Utjecaj estrogena na rak dojke

undergraduate thesis

• Title (english): Estrogen carcinogenesis in breast cancer
• Author: Martina Žarak
• Mentor: Inga Marijanović (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2011, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Rak dojke je, uz rak pluća i rak debelog crijeva, najčešća i najsmrtonosnija vrsta raka koja pogađa uglavnom žensku populaciju razvijenih zemalja, osobito žene u menopauzi (iznad 50 godina). Rak dojke nastaje kada normalne epitelne (karcinom) ili žljezdane (adenokarcinom) stanice dojke promijene svoja svojstva te počnu nekontrolirano rasti, umnožavati se i uništavati okolno zdravo tkivo. Postoji nekoliko sustava klasifikacije raka dojke, prema različitim kriterijima: histopatologija, stupanj diferenciranosti (gradus tumora), stadij tumora, status receptora. Histopatološka podjela uključuje neinvazivne i invazivne karcinome. Na površini stanica 70% vrsta raka dojke se nalaze receptori za estrogen (ER+), progesteron (PR+) i HER2/neu (HER2+). Tri skupine genetičkih, endokrinih i okolišnih čimbenika povezane su s razvojem raka dojke. Čak 80% slučajeva uzrokovano nasljednim promjenama povezano je sa mutacijama u genima BRCA1 i BRCA2. Najvažnije okolišni čimbenik je izloženost estrogenu (ranija menarha i kasnija menopauza, mali broj poroda i kasna dob pri rađanju prvog djeteta). Brojna istraživanja bave se povezanošću raka dojke s endogenim i egzogenim steroidima, estrogenima (estron, estradiol i estriol) i progesteronom. Predložena su dva mehanizma djelovanja koja vjerojatno djeluju sinergistički u procesima inicijacije i progresije raka dojke. Osim proliferativnog modela prema kojem poticanjem stanične proliferacije u tkivu dojke estrogeni omogućavaju nastanak mutacija koje promoviraju razvoj raka, utvrđen je i mutageni učinak estrogena kao posljedica genotoksičnosti estrogena i njegovih metabolita. Izrazito zanimanje i raspravu potiče pitanje o utjecaju egzogenih hormona, kao što je oralna kontracepcija (OK) te hormonsko nadomjesno liječenje (HNL). Dokazano je kako antiestrogeni (SERM) kao što su tamoxifen, raloxifen i inhibitori aromataze smanjuju učestalost raka dojke.

Abstract (english)

Breast cancer is, along with lung and colon cancer, the most common type of cancer that affects mostly the female population in developed countries, especially menopausal women (over 50 years old). Breast cancer occurs when epithelial (carcinoma) or glandular (adenocarcinoma) breast cells change their properties and start to grow uncontrollably and destroy surrounding healthy tissue. There are several classification criteria: histopatology, grading, tumor stage, receptor status. Histopatologic classification includes non-invasive and invasive cancers. Around 70% of breast cancers have estrogen receptors (ER+) as well as progesterone receptor (PR+) and HER2/neu (HER2+) on the cell surface. Three groups of genetic, endocrine and environmental factors are associated with the development of breast cancer. In 80% of hereditary breast cancers the main cause are genetic changes in genes BRCA1 and BRCA2. The most important environmental factor is exposure to estrogen (earlier menarche and later menopause, low parity and late age at birth of first child). Numerous studies are dealing with estrogen carcinogenesis in breast cancer. There are two mechanisms of estrogen action proposed which probably act synergistically when promoting initiation and progression of breast cancer. Estrogen promotes cell proliferation in breast tissue which allows mutations and cancer development. Also, estrogen and its metabolites are genotoxic. The impact of exogenous hormones, such as oral contraceptives and hormone replacement therapy is of special interest. It has been shown that anti-estrogens (SERMs) such as tamoxifene, raloxifene and aromatase inhibitors reduce the incidence of breast cancer.

• Keywords: rak dojke; estrogen
• Keywords (english): breast cancer; estrogen
• Language: croatian
• URN:NBN: urn:nbn:hr:217:889627
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-12 09:05:58