Comparative analysis of liver resection in Non-B Non-C and hepatitis virus-associated hepatocellular carcinoma.

BACKGROUND: The incidence of non-hepatitis B and non-hepatitis C hepatocellular carcinoma (NBNC-HCC) is increasing in our country. This study assesses the feasibility of employing an identical surgical treatment strategy for resectable NBNC-HCC as that for hepatitis virus-associated HCC (HV-HCC). METHODS: A retrospective analysis (1993-2023) of 1321 curative liver resections for HCC at a single institution was performed. Propensity score matching ensured a balanced comparison of preoperative clinical factors, including tumor status and background liver condition. RESULTS: The proportion of NBNC-HCC cases has gradually increased, reaching up to 70 %. After matching, 294 of 473 NBNC-HCC patients and 294 of 848 HV-HCC patients were compared. Operative outcomes, including operation time, blood loss, type of surgical procedure, and morbidity, were comparable. Long-term outcome analysis showed similar recurrence-free survival (HR: 0.86, 95 % CI: 0.70-1.06, P = 0.167) and overall survival (HR: 0.98, 95 % CI: 0.79-1.23, P = 0.865) for NBNC-HCC. Multivariable analysis identified ICGR15 ≥ 15 %, ALBI grade 2 or 3, aspartate aminotransferase ≥40, tumor size > 5 cm, multiple tumors, macrovascular invasion, and microvascular invasion as independent prognostic factors for overall survival, while hepatitis B or C virus status lost significance. CONCLUSIONS: Despite the increasing incidence of NBNC-HCC, comparable outcomes were achieved between the two groups of matched cohort.

Oligo-like liver metastasis: A novel prognostic indicator to improve survival in pancreatic cancer.

Purpose: Whether surgical intervention for patients with oligometastatic recurrence can improve their post-recurrent prognosis is unclear. In this study, we introduce a novel concept of oligometastasis in post-surgical pancreatic ductal adenocarcinoma (PDAC) patients with hepatic recurrence, which we call "oligo-like liver metastasis (OLLM)." Patients with OLLM have better post-recurrence prognosis and could therefore be eligible for surgical intervention. Methods: A total of 121 PDAC patients who underwent radical resection, and who had an initial and single-organ metastasis to the liver, were analyzed. Independent prognostic factors for overall survival after recurrence (OSAR) were examined, and patients with all of these factors were defined as OLLM. The clinicopathological features and post-recurrent prognosis of OLLM patients were evaluated. In addition, a detailed analysis using the oligo-score, which was based on the prognostic factors, was performed. Results: The prognostic analysis revealed that short recurrence-free interval (RFI) (<6 months), short stable disease interval (SDI) (≤3 months), and four or more recurrent tumors were independent poor prognostic factors. OLLM patients were defined as those with all three conditions: long RFI (≥6 months), long SDI (>3 months), and three or less recurrent tumors. OLLM patients had a significantly better prognosis for OSAR than non-OLLM patients (HR = 0.272, p < 0.001). Further analysis demonstrated that the OSAR of patients could be stratified using the oligo-score, which was calculated based on the prognostic factors. Conclusion: We recommend that OLLM should be used to predict which patients are most likely to experience better post-recurrent prognosis after surgery with curative intent.

Impact of Surgical Margin Status on Survival and Recurrence After Pancreaticoduodenectomy for Distal Cholangiocarcinoma: Is Microscopic Residual Tumor (R1) Associated with Higher Rates of Local Recurrence?

