain control group according to the difference in average pain intensity between the early (POD 1, 2, 3) and late (POD 5, 7) postoperative periods. Cox-proportional hazards multivariate analysis was performed to determine association between postoperative pain control and oncologic outcomes.
  
  
  RESULTS
  A total of 212 patients were dichotomized into good pain control group (n= 162) and poor pain control group (n= 66). Median follow-up period was 17 mo. A negative impact of poor postoperative pain control on overall survival (OS) was observed in the group of patients receiving distal pancreatectomy (DP group; 42.0 movs5.0 mo,P= 0.001). Poor postoperative pain control was also associated with poor disease-free survival (DFS) in the DP group (18.0 movs8.0 mo,P= 0.001). Patients undergoing pancreaticoduodenectomy or pylorus-preserving pancreaticoduodenectomy (PD group) did not show associations between postoperative pain control and oncologic outcomes. Poor patients' perceived pain control was revealed as an independent risk factor of both DFS (HR = 4.157; 95%CI: 1.938-8.915;P< 0.001) and OS (HR = 4.741; 95%CI: 2.214-10.153;P< 0.001) in resected left-sided pancreatic cancer.
  
  
  CONCLUSIONS
  Adequate postoperative pain relief during the early postoperative period has important clinical implications for oncologic outcomes after resection of left-sided pancreatic cancer.
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Eun-Ki
authors.initials: EK
authors.lastname: Min
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Jae Uk
authors.initials: JU
authors.lastname: Chong
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Ho Kyoung
authors.initials: HK
authors.lastname: Hwang
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Pae
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Chang Moo
authors.initials: CM
authors.lastname: Kang
authors.affiliation: Eun-Ki Min, Yonsei University College of Medicine, Seoul 03722, South Korea.
authors.forename: Woo Jung
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000150:complications* / Q000601:surgery*; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D059408:Pain Management; D010149:Postoperative Pain / Q000503:physiopathology*; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000601:surgery*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Pancreatectomy; Pancreatic cancer; Postoperative pain; Recurrence; Survival