Koji Tomiyama

Dr. Koji Tomiyama


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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1 October 2019 in Journal of Hepatology
Verified
Journal Article
Closed access
CTChristoph Tschuor
Christoph Tschuor
Alberto FerrareseAlberto Ferrarese
Alberto Ferrarese
CKChristoph Kuemmerli
Christoph Kuemmerli
PDPhilipp Dutkowski
Philipp Dutkowski
PBPatrizia Burra
Patrizia Burra
PKPhilipp Kron
Philipp Kron

24 January 2023 in Annals of Surgery
Verified
Journal Article
Open access
MVMariana Chávez Villa
Mariana Chávez Villa
LRLuis I. Ruffolo
Luis I. Ruffolo
BABandar M. Al-Judaibi
Bandar M. Al-Judaibi
MFMasato Fujiki
Masato Fujiki
KHKoji Hashimoto
Koji Hashimoto
RHRoberto Hernandez-Alejandro
Roberto Hernandez-Alejandro
Objective: To describe the rate of occult carcinoma deposits in total hepatectomy specimens from patients treated with liver transplant (LT) for colorectal liver metastases (CRLM). Background: Previous studies have shown that patients with CRLM treated with systemic therapy demonstrate a high rate of complete radiographic response or may have disappearing liver metastases. However, this does not necessarily translate into a complete pathologic response, and residual invasive cancer may be found in up to 80% of the disappearing tumors after resection. Methods: Retrospective review of 14 patients who underwent LT for CRLM, at 2 centers. Radiographic and pathologic correlation of the number of tumors and their viability before and after LT was performed. Results: The median (interquartile range) number of tumors at diagnosis was 11 (4–23). The median number of chemotherapy cycles was 24 (16–37). Hepatic artery infusion was used in 5 patients (35.7%); 6 (42.9%) underwent surgical resection, and 5 (35.7%) received locoregional therapy. The indication for LT was unresectability in 8 patients (57.1%) and liver failure secondary to oncologic treatment in the remaining 6 (42.9%). Before LT, 7 patients (50%) demonstrated fluorodeoxyglucose-avid tumors and 7 (50%) had a complete radiographic response. Histopathologically, 11 patients (78.6%) had a viable tumor. Nine (64.2%) of the 14 patients were found to have undiagnosed metastases on explant pathology, with at least 22 unaccounted viable tumors before LT. Furthermore, 4 (57.1%) of the 7 patients who demonstrated complete radiographic response harbored viable carcinoma on explant pathology. Conclusions: A complete radiographic response does not reliably predict a complete pathologic response. In patients with unresectable CRLM, total hepatectomy and LT represent a promising treatment options to prevent indolent disease progression from disappearing CRLM.

10 June 2025 in Cancers
Verified
Journal Article
Open access
PDF file
ALAbigail Faith Loszko
Abigail Faith Loszko
MBMatthew M Byrne
Matthew M Byrne
CJCristina Jiménez-Soto
Cristina Jiménez-Soto
KTKoji Tomiyama
Koji Tomiyama
YBYuki Bekki
Yuki Bekki
RHRoberto Hernandez-Alejandro
Roberto Hernandez-Alejandro
Transplant oncology is a rapidly evolving discipline that incorporates oncology, transplant medicine, and surgery. As the field continues to grow, there remains an opportunity to enhance patient selection, detect recurrence after liver transplantation, and optimize treatment after recurrence. Liquid biopsies are an emerging resource to improve patient care. In this review, we evaluate the most recent available data on circulating tumor DNA and how it pertains to primary and metastatic hepatobiliary malignancies. We discuss the opportunities and current limitations to clinical practice, especially in relation to total hepatectomy and liver transplantation. We conclude that as both transplant oncology and our understanding of circulating tumor DNA continue to evolve, rigorous, prospective study is required to integrate this technology into a clinical paradigm.