BACKGROUND: Patients undergoing macroscopically curative resection for distal cholangiocarcinoma (DCC) have high recurrence rates and poor prognoses. This study aimed to investigate the impact of surgical margin status on survival and recurrence after resection of DCC, specifically focusing on microscopic residual tumor (R1) and its relationship to local recurrence. PATIENTS AND METHODS: This was a retrospective analysis of patients who had undergone pancreaticoduodenectomy (PD) for DCC between 2005 and 2021. Surgical margin was classified as R0, R1cis (positive bile duct margin with carcinoma in situ), and R1inv (positive bile duct margin with an invasive subepithelial component and/or positive radial margin). RESULTS: In total, 29 of 133 patients (21.8%) had R1cis and 23 (17.3%) R1inv. The 5-year overall survival (OS) for R0 (55.7%) did not differ significantly from that for R1cis/R1inv (47.4%/33.6%, respectively). The 5-year recurrence-free survival (RFS) for R0 was significantly longer than that for R1inv (50.1% vs. 17.4%, p = 0.003), whereas RFS did not differ significantly between those with R0 and R1cis. R1cis/R1inv status was not an independent predictor of OS and RFS in multivariate analysis. Cumulative incidence of isolated distant recurrence was significantly higher for R1cis/R1inv than for R0 (p = 0.0343/p = 0.0226, respectively), whereas surgical margin status was not significantly associated with rates of local or local plus distant recurrence. CONCLUSIONS: Surgical margin status does not significantly impact OS and RFS in patients undergoing PD for DCC following precise preoperative imaging evaluation. Additionally, R1 status is significantly linked to higher isolated distant recurrence rather than local recurrence, highlighting the importance of multidisciplinary therapy.

Pathological complete response of initially unresectable multiple liver metastases achieved using combined peptide receptor radionuclide therapy and somatostatin analogs following pancreatic neuroendocrine tumor resection: a case report.

BACKGROUND: Peptide receptor radionuclide therapy (PRRT) serves as a novel and effective treatment option for somatostatin receptor-positive unresectable liver metastases of pancreatic neuroendocrine tumors (PNETs). However, there are few reported cases of surgical resection for initially unresectable liver metastases of PNET that were converted to resectable after PRRT. Here we report a case where PRRT and somatostatin analogs (SSAs) led to a pathological complete response of initially unresectable multiple liver metastases following PNET resection. CASE PRESENTATION: A 52-year-old man underwent pylorus-preserving pancreaticoduodenectomy for PNET at age 40 and subsequent hepatectomies for resectable liver metastases at 44 and 47 years of age. At age 48, a follow-up examination revealed unresectable multiple liver metastases, and PRRT with 177Lu-DOTATATE therapy was initiated. After four cycles of PRRT, most liver metastases diminished according to imaging studies, and the remaining two hepatic lesions continued to shrink with additional lanreotide. Conversion surgery for liver metastases was successfully performed, revealing no viable tumor cells in tissue specimens. Seventeen months after surgery, imaging showed no detectable residual tumor or recurrence. We present a review of the relevant literature that highlights the significance of our findings. CONCLUSIONS: This rare case highlights the pathological complete response of initially unresectable multiple liver metastases achieved by PRRT and SSAs following PNET resection, suggesting their potential as a multimodality treatment option for unresectable PNET.

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis.

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.

Correlation of Vein-Rich Tumor Microenvironment of Intrahepatic Cholangiocarcinoma With Tertiary Lymphoid Structures and Patient Outcome.

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive cancer composed of large-duct and small-duct types. Understanding the tumor immune microenvironment and its related vascular system is important for developing novel and efficient therapies. We focused on tertiary lymphoid structure (TLS) as a hallmark of antitumor immunity and investigated the clinicopathologic significance of TLSs and the influence of vascular microenvironment on TLS formation in iCCAs. We examined 261 iCCA cases clinicopathologically and analyzed the vascular system using immunohistochemistry. Single-cell (102,685 cells) and bulk RNA (33 iCCA cases) sequencing analyses were performed using data sets downloaded from public databases, and endothelial cell characteristics in iCCA tissues and functional networks related to the tumor microenvironment were bioinformatically examined. High densities of both intratumoral and peritumoral TLSs were significantly associated with prolonged survival only in large-duct-type iCCA. Multivariate analyses showed that peritumoral TLS was a prognostic factor for the large-duct type. TLS-rich iCCA had a significantly higher vein density and tumor-infiltrating T-cell count than TLS-poor iCCA. Both the presence of TLSs and high vein endothelial cells in iCCA tissues were significantly associated with molecular networks representing active immune responses in transcriptomic analysis. Vein density was a prognostic factor in patients with large-duct and small-duct types. This suggests that TLS formation is involved in a microenvironment with high vein density, which represents an antitumor-directed immune microenvironment.

