Felipe A. Castro

High-throughput SNP-based authentication of human cell lines.

Use of false cell lines remains a major problem in biological research. Short tandem repeat (STR) profiling represents the gold standard technique for cell line authentication. However, mismatch repair (MMR)‐deficient cell lines are characterized by microsatellite instability, which could force allelic drifts in combination with a selective outgrowth of otherwise persisting side lines, and, thus, are likely to be misclassified by STR profiling. On the basis of the high‐throughput Luminex platform, we developed a 24‐plex single nucleotide polymorphism profiling assay, called multiplex cell authentication (MCA), for determining authentication of human cell lines. MCA was evaluated by analyzing a collection of 436 human cell lines from the German Collection of Microorganisms and Cell Cultures, previously characterized by eight‐loci STR profiling. Both assays showed a very high degree of concordance and similar average matching probabilities (∼1 × 10−8 for STR profiling and ∼1 × 10−9 for MCA). MCA enabled the detection of less than 3% of contaminating human cells. By analyzing MMR‐deficient cell lines, evidence was obtained for a higher robustness of the MCA compared to STR profiling. In conclusion, MCA could complement routine cell line authentication and replace the standard authentication STR technique in case of MSI cell lines.

Association of HLA-DRB1, interleukin-6 and cyclin D1 polymorphisms with cervical cancer in the Swedish population―A candidate gene approach

High‐risk human papillomavirus (hrHPV) infection is the major risk factor for cervical cancer (CxCa). The role of genetic susceptibility in the disease has been suggested, but the existing data lack consistency. We conducted a nested case‐control study on 973 CxCa cases and 1,763 matched controls, from two Swedish population‐based cohorts to examine the association of common genetic variants with CxCa risk. Human leukocyte antigen (HLA) alleles and 24 other polymorphisms in 14 genes were selected on the basis of reported association or mechanistic plausibility with an HPV infection or cervical cancer development. Genotyping was conducted using multiplex PCR and Luminex technology. A significant association of CxCa with various polymorphisms was observed: rs1800797 in the IL‐6 gene (odds ratio [OR] = 0.88, 95% confidence intervals [CI]: 0.79–0.99); rs1041981 in the LTA gene (OR = 0.87, 95% CI: 0.78–0.98), and rs9344 in the CCND1 gene (OR = 1.14, 95% CI: 1.02–1.27), for those individuals carrying the rare allele. Additionally, the alleles 0401 and 1501 of the HLA class II DRB1 locus were associated with an increased risk (OR = 1.23, 95% CI: 1.04–1.45 and OR = 1.29, 95% CI: 1.11–1.50, respectively), and allele 1301 was associated with decreased risk (OR = 0.59, 95% CI: 0.47–0.73). The effects of CCND1 and the HLA*DRB1 alleles were independent of the effect of smoking. We did not find any association of risk with polymorphisms in genes related to the innate immune system. In conclusion, our study provides evidence for genetic susceptibility to CxCa due to variations in genes involved in the immune system and in cell cycle.

TLR-3 polymorphism is an independent prognostic marker for stage II colorectal cancer

BACKGROUND Clinicopathologic stage is still the main parameter to evaluate the prognosis of newly diagnosed colorectal cancer (CRC) patients. Although molecular markers have been suggested for follow up of treated CRC patients, their complete clinical application is still under evaluation. MATERIALS AND METHODS To evaluate the association of immune-related genes with CRC prognosis and survival, a total of 19 single nucleotide polymorphisms (SNPs) were genotyped in 614 German patients within the Kiel cohort (POPGEN). RESULTS A promoter variant (rs1800872) in the Interleukin-10 (IL-10) gene was associated with an increased lymph node metastasis involvement [odds ratio (OR) = 2.1, 95% confidence interval (CI) = 1.03-4.2, for carriers of the TT genotype]. More importantly, among 582 followed up patients the SNP rs3775291 in the toll-like receptor 3 (TLR-3) gene was associated with CRC specific survival (150 events). Patients carrying the TT genotype had a 93% increased risk of death compared with the CC carriers [hazard ratio (HR) = 1.93, 95% CI 1.14-3.28]. The observed effect of the TLR-3 variant was restricted to stage II patients (HR = 4.14, 95% CI 1.24-13.84) and to patients who did not receive adjuvant therapy (HR = 3.2, 95% CI 1.4-7.7). CONCLUSIONS Our results may provide additional candidates for risk assessment in stage II CRC patients for treatment decision. Further validation of the presented findings is warranted.

