Abstract 15P
Background
In Vietnam, breast cancer is the most common cancer in females with 21,555 (25.8%) new cases in 2020 and ranking as the fourth leading cause of death (9,345 deaths) in both genders. While Trastuzumab improves survival outcomes for HER2-positive (HER2+) breast cancer patients, not all eligible women in Vietnam have access to this essential therapy. The objective is to illustrate the prevalence of HER2-positive breast cancer, the limitations in pathology capability for diagnosis, and the accessibility of therapies for patients in a national cancer center in LMICs.
Methods
An observational study was conducted on all women diagnosed with breast cancer confirmed by histology at the Vietnam National Cancer Hospital from 2015 to 2023.
Results
From a cohort of 23318 women confirmed with breast cancer, the findings reveal an increasing number of breast cancer cases over the years from 977 patients in 2015 to 4122 patients in 2023. Among them, 81.1% (18,679 patients) were classified subtypes by immunohistochemistry (IHC). The rate of HER2 overexpression on IHC (Her2 3+) is 28.3% (5324 patients), while 13.7% (2,568 patients) showed Her2 2+ results. Among those with Her2 2+, only 26.2% (673 patients) able to afford anti-HER2 therapy underwent further testing with FISH or Dual-ISH. Only 37.5% of patients had Her2 overexpression were treated with trastuzumab for at least 1 cycle [partially (60%) covered by insurance] and 2.1% of patients received with pertuzumab (not covered by insurance). Table: 15P
| Year | No. patients | IHC | Her2 2+/3+ | Her2 3+ | Her2 2+ | FISH/Dual-ISH | Trastuzumab |
| 2015 | 977 | 856 | 424 | 222 | 202 | 4 | 69 |
| 2016 | 1833 | 1429 | 615 | 405 | 210 | 13 | 100 |
| 2017 | 2007 | 1670 | 703 | 480 | 223 | 24 | 128 |
| 2018 | 2178 | 1807 | 782 | 542 | 240 | 32 | 165 |
| 2019 | 2950 | 2240 | 883 | 626 | 257 | 41 | 267 |
| 2020 | 3310 | 2575 | 1110 | 735 | 375 | 60 | 196 |
| 2021 | 2167 | 1898 | 759 | 541 | 218 | 91 | 389 |
| 2022 | 3774 | 2835 | 1166 | 821 | 345 | 149 | 327 |
| 2023 | 4122 | 3369 | 1450 | 952 | 498 | 259 | 379 |
| Total | 23318 | 18679 | 7892 | 5324 | 2568 | 673 | 2020 |
Conclusions
This study showed the increasing numer of breast cancer cases in Vietnam between 2015 and 2023. Despite the proven efficacy of trastuzumab for HER2-positive breast cancer, financial barriers and limited access to comprehensive diagnostics this essential treatment. Urgent measures are needed to improve affordability and accessibility of essential therapies in LMICs.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.