Atsushi Oba

Dr. Atsushi Oba

Department of Hepato-Biliary-Pancreatic Surgery The Cancer Institute Hospital Of JFCR (Japanese Foundation for Cancer Research)
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 September 2021 in Journal of Hepato-Biliary-Pancreatic Sciences
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Journal Article
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AOAtsushi Oba
Atsushi Oba
MCMarco Del Chiaro
Marco Del Chiaro
Sohei SatoiSohei Satoi
Sohei Satoi
SKSun‐Whe Kim
Sun‐Whe Kim
HTHidenori Takahashi
Hidenori Takahashi
IEItaru Endo
Itaru Endo

25 January 2022 in Annals of Surgery
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Journal Article
Closed access
KOKojiro Omiya
Kojiro Omiya
AOAtsushi Oba
Atsushi Oba
YIYosuke Inoue
Yosuke Inoue
KKKosuke Kobayashi
Kosuke Kobayashi
YWY. H. Andrew Wu
Y. H. Andrew Wu
YTYu Takahashi
Yu Takahashi
Objective: This study investigates the use of serum DUPAN-2 in predicting the PC progression in CA19-9 nonsecretors. Background: Although we previously reported that serum CA19-9 >500U/ mL is a poor prognostic factor and an indication for enhanced neoadjuvant treatment, there is not a biomarker surrogate that equivalently predicts prognosis for CA19-9 nonsecretors. Methods: We evaluated consecutive PC patients who underwent pancreatectomy from 2005 to 2019. All patients were categorized as either nonsecretor or secretor (CA19-9 ≤ or >2.0U/mL). Results: Of the 984 resected PC patients, 94 (9.6%) were nonsecretors and 890 (90.4%) were secretors. The baseline characteristics were not statistically different between the 2 groups except for the level of DUPAN-2 (720 vs. 100U/mL, P < 0.001). Survival curves after resection were similar between the 2 groups (29.4 months vs. 31.3 months, P = 0.900). Survival curves of patients with DUPAN-2 >2000U/mL in the nonsecretors and patients with CA19-9 >500U/mL in the secretors were nearly equivalent as well (hazard ratio 2.08 vs. 1.89). In the multivariate analysis, DUPAN-2 >2000U/mL (hazard ratio 2.53, P = 0.010) was identified as independent prognostic factor after resection. Conclusion: DUPAN-2 >2000U/mL in CA19-9 nonsecretors can be an unfavorable factor that corresponds to CA19-9 >500U/mL in CA19-9 secretors which is an indicator for enhanced neoadjuvant treatment. The current results shed light on the subset of nonsecretors with poor prognosis that were traditionally categorized in a group with a more favorable prognosis group.


8 February 2022 in British Journal of Surgery
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Journal Article
Closed access
AOAtsushi Oba
Atsushi Oba
YWY H Andrew Wu
Y H Andrew Wu
KCKathryn L Colborn
Kathryn L Colborn
SKSana D Karam
Sana D Karam
CMCheryl Meguid
Cheryl Meguid
MCMarco Del Chiaro
Marco Del Chiaro
Background: Neoadjuvant treatment is important for improving the rate of R0 surgical resection and overall survival outcome in treating patients with pancreatic ductal adenocarcinoma (PDAC). However, the true efficacy of radiotherapy (RT) for neoadjuvant treatment of PDAC is uncertain. This retrospective study evaluated the treatment outcome of neoadjuvant RT in the treatment of PDAC. Methods: Collected from the National Cancer Database, information on patients with PDAC who underwent neoadjuvant chemotherapy (NAC) and pancreatectomy between 2010 to 2016 was used in this study. Short- and long-term outcomes were compared between patients who received neoadjuvant chemoradiotherapy (NACRT) and NAC. Results: The study included 6936 patients, of whom 3185 received NACRT and 3751 NAC. The groups showed no difference in overall survival (NACRT 16.1 months versus NAC 17.4 months; P = 0.054). NACRT is associated with more frequent margin negative resection (86.1 versus 80.0 per cent; P < 0.001) but a more unfavourable 90-day mortality than NAC (6.4 versus 3.6 per cent; P < 0.001). The odds of 90-day mortality were higher in the radiotherapy group (odds ratio 1.81; P < 0.001), even after adjusting for significant covariates. Patients who received NACRT received single-agent chemotherapy more often than those who received NAC (31.5 versus 10.7 per cent; P < 0.001). Conclusion: This study failed to show a survival benefit for NACRT over NAC alone, despite its association with negative margin resection. The significantly higher mortality in NACRT warrants further investigation into its efficacy in the treatment of pancreatic cancer.

21 January 2020 in Scandinavian Journal of Surgery
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Journal Article
Open access
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AOAtsushi Oba
Atsushi Oba
QBQuoc Riccardo Bao
Quoc Riccardo Bao
CBC. C. Barnett
C. C. Barnett
MAM. H. Al-Musawi
M. H. Al-Musawi
CCC. Croce
C. Croce
MCMarco Del Chiaro
Marco Del Chiaro
Background and Aims: It has become clear that vein resection and reconstruction for pancreatic ductal adenocarcinoma (PDAC) is the standard of care as supported by multiple guidelines. However, resection of large peri-pancreatic arteries remains debatable. Materials and Methods: This review examines the current state of vascular resection with curative intent for PDAC in the last 5 years. Herein, we consider venous (superior mesenteric vein, portal vein), as well as arterial (superior mesenteric artery, celiac trunk, hepatic artery) resection or both with or without reconstruction. Results: Improvement of multidrug chemotherapy has revolutionized care for PDAC that should shift traditional surgical thinking from an anatomical classification of resectability to a prognostic and biological classification. Conclusion: The present review gives an overview on the results of pancreatectomy associated with vascular resection, with consideration of new perspectives offered by the availability of better systemic therapies.

10 April 2021 in Cancers
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Journal Article
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YIYosuke Inoue
Yosuke Inoue
AOAtsushi Oba
Atsushi Oba
YOYoshihiro Ono
Yoshihiro Ono
TSTakafumi Sato
Takafumi Sato
Hiromichi ItoHiromichi Ito
Hiromichi Ito
YTYu Takahashi
Yu Takahashi
Aggressive arterial resection (AR) or total pancreatectomy (TP) in surgical treatment for locally advanced pancreatic cancer (LAPC) had long been discouraged because of their high mortality rate and unsatisfactory long-term outcomes. Recently, new chemotherapy regimens such as FOLFIRINOX or Gemcitabine and nab-paclitaxel have provided more adequate patient selection and local tumor suppression, justifying aggressive local resection. In this review, we investigate the recent reports focusing on arterial resection and total pancreatectomy for LAPC and discuss the rationale of such an aggressive approach in the treatment of PC. AR for LAPCs is divided into three, according to the target vessel. The hepatic artery resection is the simplest one, and the reconstruction methods comprise end-to-end, graft or transposition, and no reconstruction. Celiac axis resection is mainly done with distal pancreatectomy, which allows collateral arterial supply to the liver via the pancreas head. Resection of the superior mesenteric artery is increasingly reported, though its rationale is still controversial. Total pancreatectomy has been re-evaluated as an effective option to balance both the local control and postoperative safety. In conclusion, more and more aggressive pancreatectomy has become justified by the principle of total neoadjuvant therapy. Further technical standardization and optimal neoadjuvant strategy are mandatory for the global dissemination of aggressive pancreatectomies.