SESSION TYPE: Pleural Biomarkers
PRESENTED ON: Monday, October 22, 2012 at 04:00 PM - 05:30 PM
PURPOSE: Soluble mesothelin-related peptides (SMRP) are an FDA approved biomarker for the diagnosis and monitoring of pleural malignant mesothelioma (MPM). We report the SMRP levels in pleural fluid from a cohort of Italian patients and its utility in clinical management of MPM pleural effusions (MPM-PE).
METHODS: We evaluated SMRP in 52 MPM-PE (35 epithelioid, 9 sarcomatoid, 4 biphasic, 2 desmoplastic, 2 papillary), 129 benign PE (B-PE) and 94 non-MPM pleural metastasis (Mts-PE) by means of the MesoMark ELISA kit. The diagnostic performance parameters were estimated through analysis of the ROC curve and the Youden's index was applied to obtain the biomarker's cut-off level of maximum discrimination. For each cut off, sensitivity (Se) and specificity (Sp) were calculated. The degree of correlation and P value were calculated using the diagnostic odds ratio (DOR) and the Chi-square test, respectively. Comparison between SMRP detection and cytology was also performed.
RESULTS: The median SMRP levels was significantly higher in MPM-PE (28.2 nM) than in B-PE (3.2 nM) or Mts-PE (3.8 nM). MPM-PE yielded an AUC of 84.5 (p<0.001) vs B-PE and an AUC of 79.6 (p<0.001) vs Mts-PE. The cut off level of maximum discrimination between MPM vs each patient groups was 9.30 nmol/L. At this cut off value, we established Se=75%, Sp=93% for MPM-PE vs B-PE and SP=81% for MPM-PE vs Mts-PE. We found SMRP-positive cases (≥ cut off) in 38/52 (73.1%) MPM-PE, in 9/129 (7.0%) B-PE (DOR=40, p<0.001) and in 18/94 (19.1%) Mts-PE (DOR=13, p< 0.001). In 38/52 PE, with SMPR levels ≥ cut off, cytology was found positive in 11/38 (28.9%), negative in 20/38 (52.6%) and in 7/38 (18.4%) was considered suspicious. Moreover, in 4/15 (26.7%) cases of cytology-positive MPM-PE, the levels of SMPR resulted negative.
CONCLUSIONS: SMPR detection in MPM-PE may provide additional diagnostic value to cytology. Combination of SMPR and cytology may increase diagnostic yield if both tests are performed together.
CLINICAL IMPLICATIONS: SMPR analysis may be incorporated into clinical practice of MPM-PE in patients with suspected malignant mesothelioma.
DISCLOSURE: The following authors have nothing to disclose: Anna Maria Carletti, Massimiliano Sivori, Paola Ferro, Enrico Battolla, Maria Franceschini, Franco Fedeli, Silvio Roncella, Pier Aldo Canessa
No Product/Research Disclosure InformationS.C. Pneumologia, ASL5 Spezzino, Ospedale San Bartolomeo, Sarzana, Italy