Feasibility of S-1 adjuvant chemotherapy after major hepatectomy for biliary tract cancers: An exploratory subset analysis of JCOG1202.

INTRODUCTION: Major hepatectomy (MH) may produce the impaired liver function and affect the feasibility of adjuvant chemotherapy in terms of early period after the surgery, but there have not been detailed investigations. JCOG1202 (UMIN000011688) is a randomized phase III trial demonstrating the superiority of adjuvant S-1 chemotherapy for biliary tract cancer (BTC). The aim of this study is to examine the influence of MH for BTC on adjuvant S-1. MATERIALS AND METHODS: Of the total 424 patients, 207 received S-1 (S-1 arm) while the remaining 217 were not. We compared MH with non-major hepatectomy (NMH) for BTC. RESULTS: In the S-1 arm, 42 had undergone MH, and 165 had undergone NMH. MH had similar pretreatment features to NMH, including the proportion of biliary reconstruction, to NMH, except for a lower platelet count (17.7 vs. 23.4 × 104/mm3, p < 0.0001) and lower serum albumin level (3.5 vs. 3.8 g/dL, p < 0.0001). The treatment completion proportion tended to be lower for MH than for NMH (59.5 % vs. 75.8 %; risk ratio, 0.786 [95 % confidence interval, 0.603-1.023], p = 0.0733), and the median dose intensity was lower as well (88.7 % vs. 99.6 %, p = 0.0358). The major reasons for discontinuation were biliary tract infections and gastrointestinal disorders after MH. The frequency of grade 3-4 biliary tract infection was 19.0 % in MH vs. 4.2 % in NMH. CONCLUSION: The treatment completion proportion and dose intensity were lower in MH than in NMH. Caution should be exercised against biliary tract infections and gastrointestinal disorders during adjuvant S-1 after MH for BTC.

Acral cutaneous malignant melanoma treated with linear accelerator-based boron neutron capture therapy system: a case report of first patient.

This study reports the first patient treatment for cutaneous malignant melanoma using a linear accelerator-based boron neutron capture therapy (BNCT) system. A single-center open-label phase I clinical trial had been conducted using the system since November 2019. A patient with a localized node-negative acral malignant melanoma and the largest diameter of the tumor ≤ 15 cm who refused primary surgery and chemotherapy was enrolled. After administering boronophenylalanine (BPA), a single treatment of BNCT with the maximum dose of 18 Gy-Eq delivered to the skin was performed. The safety and efficacy of the accelerator-based BNCT system for treating localized cutaneous malignant melanoma were evaluated. The first patient with cutaneous malignant melanoma in situ on the second finger of the left hand did not develop dose-limiting toxicity in the clinical trial. After BNCT, the treatment efficacy was gradually observed, and the patient achieved PR within 6 months and CR within 12 months. Moreover, during the follow-up period of 12 months after BNCT, the patient did not exhibit a recurrence without any treatment-related grade 2 or higher adverse events. Although grade 1 adverse events of dermatitis, dry skin, skin hyperpigmentation, edema, nausea, and aching pain were noted in the patient, those adverse events were relieved without any treatment. This case report shows that the accelerator-based BNCT may become a promising treatment modality for cutaneous malignant melanoma. We expect further clinical trials to reveal the efficacy and safety of the accelerator-based BNCT for cutaneous malignant melanoma.

