Novel adjuvant dendritic cell therapy with transfection of heat-shock protein 70 messenger RNA for patients with hepatocellular carcinoma: a phase I/II prospective randomized controlled clinical trial.

INTRODUCTION: A proteomic analysis of hepatocellular carcinoma (HCC) has revealed that Heat Shock Protein 70 (HSP70) is among the cancer antigen proteins of HCC. Moreover, we confirmed that HSP70 was highly expressed in HCC by immunohistochemical staining. Based on these results, we developed an HSP70 mRNA-transfected dendritic cell (DC) therapy for treating unresectable or recurrent HCC, and the phase I trial was completed successfully. Thus, we aimed to investigate the safety and efficacy of this therapy as a postoperative adjuvant treatment after curative resection for HCC to prevent recurrence by conducting a phase I/II randomized controlled clinical trial. METHODS: Patients (n = 45) with resectable HCC of stages II-IVa were registered and randomly assigned into two groups (DC group: 31 patients, control group: 14 patients) before surgery. The primary endpoint was disease-free survival (DFS), and the secondary endpoints were safety and overall survival. The DC therapy was initially administered at approximately 1 week after surgery, and twice every 3-4 weeks thereafter. RESULTS: No adverse events specific to the immunotherapy were observed in the DC group. There was no difference in DFS between the DC and control groups (p = 0.666). However, in the subgroup with HSP70-expressing HCC, DFS of the DC group tended to be better (p = 0.090) and OS of the DC group was significantly longer (p = 0.003) than those of the control group. CONCLUSION: The HSP70 mRNA-transfected DC therapy was performed safely as an adjuvant therapy. The prognosis of HSP70-expressing HCC cases could be expected to improve with this therapy.

Development of cytoplasmic male sterile lines and restorer lines of various elite Indica Group rice cultivars using CW-CMS/Rf17 system.

BACKGROUND: A cytoplasm of CW-type cytoplasmic male sterile (CMS) line is derived from Oryza rufipogon strain W1 and fertility is restored by a single nuclear gene, Rf17. We have previously reported that CW-CMS were effective for breeding CMS lines of Indica Group rice cultivars, IR 24 and IR 64. The applicability of this CW-CMS/Rf17 system to produce other elite Indica Group rice cultivars with CMS was explored. FINDINGS: Out of seven elite Indica Group rice cultivars, complete CMS lines were obtained for six cultivars: NSIC Rc 160, NSIC Rc 240, Ciherang, BRRI dhan 29, NERICA-L-19, and Pusa Basmati. The fertility of these six lines was restored when Rf17 was present. A CMS line was not obtained for the cultivar Samba Mahsuri. CONCLUSIONS: The CW-CMS/Rf17 system will be useful to produce CMS lines and restorer lines of various elite Indica Group rice cultivars.

Antimicrobial prophylaxis for 1 day versus 3 days in liver cancer surgery: a randomized controlled non-inferiority trial.

PURPOSES: This study compared the effectiveness of 1-day vs 3-days antibiotic regimen to prevent surgical site infection (SSI) in open liver resection. METHOD: We performed a randomized controlled non-inferiority trial in 480 patients at 39 hospitals across Japan (registered as UMIN000002852). Patients with hepatocellular carcinoma scheduled to undergo resection were randomly assigned to receive either a 1-day regimen for antimicrobial prophylaxis, or a 3-day regimen. The primary endpoint was the incidence of SSI. RESULTS: Among 480 randomized patients, 232 assigned to the 1-day regimen and 235 to the 3-day regimen were included in the full analysis set. Baseline characteristics of the two groups were well balanced. SSI was diagnosed in 22 patients (9.5%) in the 1-day group vs 23 patients (9.8%) in the 3-day group (difference, - 0.30; 90% CI - 4.80 to 4.19% [95% CI - 5.66% to 5.05%]; one-sided P = 0.001 for non-inferiority), meeting the non-inferiority hypothesis. In both groups, remote site infection (16 [6.9%] vs 22 [9.4%], P ˂ 0.001 for non-inferiority) and drain-related infection (5 [2.2%] vs 4 [1.7%], P ˂ 0.001 for non-inferiority) were comparable. CONCLUSION: To prevent SSI in liver cancer surgery, a 1-day regimen of flomoxef sodium is recommended for antimicrobial prophylaxis because of confirming the non-inferiority to longer usage.

A novel somatic mutation of SIN3A detected in breast cancer by whole-exome sequencing enhances cell proliferation through ERα expression.

