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  • Author: Karin Hofmann x
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Abstract

Photoacoustic imaging combines the resolution of ultrasound imaging with the contrast of optical imaging, while maintaining a penetration depth up to a few centimeters. Inorganic gold nanorods can be employed as photoacoustic contrast agents. However, the toxicological properties of such nanoparticles are still under investigation. At the same time, there is an increasing need for clinically established photoacoustic contrast agents. In this paper, therefore, we investigate the photoacoustic properties of Ferucarbotran, which is a clinically established nanoscale contrast agent for magnetic resonance imaging. Gelatin phantoms containing cubes with different gelatin-Ferucarbotran mixture concentrations were prepared and irradiated by a Nd:YAG laser (1064 nm). First, the photoacoustic signals were acquired by a single element ultrasound transducer (7.5 MHz) and evaluated quantitatively. In a second setup, photoacoustic imaging of Ferucarbotran with a modified clinical scanner was demonstrated. The experiments showed that in order to achieve a 6 dB gain of received photoacoustic signal energy, compared to the sensitivity threshold of the used system, a Ferucarbotran concentration of 1.9 μmol Fe/ml is needed. The photoacoustic imaging was successful and showed a contrast-to-background ratio of 15.7 dB for a concentration of 11.63 μmol Fe/ml. However, for imaging in tissue the signal-to-noise ratio has to be increased.

Abstract

Background: Soluble mesothelin-related peptide (sMRP) has shown great potential for malignant mesothelioma detection. However, data on comparison with other cancer and benign diseases as well as with other established lung cancer biomarkers are rare.

Methods: In this study, SMRP was investigated in sera from 1506 individuals including 147 healthy donors, 285 patients with diverse benign diseases and 1074 patients with mesothelioma (n=39) and various malignant tumors (lung, gastrointestinal, gynecological, urological). For differential diagnosis of lung diseases, carcinoembryonic antigen, cytokeratin 19-fragments (CYFRA 21-1), neuron-specific enolase and squamous cell cancer antigen were determined additionally.

Results: Ninety-fifth percentiles of sMRP serum levels in healthy persons were 1.2 nM, in patients with benign diseases between 2.0 and 3.8 nM and in cancer patients between 1.5 and 44.3 nM. Highest values were observed in mesothelioma (median 2.3 nM; 95th percentile 44.3 nM). When differential diagnostic capacity of cancer detection vs. the relevant benign control group was tested, sMRP showed best results for mesothelioma and ovarian cancer with a sensitivity of 45% and 37%, respectively, at 95% specificity. At 100% specificity vs. normal controls, sensitivity for mesothelioma detection was found to be 59% for sMRP, 73% for CYFRA 21-1 and 88% for the combination of both. At 95% specificity vs. all other lung diseases, sensitivity for mesothelioma was 48% for sMRP, 15% for CYFRA 21-1 and 46% for the combination of both.

Conclusions: In summary, SMRP is a valuable serum biomarker that is specific at high concentrations for the detection of malignant mesothelioma. For screening purposes, the combination with CYFRA 21-1 improves the sensitivity at high specificity.

Abstract

Between 1997 and 2000 we investigated in a prospective study the voided urine samples of all consecutive patients undergoing cystoscopy independent from their clinical background (n = 705) with the BTA-TRAK™ assay (Bard Diagnostics, Redmont, USA) detecting a complement factor H-related protein (CFHrP) and the NMP22 assay (Matritech, Newton, USA) measuring a nuclear matrix protein, which is supposed to be specific for bladder cancer. The individuals were divided into three groups concerning the clinical background: 233 patients had urological diseases, 268 patients had urinary bladder cancer and 150 patients had other urological malignancies. Based on the clinical findings we compared our results with well established diagnostic methods for urinary bladder cancer such as cytology and the detection of hematuria. In addition, we investigated urine samples from 30 healthy individuals and 24 patients with urinary tract infection without performing cystoscopy. Following the recommendations of the European Group on Tumor Markers we used 95% specificity for benign urological diseases and urinary tract infections, which resulted in a sensitivity of 17% for active bladder cancer for the BTA-TRAK™ assay and 31% for NMP22. We compared these results with the detection of hematuria (specificity: 72%) and cytology, which had a sensitivity of 64% and 89%, respectively. Subsequently, we calculated sensitivity and specificity for the detection of relapse of the disease. Again using 95% specificity, in this case for patients with no evidence of disease (NED), in patients with recurrent disease the BTA-TRAK™ assay showed 8% sensitivity as compared to 12% for the NMP22 assay. Due to an insufficient specificity and sensitivity, both tests can neither be clinically useful in screening of high risk patients, nor in primary diagnosis of bladder cancer. They cannot replace neither cystoscopy nor cytology. In the follow-up care more investigations may be necessary to prove the benefit of existing diagnostic strategies for the discrimination between active and inactive bladder cancer.

Abstract

Background: The usefulness of S100 as a prognostic marker and aid in follow-up care in patients with malignant melanoma as well as in individuals with various neurological pathologies is well known. The aim of this study was to investigate its release and clinical relevance in benign and malignant disorders beyond these indications to elucidate tumor and organ specificity of S100.

Methods: S100 levels were studied in serum samples of 1856 untreated patients, among them 59 healthy individuals, 358 patients with benign disorders, and 1439 patients with malignant tumors.

Results: Healthy individuals had low S100 levels reaching a median of 0.041 ng/mL and 95th and 100th percentiles of 0.096 ng/mL and 0.144 ng/mL, respectively. The medians of patient groups with benign diseases ranged from 0.030 to 0.057 ng/mL, patients with malignant diseases from 0.020 to 0.059 ng/mL, and thus were comparable to healthy individuals. Only 2% of patients with benign diseases, mainly suffering from infectious, autoimmune, or benign gastrointestinal diseases and 1% of patients with malignant diseases showed slightly higher values than healthy individuals, in most cases up to 0.5 ng/mL.

