Interobserver Variability in Ductal Carcinoma In Situ of the Breast.
OBJECTIVES
Since most patients with ductal carcinoma in situ (DCIS) of the breast are treated upon diagnosis, evidence on its natural progression to invasive carcinoma is limited. It is estimated that around half of the screen-detected DCIS lesions would have remained indolent if they had never been detected. Many patients with DCIS are therefore probably overtreated. Four ongoing randomized noninferiority trials explore active surveillance as a treatment option. Eligibility for these trials is mainly based on histopathologic features. Hence, the call for reproducible histopathologic assessment has never sounded louder.


METHODS
Here, the available classification systems for DCIS are discussed in depth.


RESULTS
This comprehensive review illustrates that histopathologic evaluation of DCIS is characterized by significant interobserver variability. Future digitalization of pathology, combined with development of deep learning algorithms or so-called artificial intelligence, may be an innovative solution to tackle this problem. However, implementation of digital pathology is not within reach for each laboratory worldwide. An alternative classification system could reduce the disagreement among histopathologists who use "conventional" light microscopy: the introduction of dichotomous histopathologic assessment is likely to increase interobserver concordance.


CONCLUSIONS
Reproducible histopathologic assessment is a prerequisite for robust risk stratification and adequate clinical decision-making. Two-tier histopathologic assessment might enhance the quality of care.
['Van Bockstal|Mieke R|MR|', 'Berlière|Martine|M|', 'Duhoux|Francois P|FP|', 'Galant|Christine|C|']
D001940:Breast D001943:Breast Neoplasms D002285:Carcinoma, Intraductal, Noninfiltrating D005260:Female D006801:Humans D060787:Neoplasm Grading D015588:Observer Variation
Interobserver variability Ductal carcinoma in situ Breast Reproducibility Artificial intelligence Interrater agreement Nuclear atypia