Clinicopathological, molecular, and prognostic features of colorectal carcinomas with KRAS c.34G>T (p.G12C) mutation.

Evidence indicates that combinations of anti-EGFR antibodies and KRAS p.G12C (c.34G>T) inhibitors can be an effective treatment strategy for advanced colorectal cancer. We hypothesized that KRAS c.34G>T (p.G12C)-mutated colorectal carcinoma might be a distinct tumor subtype. We utilized a prospective cohort incident tumor biobank (including 1347 colorectal carcinomas) and detected KRAS c.34G>T (p.G12C) mutation in 43 cases (3.2%) and other KRAS mutations (in codon 12, 13, 61, or 146) in 467 cases (35%). The CpG island methylator phenotype (CIMP)-low prevalence was similarly higher in KRAS c.34G>T mutants (52%) and other KRAS mutants (49%) than in KRAS-wild-type tumors (31%). KRAS c.34G>T mutants showed higher CIMP-high prevalence (14%) and lower CIMP-negative prevalence (33%) compared with other KRAS mutants (6% and 45%, respectively; p = 0.0036). Similar to other KRAS mutants, KRAS c.34G>T-mutated tumors were associated with cecal location, non-microsatellite instability (MSI)-high status, BRAF wild type, and PIK3CA mutation when compared with KRAS-wild-type tumors. Compared with BRAF-mutated tumors, KRAS c.34G>T mutants showed more frequent LINE-1 hypomethylation, a biomarker for early-onset colorectal carcinoma. KRAS c.34G>T mutants were not associated with other features, including the tumor tissue abundance of Fusobacterium nucleatum (F. animalis), pks+ Escherichia coli, Bifidobacterium, or (enterotoxigenic) Bacteroides fragilis. Among 1122 BRAF-wild-type colorectal carcinomas, compared with KRAS-wild-type tumors, multivariable-adjusted colorectal cancer-specific mortality hazard ratios (95% confidence interval) were 1.82 (1.05-3.17) in KRAS c.34G>T (p.G12C)-mutated tumors (p = 0.035) and 1.57 (1.22-2.02) in other KRAS-mutated tumors (p = 0.0004). Our study provides novel evidence for clinical and tumor characteristics of KRAS c.34G>T (p.G12C)-mutated colorectal carcinoma.

Enrichment of Bacteroides fragilis and enterotoxigenic Bacteroides fragilis in CpG island methylator phenotype-high colorectal carcinoma.

OBJECTIVES: Data support that enterotoxigenic Bacteroides fragilis (ETBF) harbouring the Bacteroides fragilis toxin (bft) gene may promote colorectal tumourigenesis through the serrated neoplasia pathway. We hypothesized that ETBF may be enriched in colorectal carcinoma subtypes with high-level CpG island methylator phenotype (CIMP-high), BRAF mutation, and high-level microsatellite instability (MSI-high). METHODS: Quantitative PCR assays were designed to quantify DNA amounts of Bacteroides fragilis, ETBF, and each bft gene isotype (bft-1, bft-2, or bft-3) in colorectal carcinomas in the Health Professionals Follow-up Study and Nurses' Health Study. We used multivariable-adjusted logistic regression models with the inverse probability weighting method. RESULTS: We documented 4476 colorectal cancer cases, including 1232 cases with available bacterial data. High DNA amounts of Bacteroides fragilis and ETBF were positively associated with BRAF mutation (p ≤ 0.0003), CIMP-high (p ≤ 0.0002), and MSI-high (p < 0.0001 and p = 0.01, respectively). Multivariable-adjusted odds ratios (with 95% confidence interval) for high Bacteroides fragilis were 1.40 (1.06-1.85) for CIMP-high and 2.14 (1.65-2.77) for MSI-high, but 1.02 (0.78-1.35) for BRAF mutation. Multivariable-adjusted odds ratios for high ETBF were 2.00 (1.16-3.45) for CIMP-high and 2.86 (1.64-5.00) for BRAF mutation, but 1.09 (0.67-1.76) for MSI-high. Neither Bacteroides fragilis nor ETBF was associated with colorectal cancer-specific or overall survival. DISCUSSION: The tissue abundance of Bacteroides fragilis is associated with CIMP-high and MSI-high, whereas ETBF abundance is associated with CIMP-high and BRAF mutation in colorectal carcinoma. Our findings support the aetiological relevance of Bacteroides fragilis and ETBF in the serrated neoplasia pathway.

Mumps vaccine hesitancy: Current evidence and an evidence-based campaign in Japan.

