Variation in breast carcinoma cells proliferation assessment according to immunohistochemical nuclear antigen Ki67 staining.

Cilj istraživanja: Utvrditi da li varijabilnost u očitavanju Ki67 antigena onemogućuje točno svrstavanje raka dojke u podskupine koje ovise o očitanom Ki67. Ustroj studije: Presječna studija s povijesnim podatcima. Ispitanici i metode: Istraživanje je provedeno na 50 uzoraka tumorskog tkiva pacijentica kod kojih je u Kliničkom bolničkom centru Osijek u 2017. godini dijagnosticiran invazivni karcinom dojke bez posebnih osobitosti stadija T1. Histološki rezovi su imunohistokemijski obojeni Ki67 antitijelom, fotografirani i na fotografijama je očitavana pozitivnost na najmanje 500 tumorskih stanica u različitim dijelovima tumora: u rubnom i središnjem dijelu, unutar „hot spotsa“ i izvan njih, kao i u tri slučajno odabrana dijela tumora. Statistička obrada podataka provedena je analizom klastera i računanjem Friedmanove ANOVE i Kendallove suglasnosti. Rezultati: Klaster analiza svrstala je 7 načina uzorkovanja Ki67 u dvije skupine: skupinu 1 (rub tumora, izvan vrućih točaka, slučajni uzorak 2 i sredina tumora) χ2 = 18,98, p < 0,001, uz koeficijent suglasnosti 0,12 i skupinu 2. (vruće točke, slučajni uzorci 1 i 3) χ2 = 56,28, p < 0,001, uz koeficijent suglasnosti 0,56. U drugoj fazi statističke obrade, uspoređeni su načini na koje se grupiraju podgrupe 50 promatranih bolesnica ovisno o prva 4 pokazatelja i ovisno o zadnja tri pokazatelja. Na ta 2 načina utvrđene su po 2 podgrupe i onda je uspoređeno statistički da li pokazatelji koji su međusobno slični jednako raspoređuju bolesnice (χ2 = 31,53, p < 0,001). Pet bolesnica je različito raspoređeno što znači da je odstupanje 10 %. Zaključak: Varijabilnost u dobivenim podatcima očitavanja Ki67 antigena raka dojke je 10 % i onemogućuje točno svrstavanje raka dojke u podskupine o kojima ovisi određivanje načina liječenja bolesnika.Study objective: To determine whether the variability in the Ki67 antigen detection prevents the correct classification of breast cancer into subgroups depending on the detected Ki67. Study design: Cross-sectional retrospecitve study. Subjects and methods: The study was conducted on 50 tumor tissue samples of patients with stage T1 invasive breast cancer of no special type, diagnosed at the Osijek Cilnical Hospital Centre in 2017. Hystology slides were immunohistochemically dyed with the Ki67 antigen photographed, and a share of Ki67 positive cells was detected on at least 500 tumor cells in different regions of the tumors: in the peripheral and central regions, within the "hot spots" and beyond, as well as in three randomly selected regions. Statistical data analysis was performed using cluster analysis and by measuring the Friedman’s ANOVA and the Kendall's Coefficient of Concordance. Results: The cluster analysis has categorized 7 methods of sampling Ki67 into two groups: group 1 (tumor margins, outside hot spots, random sample 2, and tumor centre) χ2 = 18.98, p < 0,001, with a coefficient of concordance of 0.12, and group 2 (hot spots, random samples 1 and 3) χ2 = 56,28, p < 0,001, with a coefficient of concordance of 0.56. In the second phase of the statistical data analysis, the methods in which subgroups of 50 observed patients were grouped according to the first 4 and last 3 indicators were compared. These 2 methods determined 2 subgroups and then there was a statistical comparison as to whether the similar indicators were distributed equally among the patients (χ2 = 31.53, p < 0,001). In 5 patients the indicators were distributed unequally, meaning that the variation was 10 %. Conclusion: There was a 10 % variability in the data obtained from the Ki67 breast cancer antigen reading which prevents the exact classification of breast cancers into the subgroups on which the determination of patient treatment depends