Number of siblings and the risk of lymphoma, leukemia, and myeloma by histopathology

Epidemiologic evidence indicates that several markers of exposure to childhood infections are inversely associated with the risk of childhood leukemia and lymphomas. We used the Swedish Family-Cancer Database to assess the effects of number of siblings on the risk of non-Hodgkins (n = 7,007) and Hodgkins lymphomas (n = 3,115), leukemias (n = 7,650), and multiple myeloma (n = 1,492) by histopathology. Poisson regression models included terms for age, sex, family history, period, and socioeconomic index. Having four or more siblings compared with none was associated with an excess risk of childhood acute lymphoblastic leukemia [ALL; rate ratio (RR), 2.11; Ptrend = 0.001], acute monocytic leukemia (RR, 2.51; Ptrend = 0.002), and multiple myeloma (RR, 1.34; Ptrend = 0.006). Having three or more older siblings compared with none decreased the risk of acute monocytic leukemia (RR, 0.35; Ptrend = 0.001) and childhood ALL (RR, 0.69; Ptrend = 0.01). The risk of Hodgkins lymphoma for five or more older siblings compared with none was 0.41 (Ptrend = 0.003). Acute myeloid leukemia, chronic lymphocytic leukemia, and other lymphoproliferative malignancies were not associated with number of siblings. In conclusion, we found an excess risk of childhood ALL and acute monocytic leukemia in large families. However, for ALL, acute monocytic leukemia, and Hodgkins lymphoma, younger siblings were strongly protected compared with older siblings. The remarkable protective effect of number of older siblings on acute monocytic leukemia is a novel finding of potential interest. Possible interpretations of our findings in the context of a putative infectious etiology are discussed. (Cancer Epidemiol Biomarkers Prev 2006;15(7):1281–6)

Recent cancer survival in Germany: an analysis of common and less common cancers.

The monitoring of cancer survival by population‐based cancer registries is a prerequisite to evaluate the current quality of cancer care. Our study provides 1‐, 5‐ and 10‐year relative survival as well as 5‐year relative survival conditional on 1‐year survival estimates and recent survival trends for Germany using data from 11 population‐based cancer registries, covering around one‐third of the German population. Period analysis was used to estimate relative survival for 24 common and 11 less common cancer sites for the period 2007–2010. The German and the United States survival estimates were compared using the Surveillance, Epidemiology and End Results 13 database. Trends in cancer survival in Germany between 2002–2004 and 2008–2010 were described. Five‐year relative survival increased in Germany from 2002–2004 to 2008–2010 for most cancer sites. Among the 24 most common cancers, largest improvements were seen for multiple myeloma (8.0% units), non‐Hodgkin lymphoma (6.2% units), prostate cancer (5.2% units) and colorectal cancer (4.6% units). In 2007–2010, the survival disadvantage in Germany compared to the United States was largest for cancers of the mouth/pharynx (−11.0% units), thyroid (−6.8% units) and prostate (−7.5% units). Although survival estimates were much lower for elderly patients in both countries, differences in age patterns were observed for some cancer sites. The reported improvements in cancer survival might reflect advances in the quality of cancer care on the population level as well as increased use of screening in Germany. The survival differences across countries and the survival disadvantage in the elderly require further investigation.

Biliary tract cancer incidence in the United States-Demographic and temporal variations by anatomic site.

We evaluated incidence patterns of biliary tract cancers (gallbladder, extrahepatic bile duct, ampulla of Vater and not otherwise specified) to provide potential insight into the etiology of these cancers. Data were obtained from the population‐based Surveillance, Epidemiology and End Results program. Rates for cases diagnosed during 1992–2009 were calculated by racial/ethnic, gender and age groups. Temporal trends during 1974–2009 and annual percentage changes (APC) during 1992–2009 were estimated. Age‐adjusted rates by site were higher among American Indian/Alaska Natives, Hispanics (white) and Asian/Pacific Islanders (Asian/PI) and lower among whites and blacks. Gallbladder cancer was more common among women in all ethnic groups (female‐to‐male incidence rate ratio [IRR] ranged from 1.24 to 2.86), but bile duct and ampulla of Vater cancers were more common among men (female‐to‐male IRR 0.57 to 0.82). Gallbladder cancer rates declined among all racial/ethnic and gender groups except blacks (APC −0.4% to −3.9%). In contrast, extrahepatic bile duct cancer rates rose significantly in most female racial/ethnic groups; the APCs among whites were 0.8 among females and 1.3 among males, both significant. Rates for ampulla of Vater cancer decreased among Asian/PI females (APC −2.7%) but remained stable for the other groups. In addition to confirming that biliary tract cancer incidence patterns differ by gender and site and that the gallbladder cancer incidence rates have been declining, our study provides novel evidence that extrahepatic bile duct cancer rates are rising. These observations may help guide future etiologic studies.

Prevalence of and Risk Factors for Oral Human Papillomavirus Among Young Women in Costa Rica

