Performance of laboratory tests for detection for Clostridioides difficile: A multicenter prospective study in Japan.

BACKGROUND: The optimal and practical laboratory diagnostic approach for detection of Clostridioides difficile to aid in the diagnosis of C. difficile infection (CDI) is controversial. A two-step algorithm with initial detection of glutamate dehydrogenase (GDH) or nucleic acid amplification test (NAAT) alone are recommended as a predominant method for C. difficile detection in developed countries. The aim of this study was to compare the performance of enzyme immunoassays (EIA) detecting toxins A and B, NAAT detecting the toxin B gene, and GDH compared to toxigenic culture (TC) for C. difficile as the gold standard, in patients prospectively and actively assessed with clinically significant diarrhea in 12 medical facilities in Japan. METHODS: A total of 650 stool specimens were collected from 566 patients with at least three diarrheal bowel movements (Bristol stool grade 6-7) in the preceding 24 h. EIA and GDH were performed at each hospital, and NAAT and toxigenic C. difficile culture with enriched media were performed at the National Institute of Infectious Diseases. All C. difficile isolates recovered were analyzed by PCR-ribotyping. RESULTS: Compared to TC, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of EIA were 41%, 96%, 75% and 84%, respectively, and for NAAT were 74%, 98%, 91%, and 92%, respectively. In 439 specimens tested with GDH, the sensitivity, specificity, PPV, and NPV were 73%, 87%, 65%, and 91%, and for an algorithm (GDH plus toxin EIA, arbitrated by NAAT) were 71%, 96%, 85%, and 91%, respectively. Among 157 isolates recovered, 75% of isolates corresponded to one of PCR-ribotypes (RTs) 002, 014, 018/018", and 369; RT027 was not isolated. No clear differences in the sensitivities of any of EIA, NAAT and GDH for four predominant RTs were found. CONCLUSION: The analytical sensitivities of NAAT and GDH-algorithm to detect toxigenic C. difficile in this study were lower than most previous reports. This study also found low PPV of EIAs. The optimal method to detect C. difficile or its toxins to assist in the diagnosis of CDI needs further investigation.

Clostridioides (Clostridium) difficile infection burden in Japan: A multicenter prospective study.

Clostridioides (Clostridium) difficile is the leading cause of healthcare-associated infectious diarrhea in the developed world. Retrospective studies have shown a lower incidence of C. difficile infection (CDI) in Japan than in Europe or North America. Prospective studies are needed to determine if this is due lack of testing for C. difficile or a true difference in CDI epidemiology. A prospective cohort study of CDI was conducted from May 2014 to May 2015 at 12 medical facilities (20 wards) in Japan. Patients with at least three diarrheal bowel movements (Bristol stool grade 6-7) in the preceding 24 h were enrolled. CDI was defined by positive result on enzyme immunoassay for toxins A/B, nucleic acid amplification test for the toxin B gene or toxigenic culture. C. difficile isolates were subjected to PCR-ribotyping (RT), slpA-sequence typing (slpA-ST), and antimicrobial susceptibility testing. The overall incidence of CDI was 7.4/10,000 patient-days (PD). The incidence was highest in the five ICU wards (22.2 CDI/10,000 PD; range: 13.9-75.5/10,000 PD). The testing frequency and CDI incidence rate were highly correlated (R2 = 0.91). Of the 146 isolates, RT018/018″ was dominant (29%), followed by types 014 (23%), 002 (12%), and 369 (11%). Among the 15 non-ICU wards, two had high CDI incidence rates (13.0 and 15.9 CDI/10,000 PD), with clusters of RT018/slpA-ST smz-02 and 018"/smz-01, respectively. Three non-RT027 or 078 binary toxin-positive isolates were found. All RT018/018" isolates were resistant to moxifloxacin, gatifloxacin, clindamycin, and erythromycin. This study identified a higher CDI incidence in Japanese hospitals than previously reported by actively identifying and testing patients with clinically significant diarrhea. This suggests numerous patients with CDI are being overlooked due to inadequate diagnostic testing in Japan.

[A Case of Radical Resection of Rectal Cancer with Multiple Liver and Lung Metastases after Preoperative Chemotherapy].

