title: Clinical benefits of neoadjuvant chemoradiotherapy for adenocarcinoma of the pancreatic head: an observational study using inverse probability of treatment weighting.
abstract: BACKGROUND
  The efficacy of neoadjuvant chemoradiotherapy (NACRT) and subset of pancreatic ductal adenocarcinoma (PDAC) patients who are most likely to benefit from this strategy remain elusive. The aim of this study was to investigate the effects of NACRT in patients with resectable (R) or borderline resectable (BR) adenocarcinoma of the pancreatic head. BR diseases were classified into two groups: lesions involving exclusively the portal vein system (BR-PV) and those abutting the major artery (BR-A).
  
  
  METHODS
  A total of 504 patients treated with curative intent for PDAC were analyzed (R, n = 273; BR-PV, n = 129; BR-A, n = 102). Patients who underwent upfront surgery and those who underwent NACRT followed by surgery were compared using propensity score-matched and inverse probability of treatment-weighted analyses (UMIN000019719).
  
  
  RESULTS
  No significant differences were noted in the incidences of curative resection among the three categories (R, BR-PV and BR-A). Propensity score-weighted logistic regression analysis revealed that the incidence of pathologically positive resection margins was reduced by NACRT only for BR patients. Among the propensity score-matched patients, NACRT rather than upfront surgery significantly prolonged the median survival time of BR-PV patients (28.4 vs. 20.1 months; P = 0.044) but not that of R-PDAC patients (28.6 vs. 33.7 months; P = 0.960). NACRT prolonged the median survival time of BR-A patients (18.1 vs. 10.0 months; P = 0.046), but the results remained unsatisfactory.
  
  
  CONCLUSIONS
  These findings suggest that NACRT improves R0 rates and increases the survival of patients with BR-PV adenocarcinoma of the pancreatic head but not that of patients with R-PDAC.
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. fjt@med.nagoya-u.ac.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: Sohei
authors.initials: S
authors.lastname: Satoi
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Suguru
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Division of Biostatistics, Clinical Research Center, Aichi Medical University, Nagakute, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Murotani
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yanagimoto
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takami
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Kanda
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: So
authors.initials: S
authors.lastname: Yamaki
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirooka
authors.affiliation: Department of Surgery, Kansai Medical University, Osaka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kon
authors.affiliation: Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kodera
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D010180:Pancreatectomy / Q000379:methods; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000628:therapy*; D011336:Probability; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
keywords: Borderline resectable; Neoadjuvant chemoradiotherapy; Pancreatic ductal adenocarcinoma; Portal vein; Upfront surgery