EGFR expression is associated with decreased benefit from trastuzumab in the NCCTG N9831 (Alliance) trial.

BACKGROUND: Epidermal growth factor receptor (EGFR) has been hypothesised to modulate the effectiveness of anti-HER2 therapy. We used a standardised, quantitative immunofluorescence assay and a novel EGFR antibody to evaluate the correlation between EGFR expression and clinical outcome in the North Central Cancer Treatment Group (NCCTG) N9831 trial. METHODS: Tissue microarrays were constructed that allowed analysis of 1365 patients randomly assigned to receive chemotherapy alone (Arm A), sequential trastuzumab after chemotherapy (Arm B) and chemotherapy with concurrent trastuzumab (Arm C). Measurement of EGFR was performed using the EGFR antibody, D38B1, on the fluorescence-based AQUA platform. The result was validated using an independent retrospective metastatic breast cancer cohort (n=130). RESULTS: Epidermal growth factor receptor assessed as a continuous (logarithmic transformed) variable shows an association with disease-free survival in Arm C (P=0.009) but not in Arm A or B. High EGFR expression was associated with worse outcome (Hazard ratio (HR)=2.15; 95% CI 1.28-3.60, P=0.004). Validation in a Greek metastatic breast cancer cohort showed an HR associated with high EGFR expression of 1.92 (P=0.0073). CONCLUSIONS: High expression of EGFR appears to be associated with decreased benefit from adjuvant concurrent trastuzumab. Since other treatment options exist for HER2-driven tumours, further validation of these data may select patients for alternative or additive therapy.

Influence of human tryptophan hydroxylase 2 N- and C-terminus on enzymatic activity and oligomerization.

Tryptophan hydroxylase (TPH) catalyses the first and rate limiting step in the biosynthesis of the neurotransmitter serotonin. There are two TPH isoenzymes in humans, encoded by two different genes: TPH1 and the recently described TPH2. We have expressed both human enzymes and various deletion mutants of TPH2 (DeltaN44, DeltaC17, DeltaC19, DeltaC51) in COS7 cells. TPH1 and 2 displayed different kinetic properties with a lower K(m) value of TPH1. Removal of 44 amino acids from the N-terminus of TPH2 resulted in a 3-4-fold increased V(max), which indicates a strong inhibitory function of this part on the enzymes activity. TPH1 and 2 were able to form homooligomers and also heterooligomers with each other. The different deletion mutants (DeltaC17, DeltaC19 and DeltaC51), which lack the putative C-terminal leucine zipper tetramerization domain, existed as monomeric enzymes. While short deletions (DeltaC17 and DeltaC19) hardly changed V(max) values, the DeltaC51 mutant lost 99% of TPH activity. These data identify a region between the C-terminal oligomerization domain and the catalytic domain, which is indispensable for TPH2 activity.

[Histopathological alterations in rhesus monkeys after experimental infections with African lung flukes (Paragonimus africanus and P. uterobilateralis) (author's transl)]. / Histopathologische Veränderungen bei Rhesus-Affen nach experimenteller Infektion mit afrikanischen Lungenegeln (Paragonimus africanus und P. uterobilateralis).

Histopathological observations in monkeys experimentally infected with African lung flukes are reported. The observations were made on 3 Rhesus monkeys, infected with Paragonimus africanus from West-Cameroon, and on 5 Rhesus monkeys, infected with P. uterobilateralis from Eastern Nigeria. For comparison, the lung of a naturally infected Drill (Mandrillus leucophaeus) was included in the study. The following lesions were found: formation of parasite cavernae, intense infiltration of the cavern wall with plasma cells; formation of egg granulomata in the lung tissue with intense plasma cell infiltration; peribronchial and perivascular cellular infiltration, concomitant and consistent pleuritis; reactive cellular hyperplasia of hilar lymph nodes and of spleen. Evidently, in the stages of infection examined so far, the immune response of the host is mainly of the humoral type. Experimental Paragonimus infections in monkeys may serve as a model in studies on human paragonimiasis in Eastern Nigeria and West-Cameroon. Likewise, they may serve in studies on granulomatous inflammation.

A laboratorian's perspective on evaluation and implementation of new laboratory tests.

New assay development should be directed toward answering fundamental clinical questions. Caveats that must be considered before initiating assay development projects are: New assays should allow the clinician to interact with and treat a patient more effectively, thereby improving medical outcome; and new assays should facilitate recapture of system resources, enabling cost savings or reinvestment of resources. Defining the clinical questions and consideration of the caveats permit a means of prioritizing assay development activities. Laboratorians are faced with evaluating several types of development activities that lead to assay implementation in routine clinical testing. Assays can be prioritized for up-grading to newer cost-effective technologies, provided the changes maintain or improve analytical and clinical performance. Predicting which research assay will have future value is difficult when clinical performance is not fully validated. However, such assay development has the greatest potential for changing the delivery of healthcare by a clinician.