We report a case of radical resection of rectal cancer with multiple liver and lung metastases after preoperative chemotherapy. A 54-year-old woman presented with abdominal pain and loss of body weight due to rectal cancer with multiple liver and lung metastases. Therefore, the patient received 14 courses of bevacizumab+mFOLFOX6, and 7 courses of panitumumab+FOLFIRI. After the chemotherapy, the size of the distant metastases reduced by 62% on computed tomography, according to RECIST. Due to the reduction in size, a conversion surgery was attempted. First, an abdominal operation with laparoscopy was performed, and 2 months later an operation to resect the lung metastases via thoracoscopy was performed. Currently, 3 months after surgery, the patient is alive, without recurrence.

[A Case of Locally Advanced Rectal Cancer Successfully Treated by Conversion Surgery after Multidisciplinary Treatment].

A 70-year-old woman who complained of abdominal pain and a prolapsed tumor from the anus was diagnosed with an intestinal obstruction resulting from anal canal cancer. Computed tomography (CT) and magnetic resonance imaging revealed a huge tumor (11×5×12 cm) invading the vagina and levator ani muscle. Enlarged inguinal lymph nodes on both sides indicated metastasis. The clinical stage was T4b (vagina, levator ani muscle, and pudenda) N0H0M1a (LYM), stage IV (Japanese Classification of Colorectal Carcinoma: 8th edition). As curative resection was not possible, a transvers colostomy was performed to relieve the intestinal obstruction. This was followed by chemoradiotherapy (45 Gy/1.8 Gy×25; TS-1, 80 mg/body for 2 weeks and a 1-week interval, for 2 courses) and up to 10 courses of Bev+mFOLFOX6 continuously. After this regimen, there was a remarkable reduction in tumor size. Positron emission tomography-CT revealed no FDG uptake in the primary rectal site or inguinal lymph nodes, but a maximum standardized uptake value (SUVmax) of 6.3 was detected in the vagina. Six weeks after chemotherapy, the patient underwent a pelvic exenteration including resection of the vagina, bladder, and pudenda. The pathological stage was yp T4b (vagina) N0H0M0, stageⅡ. Curative resection was performed, and the patient had a Grade 2 pathological response after chemoradiotherapy.

Predominance of PCR-ribotypes, 018 (smz) and 369 (trf) of Clostridium difficile in Japan: a potential relationship with other global circulating strains?

Global spread and evolutionary links of an epidemic Clostridium difficile strain (PCR-ribotype 027) have been noted in recent decades. However, in Japan, no outbreaks caused by type 027 have been reported to date. A total of 120 C. difficile isolates from patients at 15 hospitals during non-outbreak seasons between 2011 and 2013 as well as 18 and 21 isolates collected from two hospitals in 2010 and 2009, respectively, in outbreak periods in Japan, were examined. Among these 120 isolates, Japan-ribotypes smz and ysmz (subtype variant of smz) were the most predominant (39.2 %) followed by Japan-ribotype trf (15.8 %). Types smz/ysmz and trf were also concurrently predominant at two hospitals in the outbreak settings. Out of the five binary toxin-positive isolates observed, only one was PCR-ribotype 027 and another PCR-ribotype 078. Type smz was later found to correspond to PCR-ribotype 018. High rates of resistance against gatifloxacin, moxifloxacin, erythromycin and clindamycin were observed in the PCR-ribotype 018 isolates. Interestingly, all trf isolates were toxin A-negative, toxin B-positive, but they did not correspond to PCR-ribotype 017, thus being assigned a new ribotype (PCR-ribotype 369). In conclusion, PCR-ribotypes 018 (smz) and 369 (trf) were identified as major circulating strains in both outbreak and non-outbreak settings in Japan. Given their epidemiological relevance, molecular investigations are warranted to clarify potential evolutionary links with related strains found elsewhere, such as PCR-ribotypes 018 and 017 from Europe and North America.

A case of adenoid cystic carcinoma of the esophagus.

