Invasive breast cancer reporting guidelines: ICCR, CAP, RCPath, RCPA datasets and future directions

Pathological characteristics are essential for breast cancer staging and treatment; hence, regional and country-based pathology reporting protocols have been produced to facilitate comprehensive reporting by pathologists. However, these guidelines can vary in reporting variables, terminology definition, methods of measurement/scoring, which may lead to discordant information for clinicians and disagreement among pathologists. To obviate this, the International Collaboration on Cancer Reporting (ICCR) has recently produced datasets for histological reporting of breast cancer to unify the reporting elements, facilitating international comparability. In this review, we focus on the invasive breast carcinoma reporting datasets with the aim of providing an overview of ICCR recommendations in comparison with those published by regional professional organizations (the Royal College of Pathologists of the United Kingdom (UK) (RCPath), the United States (US) College of American Pathologists (CAP), the Royal College of Pathologists of Australasia (RCPA)), including relevant evidence with practical tips on accurate reporting of breast cancer resection specimens. In addition, we discuss some divergent aspects and suggest future directions for a unified breast cancer pathology reporting framework.