Conditional survival in pediatric malignancies: analysis of data from the Childhood Cancer Survivor Study and the Surveillance, Epidemiology, and End Results Program.

BACKGROUND: Long-term survivors of pediatric cancer are at risk of life-threatening late effects of their cancer. Previous studies have shown excesses in long-term mortality within high-risk groups defined by demographic and treatment characteristics. METHODS: To investigate conditional survival in a pediatric cancer population, the authors performed an analysis of conditional survival in the original Childhood Cancer Survivor Study (CCSS) cohort and the Surveillance, Epidemiology, and End Results (SEER) database registry. The overall probability of death for patients at 5 years and 10 years after they survived 5, 10, 15, and 20 years since cancer diagnosis and cause-specific death in 10 years for 5-year survivors were estimated using the cumulative incidence method. RESULTS: Among patients in the CCSS and SEER cohorts who were alive 5 years after their cancer diagnosis, within each diagnosis group at least 92% were alive in the subsequent 5 years, except for patients with leukemia, of whom only 88% of 5-year survivors remained alive in the subsequent 5 years. The probability of all-cause mortality in the next 10 years among patients who survived at least 5 years after diagnosis was 8.8% in CCSS and 10.6% in SEER, approximately 75% of which was due to neoplasms as the cause of death. CONCLUSIONS: The risk of death among survivors of pediatric cancer in 10 years can vary between diagnosis groups by at most 12%, even up to 20 years after diagnosis. This information is clinically significant when counseling patients regarding their conditional survival, particularly when survivors are seen in long-term follow-up.

SNP-SNP interactions discovered by logic regression explain Crohn's disease genetics.

In genome-wide association studies (GWAS), the association between each single nucleotide polymorphism (SNP) and a phenotype is assessed statistically. To further explore genetic associations in GWAS, we considered two specific forms of biologically plausible SNP-SNP interactions, 'SNP intersection' and 'SNP union,' and analyzed the Crohn's Disease (CD) GWAS data of the Wellcome Trust Case Control Consortium for these interactions using a limited form of logic regression. We found strong evidence of CD-association for 195 genes, identifying novel susceptibility genes (e.g., ISX, SLCO6A1, TMEM183A) as well as confirming many previously identified susceptibility genes in CD GWAS (e.g., IL23R, NOD2, CYLD, NKX2-3, IL12RB2, ATG16L1). Notably, 37 of the 59 chromosomal locations indicated for CD-association by a meta-analysis of CD GWAS, involving over 22,000 cases and 29,000 controls, were represented in the 195 genes, as well as some chromosomal locations previously indicated only in linkage studies, but not in GWAS. We repeated the analysis with two smaller GWASs from the Database of Genotype and Phenotype (dbGaP): in spite of differences of populations and study power across the three datasets, we observed some consistencies across the three datasets. Notable examples included TMEM183A and SLCO6A1 which exhibited strong evidence consistently in our WTCCC and both of the dbGaP SNP-SNP interaction analyses. Examining these specific forms of SNP interactions could identify additional genetic associations from GWAS. R codes, data examples, and a ReadMe file are available for download from our website: http://www.ualberta.ca/~yyasui/homepage.html.

A ß-mannan trisaccharide conjugate vaccine aids clearance of Candida albicans in immunocompromised rabbits.

A ß-(1 → 2)-linked mannose trisaccharide epitope that is the optimal inhibitor of two protective monoclonal antibodies specific for the Candida albicans cell wall phosphomannan was used to create a synthetic conjugate vaccine. Two injections of the trisaccharide-tetanus toxoid conjugate administered with alum induced a robust secondary antibody response in rabbits with trisaccharide specific IgG ELISA titers in excess of 1:100,000. Fluorescent labeling studies demonstrated these antibodies (i) recognized the cell wall ß-mannan of C. albicans on hyphae and budding cells and (ii) C. albicans incubated with immune sera bound complement factor C3. The synthetic conjugate vaccine but not the carrier protein, tetanus toxoid reduced Candida load in vaccinated rabbits subsequently rendered leukocytopenic by injection of cyclophosphamide and then challenged with live C. albicans. These data support the contention that antibody mediated immunity plays a role in combating C. albicans infections and suggests that a surprisingly simple, readily accessible synthetic conjugate vaccine may have therapeutic potential.