Esophageal adenoid cystic carcinoma (EACC) is a very rare form of malignant tumor in the esophagus. Here, we report the case of a 78-year-old man who was diagnosed with EACC by preoperative endoscopic biopsy. Thoracoscopy-assisted subtotal esophagectomy with lymph node dissection was carried out. Microscopic examination of the resected specimen suggested that the tumor invaded to submucosal layer and showed no lymph node metastasis. Histologically, tumor primarily exhibited an alveolar solid pattern with partial cribriform and tubular patterns. Alcian blue staining showed many mucoid materials within the glandular cavity formed by tumor cells. Immunohistochemical studies revealed that the tumor cells reacted with pan-cytokeratin immunostains and expressed vimentin and S-100 protein. Collectively, the tumor was diagnosed as primary EACC, T1bN0M0 according to "Japanese Classification of Esophageal Cancer 10th edition." The patient showed no recurrence sign 12 months after the surgery.The current study also reviewed 35 EACC cases reported in Japanese literatures from 1990 to 2014. Combined with our case, we found that EACC is less frequently accompanied by lymph node metastasis as compared to esophageal squamous cell carcinoma, especially at the early stage. The prognosis of EACC is relatively better when tumors have no lymph node metastasis.

[A Case of Small Bowel Cancer Treated with Laparoscopic Surgery].

We report a case of small intestinal adenocarcinoma treated with laparoscopic surgery. A 70-year-old woman had abdominal pain and epigastralgia. There were no abnormal findings on upper and lower endoscopy. The symptoms continued for 4 months after endoscopy, so she presented to our hospital. After CT examination, small bowel cancer with ileus was suspected. An ileus tube was inserted to relieve the bowel pressure and she was diagnosed with ileum cancer by enteroscopy. Laparoscopic surgery was performed and the pathological stage was determined as pStage Ⅲa. She was treated with oral chemotherapy (UFT plus LV) and had no recurrence 6 months after surgery.

[Usefulness of Metallic Stent for Left-Sided Obstructive Colon Cancer].

The aim of this study was to compare the efficacy of self-expandable metallic stent (SEMS) and transanal tube as preoperative treatments for left-sided obstructive colon cancer. Forty-three patients (the SEMS group: 28 cases, the tube group: 15 cases) were included in this study. Clinicopathological data (age, sex, tumor location, depth, histological type, stage) were comparable between the 2 groups. In addition, there was no difference in intestinal decompression rate between the SEMS group and the tube group (technical success rate: 100% vs 86.7%, clinical success rate: 92.8% vs 73.3%, complication rate: 7.1% vs 0%). A significantly higher number of patients in the SEMS group underwent laparoscopic surgery because of difference of historical background. However, no significant difference was observed between the 2 groups in postoperative outcome(complication rate, hospital stay duration). SEMS insertion had several benefits compared to transanal tube placement, such as the resumption of oral intake because of rapid resolution of obstruction and easier management because SEMSs do not require washing. SEMS insertion could be a safe and effective bridge to subsequent surgery in patients with left-sided obstructive colon cancer.

Prospective cohort study comparing the effects of different artificial nutrition methods on long-term survival in the elderly: Japan Assessment Study on Procedures and Outcomes of Artificial Nutrition (JAPOAN).

BACKGROUND: The effects of various artificial nutrition methods on the long-term outcomes of elderly patients are still not well known. We aimed to compare the long-term survival of the elderly newly administered with parenteral nutrition (PN) or enteral nutrition. MATERIALS AND METHODS: This multicenter, prospective, observational cohort study was conducted on 546 elderly patients who were administered artificial nutrition. The main outcome was the survival ratio at 180 and 360 days after initiation of 3 different nutrition methods and estimated mean survival time: PN, nasal tube feeding (EN_N), and percutaneous endoscopic gastrostomy (PEG) feeding (EN_G). The incidence of systemic infection was also compared among different cohorts. RESULTS: At 180 and 360 days after initiation of artificial nutrition, the mortality rates in the PN, EN_N, and EN_G cohorts were 52% and 63%, 32% and 41%, and 22% and 33%, respectively. Multivariate logistic regression analysis showed that, whereas PN nutrition had significant associations with a higher death rate at 180 and 360 days in all samples, there is no significant difference on the main outcome among the 3 cohorts with neurological diseases. A subgroup analysis with neurological diseases showed that the proportional hazard ratios of the PN and EN_N cohorts in comparison with the EN_G cohort were 1.13 (95% confidence interval [CI], 0.66-1.92) and 1.22 (95% CI, 0.82-1.81). CONCLUSION: There is no significant superiority of PEG feeding compared with nasal tube feeding or PN. Clinicians should consider the choice of nutrition support method, taking into consideration the limitation of the patient's interest.

[A case of advanced gastric cancer with liver metastasis involving curative surgery after neoadjuvant chemotherapy].

