New and old biomarkers in the differential diagnosis of lung cancer: Pro-gastrin-releasing peptide in comparison with neuron-specific enolase, carcinoembryonic antigen, and CYFRA 21-1.

BACKGROUND: Testing for circulating biomarkers in lung cancer is hampered by the insufficient specificity. We aimed to assess the relative diagnostic accuracy of pro-gastrin-releasing peptide (ProGRP) for the differential diagnosis of small cell lung cancer and compare it with more conventional biomarkers. METHODS: We enrolled a cohort of 390 patients with a clinical suspicion of lung cancer and for whom a histologic assessment was available. Serum or plasma samples were assessed for ProGRP, carcinoembryonic antigen, CYFRA 21-2, and neuron-specific enolase. The performance of each biomarker in discriminating the small cell lung cancer and squamous cell carcinoma/adenocarcinoma from non-malignant lung disease, and small cell lung cancer from squamous cell carcinoma/adenocarcinoma, was assayed by receiver operating characteristic curve analysis. RESULTS: At the cut-off levels suggested by the manufacturers, ProGRP and neuron-specific enolase showed an almost identical sensitivity of 55.2% and 55.6%, respectively, in discriminating small cell lung cancer with respect to non-malignant lung disease. In order to quantify the added value of ProGRP to other conventional markers, we ran a multivariable logistic regression analysis, but the results showed that no markers improve the performance of ProGRP. CONCLUSIONS: ProGRP and neuron-specific enolase individually appear more accurate than other conventional biomarkers for small cell lung cancer, but the union of two markers does not increase the accuracy. The very small target group of patients with small cell lung cancer is a limitation of this study, which can explain why ProGRP alone does not show a sensitivity higher than neuron-specific enolase, as reported by other authors.

TnI-Ultra assay measurements in cancer patients: comparison with the conventional assay and clinical implication.

The serial monitoring of cardiac troponin represents an effective approach for the early identification, assessment, and monitoring of chemotherapy-induced cardiac injury. Over the last few years new generations of troponin assays, referred to as sensitive and high sensitivity assays, able to detect very low concentrations of troponin, have been progressively released on different platforms. Some studies have assessed the comparability of the cTnI measurements with the new assays versus the conventional ones, but none of these in the oncological population. We compared the cTnI results determined on Stratus CS and ADVIA Centaur CP System in 70 breast cancer patients, for a total of 327 samples collected during different cycles of treatment. Correlation (Spearman = 0.732) and agreement (91.4%) between the assays were good (244 concordant negatives and 55 concordant positives), with a frequency of 8.6% discordant results among the cTnI measurements. Despite the well-known lack in the harmonization and standardization of the currently commercially available cTnI methods, we found a good clinical concordance of cTnI determination on both systems.

Detection of squamous cell carcinoma antigen with two systems in the follow-up of patients with cervical cancer.

Since squamous cell carcinoma antigen (SCC-Ag) testing became commercially available on the Architect platform, the previously established method on the Abbott IMx platform has been progressively replaced. Aim of this work was to compare SCC-Ag values obtained with the 2 methods. Clinical and laboratory data of 188 patients for whom SCC-Ag determination was requested, were reviewed. IMx was used to determine the levels of SCC-Ag from June 2007 to May 2009, while the Architect system was used from June 2009 to April 2011. Only patients consistently diagnosed with no evidence of disease, for whom at least 2 determinations with each analyzer were available were used. Comparison of the results obtained with the 2 systems was then performed. Mean values for SCC-Ag were 0.56 ng/mL (Standard Error (SE): 0.08) with the IMx method, and 1.08 ng/mL (SE 0.10) with Architect (p<0.0001). False positive results were found in 4.8% of patients with the IMx method and in 9.5% of patients with Architect (p=0.049). The values of SCC-Ag determined on the Architect platform are higher than those obtained on the IMx, with a higher percentage of false positive results.

Comparison of the Digene HC2 assay and the Roche AMPLICOR human papillomavirus (HPV) test for detection of high-risk HPV genotypes in cervical samples.

