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Advancing HER2-low breast cancer management: enhancing diagnosis and treatment strategies

Simona Borstnar

Simona Borstnar

Institute of Oncology LjubljanaSlovenia
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Borstnar, Simona
, 
Ivana Bozovic-Spasojevic

Ivana Bozovic-Spasojevic

Institute for Oncology and Radiology of Serbia, Medical Faculty, University of BelgradeSerbia
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Bozovic-Spasojevic, Ivana
, 
Ana Cvetanovic

Ana Cvetanovic

Department of Oncology, Medical Faculty University of Niš, Clinic of Oncology, University Clinical Centre NišSerbia
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Cvetanovic, Ana
, 
Natalija Dedic Plavetic

Natalija Dedic Plavetic

University Hospital Centre Zagreb, School of Medicine, University of ZagrebCroatia
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Plavetic, Natalija Dedic
, 
Assia Konsoulova

Assia Konsoulova

National Cancer HospitalSofia, Bulgaria
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Konsoulova, Assia
, 
Erika Matos

Erika Matos

Institute of Oncology LjubljanaSlovenia
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Matos, Erika
, 
Lazar Popovic

Lazar Popovic

Oncology Institute of Vojvodina, Faculty of Medicine, University Novi SadNovi Sad, Serbia
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Popovic, Lazar
, 
Savelina Popovska

Savelina Popovska

Medical University PlevenBulgaria
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Popovska, Savelina
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Snjezana Tomic

Snjezana Tomic

University Hospital of Split, University of Split - School of MedicineCroatia
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Tomic, Snjezana
 and 
Eduard Vrdoljak

Eduard Vrdoljak

University Hospital of Split, University of Split - School of MedicineCroatia
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Vrdoljak, Eduard
  
Jun 11, 2024
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Article Category: Expert Opinion
Published Online: Jun 11, 2024
Page range: 258 - 267
Received: Jan 04, 2024
Accepted: May 14, 2024
DOI: https://doi.org/10.2478/raon-2024-0030
Keywords
© 2024 Simona Borstnar et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.

FIGURE 1.

Algorithms for HER2-low mBC in light of evolving treatment paradigms, according to the HR status and other actionable targets: (A) HR+ and (B) HR−. The ideal scenario considers availability of all treatments in all lines and unrestricted treatment access. 1L/2L/3L/4L = first/second/third/fourth line; BRCAm = BReast CAncer gene mutations; BRCAwt = BReast CAncer gene wild type; CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; CTx = chemotherapy; ET = endocrine therapy; HER2 = human epidermal growth factor receptor 2; HR = hormone receptor; IO = immunotherapy; mBC = metastatic breast cancer; mTORi = mammalian target of rapamycin inhibitor; PARPi = poly(adenosine diphosphate ribose) polymerase inhibitor; PD-L1 = programmed death-ligand 1; PI3Km = phosphatidylinositol 3-kinases mutations; PIK3wt = phosphatidylinositol 3-kinases wild type; SG = sacituzumab govitecan; T-DXd = trastuzumab deruxtecan. Treatment in 2L, 3L, 4L, and further lines is based on: previous therapy received; duration of response to previous treatment; patient’s preferences, condition, and comorbidities; toxicities of previous therapies; presumed benefit of further lines of therapy; and treatment availability. Per current approved label, trastuzumab deruxtecan as monotherapy is indicated for the treatment of adult patients with unresectable or metastatic HER2-low breast cancer who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy. Per current approved label, sacituzumab govitecan as monotherapy is indicated for the treatment of adult patients with unresectable or metastatic triple-negative BC who have received two or more prior systemic therapies, including at least one of them for advanced disease.
Algorithms for HER2-low mBC in light of evolving treatment paradigms, according to the HR status and other actionable targets: (A) HR+ and (B) HR−. The ideal scenario considers availability of all treatments in all lines and unrestricted treatment access. 1L/2L/3L/4L = first/second/third/fourth line; BRCAm = BReast CAncer gene mutations; BRCAwt = BReast CAncer gene wild type; CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; CTx = chemotherapy; ET = endocrine therapy; HER2 = human epidermal growth factor receptor 2; HR = hormone receptor; IO = immunotherapy; mBC = metastatic breast cancer; mTORi = mammalian target of rapamycin inhibitor; PARPi = poly(adenosine diphosphate ribose) polymerase inhibitor; PD-L1 = programmed death-ligand 1; PI3Km = phosphatidylinositol 3-kinases mutations; PIK3wt = phosphatidylinositol 3-kinases wild type; SG = sacituzumab govitecan; T-DXd = trastuzumab deruxtecan. Treatment in 2L, 3L, 4L, and further lines is based on: previous therapy received; duration of response to previous treatment; patient’s preferences, condition, and comorbidities; toxicities of previous therapies; presumed benefit of further lines of therapy; and treatment availability. Per current approved label, trastuzumab deruxtecan as monotherapy is indicated for the treatment of adult patients with unresectable or metastatic HER2-low breast cancer who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy. Per current approved label, sacituzumab govitecan as monotherapy is indicated for the treatment of adult patients with unresectable or metastatic triple-negative BC who have received two or more prior systemic therapies, including at least one of them for advanced disease.

Overview of cancer epidemiology across four CEE countries in 2020 (data extracted from GLOBOCAN 202025 and the European Cancer Information System34)

Characteristics Bulgaria Croatia Serbia Slovenia
Total population 6 948 445 4 105 268 8 737 370 2 078 932
Number of new cancer cases (all cancer sites) 36 451 26 092 49 043 14 180
Incidence age-standardized rate per 100 000 100 120.3 145.3 121.2
Number of new BC cases in 2020, both sexes, all ages 4061 2894 6724a 1410
BC new cases – rank across all types of cancers 3 2 2 3
5-year prevalence, all ages (per 100 000) 425.45 523.4 549.32 560.03
Mortality age-standardized rate per 100 000 36.3 32.8 50.9 32.3
Number of BC deaths 1533 832 2342 405
BC deaths – rank across all types of cancers 3 3 2 5
Mortality-to-incidence ratiob 0.36 0.27 0.35 0.27

Status of reimbursement for anticancer drugs used for treatment of HER2-negative mBC in Bulgaria, Croatia, Serbia, and Slovenia, including the year of reimbursement of at least one representative of the class

Treatment Bulgariaa Croatia Serbiac Sloveniad
CDK4/6 inhibitors 2018 2018 2022 2018
Alpelisib 2023 2021 2023 2021
PARP inhibitors 2023 2022 2021 2021
Sacituzumab govitecan 2023 2022
Trastuzumab deruxtecan 2022 2023
Atezolizumab nab-paclitaxel 2022 2021 2020
Pembrolizumab 2023b 2022 2023
Everolimus By >10 years 2021 2010
Fulvestrant By >10 years By >10 years 2019 2004
Aromatase inhibitors By >10 years By >10 years 2008 By >20 years
Language:
English
Publication timeframe:
4 times per year
Journal Subjects:
Medicine, Clinical Medicine, Internal Medicine, Haematology, Oncology, Radiology
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