Advantages and disadvantages of technologies for HER2 testing in breast cancer specimens.
OBJECTIVE
Human epidermal growth factor receptor 2 (HER2) plays a central role as a prognostic and predictive marker in breast cancer specimens. Reliable HER2 evaluation is central to determine the eligibility of patients with breast cancer to targeted anti-HER2 therapies such as trastuzumab and lapatinib. Presently, several methods exist for the determination of HER2 status at different levels (protein, RNA, and DNA level).


METHODS
In this review, we discuss the main advantages and disadvantages of the techniques developed so far for the evaluation of HER2 status in breast cancer specimens.


RESULTS
Each technique has its own advantages and disadvantages. It is therefore not surprising that no consensus has been reached so far on which technique is the best for the determination of HER2 status.


CONCLUSIONS
Currently, emphasis must be put on standardization of procedures, internal and external quality control assessment, and competency evaluation of already existing methods to ensure accurate, reliable, and clinically meaningful test results. Development of new robust and accurate diagnostic assays should also be encouraged. In addition, large clinical trials are warranted to identify the technique that most reliably predicts a positive response to anti-HER2 drugs.
From the Centre de recherche sur le cancer de l'Université Laval, Quebec City, Canada; Axe Oncologie, Centre de recherche du CHU de Québec, Hôpital du St-Sacrement, Quebec City, Canada; Département de médecine sociale et préventive, Faculté de Médecine, Quebec City, Canada;
Daniela
D
Furrer
Centre des Maladies du Sein Deschênes-Fabia, Hôpital du St-Sacrement, Quebec City, Canada and Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de Médecine, Quebec City, Canada.
François
F
Sanschagrin
Centre des Maladies du Sein Deschênes-Fabia, Hôpital du St-Sacrement, Quebec City, Canada and Département de biologie moléculaire, de biochimie médicale et de pathologie, Faculté de Médecine, Quebec City, Canada.
Simon
S
Jacob
From the Centre de recherche sur le cancer de l'Université Laval, Quebec City, Canada; Axe Oncologie, Centre de recherche du CHU de Québec, Hôpital du St-Sacrement, Quebec City, Canada; Département de médecine sociale et préventive, Faculté de Médecine, Quebec City, Canada; Centre des Maladies du Sein Deschênes-Fabia, Hôpital du St-Sacrement, Quebec City, Canada and caroline.diorio@crchudequebec.ulaval.ca.
Caroline
C
Diorio
D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D000077341:Lapatinib; D015336:Molecular Probe Techniques; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D011379:Prognosis; D011799:Quinazolines / Q000627:therapeutic use; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D000068878:Trastuzumab / Q000627:therapeutic use
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D000077341:Lapatinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human
Breast cancer; HER2 inhibitors; HER2 status; Lapatinib; Trastuzumab