Conclusions: In contrast to many other oncological biomarkers, S100 is only rarely released in elevated levels from most benign and malignant diseases apart from malignant melanoma and neurological diseases, resulting in superior organ and tumor specificity. As potentially influencing factors, severe infectious diseases have to be considered.

Abstract

Background: Human epididymis protein 4 (HE4) is described as a useful new biomarker in ovarian cancer. As HE4 is neither tumor nor organ specific, we intensively investigated the occurrence of this protein in female and male patients with various benign and malignant diseases in order to avoid misinterpretation and to identify potential additional clinical relevance.

Methods: We retrospectively investigated HE4 (ARCHITECT®, Abbott Diagnostics, US) in the sera of 205 healthy individuals, 654 patients with benign disorders and 720 patients with cancer before initial treatment.

Results: The lowest concentrations of HE4 were observed in healthy men (median 26.2 pmol/L) followed by healthy women (median 40.4 pmol/L). In benign diseases, highest HE4 concentrations were seen in both women and men with renal failure (women, median 1041 pmol/L; men, median 1368 pmol/L). In women, the highest HE4 levels in malignant diseases were observed in ovarian cancer (median 242 pmol/l), whereas the highest HE4 concentrations in men occurred in lung cancer (median 89.2 pmol/L). The area under the curve (AUC) of HE4 in women was highest in ovarian cancer and borderline tumors as compared to benign gynecological disorders (88.9%), with a sensitivity of 67.4% at 95% specificity. Also, significantly elevated concentrations of HE4 with reference to the respective group of benign diseases were observed in uterus corpus and breast cancer as well as in lung cancer for men and women.

Conclusions: HE4 has the highest relevance in ovarian cancer but can be elevated in a variety of benign and malignant diseases.

Abstract

Background: Cancer antigen 125 (CA125) is the best known single tumor marker for ovarian cancer (OC). We investigated whether the additional information of the human epididymis protein 4 (HE4) improves diagnostic accuracy.

Methods: We retrospectively analyzed preoperative sera of 109 healthy women, 285 patients with benign ovarian masses (cystadenoma: n=78, leimyoma: n=66, endometriosis: n=52, functional ovarian cysts: n=79, other: n=10), 16 low malignant potential (LMP) ovarian tumors and 125 OC (stage I: 22, II: 15, III: 78, IV: 10). CA125 was analyzed using the ARCHITECT system, HE4 using the ARCHITECT(a) system and EIA(e) technology additionally.

Results: The lowest concentrations of CA125 and HE4 were observed in healthy individuals, followed by patients with benign adnexal masses and patients with LMP tumors and OC. The area under the curve (AUC) for the differential diagnosis of adnexal masses of CA125 alone was not significantly different to HE4 alone in premenopausal (CA125: 86.7, HE4(a): 82.6, HE4(e): 81.6% p>0.05) but significantly different in postmenopausal [CA125: 93.4 vs. HE4(a): 88.3 p=0.023 and vs. HE4(e): 87.8% p=0.012] patients. For stage I OC, HE4 as a single marker was superior to CA125, which was the best single marker in stage II-IV. The combination of CA125 and HE4 using risk of malignancy algorithm (ROMA) gained the highest sensitivity at 95% specificity for the differential diagnosis of adnexal masses [CA125: 70.9, HE4(a): 67.4, HE4(e): 66.0, ROMA(a): 76.6 and ROMA(e): 74.5%], especially in stage I OC [CA125: 27.3, HE4(a): 40.9, HE4(e): 40.9, ROMA(a): 45.5 and ROMA(e): 45.5%].

Conclusions: CA125 is still the best single marker in the diagnosis of OC. HE4 alone and even more the combined analysis of CA125 and HE4 using ROMA improve the diagnostic accuracy of adnexal masses, especially in early OC.

Abstract

Background: Pro-gastrin releasing peptide (ProGRP) concentrations in blood play an important role in the diagnosis and treatment of patients with small cell lung cancer (SCLC). The automated quantitative ARCHITECT® ProGRP assay was developed to aid in the differential diagnosis and in the management of SCLC. The purpose of this study was to evaluate the analytical performance of this chemiluminescent microparticle immunoassay at multiple sites.

Methods: ARCHITECT ProGRP measures ProGRP using a two-step sandwich using monoclonal anti-ProGRP antibodies coated on paramagnetic microparticles and labeled with acridinium. Analytical performance of the assay was evaluated at four sites: Abbott Japan, Denka Seiken, the Johns Hopkins University, and the University of Munich.

Results: Total precision (%CV) for nine analyte concentrations was between 2.2 and 5.7. The analytical sensitivity of the assay was between 0.20 pg/mL and 0.88 pg/mL. The functional sensitivity at 20% CV was between 0.66 pg/mL and 1.73 pg/mL. The assay was linear up to 50,000 pg/mL using a 1:10 autodilution protocol. The calibration curve was stable for 30 days. Comparison with the Fujirebio microtiter plate enzyme-linked immunosorbent assay (EIA) ProGRP assay gave a slope of 0.93 and a correlation coefficient (r) of 0.99.

Conclusions: These results demonstrate that the ARCHITECT ProGRP assay has excellent sensitivity, precision, and correlation to a reference method. This assay provides a convenient automated method for ProGRP measurement in serum and plasma in hospitals and clinical laboratories.

Clin Chem Lab Med 2009;47:1557–63.