Clinical characteristics and sick leave associated with infectious mononucleosis in a real-world setting in Germany.

BACKGROUND: Infectious mononucleosis (IM), mainly caused by the Epstein-Barr virus, can result in prolonged symptoms. The objective of this study was to look at the length of sick leave, diagnosis of IM, treatment and comorbidities in a real-world setting in Germany. METHODS: This retrospective, cross-sectional study used electronic medical record data from office-based practices in Germany and included patients with an initial confirmed diagnosis of IM between the 1 January 1 2016 and December 31 2018. Patients of working age (18-65 years) with statutory health insurance were included in order to look at the working population who would need a sick note for their employers in case of illness. RESULTS: Epstein-Barr virus was the most common cause of IM in this population of 1,596 patients with an average age of 32 years. The majority of patients were women in all cohorts (~60%). Although CFS, myocarditis and thrombocytopenia were not recorded frequently around the index date, the occurrence did increase during the follow-up period. Around half of patients received antibiotics. About 62% of all patients were on sick leave for an average of 20 calendar days around the time of their IM diagnosis. Only 1% were still on sick leave after 6 months. CONCLUSIONS: A small percentage of patients remained on continuous sick leave after 6 months, suggesting that the long-term effect of IM on the ability to work was minor in our cohort. However, patients could still be experiencing symptoms that influence their quality of life.

Pathway analysis of genetic variants in folate-mediated one-carbon metabolism-related genes and survival in a prospectively followed cohort of colorectal cancer patients.

Folate-mediated one-carbon metabolism (FOCM) is a key pathway essential for nucleotide synthesis, DNA methylation, and repair. This pathway is a critical target for 5-fluorouracil (5-FU), which is predominantly used for colorectal cancer (CRC) treatment. A comprehensive assessment of polymorphisms in FOCM-related genes and their association with prognosis has not yet been performed. Within 1,739 CRC cases aged ≥30 years diagnosed from 2003 to 2007 (DACHS study), we investigated 397 single nucleotide polymorphisms (SNPs) and 50 candidates in 48 FOCM-related genes for associations with overall- (OS) and disease-free survival (DFS) using multiple Cox regression (adjusted for age, sex, stage, grade, BMI, and alcohol). We investigated effect modification by 5-FU-based chemotherapy and assessed pathway-specific effects. Correction for multiple testing was performed using false discovery rates (FDR). After a median follow-up time of 5.0 years, 585 patients were deceased. For one candidate SNP in MTHFR and two in TYMS, we observed significant inverse associations with OS (MTHFR: rs1801133, C677T: HRhet  = 0.81, 95% CI: 0.67-0.97; TYMS: rs1001761: HRhet  = 0.82, 95% CI: 0.68-0.99 and rs2847149: HRhet  = 0.82, 95% CI: 0.68-0.99). After FDR correction, one polymorphism in paraoxonase 1 (PON1; rs3917538) was significantly associated with OS (HRhet  = 1.28, 95% CI: 1.07-1.53; HRhzv  = 2.02, 95% CI:1.46-2.80; HRlogAdd  = 1.31, pFDR  = 0.01). Adjusted pathway analyses showed significant associations for pyrimidine biosynthesis (P = 0.04) and fluorouracil drug metabolism (P < 0.01) with significant gene-chemotherapy interactions, including PON1 rs3917538. This study supports the concept that FOCM-related genes could be associated with CRC survival and may modify effects of 5-FU-based chemotherapy in genes in pyrimidine and fluorouracil metabolism, which are relevant targets for therapeutic response and prognosis in CRC. These results require confirmation in additional clinical studies.

Nucleotide excision repair and response and survival to chemotherapy in colorectal cancer patients.

Several new chemotherapeutic agents have become available for the treatment of colorectal cancer, which has led to increased complexity in treatment planning. Treatment decision making for individual patients could be facilitated if guided by predictive and prognostic markers. As most cytotoxic drugs induce DNA damage, the DNA damage repair pathways hold potential for yielding such biomarkers. Here, we review the current evidence of a possible involvement of the nucleotide excision repair pathway in the efficacy of chemotherapeutic agents used in the treatment of colorectal cancer. Although a large number of studies have been conducted, they are generally of moderate size and heterogeneous in design. Up to date no firm conclusions can be drawn to translate these results into the clinic. We recommend further comprehensive investigations of the nucleotide excision repair pathway in large patient studies that include both discovery and validation cohorts.

SNPs in transporter and metabolizing genes as predictive markers for oxaliplatin treatment in colorectal cancer patients.

