D. Casado Elia (Salamanca, Spain)
Hospital Universitario de SalamancaAuthor Of 1 Presentation
- A. Olivares (Salamanca, Spain)
- R. Escala Cornejo (Ávila, Spain)
- M. García Muñoz (Salamanca, Spain)
- L. Figuero-Perez (Salamanca, Spain)
- J. Martín Vallejo (Salamanca, Spain)
- M. Sancho de Salas (Salamanca, Spain)
- M. Gómez Muñoz (Salamanca, Spain)
- E. Escalera Martín (Salamanca, Spain)
- J. Claros Ampuero (Salamanca, Spain)
- Á. López Gutiérrez (Salamanca, Spain)
- E. Terán Brage (Salamanca, Spain)
- B. Barrios Collado (Salamanca, Spain)
- D. Casado Elia (Salamanca, Spain)
- G. Martín García (Salamanca, Spain)
- R. Seijas Tamayo (Salamanca, Spain)
- J. Cruz Hernandez (Salamanca, Spain)
- C. Rodríguez (Salamanca, Spain)
62P - Influence of PAM50 on therapeutic decisions in patients with early-stage Luminal Breast Cancer in a single centre
Abstract
Background
One of the greatest challenges in the treatment of breast cancer (BC) is the correct detection of those patients with early-stage (ES) Luminal BC who do not require treatment with adjuvant chemotherapy (CT). The use of genomic platforms shows a prognostic / predictive value, and information on the intrinsic subtype of BC. This is a fundamental tool for the identification of these patients. The objective of this study is to assess the influence that the use of the Prosignaâ/PAM50 genomic platform has on therapeutic decisions in patients with ES Luminal BC.
Methods
A prospective study of 143 patients diagnosed with ES BC was carried out at the University Hospital of Salamanca between 2015 and 2020. All tumour samples were analysed with PAM50 / Prosignaâ (NanoString Technologies, Seattle, WA, USA). Statistical analysis was performed using EZR (Easy R) v1.5 software.
Results
The median age was 54 years [32–74]. Using immunohistochemistry (IHC), 64 tumours (44.8%) were classified as Luminal A-like and 79 (55.2%) as Luminal B-like. After reclassifying the tumours using PAM50, a total of 91 (63.6%) tumours were reclassified as Luminal A, and 52 (36.7%) were deemed Luminal B. A resulting change in post-test therapeutic decisions occurred in 41 patients (29%). Of the 97 patients with a pre-test decision of only adjuvant hormonal therapy (HT), 27 of them (28%) decided to add CT. Of the 46 patients with a pre-test decision of CT + HT, 14 (30%) received only HT after the test results. In 28% of the patients, the decision change was from HT to CT + HT. The change from CT + HT to HT alone occurred in 39% of the cases. With a median follow-up of 32 months, there have been no relapses to date, after making the decision using PAM50.
Conclusions
Despite the small sample size of our series, we have confirmed the great importance of the performance of a gene expression profile in clinical practice, as it directly impacts decisions concerning the adjuvant treatment of Luminal BC. PAM50 also made it possible to reclassify the intrinsic subtype in a significant proportion of patients. As no relapse has occurred in the included patients, this tool should be used in the selection of the most appropriate treatment for these patients.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.