Breast cancer is the most frequent tumor in women, and in nearly two-thirds of cases, the tumors express estrogen receptor α (ERα, encoded by ESR1). Here, we performed whole-exome sequencing of 16 breast cancer tissues classified according to ESR1 expression and 12 samples of whole blood, and detected 310 somatic mutations in cancer tissues with high levels of ESR1 expression. Of the somatic mutations validated by a different deep sequencer, a novel nonsense somatic mutation, c.2830 C>T; p.Gln944*, in transcriptional regulator switch-independent 3 family member A (SIN3A) was detected in breast cancer of a patient. Part of the mutant protein localized in the cytoplasm in contrast to the nuclear localization of ERα, and induced a significant increase in ESR1 mRNA. The SIN3A mutation obviously enhanced MCF7 cell proliferation. In tissue sections from the breast cancer patient with the SIN3A c.2830 C>T mutation, cytoplasmic SIN3A localization was detected within the tumor regions where nuclear enlargement was observed. The reduction in SIN3A mRNA correlates with the recurrence of ER-positive breast cancers on Kaplan-Meier plots. These observations reveal that the SIN3A mutation has lost its transcriptional repression function due to its cytoplasmic localization, and that this repression may contribute to the progression of breast cancer.

Antimicrobial susceptibility of common pathogens isolated from postoperative intra-abdominal infections in Japan.

The principle of empirical therapy for patients with intra-abdominal infections (IAI) should include antibiotics with activity against Enterobacteriaceae and Bacteroides fragilis group species. Coverage of Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis is also recommended for hospital-associated IAI. A nationwide survey was conducted to investigate the antimicrobial susceptibility of pathogens isolated from postoperative IAI. All 504 isolates were collected at 26 institutions and referred to a central laboratory for susceptibility testing. Lower susceptibility rates to ciprofloxacin and cefepime were demonstrated in Escherichia coli. Among E. coli, 24.1% of strains produced extended-spectrum ß-lactamase (ESBL). Carbapenems, piperacillin/tazobactam, cephamycins/oxacephem, aminoglycosides, and tigecycline had high activity against E. coli, including ESBL-producing isolates. Among E. cloacae, low susceptibility rates to ceftazidime were demonstrated, whereas cefepime retained its activity. P. aeruginosa revealed high susceptibility rates to all antimicrobials tested except for imipenem. Among B. fragilis group species, low levels of susceptibility were observed for cefoxitin, moxifloxacin, and clindamycin, and high susceptibility rates were observed for piperacillin/tazobactam, meropenem, and metronidazole. Ampicillin, piperacillin, and glycopeptides had good activity against E. faecalis. Imipenem had the highest activity against E. faecalis among carbapenems. In conclusion, we suggested the empirical use of antimicrobials with the specific intent of covering the main organisms isolated from postoperative IAI. Piperacillin/tazobactam, meropenem, or doripenem, are appropriate in critically ill patients. Combination therapy of cefepime (aztreonam in patients with ß-lactam allergy) plus metronidazole plus glycopeptides, imipenem/cilastatin or cephamycins/oxacephem plus ciprofloxacin plus metronidazole are potential therapeutic options.

Expression levels of UL16 binding protein 1 and natural killer group 2 member D affect overall survival in patients with gastric cancer following gastrectomy.

UL16 binding protein 1 (ULBP1) expressed on the tumor cell surface binds to the natural killer group 2 member D (NKG2D) receptor presenting on natural killer (NK), cluster of differentiation (CD)8+ T, and γ δ T cells. However, the roles of ULBP1 and NKG2D expression and associated immune responses in gastric cancer are unclear. The present study investigated the associations between ULBP1 and NKG2D expression and clinical outcomes in patients with gastric cancer. The levels of ULBP1 and NKG2D expression were examined in human gastric cancer cell lines and gastric cancer tissues from 98 patients who underwent surgery from 2004 to 2008. MKN-74 cells expressed ULBP1 with ULBP2, -5, or -6. NKG2D was expressed at a higher level following activation of T cells and NK cells. Among the tissue sections positive for NKG2D expression, 6 patients were positive for CD8 and CD56. In all tissues, NKG2D-expressing cells were typically aCD8+ T cells. Patients with NKG2D expression in tumors exhibited significantly longer overall survival (OS) compared with patients without NKG2D expression in tumors (P=0.0217). The longest OS was observed in patients positive for ULBP1 and NKG2D, whereas the shortest OS was observed in patients negative for ULBP1 and NKG2D. The interaction between ULBP1 and NKG2D may improve OS in patients with gastric cancer, and may have applications in immunotherapy for the induction of adaptive immunity in patients with cancer. Additionally, ULBP1 and NKG2D may be useful as prognostic biomarkers in gastric cancer.