Novel insights into the intraepithelial spread of extrahepatic cholangiocarcinoma: clinicopathological study of 382 cases on extrahepatic cholangiocarcinoma.

Background: Extrahepatic cholangiocarcinoma (eCCA) is a rare and aggressive disease and consisted of conventional eCCA and intraductal papillary neoplasm of the bile duct (IPNB). Intraepithelial spread (IES) of cancer cells beyond the invasive area is often observed in IPNBs; however, the prevalence of IES remains to be examined in conventional eCCAs. Here, we evaluated the clinicopathological features of eCCAs according to tumor location, with a focus on the presence of IES. The IES extension was also compared among biliary tract cancers (BTCs). Methods: We examined the prevalence and clinicopathological significance of IES in eCCAs (n=382) and the IES extension of BTCs, including gallbladder (n=172), cystic duct (n=20), and ampullary cancers (n=102). Results: Among the invasive eCCAs, IPNB had a higher rate of IES (89.2%) than conventional eCCAs (57.0%). Among conventional eCCAs, distal eCCAs (75.4%) had a significantly higher prevalence of IES than perihilar eCCAs (41.3%). The presence of IES was associated with a significantly higher survival rate in patients with distal eCCAs (P=0.030). Extension of the IES into the cystic duct (CyD) in distal eCCAs that cancer cells reached the junction of the CyD was a favorable prognostic factor (P<0.001). The association of survival with IES, either on the extrahepatic bile duct or on the CyD, differed depending on the tumor location and type of eCCA. The extension properties of IES were also dependent on different types of tumors among BTCs; usually, the IES incidence became higher than 50% in the tissues that the tumor developed, whereas IES extension to other tissues decreased the incidence. Conclusion: Thus, eCCAs have different clinicopathological characteristics depending on the tumor location and type.

Incidence and risk factors for venous thromboembolism in the Cancer-VTE Registry pancreatic cancer subcohort.

BACKGROUND: This substudy of the Cancer-VTE Registry estimated venous thromboembolism (VTE) incidence and risk factors in pancreatic cancer patients. METHODS: The Cancer-VTE Registry was an observational study that collected VTE data from patients with solid tumors across Japan. We measured baseline VTE prevalence, and at 1-year follow-up, the cumulative incidence of symptomatic and composite VTE (symptomatic VTE and incidental VTE requiring treatment), bleeding, cerebral infarction/transient ischemic attack (TIA)/systemic embolic event (SEE), and all-cause death. RESULTS: Of 1006 pancreatic cancer patients, 86 (8.5%) had VTE at baseline, and seven (0.7%) had symptomatic VTE. Significant risk factors of baseline VTE were Eastern Cooperative Oncology Group performance status (ECOG PS) of 1, body mass index (BMI) ≥ 25 kg/m2, history of VTE, D-dimer > 1.2 µg/mL, and hemoglobin < 10 g/dL. At 1-year follow-up, the cumulative incidence of events was higher for pancreatic cancer vs other cancers. Pancreatic cancer patients with VTE vs those without VTE had significantly higher incidences of bleeding, cerebral infarction/TIA/SEE, and all-cause death. No significant risk factors for composite VTE were identified. CONCLUSIONS: The cumulative incidence of composite VTE during cancer treatment was higher in pancreatic cancer than in other cancer types. Some risk factors for VTE prevalence at cancer diagnosis were identified. Although VTE prevalence at cancer diagnosis did not predict the subsequent 1-year incidence of composite VTE, it was a significant predictor of other events such as all-cause death in pancreatic cancer patients. TRIAL REGISTRATION: UMIN Clinical Trials Registry; UMIN000024942.

Objective Definition and Optimized Strategy for "Biologically Borderline Resectable" Colorectal Liver Metastases.

