Henrik Alfthan

High levels of circulating testosterone are not associated with increased prostate cancer risk: A pooled prospective study

Androgens stimulate prostate cancer in vitro and in vivo. However, evidence from epidemiologic studies of an association between circulating levels of androgens and prostate cancer risk has been inconsistent. We investigated the association of serum levels of testosterone, the principal androgen in circulation, and sex hormone‐binding globulin (SHBG) with risk in a case‐control study nested in cohorts in Finland, Norway and Sweden of 708 men who were diagnosed with prostate cancer after blood collection and among 2,242 men who were not. In conditional logistic regression analyses, modest but significant decreases in risk were seen for increasing levels of total testosterone down to odds ratio for top vs. bottom quintile of 0.80 (95% CI = 0.59–1.06; ptrend = 0.05); for SHBG, the corresponding odds ratio was 0.76 (95% CI = 0.57–1.01; ptrend = 0.07). For free testosterone, calculated from total testosterone and SHBG, a bell‐shaped risk pattern was seen with a decrease in odds ratio for top vs. bottom quintile of 0.82 (95% CI = 0.60–1.14; ptrend = 0.44). No support was found for the hypothesis that high levels of circulating androgens within a physiologic range stimulate development and growth of prostate cancer.

Negative Interference in Cardiac Troponin I Immunoassays from a Frequently Occurring Serum and Plasma Component

BACKGROUND Cardiac troponin I (cTnI) is a sensitive marker of cardiac injury, but cTnI assays, like other immunoassays, are susceptible to interferences. We evaluated the presence of interfering substances by measuring the recovery of cTnI added to samples from volunteers and from patients with acute coronary syndromes (ACS). METHODS We added a ternary complex of human cardiac troponin (30-500 microg/L) or cTnI from serum to samples from healthy volunteers and ACS patients. We measured cTnI with a two-site sandwich time-resolved immunofluorometric assay using two antibodies against epitopes in the central stable part of cTnI. We also analyzed 108 heparin-plasma samples from 16 ACS patients with this assay, with an assay based on four antibodies, and with two commercial cTnI assays, AxSYM and ACS:180. RESULTS In samples from both healthy persons and ACS patients, recoveries for our assay were 1-167% (range). Recoveries were increased by addition of an antibody with an epitope in the N-terminal region of cTnI to the solid phase and an antibody with an epitope in the C-terminal region as a second detection antibody. In 2 of 16 patients with ACS, normal cTnI concentrations found when measured with the original assay demonstrated clinically abnormal (up to 10-fold higher) results with the additional N- and C-terminal antibodies in the early phase of infarction. Both commercial cTnI assays also demonstrated clinically misleading, falsely low cTnI concentrations. CONCLUSIONS Some yet unidentified, variable component, present in the blood from healthy volunteers and ACS patients, interferes with the binding of antibodies against epitopes in the central part of cTnI used in two commercial assays. Our approach to supplement the mid-fragment cTnI antibodies with antibodies in the N- and C-terminal parts of the molecule in an experimental assay represents a step in resolving this interferent.

Serum HCGβ and CA 72-4 Are Stronger Prognostic Factors than CEA, CA 19-9 and CA 242 in Pancreatic Cancer