A 77-year-old-woman, whose chief complaint was anemia, was referred to our hospital and diagnosed with advanced gastric cancer with liver metastasis and lymph node metastasis.Gastrointestinal endoscopy showed a tumor on the lesser curvature of the gastric corpus.Histologically, biopsy specimens indicated adenocarcinoma with genetic amplification of human epidermal growth factor receptor type 2.Computed tomography and magnetic resonance imaging showed lymph node metastasis and liver metastasis.The patient received a total gastrectomy and a partial liver resection after combination chemotherapy consisting of capecitabine, cisplatin, and trastuzumab.Histopathological examination of a resected specimen showed a minute residual cancer nest at the subserosa of the stomach and lymph node metastasis, but no liver metastasis. This combined modality therapy can be considered an effective treatment for gastric cancer with liver metastasis, and we hope that it will be established as a standard therapy.

[Long-term survival of a case of advanced cancer of the esophagogastric junction with complete response to low-dose 5-fluorouracil and cisplatin chemotherapy].

A 58-year-old man was admitted to the author's institution with complaints of dysphagia and tarry stool. An advanced squamous cell carcinoma of the esophagogastric junction was revealed by endoscopy. The clinical stage was GE, T4, N1, H0, M0, cStageIVa, according to the Japanese Classification of Esophageal Cancer. Low-dose FP chemotherapy(continuous 5-FU div of 500mg/day with intermittent CDDP div of 10mg/day)was used. The tumor size was remarkably reduced while the side effects were trivial. A clinically complete response was recognized with CT and with pathological findings from endoscopic biopsy. As a recurrence was diagnosed in the off-treatment period, the same regimen was resumed. Soon, a complete response was again. The patient is doing well with no reoccurrence after almost 10 years, with a low-dose FP chemotherapy.

Multi-center phase II study of FLOX for advanced colorectal cancer patients in Japan: SWIFT 3 study.

AIM: This is a multicenter phase II study to assess the efficacy and toxicity of the 5-FU, leucovorin, and oxaliplatin (FLOX) (SWIFT 3) regimen in Japanese patients with advanced colorectal cancer (CRC). PATIENTS AND METHODS: Fifty-two patients were enrolled and evaluated from 12 institutions. The median age was 66 years, with 40.4% of patients with colon cancer and 59.6% with rectal cancer. RESULTS: Forty-one patients underwent chemotherapy for first-line therapy and 11 patients for second-line. The response rate for first-line was 46.3% and that for second-line was 9.1%. The response rates categorized by metastatic sites were 59.4% for liver, 33.3% for lung, and 22.2% for lymph nodes. Grade 3/4 neutropenia occurred in 21.2% and Grade 3/4 non-hematologic toxicity in 46.1%. There were no deaths within 60 days following the administration. CONCLUSION: Standard FLOX regimen can be administered for Japanese patients. It is suggested that FLOX is an appropriate option for adjuvant therapy in CRC.

OSNA-based novel molecular testing for lymph node metastases in colorectal cancer patients: results from a multicenter clinical performance study in Japan.

BACKGROUND: Lymph node (LN) metastasis in colorectal cancer (CRC) is a critical factor in making accurate prognoses and therapeutic decisions. This study evaluated the clinical performance of the one-step nucleic acid amplification (OSNA) assay in accurately diagnosing LN metastases in CRC patients through the specific detection of cytokeratin 19 mRNA levels in LNs. METHODS: The OSNA assay was performed on 121 LNs dissected from early-stage CRC patients (pStage 0 or I) or from patients with benign colorectal disease (study 1). Separately, 385 LNs were dissected from 85 CRC patients (any stage); the OSNA assay was performed on half of each LN, and the results were compared with histopathological examination in 2-mm intervals of the other LN half (study 2). RESULTS: In study 1, all 121 histopathologically negative LNs were also negative by the OSNA assay (concordance rate for metastasis negative: 1.0, 95% confidence interval [95% CI]: 0.976-1.0). In study 2, the concordance rate between the OSNA assay and the 2-mm-interval histopathological examination was 0.971 (95% CI: 0.950-0.984), with a sensitivity of 0.952 (95% CI: 0.881-0.987) and a specificity of 0.977 (95% CI: 0.953-0.991). CONCLUSIONS: The OSNA assay provided a judgment performance equivalent to a 2-mm-interval histopathological examination, a more detailed assay than the common pathological examination. Therefore, the OSNA assay is considered a new molecular examination method for the diagnosis of LN metastases in CRC patients in clinical settings.

