Dados do Trabalho

Título

FIRST RESULTS OF A REAL-WORLD STUDY ADDRESSING THE POTENTIAL IMPACT OF ONCOTYPE DX TESTING ON CHEMOTHERAPY INDICATION IN BRAZIL IN THE POST-TAILORX AND RXPONDER ERA

Introdução

Due to limited access to novel genomic signatures in Brazil, treatment decisions for patients with early breast cancer (eBC) remain largely driven by traditional clinicopathologic risk factors. Oncotype DX (ODX) is a 21-gene assay that has been validated for the prediction of recurrence and chemotherapy benefit in lymph node negative (N0) and lymph node positive (N1), hormone receptor positive (HR+), HER2 negative (HER2-) eBC. The results of the TAILORx and RxPONDER trials support the use of genomic testing in T1-3, N0-1 eBC in order to spare chemotherapy.

Objetivo

We evaluated the impact of ODX results in a large cohort of Brazilian patients.

Método

Data was retrieved from electronic medical records in seven cancer centers to evaluate the impact of ODX on adjuvant chemotherapy indication based on TAILORx and RxPONDER results compared with clinicopathologic factors. Clinicopathologic and ODX information were collected from patients with T1-T3, N0-N1, HR+/HER2- eBC and an ODX between 2005 and 2020. Projections of chemotherapy indication by clinicopathologic criteria were based on binary clinical risk categorization based on the Adjuvant! Algorithm. The ODX score was correlated with the indication of chemotherapy according to TAILORx and RxPONDER data.

Resultado

Six hundred and forty-seven patients were included. Two hundred and sixty-nine patients (41.6%) were ≤ 50yo and 378 patients (58.4%) were >50yo; 2.2% / 24.6% / 52% / 20% / 0.8% of tumors were T1a / T1b / T1c / T2 / T3, respectively; 19.6% were grade 1 (G1), 66.9% G2 tumors and 12.7% G3. 80 (12.4%) were N1. Using the modified Adjuvant! Online criteria for clinical risk classification, 413 tumors (63.8%) had low risk and 234 tumors (36.2%) had high risk disease. The ODX indicated low (<11), intermediate (11-25) and high (>25) risk in 119 (18.4%), 417 (64.5%) and 111 (17.1%) tumors, respectively. Among 234 tumors with high clinical risk, only 92 (39.3%) had genomic indication of adjuvant chemotherapy, corresponding to a potential 60.7% reduction in adjuvant chemotherapy use. Among 413 tumors with low clinical risk, 122 had genomic indication of adjuvant chemotherapy, corresponding to a potential 29.5% increase in the use of adjuvant chemotherapy in this group.

Conclusão

Incorporating ODX testing into routine clinical practice for patients with N0 and N1 HR+/HER2- eBC may potentially decrease adjuvant chemotherapy use. Cost-effectiveness of ODX should be further investigated in Brazil.

Palavras-chave

Early Breast Cancer; Genomic signatures

Área

Oncologia - Tumores de Mama