Objective: In pancreatic cancer, the extent of the spread of the disease is considered to be the strongest prognostic factor. In addition, tumor markers, particularly CA 19-9, may also provide prognostic information. In this study, we evaluated the prognostic value of serum tumor markers CEA, CA 19-9, CA 242, CA 72-4 and hCGβ in pancreatic cancer. Methods: Preoperative serum samples were obtained from 160 patients with pancreatic cancer, including 10 with stage I, 25 with stage II, 24 with stage III and 101 patients with stage IV cancer. Quantitation of CEA, CA 19-9, CA 242, and CA 72-4 in serum was performed with commercial assays. HCGβ was measured with an in-house immunofluorometric assay based on monoclonal antibodies specific for the free β-subunit of hCG. Survival analysis was performed with univariate Kaplan-Meier life-tables and log-rank test, and with multivariate Cox regression analysis. Results: Of the tumor markers studied, CA 19-9 was most frequently elevated. Overall 2-year survival was 10%. Stage, tumor location and size, curative resection, and CEA, CA 72-4 and hCGβ were all found to be prognostic factors (p < 0.026) in univariate analysis. In multivariate analysis, each marker had independent prognostic value (p < 0.011) when analyzed individually but adjusting for stage. When all the covariates were included in the same model, the strongest prognostic factor was hCGβ followed by CA 72-4 and stage. The other clinical characteristics and serum tumor markers contributed insignificant prognostic information. Conclusions: All the tumor markers studied (CEA, CA 19-9, CA 242, CA 72-4, and hCGβ) had prognostic value in pancreatic cancer, and hCGβ, CA 72-4, and stage were the strongest independent prognostic factors in this study.

Pulsatile Secretion of LH and FSH in Prepubertal and Early Pubertal Boys Revealed by Ultrasensitive Time-Resolved Immunofluorometric Assays

ABSTRACT: Pulsatile secretion of LH and FSH was examined in 10 prepubertal (aged 4.5–12.9 y) and seven early pubertal (aged 12.8–14.5 y) boys with ultrasensitive (0.019 and 0.014 IU/L time-resolved immunofluorometric assays. Plasma LH and FSH levels were measured every 15 or 20 min for 6 h during the day and night. The lowest mean LH level in a prepubertal boy was 0.02 IU/L and in eight other prepubertal boys mean LH levels were less than 0.4 IU/L. In early pubertal boys the mean LH levels ranged from 0.3 to 6.5 IU/L. The difference in mean FSH level between prepubertal (0.61 IU/L) and early pubertal boys (1.85 IU/L) was smaller than the difference in LH level. All boys had significant LH and FSH pulses. The LH interpulse interval was 135 ± 86 min (mean ± SD) and 76 ± 65 min for the prepubertal and pubertal boys, respectively (p < 0.01). For FSH, the respective values were 150 ± 122 and 221 ± 157 min (p = NS). The mean LH pulse amplitudes were 11-fold greater in the early pubertal boys than in the prepubertal boys, whereas the mean FSH pulse amplitudes were similar between the two groups. The present method shows that the mean LH levels in prepubertal boys are much lower, and the increase during puberty larger, than previously reported. The increase is apparently due to increased pulse frequency and amplitude. The increase in mean FSH level is smaller and evidently not caused by an increase in pulse frequency or pulse amplitude.

Fecal calprotectin and S100A12 have low utility in prediction of small bowel Crohn's disease detected by wireless capsule endoscopy

Abstract Objective. Data on fecal calprotectin and S100A12 in predicting wireless capsule endoscopy (WCE) findings in suspicion of Crohns disease (CD) are scarce. Our aim was to study the role of calprotectin and S100A12 in predicting inflammatory lesions of small bowel in patients undergoing WCE. Material and methods. 84 patients undergoing WCE (77 for suspicion of CD and 7 CD patients for evaluation of disease extent) were prospectively recruited. WCE findings were scored. Patients provided a stool sample for measurements of biomarkers. Patients underwent an esophagogastroduodenoscopy and ileocolonoscopy before WCE. Results. WCE was abnormal in 35 (42%) of 84 patients: 14 patients with CD, 8 with NSAID enteropathies, 8 with angioectasias, 4 with polyps or tumors, and 1 with ischemic stricture. Median calprotectin concentration in the study population was 22 μg/g (range 2–342) and S100A12 concentration 0.048 μg/g (range 0.003–1.215). Fecal calprotectin was significantly higher in CD patients (median 91, range 2–312) compared with those with normal WCE or other abnormalities (p = 0.008), whereas fecal S100A12 (0.087 μg/g, range 0.008–0.896) did not differ between the groups (p = 0.166). In detecting inflammatory small bowel lesions, sensitivity, specificity, positive predictive value, and negative predictive value for fecal calprotectin (cutoff 50 μg/g) were 59%, 71%, 42%, and 83%, and for S100A12 (cutoff 0.06 μg/g) these were 59%, 66%, 38%, and 82%. Conclusions. In predicting small bowel inflammatory changes, fecal biomarkers calprotectin and S100A12 have moderate specificity, but low sensitivity. Neither fecal calprotectin nor S100A12 can be used for screening or excluding small bowel CD.

