Breast cancer with HER2 positivity accounts for about 15% of all diagnosed breast cancers. Overexpression and amplification of HER2 is associated with a worse prognosis however, it is also an effective target for anti-HER2 therapy.
Complete blockade of the HER2 receptor-mediated signal for tumour growth and progression is a bigger guarantee of the efficacy of anti-HER2 therapy at different stages of the disease.