Therapeutic impact and diagnostic performance of multiplex PCR in patients with malignancies and suspected sepsis.

OBJECTIVES: New molecular methods allow rapid pathogen detection in patients with sepsis, but their impact on treatment decisions remains to be established. We evaluated the therapeutic usefulness of multiplex PCR testing in patients with cancer and sepsis. METHODS: 110 patients with cancer and sepsis were included prospectively and underwent LightCycler® SeptiFast (LC-SF) multiplex PCR testing in addition to standard tests. Two independent panels of experts assessed the diagnosis in each patient based on medical record data; only one panel had the LC-SF results. The final diagnosis established by a third panel was the reference standard. RESULTS: The final diagnosis was documented sepsis in 50 patients (55 microorganisms), undocumented sepsis in 54, and non-infectious disease in 6. LC-SF detected 17/32 pathogens recovered from blood cultures (BC) and 11/23 pathogens not recovered from BC; 12 microorganisms were detected neither by BC nor by LC-SF. LC-SF produced false-positive results in 10 cases. The LC-SF results would have significantly improved treatment in 11 (10%) patients and prompted immediate antimicrobial therapy not given initially in 3 patients. CONCLUSIONS: In cancer patients with suspected sepsis, LC-SF detected 11/55 (20%) true pathogens not recovered from BCs and would have improved the initial management in 11/110 (10%) patients.

Kinetics of HER2/neu ECD in 45 patients treated with trastuzumab (Herceptin) between January 2001 and June 2005 at the Grenoble University Hospital.

UNLABELLED: The aim of this study was to evaluate the utility of HER2/neu ECD concentration as a marker of the efficacity of clinical response to Herceptin. PATIENTS AND METHODS: Iterative measurements of HER2/neu ECD (ELISA c-erbB2/c-neu Rapid Format Elisa kit QIA10 Calbiochem) concentrations in 45 patients treated with Herceptin between January 2001 and June 2005 at the Grenoble University Hospital. RESULTS: Changes in HER2/neu ECD concentrations were observed in 21 patients (47%). The baseline concentration was the concentration of circulating HER2/neu ECD before treatment with Herceptin. In 15 patients, the mean baseline concentration was 52 ng mL(-1) (extreme values 13-170), which normalized no later than at the time of the 3rd administration of Herceptin. Nine patients (60%) were still alive 5 years later (p<0.05). For 6 patients, the mean baseline concentration was 800 ng mL(-1) (extreme values 140-2000) which persisted and even increased during Herceptin therapy; fewer than 25% were alive 30 months later (p<0.05). In the case of the 24 patients whose HER2/neu ECD concentration remained <5 ng mL(-1), survival time was intermediate. CONCLUSION: The study confirmed the utility of HER2/neu ECD in predicting therapeutic response. However, as in the case of other circulating tumor markers, it is only useful when there is a variation in concentration. This marker should now be evaluated in multi-center studies covering a large number of homogeneous subjects.

Evaluation of a manual ELISA kit for determination of HER2/neu in serum of breast cancer patients.

BACKGROUND: Our aim was to conduct an analytical validation in a routine laboratory setting of the cerb-B2/c-neu ELISA assay kit from Calbiochem used to measure the extracellular domain (ECD) of HER2/neu in the serum of breast cancer patients. MATERIALS AND METHODS: The evaluation was based on three different production lots used in a routine laboratory setting. The reference value was based on a population of 217 patients with breast cancer not overexpressing HER2. RESULTS: The detection limit, below that given by the manufacturer, was 0.34 ng ml(-1) and the quantification limit was 0.90 ng ml(-1). Reproducibility and repeatability were at least 95%, precision coefficients of variation varied between 6 and 8.5% and trueness measured by dilution tests and the standard additions method varied between 97 and 107%. The threshold was estimated at 5 ng ml(-1). CONCLUSION: This technique presents satisfactory levels of accuracy for routine laboratory use.

Prospect for anti-HER2 receptor therapy in breast cancer.

The carcinogenesis process is characterized, in part, by the dysfunction of cellular communication pathways, such as the one involving HER2. HER2 is a member of the EGF receptor family, which participates in cell growth and proliferation. HER2 may be overexpressed in 15 to 30% of breast cancer cases and is associated with poor prognosis, shortened overall survival and shorter time to disease progression. Furthermore, an increasing number of studies have demonstrated the relevance of HER2 serum concentrations (sHER2, extracellular domain released into blood by proteolysis) as a predictive marker of resistance to chemotherapy in HER2-overexpressing metastatic breast cancer. The determination of HER2 overexpression/ amplification in the diagnosis of relapse of breast cancer is currently a routine procedure. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) techniques, which are used to detect HER2 expression in the tumor, are improving constantly, and other parallel techniques such as chromogenic in situ hybridization (CISH) are starting to emerge. sHER2 concentrations can be measured using ELISA techniques, which can be automated. All of these procedures still need to be standardized. The discovery of a monoclonal antibody (4D5) that can inhibit the growth and proliferation of cells overexpressing HER2 led to the development of trastuzumab. Like 4D5, trastuzumab recognizes an epitope on the extracellular domain of HER2. Moreover, trastuzumab is also able to stimulate antibody-dependent cellular toxicity (ADCC). It is administered alone or in combination (with navelbine, taxol, carboplatin...) in patients with metastatic breast cancer overexpressing HER2. Other active antibodies have since been discovered, as well as other specific molecules, such as tyrosine kinase inhibitors which will undoubtedly find a place in the therapeutic arsenal used in breast cancer, especially to avoid the emergence of resistance to treatment.

Prospect for anti-her2 receptor therapy in breast cancer.

The carcinogenic process is characterized, in part, by the dysfunction of cellular communication pathways, such as the one involving HER2. HER2 is a member of the EGF receptor family, which participates in cell growth and proliferation. HER2 may be overexpressed in 15 to 30% of breast cancer cases and is associated with poor prognosis, shortened overall survival and shorter time to disease progression. Furthermore, an increasing number of studies have demonstrated the relevance of HER2 serum concentrations (sHER2, extracellular domain released into the blood by proteolysis) as a predictive marker of resistance to chemotherapy in HER2-overexpressing metastatic breast cancer. The determination of HER2 overexpression/ amplification in the diagnosis of relapse of breast cancer is currently a routine procedure. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) techniques, used to detect HER2 expression in the tumor, are improving constantly and other parallel techniques such as chromogenic in situ hybridization (CISH) are emerging. sHER2 concentrations can be measured using ELISA techniques, which can be automated. All of these procedures still need to be standardized. The discovery of a monoclonal antibody (4D5) that can inhibit the growth and proliferation of cells overexpressing HER2 led to the development of trastuzumab. Like 4D5, trastuzumab recognizes an epitope on the extracellular domain of HER2. Moreover, trastuzumab is also able to stimulate antibody-dependent cellular toxicity (ADCC). It is administered alone or in combination (with navelbine, taxol, carboplatin, etc.) in patients with metastatic breast cancer overexpressing HER2. Other active antibodies have since been discovered, as well as other specific molecules, such as tyrosine kinase inhibitors which will undoubtedly find a place in the therapeutic arsenal used in breast cancer, especially to avoid resistance to treatment.