  Breast cancer is the most common malignancy in women, being responsible for
more than half a million deaths every year. As such, early and accurate
diagnosis is of paramount importance. Human expertise is required to diagnose
and correctly classify breast cancer and define appropriate therapy, which
depends on the evaluation of the expression of different biomarkers such as the
transmembrane protein receptor HER2. This evaluation requires several steps,
including special techniques such as immunohistochemistry or in situ
hybridization to assess HER2 status. With the goal of reducing the number of
steps and human bias in diagnosis, the HEROHE Challenge was organized, as a
parallel event of the 16th European Congress on Digital Pathology, aiming to
automate the assessment of the HER2 status based only on hematoxylin and eosin
stained tissue sample of invasive breast cancer. Methods to assess HER2 status
were presented by 21 teams worldwide and the results achieved by some of the
proposed methods open potential perspectives to advance the state-of-the-art.