Highly sensitive faecal DNA testing of TWIST1 methylation in combination with faecal immunochemical test for haemoglobin is a promising marker for detection of colorectal neoplasia.

Background As TWIST1 methylation is specific to colorectal neoplasia, detection of TWIST1 methylation from faeces samples might be useful for colorectal neoplasia screening. However, because the content of human DNA in faeces is very small, it is very difficult to detect TWIST1 methylation by conventional bisulphite-based methylation assays. Therefore, we developed a new methylation assay without bisulphite treatment, the combined restriction digital PCR assay, and evaluated its sensitivity and specificity in combination with and without the faecal immunochemical test for haemoglobin for colorectal neoplasia detection from faeces samples. Methods For the combined restriction digital PCR assay, DNA was treated with three methylation-sensitive restriction enzymes and an exonuclease, followed by measurement of TWIST1 methylation level by droplet digital PCR. Faecal DNA testing and faecal immunochemical test for haemoglobin were performed on 109 patients with colorectal neoplasia and 10 control individuals. Results Basic performance testing showed that the combined restriction digital PCR assay enabled detection of 0.14% of the TWIST1 methylation level for the lymphocyte DNA. The combined restriction digital PCR assay from faeces samples had a sensitivity of 22.2% (95% confidence interval, 2.8-60.0%) for non-advanced adenoma, 47.1% (95% confidence interval, 23.0-72.2%) for advanced adenoma, and 33.7% (95% confidence interval, 23.7-45.0%) for colorectal cancer, and a specificity of 100.0%. Combination of faecal immunochemical test for haemoglobin and faecal combined restriction digital PCR assay increased sensitivity to 82.4% (95% confidence interval, 56.6-96.2%) for the detection of advanced adenoma. Conclusions We developed the combined restriction digital PCR assay, a possible highly sensitive methylation assay. Combination of faecal combined restriction digital PCR assay with faecal immunochemical test for haemoglobin may provide an alternative screening strategy for colorectal neoplasia, especially for potentially precancerous lesions.

Boundary-artifact-free determination of potential distribution from differential phase contrast signals.

The differential phase contrast (DPC) imaging in STEM was mainly used for a study of magnetic material in a medium resolution. An ideal DPC signals give the center of mass of the diffraction pattern, which is proportional to an electric field. Recently, the possibility of the DPC imaging at atomic resolution was demonstrated. Thus, the DPC imaging opens up the possibility to observe the object phase that is proportional to the electrostatic potential.In this report we investigate the numerical procedures to obtain the object phase from the two perpendicular DPC signals. Specifically, we demonstrate that the discrete cosine transform (DCT) is the method to solve the Poisson equation, since we can use the Neumann boundary condition directly specified by the DPC signals. Furthermore, based on the fast Fourier transform (FFT) of an extended DPC signal we introduce the scheme that gives an equivalent result that is obtained with the DCT. The results obtained with the DCT and extended FFT method are superior to the results obtained with commonly used FFT. In addition, we develop real-time integration schemes that update the result with the progress of the scan. Our real-time integration gives the reasonable result, and can be used in a view mode. We demonstrate that our numerical procedures work excellently with the experimental DPC signals obtained from SrTiO3 single crystal.

miR-196b, miR-378a and miR-486 are predictive biomarkers for the efficacy of vaccine treatment in colorectal cancer.

MicroRNAs (miRNAs/miRs) regulate the levels of transcripts and serve a critical function in the regulation of tumor microenvironments. Therefore, miRNA levels in cancer tissues are thought to be potential biomarkers for immunotherapy. From a phase I trial of a vaccine treatment using 5 human leukocyte antigen (HLA)-A*2402-restricted peptides (registration no. UMIN000004948), colorectal cancer (CRC) tissues were obtained from 8 patients and normal colorectal tissues from 5 patients via surgery. From a phase II trial using the same peptides (registration no. UMIN000001791), CRC tissues were obtained from 16 patients from the HLA-A*2402-matched group and 10 patients from the HLA-A*2402-unmatched group. These tissues were used for miRNA microarray analysis. As the first step, cancer tissues from the phase I study were used and 10 candidate miRNAs were selected by comparing the miRNA expression between two groups; one with improved prognosis and the other with poor prognosis. The miRNAs were subsequently validated using the cases enrolled in the phase II study. Significantly improved prognoses were identified in 16 patients in the HLA-A*2402-matched group with high expression of miR-196b-5p and low expression of miR-378a-3p and miR-486-5p. There was no difference in prognosis in the 10 patients in the HLA-A*2402-unmatched group. Therefore, high miR-196b expression and low miR-378a-3p and miR-486-5p expression were indicated as useful biomarkers for prediction of the efficacy of vaccine treatment for patients with metastatic CRC. In a planned phase III study, expression levels of these 3 miRNAs (miR-196b-5p, miR-378a-3p and miR-486-5p) may be useful biomarkers for assessing patients who are likely to have an improved outcome following vaccination.

