To identify potential cancers as early as possible
specific screening procedures are available and
promoted through screening programs such as:
Further diagnostic testing of tissue biopsies is necessary to establish the pathological stage, the histologic type, the histologic tumour grade and the molecular subtype of the tumour. Biomarkers are used to distinguish different molecular subtypes of breast cancer.
Information on the molecular subtype is used by oncologists to assess individual prognosis of the patient and helps to select the best-suited therapy. The following are the most commonly used tests for determining the status of biomarkers and thus the molecular subtype of the tumour:
Antibody staining of protein in tissue sections shows the expression of biomarkers on protein level. Pathologists visually assess the degree of staining and report a semi-quantitative score which is used to determine whether a biomarker is positive (above threshold) or negative (below threshold value). This approach is semi-quantitative by nature.
FISH (Fluorescence in situ hybridization) or CISH (Chromogenic in situ hybridization)
FISH probes are generally labelled with a variety of different fluorescent tags and can only be detected under a fluorescence microscope, whereas CISH probes are labelled with biotin or digoxigenin and can be detected using a bright-field microscope after other treatment steps have been applied.
RT-qPCR (reverse transcription quantitative real time PCR), determines actual gene expression of biomarkers on an mRNA level. This new generation of test delivers quantitative results, shows a much higher resolution and a broader dynamic range compared to IHC and eliminates several causes of variability that affect IHC measurements (MammaTyper® is based on RT-qPCR technique).