Survivin i proliferativni indeks Ki67 u raku dojke

Abstract

Survivin is a member of the inhibitor of apoptosis (IAP) family. It is also involved in the regulation of cell division.Survivin is widely expressed in foetal tissues and in human cancers, but generally not in normal adult tissue. This study examined the expression of survivin protein in a series of 50 cases of invasive primary breast carcinoma. Our study comprised 50 cases of breast cancer, 10 of each immunophenotype. All tumours were diagnosed as invasive ductal carcinoma (Not Otherwise Specifi ed, NOS). Formalin-fi xed, paraffi n-embedded tissue sections were immunostained for survivin. Survivin immunoreactivity was evaluated as follows: 0(0-5% positive cells); 1(5–20%); 2(21–50%); 3(51–75%); 4(>76%) with cutoff value of 20% that was established as a positive result. Immunohistochemical analysis showed positive expression for survivin in 18 of 50 cases (36%) of breast carcinomas of TNM stages I to III. In previous studies, there was significant relationship between survivin expression and negative prognostic factors like larger tumour size, higher histologic grade and negative hormonal status. What we should emphasize in our study is the correlation between HER2 positive tumours and survivin expression (P=0.007) and strong association of survivin expression in cytoplasm in HER2 positive tumours as a predictor of unfavourable outcome. Further larger studies are needed in future to explore and explain the facts about survivin and its connection with breast cancer.Survivin je protein koji je član obitelji inhibitora apoptoze, a uključen je i u regulaciju stanične diobe. Široko je rasprostranjen u fetalnim tkivima i ljudskim tumorima, ali se u pravilu ne javlja u normalnim odraslim tkivima. Studijom smo ispitali izražajnost survivina u seriji od 50 slučajeva invazivnog primarnog karcinoma dojke. Obrađeno je 50 slučajeva, po 10 od svakog imunofenotipa. Svi tumori su dijagnosticirani kao invazivni duktalni karcinom (NOS). Dijelovi tumorskog tkiva su fiksirani u formalinu i uklopljeni u parafinske kocke te je napravljena imunohistokemijska obrada na survivin. Imunoreaktivnost survivina je procijenjena: 0 (0-5% pozitivnih tumorskih stanica); 1 (5-20%); 2 (21-50%); 3 (51-75%) i 4(> 76%) uz graničnu vrijednost od 20%, koja je ustanovljena kao pozitivan rezultat. Imunohistokemijska analiza pokazala je pozitivnu izraženost survivina u 18 slučajeva (36%) TNM stadija I do III. U prethodnim studijama vidljiva je značajna povezanost izraženosti survivina i negativnih prognostičkih čimbenika kao što su veličina tumora, visoki histološki gradus i negativni hormonalni status. Treba naglasiti da je prediktor nepovoljnog ishoda pozitivna korelacija HER2 pozitivnih tumora i izražajnosti survivina u njihovoj citoplazmi (P=0.007). Potrebne su buduće studije koje će istražiti i objasniti činjenice vezane uz survivin i njegov odnos s karcinomom dojke