Recent pre-clinical evidence suggests that the active metabolite of tamoxifen, endoxifen, is a substrate for efflux pump P-glycoprotein. The aim of our study was to evaluate, if the polymoprhisms within ABCB1 gene alter tamoxifen adjuvant treatment efficacy in premenopausal women. Totally 71 premenopausal women with estrogen receptor positive breast cancer indicated for tamoxifen adjuvant treatment were followed retrospectively for median period of 56 months. The gentic polymorphisms of CYP2D6 and ABCB1 were analyzed and potential covariates as tumor grading, staging, age at the diagnosis, comedication, quantitative positivity of ER or PR were also evaluated. Cox proportional-hazards regression model indicated that patients carrying at least one variant allele in ABCB1 rs1045642 had significantly longer time to event survival compared to wild type subjects. Non-significant trend was noted for better treatment outcome of patients carrying at least one variant allele in the SNP rs2032582, while for the CYP2D6 polymorphism poor metabolizer phenotype resulted in worse outcome in comparison to extensive metabolizers subjects with HR of 4.04 (95 % CI 0.31-52.19). Similarly, patients using CYP2D6 inhibitors had non-significantly shorter time-to-event as compared to never users resulting in hazard ratio of 2.06 (95 % CI 0.40-10.63). ABCB1 polymorphisms may affect outcome of tamoxifen adjuvant treatment in premenopausal breast cancer patiens. This factor should be taken into account in addition to the CYP2D6 polymorphism or phenotypic inhibition of CYP2D6 activity., S. Argalácsová, O. Slanař, P. Vítek, P. Tesařová, H. Bakhouche, M. Dražďáková, O. Bartošová, T. Zima, L. Pertuželka., and Obsahuje bibliografii
Jedním ze základních léčebných postupů u metastatického karcinomu prsu je hormonální léčba. U pacientek s pozitivními estrogenovými receptory by měla být zvažována jako první léčebná možnost, a to hlavně kvůli účinnosti a dobré toleranci. Viscerální metastázy by neměly být kritériem pro upřednostnění chemoterapie před hormonální léčbou. V první linii hormonální léčby postmenopauzálních pacientek je doporučován inhibitor aromatázy, a to hlavně kvůli dobré toleranci. Tamoxifen však zůstává akceptovatelnou možností. Výsledky nejnovějších klinických studií CONFIRM a FIRST podporují použití fulvestrantu v dávce 500 mg každé 4 týdny u pacientek po selhání předchozí hormonální léčby., One of the principal therapeutic procedures in metastatic breast cancer is hormonal therapy. In patients with positive oestrogen receptors, it should be considered as first-line therapy, particularly due to its efficacy and good tolerability. Visceral metastases should not be a criterion in favour of chemotherapy over hormonal therapy. Since they are well tolerated, aromatase inhibitors are recommended as first-line hormonal therapy in postmenopausal patients. However, tamoxifen remains an acceptable option. The results of the recent CONFIRM and FIRST clinical trials support the use of 500 mg fulvestrant every four weeks in patients in whom prior hormonal therapy failed., Katarína Petráková, and Lit.: 14
Pituitary hyperplasia as well as proliferation of the endometrium are typical responses to estrogen administration in rodents. Both insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) have been implicated as paracrine mediators and amplifiers of estrogen action in the rodent uterus. The auto/paracrine role of IGF-I, EGF, their receptors and IGF binding proteins in pituitary proliferation has not yet been solved. Here we have used a semi-quantitative reverse transcription polymerase chain reaction (RT PCR) assay to demonstrate the changes in IGF-I mRNA and EGF mRNA abundance in the proliferating male rat pituitary in response to estradiol benzoate (EB; 1 mg/kg b.w. twice weekly i.m. for 3 weeks) and modifying effect of drugs antagonizing the pituitary enlargement — antiestrogen tamoxifen (TAM, 5 mg/kg b.w. daily) and also the dopaminergic agonist terguride (TER, 0.66 mg/kg b.w. daily, routinely used for the treatment of prolactinomas). In three separate experiments, EB induced a 2.2-2.5 fold increase in pituitary weight. The abundance of IGF-I and EGF mRNAs in pituitaries of EB-treated animals did not differ from the controls in two experiments and in the third series with the most marked pituitary hyperplasia mRNAs of both growth factors were even significantly decreased. Antiestrogen TAM administered with EB partially blocked the EB-induced proliferation and significantly stimulated IGF-I mRNA (p = 0.003) and EGF mRNA (p = 0.023) expression, while EB or TAM alone did not stimulate mRNAs of the studied growth factors. Significant antiproliferative effect of dopaminergic agonist TER on EB-induced pituitary proliferation (p = 0.006) was accompanied with decreased IGF-I mRNA (p = 0.025), but not EGF mRNA abundance. Our results suggest that the estrogen-induced pituitary proliferation is independent of the local expression of IGF-I and EGF mRNAs.
Pro mladé pacientky s hormonálně dependentním karcinomem prsu je adjuvantní hormonální léčba klíčovou léčebnou komponentou, která zajistí nemocné významné zlepšení šance na úplnou úzdravu. Její správné složení i sekvence k ostatním léčebným modalitám (chemoterapie, radioterapie, biologická léčba) zajistí její maximální účinnost., Adjuvant hormonal therapy is a key component of treatment for young patients with estrogen receptor positive breast cancer, ensuring patients a significant improvement in the chances of full health. Its right composition and sequence to other therapeutic modalities (chemotherapy, radiotherapy, biological therapy) ensure maximum efficiency., Petra Tesařová, and Lit.: 36