11 June 2025 in Transplantation
Verified
Journal Article
Closed access
MBMatthew M. Byrne
Matthew M. Byrne
MCMariana Chávez-Villa
Mariana Chávez-Villa
YEYutaka Endo
Yutaka Endo
CJCristina Jimenez-Soto
Cristina Jimenez-Soto
LCLuke Cybulski
Luke Cybulski
KTKoji Tomiyama
Koji Tomiyama
Living donor liver transplantation for oncologic indications is a complex topic that involves transplantation, oncology, and ethical considerations. The incidence of primary and secondary malignancy of the liver is growing. As transplant oncology continues to provide promising outcomes, the patient population that may benefit from transplantation will grow. In this review, we provide evidence that justify attempting transplantation for oncologic indications through the exploration of outcomes in both deceased donor and living donor liver transplants. This will focus on outcomes for patients with hepatocellular carcinoma, cholangiocarcinoma, neuroendocrine liver metastasis, and colorectal liver metastases. This review aims to summarize the current status of transplant oncology and to develop the considerations of living donor liver transplantation for these indications.

13 May 2025 in Cancers
Verified
Journal Article
Open access
PDF file
Yutaka EndoYutaka Endo
Yutaka Endo
YBYuki Bekki
Yuki Bekki
RHRoberto Hernandez-Alejandro
Roberto Hernandez-Alejandro
KTKoji Tomiyama
Koji Tomiyama
Hepatocellular carcinoma (HCC) is one of the leading causes of liver transplant worldwide. While liver transplantation offers a survival advantage for early-stage HCC patients, post-transplant recurrence remains a significant concern, affecting up to 15% of recipients. We sought to conduct a comprehensive review related to HCC recurrence after liver transplant. Tumor-related factors such as poor differentiation, vascular invasion, and elevated tumor biomarkers like alpha-fetoprotein are key predictors of recurrence. Donor-related factors, including graft type and surgical procedures, can also influence outcomes, though their effects are less conclusive. Advancements in patient selection criteria and scoring systems, such as the Milan Criteria and RETREAT score, have improved risk stratification by incorporating tumor size, biomarkers, and response to pre-transplant treatment. Despite these measures, recurrent HCC after transplantation poses treatment challenges. Curative approaches such as resection are feasible for localized or oligometastatic recurrence and offer the best outcomes when applicable. Locoregional treatments, including ablation and transarterial chemoembolization, provide options for unresectable cases but have limited long-term efficacy. Systemic therapies, including targeted agents like sorafenib, regorafenib, and lenvatinib, have shown modest benefits in managing advanced recurrent HCC. Emerging immunotherapy approaches hold promise but face unique challenges due to the required immunosuppression in transplant recipients. Multidisciplinary evaluation remains essential for tailoring treatment plans. Future efforts should focus on refining predictive tools and exploring novel therapies to improve survival outcomes for patients with recurrent HCC after liver transplantation.

2 March 2020 in Digestive Disease Interventions
Verified
Journal Article
Closed access
PDF file
KTKoji Tomiyama
Koji Tomiyama
MDM. Katherine Dokus
M. Katherine Dokus
JEJennie Errigo
Jennie Errigo
MLMarie Laryea
Marie Laryea
RHRoberto Hernandez-Alejandro
Roberto Hernandez-Alejandro
As chemotherapy for colorectal cancer becomes effective for extending long-term survival, its liver metastases (colorectal cancer liver metastases [CRCLM]) are considered as the progression that best defines patient survival. Surgical resection is the most effective and only curative treatment for CRCLM. Although advancement in liver surgery to increase resectability of CRCLM has borne fruit, there are still limitations, namely tumor burden, remnant liver volume, and chemotherapy-related liver damage. CRCLM used to be considered a contraindication for liver transplantation (LTx) based on preliminary experience in the early era of LTx. Recent advancement in chemotherapy and surgical resection for CRCLM as well as improved outcome of LTx have attracted interest in revisiting this old dogma of LTx for CRCLM. Preliminary experience from Norway has shown promising results and potential for long-term survival with LTx. In this article, we review the history of LTx for CRCLM, rationale for revisiting the concept, early experience from Norway and discuss the issues around and future perspectives on LTx for CRCLM.