Abstract | HER2 pozitivni karcinom dojke podtip je karcinoma dojke kod kojeg je suviše eksprimiran HER2 protein odnosno humani epidermalni faktor rasta. Prilikom razvoja ovog podtipa karcinoma dojke, dolazi do prevelike ekspresije HER2 gena i amplifikacije HER2 proteina što stanice dojke na dodatno stvaranje receptora zbog ĉega dolazi do ubrzanog nekontroliranog rasta i dijeljenja stanica dojke. Za dijagnozu ovog podtipa vaţno je proći dijagnostiĉke postupke kao što su IHC test, FISH test, SPoT – Light HER2 CISH test i Inform HER2 DUAL test. HER2 pozitivni karcinom dojke ĉini 25% svih oblika krcinoma dojke. Na trţištu su posebni lijekovi koji napadaju specifiĉne mete, HER2 pozitivnog karcinoma dojke, a to su trastuzumab, trastuzumabemtanisin, pertuzumab i lapatinib.
Rezultati mnogih farmakoekonomskih studija i dalje najviše u terapiji zagovaraju trastuzumab (Herceptin®), rekombinantno protutijelo za humani epidermalni faktor rasta (HER2). Zemlje srednje visokog BDP-a, kao što je Iran, zbog visokih troškova terapije, potiĉu skraćivanje terapije uz jednaku uĉinkovitost. Studija pokazuje da terapija od 6 mjeseci umjesto 12 mjeseci moţe smanjiti troškove za 40.000.000,00 € godišnje zdravstvenom sustavu. S druge strane, terapija trastuzumaba u kombinaciji s taksanima opravdana je samo u sluĉaju da se izravni medicinski troškovi smanje za 50%. Pertuzumab (Perjeta®), rekombinantnomonoklonsko protutijelo usmjereno na HER2 protein, kao noviji lijek nije farmakoekonomski isplativ naspram trastuzumaba. Mjeseĉni troškovi terapije pertuzumabom su 4.800,00 € dok je isti tretman trastuzumabom 3.650,00 €. Trajanje terapije pertuzumabomprocijenjeno je na 18,1 mjeseci što na kraju stoji 151.470,00 €. Konaĉni rezultati studije pokazali su da terapija pertuzumabom povisuje troškove lijeĉenja za 4 milijarde EUR i jaĉe tereti zdravstveni sustav. Trajanje terapije je duţe te se prema izraĉunu kanadske studije troši 4 milijarde EUR više iz zdravstvenog sustava nego primjenom trastuzumaba. Dobra procjena stanja i stadija karcinoma te dobar odabir terapije uvelike moţe smanjiti troškove lijeĉenja. Kada bi se promijenio naĉin lijeĉenja metastatskog HER2 pozitivnog karcinoma dojke te odmah pristupilo s terapijom zasnovanoj na kombinaciji lapatinib (Tyverb®), inhibitorintracelularnihtirozinkinaznih domena i EFGR (ErbB1) i HER2 (ErbB2) receptora, uz kapecitabin, umjesto lijekom prve linije (trastuzumab), ušteda bi kroz tri godine po osobi bila 3.044,00 €. |
Abstract (english) | HER2 - positive breast cancer is a subtype of breast cancer, which has higher expression of HER2 genes. HER2 is an abbreviation for human epidermal growth factor. The HER2 gene is important for synthesis of HER2 proteins. HER2 proteins are receptors on breast cells. HER2 receptors are important for control of normal and healthy breast cell grows and the mechanisms of repairing itself. In about 25% of breast cancers, the HER2 gene does not work correctly and makes too much copies of itself and it is called HER2 gene amplification. All these extra HER2 genes send signals to breast cells and their response is making too much HER2 receptors, which is called HER2 protein overexpression. It makes breast cells grow and divides it in an uncontrolled way. There are four tests for patients to establish if they have HER2 - positive breast cancer: IHC test, FISH test, SPoT – Light HER2 CISH test and Inform HER2 DUAL test. Treatment for that special kind of cancer includes four drugs: trastuzumab, trastuzumabemtanisine, partuzumab and lapatinib.
The results of many pharmacoeconomic studies still give preference to trastuzumab (Herceptin®), humanized monoclonal antibody for human epidermal growth factor (HER2). Study for middle – income countries, made in Iran, concludes that six months therapy can be more cost effective than 12 months and the costs could be reduced for 40.000.000 €. On the other hand, trastuzumab therapy combined with taxanes is justified only if direct medical expenses are decreased for 50%. Pertuzumab (Perjeta®), humanized monoclonal antibody for HER2 protein, is the newest drug for HER2 – positive breast cancer. Studies showed that Perjeta® therapy is still not profitable if expenses are compared with trastuzumab. Monthly costs for Perjeta® therapy are 4.800 € and the same treatment with Herceptin® is 3.650 €. Also, duration of the therapy with Perjeta® is 18,1 months which in the end increases expenses up to 151.470 €. Results show that Perjeta® treatmant raises expenses for 4 billion € more than Herceptin® treatment in Canada. Good assessment of the illness and diagnosis of the stage can decrease expenses of the treatment. If oncologist would estimate metastatic breast cancer in the beginning of treatment and start with lapatinib (Tyverb®), dual tyrosine kinase inhibitor which interrupts the HER2 and epidermal growth factor receptor (EGFR) pathways, combined with capecitabine in therapy instead of Herceptin®, it would save 3.044 € per person in three years therapy. |