Correlation Between NKG2DL Expression and Antitumor Effect of Protein-bound Polysaccharide-K in Tumor-bearing Mouse Models.

BACKGROUND/AIM: We investigated the relationship between the expression of natural killer group 2, member D ligands (NKG2DLs) and the antitumor effects of protein-bound polysaccharide-K (PSK). MATERIALS AND METHODS: PSK was administered to evaluate its effectiveness against tumor growth. The expression of Rae-1 and H60 were analyzed in multiple cell lines. RESULTS: PSK showed the highest antitumor effects in mice implanted with cells expressing neither Rae-1 nor H60. PSK had little antitumor effect in mice implanted with cells expressing both Rae-1 and H60. A correlation between the expression of NKG2DLs and the antitumor effect of PSK was observed. After PSK administration, INF-γ production in CD8+ T cells increased in mice with cells expressing neither Rae-1 nor H60, but did not change in mice implanted with cells expressing both Rae-1 and H60. CONCLUSION: We demonstrated that the expression of NKG2DLs affects tumor immunity and the efficacy of immuno therapy in tumor-bearing mouse model.

Postoperative Adjuvant Therapy for Resectable Pancreatic Cancer With Gemcitabine and Adoptive Immunotherapy.

OBJECTIVES: We previously described adoptive immunotherapy (AIT) with cytotoxic T lymphocytes (CTLs) stimulated by the mucin 1 (MUC1)-expressing human pancreatic cancer cell line YPK-1 (MUC1-CTLs) and demonstrated that MUC1-CTLs might prevent liver metastasis. In the present study, we combined gemcitabine (GEM) and AIT for the treatment of pancreatic cancer. METHODS: A total of 43 patients who underwent radical pancreatectomy received treatment with MUC1-CTLs and GEM. After surgery, MUC1-CTLs were induced and administered intravenously 3 times, and GEM administered according to the standard regimen for 6 months. The patients whose relative dose intensity of GEM was 50% or more and who received 2 or more MUC1-CTL treatments were used as the adequate treatment group (n = 21). RESULTS: In the adequate treatment group, disease-free survival was 15.8 months, and overall survival was 24.7 months. Liver metastasis was found only in 7 patients (33%), and local recurrence occurred in 4 patients (19%). The independent prognostic factor of long-term disease-free survival on multivariate analysis was the average number of CTLs administered (P = 0.0133). CONCLUSIONS: The combination therapy with AIT and GEM prevented liver metastasis and local recurrence. Moreover, the disease free-survival was improved in patients who received sufficient CTLs.

Rapid and sensitive detection of UGT1A1 polymorphisms associated with irinotecan toxicity by a novel DNA microarray.

Recent developments in the field of human genomics have greatly enhanced the potential for precision and personalized medicine. We have developed a novel DNA microarray, using a 3-mm square chip coated with diamond-like carbon to enhance the signal-to-background ratio, for use as an in vitro diagnostic tool in precision medicine. To verify the genotyping effectiveness of this newly developed DNA microarray we examined UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms in DNA extracted from patients with metastatic colorectal cancer. It is established that the polymorphisms of UGT1A1*28 and UGT1A1*6 are significantly associated with severe toxicity induced by the anti-cancer drug irinotecan. For each sample, the results obtained with the novel microarray platform were compared with those obtained using other, more established, methods, including direct sequencing and the Invader assay. The polymorphisms tested included a single nucleotide substitution (UGT1A1*6) and a TA-repeat polymorphism (UGT1A1*28), both of which were detected simultaneously and accurately using our method. Moreover, our method required 1.5-fold less time to assay and 20-fold less sample than those required by the Invader assay. In summary, our newly developed DNA microarray is more practical than established methods, and is at least as accurate; this will increase the efficiency of polymorphism detection prior to diagnosis and the commencement of treatment, and can feasibly be applied in precision medicine.