Oxaliplatin is frequently used as part of a chemotherapeutic regimen with 5-fluorouracil in the treatment of colorectal cancer (CRC). The cellular availability of oxaliplatin is dependent on metabolic and transporter enzymes. Variants in genes encoding these enzymes may cause variation in response to oxaliplatin and could be potential predictive markers. Therefore, we used a two-step procedure to comprehensively investigate 1,444 single nucleotide polymorphisms (SNPs) from these pathways for their potential as predictive markers for oxaliplatin treatment, using 623 stage II-IV CRC patients (of whom 201 patients received oxaliplatin) from a German prospective patient cohort treated with adjuvant or palliative chemotherapy. First, all genes were screened using the global test that evaluated SNP*oxaliplatin interaction terms per gene. Second, one model was created by backward elimination on all SNP*oxaliplatin interactions of the selected genes. The statistical procedure was evaluated using bootstrap analyses. Nine genes differentially associated with overall survival according to oxaliplatin treatment (unadjusted p values < 0.05) were selected. Model selection resulted in the inclusion of 14 SNPs from eight genes (six transporter genes, ABCA9, ABCB11, ABCC10, ATP1A1, ATP1B2, ATP8B3, and two metabolism genes GSTM5, GRHPR), which significantly improved model fit. Using bootstrap analysis we show an improvement of the prediction error of 3.7% in patients treated with oxaliplatin. Several variants in genes involved in metabolism and transport could thus be potential predictive markers for oxaliplatin treatment in CRC patients. If confirmed, inclusion of these variants in a predictive test could identify patients who are more likely to benefit from treatment with oxaliplatin.

Common genetic variation and survival after colorectal cancer diagnosis: a genome-wide analysis.

Genome-wide association studies have identified several germline single nucleotide polymorphisms (SNPs) significantly associated with colorectal cancer (CRC) incidence. Common germline genetic variation may also be related to CRC survival. We used a discovery-based approach to identify SNPs related to survival outcomes after CRC diagnosis. Genome-wide genotyping arrays were conducted for 3494 individuals with invasive CRC enrolled in six prospective cohort studies (median study-specific follow-up = 4.2-8.1 years). In pooled analyses, we used Cox regression to assess SNP-specific associations with CRC-specific and overall survival, with additional analyses stratified by stage at diagnosis. Top findings were followed-up in independent studies. A P value threshold of P < 5×10(-8) in analyses combining discovery and follow-up studies was required for genome-wide significance. Among individuals with distant-metastatic CRC, several SNPs at 6p12.1, nearest the ELOVL5 gene, were statistically significantly associated with poorer survival, with the strongest associations noted for rs209489 [hazard ratio (HR) = 1.8, P = 7.6×10(-10) and HR = 1.8, P = 3.7×10(-9) for CRC-specific and overall survival, respectively). No SNPs were statistically significantly associated with survival among all cases combined or in cases without distant-metastases. SNPs in 6p12.1/ELOVL5 were associated with survival outcomes in individuals with distant-metastatic CRC, and merit further follow-up for functional significance. Findings from this genome-wide association study highlight the potential importance of genetic variation in CRC prognosis and provide clues to genomic regions of potential interest.

Genetic variants in the glutathione S-transferase genes and survival in colorectal cancer patients after chemotherapy and differences according to treatment with oxaliplatin.

INTRODUCTION: The glutathione S-transferase (GST) enzymes are involved in the detoxification of a range of carcinogenic compounds as well as chemotherapeutic agents. Therefore, genetic variants in the GST genes could influence survival in patients with colorectal cancer (CRC). Results from previous studies have been inconsistent and therefore we investigated the association between the GSTP1 ile105val polymorphism and the copy number variants of the GSTM1 and GSTT1 genes and survival in CRC patients treated with adjuvant/palliative chemotherapy. PATIENTS AND METHODS: We included 755 CRC patients with stage II-IV disease from two population-based studies carried out in Germany. Genotyping of the GSTP1 polymorphism was carried out using fluorescence-based melting curve analysis and copy number variants were determined using a multiplex PCR. Survival analysis was carried out using the Cox regression model, adjusting for age, sex, UICC stage, cancer site, and radiation therapy. RESULTS: Compared with noncarriers, CRC patients who were homozygote carriers of GSTM1 had significantly poorer survival after treatment with oxaliplatin [hazard ratio (HR) 2.25, 95% confidence interval (CI) 0.93-5.44] than those not treated with oxaliplatin (HR 0.64, 95% CI 0.30-1.34; P for heterogeneity=0.031). The association was significant in metastatic CRC patients treated with oxaliplatin (HR 3.59, 95% CI 1.29-10.03). Neither the GSTP1 105val allele nor the GSTT1 deletion was significantly associated with CRC survival. CONCLUSION: Our data suggest that GSTM1 may be a predictive marker for oxaliplatin therapy; however, independent large studies are warranted to confirm these results.