BACKGROUND Little is known about the epidemiology of oral human papillomavirus (HPV) in Latin America. METHODS Women (N = 5838) aged 22-29 in the control and vaccine arms of an HPV-16/18 vaccine trial in Costa Rica had oral, cervical, and anal specimens collected. Samples were tested for alpha mucosal HPV types (SPF10/LiPA25 version 1); a subset of oral samples (n = 500) was tested for cutaneous HPV types in the genera alpha, beta, gamma, mu, and nu. RESULTS In the control arm (n = 2926), 1.9% of women had an oral alpha mucosal HPV detected, 1.3% had carcinogenic HPV, and 0.4% had HPV-16; similar patterns for non-16/18 HPV types were observed in the vaccine arm. Independent risk factors for any oral alpha mucosal HPV among women in the control arm included marital status (adjusted odds ratio [AOR], 3.2; 95% confidence interval [CI], 1.8-5.7 for single compared to married/living as married), number of sexual partners (AOR, 2.4; 95% CI, 1.0-6.1 for ≥4 partners compared to 0-1 partners), chronic sinusitis (AOR, 3.1; 95% CI, 1.5-6.7), and cervical HPV infection (AOR, 2.6; 95% CI, 1.4-4.6). Detection of beta HPV was common (18.6%) and not associated with sexual activity. CONCLUSIONS Unlike cutaneous HPV types, alpha mucosal HPV types were uncommon in the oral region and were predominately associated with sexual behavior. Clinical Trials Registration. NCT00128661.

Trends in survival of multiple myeloma patients in Germany and the United States in the first decade of the 21st century

Multiple myeloma is a chronic, incurable but highly treatable neoplasm. Recent population‐based studies have shown improvements in survival for patients diagnosed in the early 21st century. Here, we examine trends in survival for patients diagnosed with multiple myeloma in Germany and the United States (US) between 2002 and 2010. Data were extracted from 11 population‐based cancer registries in Germany and from the Surveillance, Epidemiology and End Results database in the US. Myeloma patients aged 15–74 years with diagnosis and follow‐up between 1997 and 2010 from Germany and the US were included. Period analysis was employed to assess trends in 5‐year relative survival in Germany and the US between 2002–04 and 2008–10. Age‐adjusted 5‐year relative survival increased from 47·3% to 53·8% in Germany and from 39·8% to 53·2% in the US between 2002–04 and 2008–10. There was a strong age gradient with lower survival among older patients, which persisted over time and was more pronounced in Germany than the US. Five‐year relative survival estimates for patients diagnosed with multiple myeloma below 75 years of age steadily increased throughout the first decade of the 21st century and reached levels above 50% in both Germany and the US, probably reflecting the increased use of newer agents in myeloma treatment.

Association between number of siblings and nervous system tumors suggests an infectious etiology.

Objective: To estimate the effect of the number of siblings on the risk of histopathologic subtypes of tumors of the nervous system using large population-based data. Methods: The Swedish Family-Cancer Database comprises 13,613 diagnoses of nervous system tumors with histopathologic information. We analyzed the data using Poisson regression models taking into account potential confounding effects of age, birth cohort, socioeconomic status, and family history of cancer. Results: The rate ratios (RR) for having four or more siblings vs none were significantly increased for hemangioblastoma (RR = 1.68), childhood neuroblastoma (RR = 2.01), and ependymoma (RR = 1.83, p trend < 0.01). For age at diagnosis ≤15 years, the RRs for individuals with three or more younger siblings compared to none were 1.34 for astrocytoma, 2.30 for medulloblastoma, 2.61 for ependymoma, 3.71 for meningioma, and 2.13 for neuroblastoma, with significant trends in risk. Non-significant decreased risks were found between the number of older siblings and nervous system tumors. Conclusions: We provide the first reliable quantification of the effects of number of siblings on the risk of nervous system tumors. Sibship size and number of younger siblings correlate with the incidence of childhood nervous system tumors, suggesting a role of infectious agents in the etiology of the disease.

Epstein-Barr virus infection and gastric cancer: a systematic review.

AbstractEpstein–Barr virus (EBV) infection is found in a subset of gastric cancers. Previous reviews have exclusively focused on EBV-encoded small RNA (EBER) positivity in gastric cancer tissues, but a comprehensive evaluation of other type of studies is lacking.We searched the PubMed database up to September, 2014, and performed a systematic review.We considered studies comparing EBV nucleic acids positivity in gastric cancer tissue with positivity in either adjacent non-tumor tissue of cancer patients or non-tumor mucosa from healthy individuals, patients with benign gastric diseases, or deceased individuals. We also considered studies comparing EBV antibodies in serum from cancer patients and healthy controls.Selection of potentially eligible studies and data extraction were performed by 2 independent reviewers. Due to the heterogeneity of studies, we did not perform formal meta-analysis.Forty-seven studies (8069 cases and 1840 controls) were identified. EBER positivity determined by in situ hybridization (ISH) was significantly higher in cancer tissues (range 5.0%–17.9%) than in adjacent mucosa from the same patients or biopsies from all control groups (almost 0%). High EBV nuclear antigen-1 (EBNA-1) positivity by PCR was found in gastric cancer tissues, but most were not validated by ISH or adjusted for inflammatory severity and lymphocyte infiltration. Only 4 studies tested for EBV antibodies, with large variation in the seropositivities of different antibodies in both cases and controls, and did not find an association between EBV seropositivity and gastric cancer.In summary, tissue-based ISH methods strongly suggest an association between EBV infection and gastric cancer, but PCR method alone is invalid to confirm such association. Very limited evidence from serological studies and the lack of novel antibodies warrant further investigations to identify potential risk factors of EBV for gastric cancer.