A phase II, multicenter, single-arm study of tri-weekly low-dose nanoparticle albumin-bound paclitaxel chemotherapy for patients with metastatic or recurrent breast cancer.

BACKGROUND: Nanoparticle albumin-bound (nab)-paclitaxel is a solvent-free formulation of paclitaxel that is bound to albumin and has demonstrated improved progression free survival in previous studies of breast cancer. However, it is difficult to treat Japanese patients with metastatic or recurrent breast cancer with the recommended dose of 260 mg/m2 of (nab)-paclitaxel for more than six cycles due to the occurrence of adverse events. To evaluate the treatment continuity and safety of low-dose nab-paclitaxel, we conducted a phase II study of nab-paclitaxel in patients with metastatic or recurrent breast cancer who had received up to one prior chemotherapy. PATIENTS AND METHODS: Treatment included low doses of 180 mg/m2 nab-paclitaxel that were administered on day 1 of each 3-week cycle to 35 patients. The primary endpoint was the completion rate of six cycles of treatment. RESULTS: A total of 35 eligible patients were enrolled and received a median of eight (range 2-24) cycles of low-dose nab-paclitaxel therapy. The completion rate of six cycles of treatment was 66%. ORR and clinical benefit rate was 23 and 71%, respectively. Median PFS was 6.5 months and median OS was 44 months. Adverse events were relatively mild. Commonly observed grade 3/4 adverse events were neutropenia (46%), leukopenia (9%), and hypertension (3%). No grade 3-4 peripheral sensory neuropathy occurred. CONCLUSION: Treatment with a low dose of nab-paclitaxel once every 3 weeks was tolerable and of acceptable safety and might be beneficial for patients with metastatic or recurrent breast cancer.

Antimicrobial susceptibility of pathogens isolated from surgical site infections in Japan: Comparison of data from nationwide surveillance studies conducted in 2010 and 2014-2015.

A nationwide survey was conducted in Japan from 2014 to 2015 to investigate the antimicrobial susceptibility of pathogens isolated from surgical site infections (SSI). The resulting data were compared with that obtained in an earlier survey, conducted in 2010. Seven main organisms were collected, and 883 isolates were studied. A significant reduction in methicillin resistance was observed among Staphylococcus aureus isolates, dropping from 72.5% in 2010 to 53.8% in 2014-2015 (p < 0.001). MRSA isolates with a vancomycin minimum inhibitory concentration (MIC) of 2 µg/mL accounted for 1.2% of all MRSA isolates, which was significantly lower than in 2010 (9.7%, p = 0.029). Of the Escherichia coli isolates, 23.0% produced an extended spectrum ß-lactamase (ESBL) in the 2014-2015 survey, which was a significant increase from 9.5% in 2010 (p = 0.011). The geometric mean MICs for ESBL-producing isolates were 0.07 µg/mL for meropenem, 9.51 µg/mL for tazobactam/piperacillin, 0.15 µg/mL for flomoxef, and 1.56 µg/mL for gentamycin. There was a significant increase in the isolation rate of non-fragilis Bacteroides among Bacteroides fragilis group species between the two study periods (35.2% vs. 53.1%, p = 0.007). More than 90% of isolates belonging to the B. fragilis group remained susceptible to tazobactam/piperacillin, meropenem, and metronidazole. In contrast, lower levels of susceptibility were observed for cefmetazole (49.6%), moxifloxacin (61.9%), and clindamycin (46.9%). Non-fragilis Bacteroides isolates had lower rates of antibiotic susceptibility compared with B. fragilis. Overall, the surveillance data clarified trends in antimicrobial susceptibility for organisms commonly associated with SSI.

Predictive biomarkers for the efficacy of peptide vaccine treatment: based on the results of a phase II study on advanced pancreatic cancer.