Many different methods with different sensitivity and specificity have been proposed to detect the presence of high-risk human papillomavirus (HR HPV) in cervical samples. The HC2 is one of the most widely used. Recently, a new standardized PCR-based method, the AMPLICOR HPV test, has been introduced. Both assays recognize the same 13 HR HPV genotypes. The performances of these two commercially available assays were compared in 167 consecutive women (for a total of 168 samples) who presented at the Colposcopy Clinic either for a follow-up or for a diagnostic visit. Concordant results were found in 140/168 cervical samples (overall agreement, 83%; Cohen's kappa = 0.63). Twenty-eight samples gave discordant results: 20 were positive with the AMPLICOR HPV test and negative with the HC2 assay, and 8 were negative with the AMPLICOR HPV test and positive with the HC2 assay. The genotyping showed that no HR HPV was detected in the 8 HC2 assay-positive AMPLICOR HPV test-negative samples, while in 8/20 AMPLICOR HPV test-positive HC2 assay-negative samples, an HR HPV genotype was found. The AMPLICOR HPV test scored positive in a significantly higher percentage of subjects with normal Pap smears. All 7 cervical intraepithelial neoplasia grade 3 patients scored positive with the AMPLICOR HPV test, while 2 of them scored negative with HC2. Both tests had positive results in the only patient with squamous cell carcinoma. In conclusion, this study shows that the HC2 assay and the AMPLICOR HPV test give comparable results, with both being suitable for routine use. The differences noted in some cases may suggest a different optimal clinical use.

N-terminal pro-B-type natriuretic peptide after high-dose chemotherapy: a marker predictive of cardiac dysfunction?

BACKGROUND: Chronic cardiac dysfunction may develop after administration of aggressive chemotherapy, sometimes leading to development of congestive heart failure (CHF). Recently, N-terminal pro-B-type natriuretic peptide (NT-proBNP) was implicated as a marker of CHF. In this study we evaluated the predictive role of NT-proBNP in patients treated with high-dose chemotherapy (HDC). METHODS: NT-proBNP was measured after 62 chemotherapy treatments in 52 patients affected by aggressive malignancies. Blood samples were drawn before the start of HDC, at the end of HDC administration, and 12, 24, 36, and 72 h thereafter. In these patients, echocardiograms were performed regularly during a 1-year follow-up. RESULTS: Seventeen patients (33%) had persistently increased NT-proBNP, 19 patients (36%) had only transient increases (concentrations went back to baseline at 72 h), and 16 (31%) had no increases [mean (SD) values at 72 h, 1163 (936) ng/L vs 185 (101) ng/L vs 39 (19) ng/L, respectively; P <0.0001]. Only patients with persistently increased NT-proBNP had a significant worsening of the left ventricular diastolic indexes from baseline to 12 months [ratio of peak early to peak late flow velocities from 1.42 (0.33) to 0.78 (0.11); P <0.0001; isovolumetric relaxation time from 90 (15) to 141 (26) ms; P <0.0001; E-wave deceleration time from 162 (17) to 224 (32) ms; P = 0.0004] and of the left ventricular ejection fraction [from 62.8 (3.4)% to 45.6 (11.5)%; P <0.0001]. CONCLUSIONS: Persistently increased NT-proBNP early after administration of HDC is strongly associated with development of cardiac dysfunction. This finding has important implications for identifying patients at risk of developing chemotherapy-induced cardiotoxicity.

Minor increases in plasma troponin I predict decreased left ventricular ejection fraction after high-dose chemotherapy.

BACKGROUND: Increased cardiac troponin I (cTnI) in patients treated with high-dose chemotherapy (HDCT) for aggressive malignancy has been proposed as an early marker of late HDCT-induced cardiac dysfunction. We investigated whether cTnI measured by the Stratus CS (Dade Behring) would allow detection of minimal cTnI increases in patients treated with HDCT. METHODS: Plasma cTnI concentrations were determined in 179 consecutive patients before HDCT, at the end of the treatment, and after 12, 24, 36, and 72 h. Cardiac function was explored by echocardiography, and left ventricular ejection fraction (LVEF) was recorded during follow-up. The greatest variation in LVEF from the baseline value was used as a measure of cardiac damage. RESULTS: In 99 healthy volunteers, the 99th percentile was at 0.07 microg/L. On the basis of ROC curve analysis (area under the curve, 0.89), a cutoff of 0.08 microg/L was chosen (sensitivity, 82%; specificity, 77%). cTnI > or =0.08 microg/L occurred in 57 patients (32%) with echocardiographic monitoring revealing a mean decrease in LVEF of 18%. In comparison, the group of cTnI-negative patients had a mean decrease in LVEF of 2.5% (P <0.001). CONCLUSIONS: Plasma cTnI, as measured with the Stratus CS, can detect minor myocardial injury in patients treated with HDCT.