A simple and reproducible prognostic index in luminal ER-positive breast cancers
Menée initialement sur 495 patientes atteintes d'un cancer du sein ER+, puis validée sur une cohorte complémentaire de 581 patientes, cette étude évalue l'intérêt d'un outil de pronostic basé sur la taille de la tumeur, le nombre de ganglions métastasés et l'expression du récepteur aux androgènes
Background The group of estrogen receptor (ER)-positive breast cancers (both luminal-A and -B) behaves differently from the ER-negative group. At least in early follow-up, ER expression influences positively patients' prognosis. This low aggressive biology flattens out the differences of clinical management. Thus we aimed to produce a prognostic index specific for ER-positive (ERPI) cancers that could be of aid for clinical decision.
Patients and methods The test set comprised 495 consecutive ER-positive breast cancers. Tumor size, number of metastatic lymph nodes and androgen receptor expression were the only independent variables related to disease-specific survival. These variables were used to create the ERPI, which was applied to the entire test set and to selected subpopulations (grade 2 (G2)-tumors, luminal-A and -B breast cancers). A series of 581 ER-positive breast cancers, collected from another hospital, was used to validate ERPI.
Results In the test population, 96.9% of patients classified as ERPI-good showed a good prognosis compared with 79.6% classified as ERPI-poor (P < 0.001). ERPI effectively discriminated outcome in luminal-A and luminal-B and in G2-tumors. In the validation series, the ERPI maintained its value.
Conclusion ERPI is a practical tool in refining the prediction of outcome of patients with ER-positive breast cancer.
Annals of Oncology , résumé, 2013