Abstract PS9-27: Estimation of clinical benefit and economic burden for using a commercial 70-gene signature test for Brazilian breast cancer patients in the public health system
Authors: Pimentel Franklin F , Buzatto Isabela PC , Rodrigues Tamara CGF , Borba Jessica MC , Peruchi Karoline PI , de Andrade Jurandyr M , Tiezzi Daniel G 
Published: February 2021

Background

The clinical benefit of adjuvant chemotherapy (CT) for breast cancer (BC) depends on several factors, like menopausal status, stage and molecular subtype. Commercial available gene signatures make possible a more accurate selection of the patients who could benefit more with adjuvant chemotherapy. In Brazil, gene signatures are not available to public health system users, nor even reimbursed for privately insured patients, making this matter a major cause of frustration for patients and oncologists. MINDACT trial evaluated 70-gene signature MammaPrint (70-GS) as predictive test for chemotherapy benefit. Long-term follow up showed premenopausal patients who had not received CT and were in in the high clinical risk/ low genomic risk group presented unfavorable outcomes. We aimed to estimate clinical impact and economic burden that a hypothetical access to 70-GS may result based on a Brazilian BC population treated in a university hospital.

Methods

Medical records from BC patients who received neo/adjuvant chemotherapy from January/2018 to June/2020 at the Hospital das Clínicas de Ribeirão Preto - USP (HCRP-USP) were retrospectively analyzed. The following inclusion criteria were considered to select patients who could benefit most with 70-GS: stage I or II invasive BC, tumors smaller than 5 cm, up to three positive lymph nodes (LN+), postmenopausal status and HR+/HER2- (hormone receptor-positive, HER2-negative) tumors. Online search for costs and reimbursed values. The Brazilian public health system reimburses clinics R$ 571 (US$ 107) (US$ 1=R$ 5.32; July 1, 2020) each month a patient receives adjuvant CT for stage I BC and R$ 800 (US$ 150) each month for stage II BC. The 70-GS test, purchased privately, costs R$ 15,000 (US$ 2,820). The study was approved by the local ethics committee (HCFMRPUSP no 4.078.614).

Results

From Jan/2018 to June/2020, 311 patients were treated with neo/adjuvant chemotherapy. Mainly 4 cycles of AC (doxorubicin-cyclophosphamide), 8 cycles of ACT (AC + docetaxel or paclitaxel) or 4 cycles of TC (docetaxel-cyclophosphamide) regimens were delivered, which lasted from 3 to 6 months. For an entire CT period, we estimate the maximum reimbursement amount of R$ 4,800 (US$ 752) (6 months for stage II BC). In our population, patient who received CT, according to subtypes, were 174 (56%) HR+/HER2-, 30 (10%) HR+/HER2+, 38 (12%) HR-/HER2+ and 69 (22%) triple-negative. Among RH+/HER2-, 96 (55%) were postmenopausal BC, 77 (44%) were premenopausal BC and one was male BC (1%). Taking in accountpostmenopausal stage I and II BC, tumors &lt;5 cm and ≤3 LN+, a total of 54 patients who received CT (17%) would be candidates to 70-GS testing. For this group, the maximum reimbursement with CT would be R$ 259,200 (US$ 48,722) while the costs with 70-GS would be R$ 810,000 (US$ 152,280).

Conclusions

Among 311 patients who received CT at our institution, 54 met the inclusion criteria we chose as the most beneficial to perform 70-GS test. Considering that MINDACT trial found that 46% of high clinical risk may not require CT, approximately 25 patients (8%) could have avoided CT, saving R$ 120,000 (USS$ 22,556). The 70-GS test valuation for the public health system, considering only savings from chemotherapy, would be R$ 2,222 (US$ 418) and the current cost of 70-GS is 6.75 times higher than the money saved. Additional pharmacoeconomic analyses should include the estimated costs of early and late toxicities (i.e. febrile neutropenia, leukemia and cardiotoxicity) for this population, which can reduce the difference between the cost of 70-GS test and the amount saved. A national agreement between the company and the government could also contribute to increase access and make treatment de-escalation a reality also in lower-middle-income countries.

Citation Format: Franklin F Pimentel, Isabela PC Buzatto, Tamara CGF Rodrigues, Jessica MC Borba, Karoline PI Peruchi, Jurandyr M de Andrade, Daniel G Tiezzi. Estimation of clinical benefit and economic burden for using a commercial 70-gene signature test for Brazilian breast cancer patients in the public health system [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-27.