Noninvasive dual modality in vivo monitoring of the persistence and potency of a tumor targeted conditionally replicating adenovirus

In clinical trials with cancer patients, the safety of conditionally replicating adenoviruses (CRAds) has been good. However, marginal data are available on the persistence or antitumor efficacy of these agents. The oncolytic potency of CRAds is determined by their capacity for entering target cells. Consequently, we constructed a retargeted CRAd featuring a secreted marker protein, soluble human carcinoembryogenic antigen (hCEA), which can be measured in growth medium or plasma. We found that virus replication closely correlated with hCEA secretion both in vitro and in vivo. Further, antitumor efficacy and the persistence of the virus could be deduced from plasma hCEA levels. Finally, using in vivo bioluminescence imaging, we were able to detect effective tumor cell killing by the virus, which led to enhanced therapeutic efficacy.

Gonadotropins in doping: pharmacological basis and detection of illicit use

Parenteral administration of human chorionic gonadotropin (hCG) or luteinizing hormone (LH) stimulates the production of testosterone in males and these gonadotropins can therefore be used by athletes to enhance muscle strength. However, they are more expensive and less efficient than testosterone and anabolic steroids. Therefore their main use is probably to stimulate gonadal testosterone production during and after self‐administration of testosterone or anabolic steroids. A positive effect of hCG on muscle strength has not been demonstrated in women and elevated concentrations of hCG in females are often caused by pregnancy. The use of gonadotropins is therefore prohibited only in males but not in females. HCG occurs at low but measurable concentrations in plasma and urine of healthy males and can be measured by sensitive methods. However, the characteristics of the method to be used for doping control have not been defined. Virtually all commercially available hCG assays have been designed for determination of hCG in serum rather than urine, which is used for doping control. Methods based on mass spectrometric detection of fragments derived from hCG extracted from urine by immunoadsorption have been developed but their suitability for doping control remains to be determined. The concentrations of LH in serum and urine are variable and more then 10‐fold higher than those hCG. It is therefore difficult to detect illicit use of LH. The characteristics and reference values for hCG and LH assays used in doping control and the cutoff values need to be defined.

Preoperative hCGβ and CA 72‐4 are prognostic factors in gastric cancer

In gastric cancer, the role of tumour markers in assessment of prognosis is unconfirmed. In our study, we evaluated the prognostic significance of serum tumour markers carcinoembryonic antigen (CEA), CA 19‐9, CA 72‐4, CA 242 and free β subunit of human chorionic gonadotropin (hCGβ) in gastric cancer. Preoperative serum samples were obtained from 146 patients with gastric cancer, including 29 with stage I, 11 with stage II, 42 with stage III and 64 patients with stage IV cancer. Quantitation of CEA, CA 19‐9, CA 72‐4 and CA 242 in serum was performed with commercial assays. HCGβ was measured with an in‐house immunofluorometric assay based on monoclonal antibodies specific for the free β‐subunit of hCG. Survival analysis was performed with Kaplan‐Meier life‐tables and log‐rank test, and with multivariate Cox regression analysis. Disease‐specific cumulative 2‐year survival rate was 40%. Serum levels of CEA, CA 72‐4, CA 242 and hCGβ showed significant correlation with stage (p<0.027); for CA 19‐9 the association was of borderline significance (p=0.056). Of the studied markers, CA 19‐9, CA 72‐4, CA 242 and hCGβ were found to be prognostic factors in univariate analysis (p< 0.022). In multivariate analysis, stage had the statistically most significant association with prognosis followed by hCGβ, tumour histology according to the Laurén classification and by CA 72‐4. In gastric cancer, tumour markers hCGβ and CA 72‐4 are independent prognostic factors in addition to stage and histological type of the tumour.