BACKGROUND: The prognostic benefit of preoperative chemotherapy leading to conversion surgery for unresectable colorectal liver metastases (CRLM) is well recognized, while that of neoadjuvant chemotherapy (NAC) compared with upfront surgery (UFS) for resectable CRLM is negligible. This study aims to assess the prognostic benefit and search for optimal indication of NAC for resectable advanced CRLM by establishing an objective definition of biologically borderline resectable (bBR) CRLM. METHODS: A bicentric retrospective analysis of patients with CRLM undergoing curative-intent initial liver resection between 2007 and 2021 was performed. An original classification matrix was established, which reassessed technical resectability using virtual hepatectomy and oncological favorability using Beppu's nomogram. Patients with technically resectable but biologically unfavorable CRLM were classified into the bBR group. The propensity score matching analysis using preoperatively available factors was performed to assess long-term outcomes of the bBR-UFS and bBR-NAC groups. RESULTS: Of 831 patients reviewed, 240 were categorized into the bBR group: bBR -UFS (n = 139) and bBR-NAC (n = 101). Ten (10%) in the bBR-NAC group (n = 101) experienced biological status change from unfavorable to favorable after NAC (Biological Conversion) and showed significantly longer overall survival (hazard ratio 5.63, 95% confidence interval 1.37-23.1; P = 0.016) than the bBR-UFS group. However, after propensity score matching, no significant difference between the UFS and NAC groups (n = 67 for each) was found in long-term outcomes. CONCLUSIONS: NAC for bBR-CRLM did not enhance the prognostic impact of the following liver resection, except for a limited number of optimal candidates experiencing the Biological Conversion.

A multi-centre, double-blind, randomized, placebo-controlled trial to evaluate the effectiveness and safety of ramelteon for the prevention of postoperative delirium in elderly cancer patients: a study protocol for JORTC-PON2/J-SUPPORT2103/NCCH2103.

Postoperative delirium is an important issue in cancer patients, affecting surgical outcomes and the quality of life. Ramelteon is a melatonin receptor agonist with high affinity for MT1 and MT2 receptors. Clinical trials and observational studies in Japan, including in surgical cancer patients, have shown efficacy of ramelteon in delirium prevention, with no serious safety concerns. However, clinical trials from the USA have reported conflicting results. A Japanese phase II study investigated the efficacy and safety of ramelteon for delirium prevention following gastrectomy in patients aged ≥75 years, with findings suggesting the feasibility of a phase III trial. The aim of this multi-centre, double-blind, randomized placebo-controlled phase III trial is to evaluate the effectiveness and safety of oral ramelteon for postoperative delirium prevention in cancer patients aged ≥65 years as advanced medical care. The trial protocol is described here.

A new era of the Asian clinical research network: a report from the ATLAS international symposium.

This report summarizes the presentations and discussions in the first Asian Clinical Trials Network for Cancers (ATLAS) international symposium that was held on 24 April 2022, in Bangkok, Thailand, and hosted by the National Cancer Center Hospital (NCCH), co-hosted by the Pharmaceuticals and Medical Devices Agency (PMDA), Clinical Research Malaysia (CRM) and the Thai Society of Clinical Oncology (TSCO), and supported by Embassy of Japan in Thailand. Since 2020, the NCCH has conducted the ATLAS project to enhance research environments and infrastructures to facilitate international clinical research and cancer genomic medicine in the Asian region. The purpose of the symposium was to discuss what we can achieve under the ATLAS project, to share the latest topics and common issues in cancer research and to facilitate mutual understanding. Invitees included stakeholders from academic institutions, mainly at ATLAS collaborative sites, as well as Asian regulatory authorities. The invited speakers discussed ongoing collaborative research, regulatory perspectives to improve new drug access in Asia, the status of phase I trials in Asia, the introduction of research activities at the National Cancer Center (NCC) and the implementation of genomic medicine. As the next steps after this symposium, the ATLAS project will foster increased cooperation between investigators, regulatory authorities and other stakeholders relevant to cancer research, and establish a sustainable pan-Asian cancer research group to increase the number of clinical trials and deliver novel drugs to patients with cancer in Asia.

