Morphological and immunohistochemical features of breast cancer important for treatment decision

Rak dojke je najčešći zloćudni tumor u žena. Dijagnoza raka dojke postavlja se kombinacijom različitih metoda koje uključuju klinički pregled, ultrazvučni pregled dojki, mamografiju, nuklearnu magnetsku rezonanciju te najvažniju, patohistološku dijagnostiku. Patohistološkom dijagnostikom moguće je utvrditi brojne prognostičke i prediktivne čimbenike važne za odluku o kasnijoj terapiji. Najvažniji prognostički čimbenici su veličina i stupanj diferenciranosti tumora, histološki tip te status regionalnih limfnih čvorova. Najvažniji prediktivni čimbenici su status steroidnih receptora, proliferacijski indeks tumorskih stanica i HER2-neu status i sastavni su dio imunohistokemijske klasifikacije raka dojke. Konačan patohistološki nalaz mora sadržavati mjesto tumora, veličinu i broj tumora, histološki tip, stupanj diferenciranosti, prisustvo vaskularne invazije, stanje resekcijskih rubova te status limfnih čvorova. Veličina tumora i status limfnih čvorova čine patološki stadij prema pTNM klasifikaciji. Uz navedeno, navode se rezultati imunohistokemijske analize steroidnih receptora, proliferacijski indeks i HER2-neu status. Na temelju navedenih nalaza multidisciplinarni tim onkologa, radiologa, patologa i kirurga individualno odlučuje o načinu liječenja. U slučaju dobro diferenciranih tumora pozitivnih na steroidne receptore kao prva linija, uz kirurško liječenje preporuča se antihormonska terapija. Slabo diferencirani tumori negativni na steroidne receptore liječe se kemoterapijom, a u slučaju amplifikacije HER2-neu gena, može se koristiti i ciljana terapija.Breast cancer is the most common cancer in female population. For the diagnosis of breast cancer, several methods are used including clinical examination, ultrasound, mammography, nuclear magnetic resonance, and the most important, pathohistological analysis. From pathological examination it's possible to define several valuable prognostic and predictive factors needed for further decision about treatment approach. The most important histological prognostic factors include size, histological type of tumor, grade and pathological stage. The most predictive factors are steroid receptor status, proliferation index and HER2-neu status. All of them are included in immunohistochemical classification of breast cancers. Final pathological report should include site of the tumor, focality, size, type of cancer, histological grade, presence of vascular invasion, description of resection margins and lymph node status. Size and lymph node status should be reported as pathological pTNM stage. Moreover, every report should include results of immunohistochemical analysis of steroid receptors, proliferation index and HER2-neu status. Based on final report, multidisciplinary team of oncologist, radiologist, pathologists and breast surgeons will on individual ground decide the best treatment approach. In general, small localized well differentiated breast cancers with positive steroid receptors are treated with surgery and anti- hormone therapy. High grade, steroid negative cancers are most commonly treated with chemotherapy and in case of proved HER2 amplification specific targeted therapy can be used