Infectivity-Enhanced Adenoviruses Deliver Efficacy in Clinical Samples and Orthotopic Models of Disseminated Gastric Cancer

Purpose: Metastatic gastric cancer remains a common and devastating disease without curative treatment. Recent proof-of-concept clinical trials have validated gene therapy with adenoviruses as an effective and safe modality for the treatment of cancer. However, expression of the primary coxsackie-adenovirus receptor is variable in advanced cancers, and therefore, the use of heterologous receptors could be advantageous. Experimental Design: Here, we used capsid-modified adenoviruses for increasing the transduction and subsequent antitumor efficacy. 5/3 chimeric viruses have a serotype 3 knob which allows binding to a receptor distinct from coxsackie-adenovirus receptor. The fiber of Ad5lucRGD is modified with an integrin-targeted motif. Polylysine motifs, pK7 and pK21, bind to heparan sulfates. Oncolytic adenoviruses replicate in and kill tumor cells selectively. Gastric cancer cell lines and fresh clinical samples from patients were infected with transductionally targeted viruses. Capsid-modified oncolytic adenoviruses were used in cell killing experiments. To test viral transduction and therapeutic efficacy in vivo, we developed orthotopic mouse models featuring i.p. disseminated human gastric cancer, which allowed the evaluation of biodistribution and antitumor efficacy in a system similar to humans. Results: Capsid modifications benefited gene transfer efficiency and cell killing in gastric cancer cell lines and clinical samples in vitro and in vivo. Modified oncolytic adenoviruses significantly increased the survival of mice with orthotopic gastric cancer. Conclusions: These preclinical data set the stage for the clinical evaluation of safety and efficacy in patients with disease refractory to current modalities.

CEA, CA 242, CA 19-9, CA 72-4 and hCGβ in the Diagnosis of Recurrent Colorectal Cancer

Objective: The purpose of this study was to compare the utility of serum CEA, CA 19-9, CA 242, CA 72-4 and human chorionic gonadotropin (hCG)β in the follow-up of 102 surgically treated colorectal cancer patients, out of which 40 patients developed clinical recurrence. Methods: In patients with recurrent disease, serum samples were obtained at the time of clinical recurrence, and in the disease-free group, they were obtained postoperatively. The combined use of the markers was evaluated with logistic regression analysis. The sensitivities of the different tumour markers at various specificity levels were compared by receiver operating characteristic (ROC) curve analysis. Results: When the five tumour markers, Dukes stage and location of the primary tumour were evaluated together in the same model, only CEA provided significant diagnostic information (p < 0.0005) in addition to the location of the primary tumour (p = 0.003). The diagnostic information provided by the other serum tumour markers was insignificant, although CA 72-4 approached borderline significance (p = 0.053). ROC curves were constructed and the difference in the values of the area under the curve (AUC) between the different serum tumour markers was determined at the time of clinical recurrence. Of the individual markers, the highest AUC was observed for CEA (AUC = 0.931). The difference in AUC values between CEA and the other tumour markers was highly significant (p ≤ 0.001). Conclusions: CEA had the highest diagnostic accuracy in detecting recurrent colorectal cancer. Inclusion of CA 19-9, CA 242, CA 72-4 or hCGβ in the model did not improve the accuracy, although CA 72-4 approached borderline significance (p = 0.053). Thus, CEA seems to retain its position as the surveillance marker of choice for patients surgically treated for colorectal cancer.