Enhanced Recognition Confidence of Millimeter-Sized Intrahepatic Targets by Real-Time Virtual Sonography.

OBJECTIVES: Real-time virtual sonography (RVS) is an artificial-intelligence-assisted ultrasonographic navigation system that displays synchronized preoperative computed tomography (CT) images corresponding to real-time intraoperative ultrasonograms (IOUS). This study aimed to investigate whether RVS can enhance IOUS identification of small intrahepatic targets found in preoperative CT. METHODS: Patients with small intrahepatic targets detected by preoperative thin-slice dynamic CT before liver resection were included. The targets included millimeter-sized liver tumors or a third-order or more distal portal branch and were marked on CT images using 3D simulation software. After laparotomy, the targets were searched using fundamental IOUS, and participating liver surgeons subjectively scored the target identifying confidence on a scale of 1-5 (5 points for detection with the highest confidence and one point for undetectable). Then, the search procedure was repeated using the RVS, and the scores were compared. RESULTS: Totally, 55 patients with 117 small targets were investigated. The median target size was 6.0 mm, and the median registration time was 3.6 seconds. The target identification confidence score significantly increased from 2.78 to 4.52 points after using RVS. Seventeen targets (14.5%) were undetectable in fundamental IOUS, and 14 of them were identified by RVS. The detectability of small liver tumors (2-5 points of identification confidence) by IOUS was 81.1 and 96.7% by RVS. CONCLUSION: RVS enhanced surgeons' confidence in identifying millimeter-sized intrahepatic targets found in preoperative CT.

Novel Insights Into Immunohistochemical Analysis For Acinar Cell Neoplasm of The Pancreas: Carboxypeptidase A2, Carboxypeptidase A1, and Glycoprotein 2.

Acinar cell carcinoma (ACC) is a rare and highly malignant pancreatic tumor. Owing to histologic similarity, ACC is often difficult to distinguish from other solid medullary pancreatic tumors, particularly neuroendocrine neoplasm (NEN) and intraductal tubulopapillary neoplasm (ITPN). We aimed to identify new immunohistochemical markers commonly expressed in tumor cells with acinar cell differentiation and useful for both surgical and small biopsy specimens. Candidate molecules exclusively expressed in neoplastic or non-neoplastic acinar cells in pancreatic tissues with specific and available antibodies suitable for immunohistochemistry were selected. We selected carboxypeptidase A1 (CPA1), carboxypeptidase A2 (CPA2), and glycoprotein 2 (GP2), which were expressed in 100%, 100%, and 96% of cases, respectively, in ACC (n=27) or neoplasia with acinar cell differentiation, including mixed acinar-neuroendocrine carcinoma (n=9), mixed acinar-ductal carcinoma (n=3), pancreatoblastoma (n=4), and acinar cystic transformation (n=2), in the cytoplasm of tumor cells with a granular pattern. Both CPA2 and CPA1 were not expressed in any other tumors without acinar cell differentiation, including NEN (n=44), pancreatic ductal adenocarcinoma (n=44), and ITPN (n=4). GP2 was not expressed in these tumors except in rare cases, including 14% of NEN, 15% of intraductal papillary-mucinous neoplasm, 25% of intraductal oncocytic papillary neoplasm, 25% of ITPN, and 7% of pancreatic ductal adenocarcinoma, wherein a small proportion of tumor cells expressed GP2 in their apical cell membrane. NEN cases also showed cytoplasmic GP2 expression. Therefore, CPA2, CPA1, and potentially GP2 may act as ACC markers.

Adjuvant S-1 compared with observation in resected biliary tract cancer (JCOG1202, ASCOT): a multicentre, open-label, randomised, controlled, phase 3 trial.

