Interlaboratory concordance in HER2 testing: Results of a Serbian ring-study.

PURPOSE: The purpose of this study was to assess the immunohistochemistry and chromogenic in situ hybridization (CISH) inter-laboratory consensus between national pathology laboratories in Serbia. METHODS: This study was conducted between 2013 and 2016. In 2013, HER2 results were evaluated using two sets of four different breast cancer specimens in five laboratories. A total of 20 immunohistochemistry and 20 CISH cases were tested. In 2014, there were 6 testing rounds, and a total of 24 specimens were analyzed, whereas in 2015 and 2016, seven testing rounds were conducted, with four additional cases (i.e. a total of 28 specimens). In 2014, 2015 and 2016, all institutions performed immunohistochemical analysis only. RESULTS: We found discrepan¬cies in HER2 immunohistochemical (IHC) results in all four surveys. IHC testing resulted in diagnostic discordance between participating centers in two (2/17) cases in 2013, two (2/24) in 2014, four (4/27) cases in 2015 and three cases (3/27) in 2016. The overall agreement among the centers was 79%, 85.5%, 83.5% and 89.4%, respectively. For CISH analyses, the results for 16 (84.2%) of 19 samples were consistent for all participants. Three results were found to be discordant, indicating a misdiagnosis rate of 15.8%. In all the discrepant cases, interinstitutional discordances were related to technical and evaluation issues. CONCLUSIONS: Our study highlights the difficulty encountered during HER2 testing using immunohistochemistry and CISH. This also emphasizes the need for rigorous quality control procedures for specimen preparation and analysis.

Serbian consensus of neoadjuvant therapy for breast cancer: NeoPULSE.

Even though surgery is the primary treatment of operable breast cancer, it has been known for decades that the administration of postoperative adjuvant or preoperative neoadjuvant therapy is extremely important. Indications for neodjuvant therapy administration have been expanded over the years, and nowadays this kind of treatment represents an inevitable option in early breast cancer treatment. The NeoPULSE project, which gathered a group of experts in the field of breast cancer from five Serbian university centres, was formed with the aim to define optimal breast cancer diagnosis, indications for neoadjuvant therapy, therapeutic combinations in relation to molecular/biological parameters of breast cancer, as well as the treatment after neoadjuvant therapy. During two separate expert meetings involving surgeons, medical oncologists, radiation oncologists, a pathologist, and a "Blueprint" workshop, the project participants answered questions over the indications for neoadjuvant therapy. The first part covered local practice and referred to the existence and work of a multidisciplinary team, as well as commonly applied therapeutic regimens in the neoadjuvant setting. Experts analysed personal views regarding indications for the administration and benefits of neoadjuvant therapy, their perception on the correlation between achieving a pathological complete response (pCR) and the outcome of treatment, as well as the attitude towards controversies about this type of treatment, primarily regarding a possible change in the receptor status after therapy and therapeutic options after a suboptimal response. The analysis of the answers pointed to problems and deviations from recommendations in everyday clinical practice, based on which appropriate solutions were proposed. The establishment of such a panel and consensus is an attempt to modernize multidisciplinary teams in Serbia, achieve reaching uniform decisions of all subjects dealing with breast cancer, and therefore, at least in one segment, improve breast cancer treatment in Serbia.