http://repub.eur.nl/res/aut/15750/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/19556/ 2010-01-01T00:00:00Z Serum-tumour markers are molecules that are used frequently for diagnosis and treatment of malignancy. The present paper informs the reader about the use and limitations of common serum-tumour markers. We describe the use of serum-tumour markers for screening, diagnosis, staging and prognostic evaluation, detection of recurrence and treatment monitoring. Overall, the common serum-tumour markers are poorly sensitive and specific for screening in an asymptomatic population. The benefits of an improved prognosis by early detection should be weighted to the cost of substantial overdiagnosis and over-treatment. Serum-tumour markers often support the diagnostic process and give useful prognostic information. However, at present serum-tumour markers are above all applicable for treatment monitoring and detection of recurrence. http://repub.eur.nl/res/pub/19560/ 2010-01-01T00:00:00Z The squamous-cel cancer antigen (SCC Ag) is expressed by squamous cells of skin, lung, digestive tract and uterine cervix. Its expression increases with increasing malignant transformation. Increased concentrations of SCC Ag can therefore be found in patients with squamous cell cancers. Although several publications describe the use of this tumormarker in squamous-cell cancers, like carcinoma of head- and neck, lung carcinoma, bladder carcinoma or rectal carcinoma, SCC Ag measurements are mainly used in follow up and/or prognosis of patients with cervix carcinoma. The SCC Ag belongs to the family of serine-protease inhibitors (Serpins) and is known to have two isoforms: SCCA1 and SCCA2. Current assays used for routine analysis of SCC Ag all detect both isoforms. Little is known about the sensitivity for both isoforms in current routine assays. In this paper we discuss assay characteristics and clinical application of the assays currently avalable for SCC Ag. Furthermore, preanalytical aspects and the results of a Dutch external quality-assurance initiative are discussed. http://repub.eur.nl/res/pub/19582/ 2010-01-01T00:00:00Z http://repub.eur.nl/res/pub/13830/ 2005-09-01T00:00:00Z Leptomeningeal metastasis (LM) is a devastating complication that occurs in 5% of patients with breast cancer. Early diagnosis and initiation of treatment are essential to prevent neurological deterioration. However, early diagnosis of LM remains challenging because 25% of cerebrospinal fluid (CSF) samples produce false-negative results at first cytological examination. We developed a new, MS-based method to investigate the protein expression patterns present in the CSF from patients with breast cancer with and without LM. CSF samples from 106 patients with active breast cancer (54 with LM and 52 without LM) and 45 control subjects were digested with trypsin. The resulting peptides were measured by MALDI-TOF MS. Then, the mass spectra were analyzed and compared between patient groups using newly developed bioinformatics tools. A total of 895 possible peak positions was detected, and 164 of these peaks discriminated between the patient groups (Kruskal-Wallis, p<0.01). The discriminatory masses were clustered, and a classifier was built to distinguish patients with breast cancer with and without LM. After bootstrap validation, the classifier had a maximum accuracy of 77% with a sensitivity of 79% and a specificity of 76%. Direct MALDI-TOF analysis of tryptic digests of CSF gives reproducible peptide profiles that can assist in diagnosing LM in patients with breast cancer. The same method can be used to develop diagnostic assays for other neurological disorders.