BACKGROUND: Mumps is still endemic in Japan because mumps vaccination is voluntary. In this study, we investigated associations of parental socioeconomic status, family structure, and knowledge/belief about mumps and mumps vaccine with parental decision to vaccinate their children. We also evaluated effectiveness of a campaign based on survey results. METHODS: We conducted a cross-sectional survey of parents with children aged 1-6 years attending preschools or kindergartens in Tokamachi City, Japan. We assessed the association of parental factors with their decision to vaccinate their children using multivariable logistic regression analyses. We designed a campaign based on the survey results, and compared the number of annual vaccinations at Tokamachi Hospital per the child population aged 1-6 years in Tokamachi City before and after the campaign using a trend test. RESULTS: In total, 1391 of 1617 (86%) eligible parents completed the survey. Among these parents, 229 (16%) vaccinated their children. In multivariable analyses, higher parental education [odds ratio (OR) = 2.21; 95% CI, 1.59-3.08; P < 0.001], greater knowledge about mumps and the mumps vaccine (OR = 1.88; 95% CI, 1.60-2.21; P < 0.001), and living without grandparents (OR = 1.44; 95% CI, 1.05-1.99; P = 0.024) were significantly associated with parental decision to vaccinate their children. The number of annual vaccinations per the child population significantly increased following the campaign (P < 0.001). CONCLUSION: Our study showed several sociodemographic factors significantly associated with mumps vaccination. Further research is needed to examine the relevance of our findings to the uptake of other voluntary vaccines among children.

Inverse relationship between Fusobacterium nucleatum amount and tumor CD274 (PD-L1) expression in colorectal carcinoma.

Objectives: The CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) immune checkpoint axis is known to regulate the antitumor immune response. Evidence also supports an immunosuppressive effect of Fusobacterium nucleatum. We hypothesised that tumor CD274 overexpression might be inversely associated with abundance of F. nucleatum in colorectal carcinoma. Methods: We assessed tumor CD274 expression by immunohistochemistry and F. nucleatum DNA within tumor tissue by quantitative PCR in 812 cases among 4465 incident rectal and colon cancer cases that had occurred in two prospective cohort studies. Multivariable logistic regression analyses with inverse probability weighting were used to adjust for selection bias because of tissue data availability and potential confounders including microsatellite instability status, CpG island methylator phenotype, LINE-1 methylation level and KRAS, BRAF and PIK3CA mutations. Results: Fusobacterium nucleatum DNA was detected in tumor tissue in 109 (13%) cases. Tumor CD274 expression level was inversely associated with the amount of F. nucleatum in colorectal cancer tissue (P = 0.0077). For one category-unit increase in three ordinal F. nucleatum categories (negative vs. low vs. high), multivariable-adjusted odds ratios (with 95% confidence interval) of the low, intermediate and high CD274 categories (vs. negative) were 0.78 (0.41-1.51), 0.64 (0.32-1.28) and 0.50 (0.25-0.99), respectively (P trend = 0.032). Conclusions: Tumor CD274 expression level was inversely associated with the amount of F. nucleatum in colorectal cancer tissue, suggesting that different immunosuppressive mechanisms (i.e. PDCD1 immune checkpoint activation and tumor F. nucleatum enrichment) tend to be used by different tumor subgroups.

Clinical Characteristics of Saffold Virus Infection in Children.

BACKGROUND: Saffold virus (SAFV) is a novel human cardiovirus that was identified in 2007. Recently, SAFV has been isolated from nasal and stool specimens of infants presenting with respiratory and gastrointestinal symptoms and from cerebrospinal fluid (CSF) specimens of children with central nervous system infection. However, little is known regarding clinical characteristics of SAFV in children. METHODS: We reviewed 5412 specimens from the database of the infectious agents surveillance system in Niigata prefecture, Japan, between January 2006 and December 2013, and identified SAFV-infected patients. Subsequently, we retrospectively reviewed their medical records and evaluated their clinical characteristics. RESULTS: We identified 9 SAFV-infected patients (median age: 5 years; range: 2-16 years). Seven patients were diagnosed with pharyngitis, one with meningitis and one with fever of unknown origin. Dominant symptoms were high fever, appetite loss and headache. The median duration of the fevers was 2 days in patients with pharyngitis; however, the patient with meningitis remained febrile for 5 days. All blood tests available in this case series revealed leukocytosis with a predominance of neutrophils. CSF profiles showed mild lymphocytic pleocytosis. All patients recovered fully without complications. CONCLUSIONS: A few clinical characteristics of SAFV infection were clarified, including high fever of short duration in patients with pharyngitis, and neutrophil-dominant leukocytosis. The clinical course and CSF profiles of a case of meningitis were similar to those of other aseptic meningitis. SAFV needs to be included in the differential diagnosis of pharyngitis or meningitis when commonly identified viruses are not identified in such patients.

Parvovirus B19: A Cause of Sepsislike Syndrome in an Infant.

Parvovirus B19 (PB19) is an important human pathogen that results in a wide spectrum of clinical outcomes, from mild, self-limiting erythema infectiosum in immunocompetent children and arthralgia in adults to lethal cytopenia in immunocompromised patients and intrauterine fetal death. However, there have been few reports of PB19 infection in neonates or young infants (aged 28-90 days), and no previous reports contained descriptions of PB19 infection as a cause of sepsislike syndrome in this age group. We report a case of sepsislike syndrome caused by PB19 infection in a 56-day-old infant whose mother had polyarthralgia at the time of his admission. PB19 infection was diagnosed on the basis of positive polymerase chain reaction results for PB19 DNA in the serum and cerebrospinal fluid. Positive immunoglobulin M and negative immunoglobulin G for PB19 suggested acute infection. He was admitted to the ICU because of poor peripheral circulation, but fully recovered without antibiotic administration. After excluding other possible pathogens, PB19 should be suspected as a cause of sepsislike syndrome in young infants, especially those who have close contact with PB19-infected individuals.