BACKGROUND: The purpose of the present study was to explore novel biomarkers that can predict the clinical outcome of patients before treatment or during vaccination. These would be useful for the selection of appropriate patients who would be expected to exhibit better treatment outcomes from vaccination, and for facilitating the development of cancer vaccine treatments. METHODS: From a single-arm, non-randomized, human leukocyte antigen (HLA)-A-status-blind phase II trial of a vaccine treatment using three HLA-A*2402-restricted peptides for advanced pancreatic cancer (PC), we obtained peripheral blood samples from 36 patients of an HLA-A*2402-matched group and 27 patients of an HLA-A*2402-unmatched group. RESULTS: Multivariate analysis (HR = 2.546; 95% CI = 1.138 to 5.765; p = 0.0231) and log-rank test (p = 0.0036) showed that a high expression level of programmed death-1 (PD-1) on CD4+ T cells was a negative predictive biomarker of overall survival in the HLA-A*2402-matched group . Moreover, a high expression level of PD-1 on CD4+ T cells was a negative predictor for the induction of cytotoxic T lymphocytes (p = 0.0007). After treatment, we found that the upregulation of PD-1 and T cell immunoglobulin mucin-3 (Tim-3) expression on CD4+ and CD8+ T cells was significantly associated with a poor clinical outcome in the HLA-A*2402-matched group (p = 0.0330, 0.0282, 0.0046, and 0.0068, respectively). In contrast, there was no significant difference for these factors in the HLA-A*2402-unmatched group. CONCLUSIONS: Our results indicate that the upregulation of PD-1 and Tim-3 expression on CD4+ and CD8+ T cells may restrict T cell responses in advanced PC patients; therefore, combination immunotherapy with blockade of PD-1 and Tim-3 to restore T cell responses may be a potential therapeutic approach for advanced PC patients. TRIAL REGISTRATION: Clinical-Trail-Registration: UMIN000008082 .

Phase II clinical trial of peptide cocktail therapy for patients with advanced pancreatic cancer: VENUS-PC study.

We previously conducted a phase I clinical trial combining the HLA-A*2402-restricted KIF20A-derived peptide vaccine with gemcitabine for advanced pancreatic cancer (PC) and confirmed its safety and immunogenicity in cancer patients. In this study, we conducted a multicenter, single-armed, phase II trial using two antiangiogenic cancer vaccines targeting VEGFR1 and VEGFR2 in addition to the KIF20A peptide. We attempted to evaluate the clinical benefit of the cancer vaccination in combination with gemcitabine. Chemotherapy naïve PC patients were enrolled to evaluate primarily the 1-year survival rate, and secondarily overall survival (OS), progression free survival (PFS), response rate (RR), disease control rate (DCR) and the peptide-specific immune responses. All enrolled patients received therapy without the HLA-A information, and the HLA genotypes were used for classification of the patients. Between June 2012 and May 2013, a total of 68 patients were enrolled. No severe systemic adverse effects of Grade 3 or higher related to these three peptides were observed. The 1-year survival rates between the HLA-A*2402-matched and -unmatched groups were not significantly different. In the HLA-A*2402 matched group, patients showing peptide-specific CTL induction for KIF20A or VEGFR1 showed a better prognosis compared to those without such induction (P = 0.023, P = 0.009, respectively). In the HLA-A*2402-matched group, the patients who showed a strong injection site reaction had a better survival rate (P = 0.017) compared to those with a weak or no injection site reaction. This phase II study demonstrated that this therapeutic peptide cocktail might be effective in patients who demonstrate peptide-specific immune reactions although predictive biomarkers are needed for patient selection in its further clinical application.

Highly sensitive stool DNA testing of Fusobacterium nucleatum as a marker for detection of colorectal tumours in a Japanese population.

Background Accumulating evidence shows an over-abundance of Fusobacterium nucleatum in colorectal tumour tissues. Although stool DNA testing of Fusobacterium nucleatum might be a potential marker for the detection of colorectal tumours, the difficulty in detecting Fusobacterium nucleatum in stool by conventional methods prevented further explorations. Therefore, we developed a droplet digital polymerase chain reaction (PCR) assay for detecting Fusobacterium nucleatum in stool and investigated its clinical utility in the management of colorectal tumours in a Japanese population. Methods Feces were collected from 60 healthy subjects (control group) and from 11 patients with colorectal non-advanced adenomas (non-advanced adenoma group), 19 patients with colorectal advanced adenoma/carcinoma in situ (advanced adenoma/carcinoma in situ (CIS) group) and 158 patients with colorectal cancer of stages I to IV (colorectal cancer group). Absolute copy numbers of Fusobacterium nucleatum were measured by droplet digital PCR. Results The median copy number of Fusobacterium nucleatum was 17.5 in the control group, 311 in the non-advanced adenoma group, 122 in the advanced adenoma/CIS group, and 317 in the colorectal cancer group. In comparison with that in the control group, the Fusobacterium nucleatum level was significantly higher in the non-advanced adenoma group, the advanced adenoma/CIS group and the colorectal cancer group. Conclusions This study illustrates the potential of stool DNA testing of Fusobacterium nucleatum by droplet digital PCR to detect individuals with colorectal tumours in a Japanese population.