BACKGROUND: S-1 has shown promising efficacy with a mild toxicity profile in patients with advanced biliary tract cancer. The aim of this study was to evaluate whether adjuvant S-1 improved overall survival compared with observation for resected biliary tract cancer. METHODS: This open-label, multicentre, randomised phase 3 trial was conducted in 38 Japanese hospitals. Patients aged 20-80 years who had histologically confirmed extrahepatic cholangiocarcinoma, gallbladder carcinoma, ampullary carcinoma, or intrahepatic cholangiocarcinoma in a resected specimen and had undergone no local residual tumour resection or microscopic residual tumour resection were randomly assigned (1:1) to undergo observation or to receive S-1 (ie, 40 mg, 50 mg, or 60 mg according to body surface area, orally administered twice daily for 4 weeks, followed by 2 weeks of rest for four cycles). Randomisation was performed by the minimisation method, using institution, primary tumour site, and lymph node metastasis as adjustment factors. The primary endpoint was overall survival and was assessed for all randomly assigned patients on an intention-to-treat basis. Safety was assessed in all eligible patients. For the S-1 group, all patients who began the protocol treatment were eligible for a safety assessment. This trial is registered with the University hospital Medical Information Network Clinical Trials Registry (UMIN000011688). FINDINGS: Between Sept 9, 2013, and June 22, 2018, 440 patients were enrolled (observation group n=222 and S-1 group n=218). The data cutoff date was June 23, 2021. Median duration of follow-up was 45·4 months. In the primary analysis, the 3-year overall survival was 67·6% (95% CI 61·0-73·3%) in the observation group compared with 77·1% (70·9-82·1%) in the S-1 group (adjusted hazard ratio [HR] 0·69, 95% CI 0·51-0·94; one-sided p=0·0080). The 3-year relapse-free survival was 50·9% (95% CI 44·1-57·2%) in the observation group compared with 62·4% (55·6-68·4%) in the S-1 group (HR 0·80, 95% CI 0·61-1·04; two-sided p=0·088). The main grade 3-4 adverse events in the S-1 group were decreased neutrophil count (29 [14%]) and biliary tract infection (15 [7%]). INTERPRETATION: Although long-term clinical benefit would be needed for a definitive conclusion, a significant improvement in survival suggested adjuvant S-1 could be considered a standard of care for resected biliary tract cancer in Asian patients. FUNDING: The National Cancer Center Research and the Ministry of Health, Labour, and Welfare of Japan.

Prediction of tissue-of-origin of early stage cancers using serum miRNomes.

BACKGROUND: Noninvasive detection of early stage cancers with accurate prediction of tumor tissue-of-origin could improve patient prognosis. Because miRNA profiles differ between organs, circulating miRNomics represent a promising method for early detection of cancers, but this has not been shown conclusively. METHODS: A serum miRNA profile (miRNomes)-based classifier was evaluated for its ability to discriminate cancer types using advanced machine learning. The training set comprised 7931 serum samples from patients with 13 types of solid cancers and 5013 noncancer samples. The validation set consisted of 1990 cancer and 1256 noncancer samples. The contribution of each miRNA to the cancer-type classification was evaluated, and those with a high contribution were identified. RESULTS: Cancer type was predicted with an accuracy of 0.88 (95% confidence interval [CI] = 0.87 to 0.90) in all stages and an accuracy of 0.90 (95% CI = 0.88 to 0.91) in resectable stages (stages 0-II). The F1 score for the discrimination of the 13 cancer types was 0.93. Optimal classification performance was achieved with at least 100 miRNAs that contributed the strongest to accurate prediction of cancer type. Assessment of tissue expression patterns of these miRNAs suggested that miRNAs secreted from the tumor environment could be used to establish cancer type-specific serum miRNomes. CONCLUSIONS: This study demonstrates that large-scale serum miRNomics in combination with machine learning could lead to the development of a blood-based cancer classification system. Further investigations of the regulating mechanisms of the miRNAs that contributed strongly to accurate prediction of cancer type could pave the way for the clinical use of circulating miRNA diagnostics.