Significance of β-Crosslaps and the tumour markers in diseases of the prostate gland

Objective of this study was to assess the validity of β-Crosslap concerning prostate carcinoma and to evaluate its benefit in the early detection, the diagnosis and the monitoring of this prostatic disorder. β-Crosslap and prostate-specific antigen (PSA) were measured as a comparison. The serum samples of 210 patients were analyzed using a specific immunoassay. The patients were divided into seven groups according to the Whitmore Jewett Classification: 100 healthy subjects, 27 patients with benign prostate hyperplasia (BPH), 8 patients with prostate carcinoma level A, 17 patients with prostate carcinoma level B, 17 patients with prostate carcinoma level C, 29 patients with prostate carcinoma level D, 12 patients were not assigned. In patients with benign prostatic hyperplasia β-Crosslap showed a sensitivity of 51.85% and a specificity of 93%. PSA showed a sensitivity of 62.96% and a specificity of 92% in the same cohort. Irrespective of the stage of prostate cancer β-Crosslap showed a sensitivity of 90.36% and a specificity of 100%. PSA showed a sensitivity of 86.74% and a specificity of 100%. If one refers to the different disease stages β-Crosslap showed a sensitivity of 75% at stage A, a sensitivity of 94.11% at stage B, a sensitivity of 88.23% at stage C and a sensitivity of 96.55% at stage D. At all stages there was a specificity of 100%. Elevated concentrations of this marker could always be detected. PSA showed a sensitivity of 62.5% at stage A, a sensitivity of 76.47% at stage B, a sensitivity of 88.23% at stage C and a sensitivity of 96.55% at stage D. Elevated concentrations of this marker could always be detected. For the diagnosis of benign prostatic hyperplasia β-Crosslap does not provide any benefit due to its lower sensitivity. However, for the diagnosis of prostatic carcinoma one could profit from β-Crosslap as a prognostic marker especially at early stages of the disease. Introduction In Germany prostatic cancer is ranked first among all cancers in the male population showing an annual incidence of approximately 58,000 cases [1] which is higher than that of intestinal or lung cancer. Also in the United Stated prostate carcinoma was the most frequent cancer with about 218.890 new cases and about 27.050 deaths in 2007 [2]. The incidence increases with age and reaches a level of 1,000/100,000/year at the age of 80. Latent or occult carcinomas are not included in these figures. Therefore an even higher incidence can be assumed [3]. The “life time” risk to die from a clinically pronounced prostatic carcinoma is approximately 10% [3]. With an incidence of 65 to 75% the bone involvement, especially the metastatic spread into the axial skeleton is a major cause of the mortality and the morbidity [4]. Lower back pain may be symptoms of metastatic disease occur at an advanced and at the late stage [3]. On account of preventive medical check-ups and the currently available diagnostic measures the 5 year survival rate increased substantially in the past years [1]. Within this frame laboratory chemistry tests are available to assess the extent of the disease, the kind of the transformation and to monitor the course of the disease after a therapeutic intervention [3]. PSA can be detected in serum as prostate specific biomarker. This still leading tumor marker for the evaluation of disorders of the prostate gland does not show a sufficient sensitivity for the detection of prostate carcinomas. Not only for this reason the search for new biomarkers with a higher specificity and sensitivity for the detection of a malignancy and for its staging and the assessment of the presence of metastases is of high importance [5]. In this context various products of metabolism play major roles which are formed during the bone remodeling and absorption driven by osteoblasts and bone absorbing osteoclasts, respectively. Furthermore, the associated regulation factors and ligands are of relevance. These biochemical markers have turned out to be a useful, noninvasive and comparatively inexpensive method for the assessment and monitoring of metastatic bone involvement [6]. β-Crosslap is a degradation product of bone metabolism. It is detectable in serum if bone metabolism is increased, e.g. in osteoporosis but also in patients with cancer where the primary tumor has impact on bone metabolism. This is enabled through certain mediators or tumor metastases [7-13]. Accordingly, subject of the present study was to measure sensitivity and specificity of the tumor marker β-Crosslap and to evaluate its clinical relevance for different disorders of the prostate gland. Correspondence to: Lukas J. Becker, Departments of Laboratory Medicine – Internal Medicine, Hospital of the Johann Wolfgang Goethe University, TheodorStern-Kai 7, D-60590, Frankfurt am Main, Germany, Tel: +49 69 63015024; Fax: +49 69 63017201; E-mail: lukasjbecker@web.de