Treatment for gastric carcinoma in the oldest old patients.

BACKGROUND: The strategy for treating extremely aged patients with gastric carcinoma is controversial. This study reviews the prognoses of patients aged 85 years and older who were diagnosed with gastric carcinoma. METHODS: One hundred seventeen patients aged 85 years and older were diagnosed as having gastric carcinoma after 1969 in our institution. After excluding those at stage IV, 36 cases underwent curative resection and 30 cases received best supportive care (BSC), which we reviewed retrospectively. RESULTS: Surgical methods included distal gastrectomy for 28 cases, total gastrectomy for five cases, and other procedures for three cases. Postoperatively, pneumonia developed in four cases, anastomotic leakage in two cases, and pancreatic fistula in one case. Two patients died of pneumonia within 1 month of surgery. Univariate analysis demonstrated that age, surgery, performance status, and sodium level were statistically significant prognostic factors. Multivariate analysis demonstrated that surgery was the only independent prognostic factor. When patients with a performance status of 4 were excluded, the clinical characteristics of the surgery group (n = 36) and BSC group (n = 20) were statistically identical, and the overall survival was significantly better in the surgery group (p = 0.0078). CONCLUSIONS: Postoperative outcomes were relatively acceptable. Surgery may be feasible and beneficial even for extremely aged patients 85 years and older, except for those with a performance status of 4.

Primary colorectal signet-ring cell carcinoma: clinicopathological features and postoperative survival.

PURPOSE: The objective of this study was to investigate the clinicopathological features and postoperative survival of primary colorectal signet-ring cell carcinoma. METHODS: Nineteen patients with primary colorectal signet-ring cell carcinoma were identified from a database of 5884 surgical patients with colorectal cancers treated surgically at Osaka University Hospital and affiliated hospitals between 1993 and 2007. The clinicopathological data of those patients were compared with those of 5792 patients with non-signet-ring cell colorectal carcinoma (5417 with well or moderately differentiated adenocarcinoma and 375 with poorly differentiated adenocarcinoma or mucinous carcinoma). RESULTS: All patients showed a tumor depth of over T3. Lymph node involvement occurred in 14 patients. Seven of 19 patients presented with distant metastasis at the time of diagnosis. The overall 5-year survival rate in primary signet-ring cell carcinoma was significantly lower at 24.1%, in comparison to 77.5% in well or moderately differentiated adenocarcinoma and 57.7% in poorly differentiated adenocarcinoma or mucinous carcinoma. Likewise, the postoperative survival in Stage III was also significantly worse. On the other hand, no significant difference was observed in Stage II or IV. CONCLUSION: The most important feature of primary colorectal signet-ring cell carcinoma is the advanced stage at the time of diagnosis. In addition, the postoperative survival is worse than for other types of colorectal cancer.

Combination analysis of a whole lymph node by one-step nucleic acid amplification and histology for intraoperative detection of micrometastasis.

OBJECTIVE: The aim was to develop a more efficient molecular detection system than histological examination (HE) for lymph node (LN) metastasis. METHODS: Cytokeratin (CK) 19 mRNA copy numbers of 5 colon carcinoma cell lines (Lovo, DLD1, WiDr, Colo201 and Colo320) were calculated and compared by one-step nucleic acid amplification (OSNA) and conventional real-time reverse-transcription polymerase chain reaction (RT-PCR). Then, 91 LN submitted for HE from 6 patients with advanced colorectal adenocarcinoma and 64 LN submitted for frozen diagnosis from 47 patients with different malignancies were examined by OSNA and HE. RESULTS: CK19 mRNA copy numbers of all but Colo320 cells detected by OSNA were within double of those detected by RT-PCR. The least cell count of Lovo cells detected at one reaction (2 microl) by OSNA was calculated as 0.8 cells. Carcinoma metastasis showing either HE+ or OSNA+ was detected in 7.9% of the LN from advanced colorectal adenocarcinomas and in 30.0% of the LN for frozen diagnosis from different malignancies; HE-/OSNA+ metastasis was detected in 4.8 and 4.0%, respectively. OSNA analysis of 1 LN could be completed within 40 min. CONCLUSION: A combined analysis of LN by HE and OSNA could increase the sensitivity for detecting micrometastasis during surgery.