A29 - Multigene prognostic and predictive tests in Luminal breast cancer patients: relation between Mammaprint® results and nodal status in a retrospectively monocentric analysis

Abstract

Background: Breast cancer prognosis and predictive biomarkers development would allow sparing some patients from chemotherapy or identifying patients for whom chemotherapy would be indicated. Mammaprint® can discriminate patients with good or poor prognosis and could help us to decide for using chemotherapy, especially in intermediate risk patients with Luminal subtypes.Material and methods: We evaluated with MP 81 consecutive patients (pts) with invasive operable Luminal A or Luminal B breast cancer (pT1-4pN1-3M0) diagnosed from 2008 to December 2009 at Ferrara University Hospital. Treatment decisions were based on clinical-pathological features, regardless of the MP results. Then we retrospectively evaluated the patients clinic-pathological characteristics, focusing especially on nodal status, and their progression free survival in relation to the MP results.Results: Forty-two pts (51.9%) were Luminal A (LA) (ER = 10%, PR = 20% and Mib1 < 20%) and 39 pts (48.1%) were Luminal B (LB) (ER = 10%, PR < 20% or Mib1 = 20%), MP indicated a good prognosis in 27 (64.3%) LA and 14 (35.9%) LB pts and poor prognosis in 15 (35.7%) LA and 25 (64.1%) LB pts. MP results were significantly correlated with proliferative activity (p = 0.002), histological grade (p = 0.002), but not significantly correlated with nodal involvement (p = 0.220) and tumor size (p = 0.426). Between Luminal A pts, 22 (52.4%) were pN0 (15 MP low and 7 MP high risk), 15 (35.7%) with 1 to 3 node metastases (7 MP low and 8 MP high risk) and 5 (11.9%) with more than 3 lymph node metastases (all MP low risk). Considering instead LB pts 15 (38.5%) were pN0 (7 MP low and 8 MP high risk), 15 (38.5%) with 1 to 3 node metastases (7 MP low and 8 MP high risk) and 9 (23.1%) with more tha 3 lymph node metastases (all MP high risk). At a median follow-up of 70.5 months, 6 pts experienced disease recurrence: 1 (2.4%) between 42 LA pts with MP high risk and pN1 stage and 5 (12.8%) between 39 LB pts, 1 with MP low and pN0, and 3 with MP high (1 pN0, 1 pN1 and 1 with more than 3 lymph node metastases).Conclusions: Accurate prediction of recurrence risk is of vital importancefor tailoring adjuvant chemotherapy for each breast cancer patient, but our data confirm the unclear utility of Mammaprint® in our clinical practice in comparison to classical prognostic parameters. Background: Breast cancer prognosis and predictive biomarkers development would allow sparing some patients from chemotherapy or identifying patients for whom chemotherapy would be indicated. Mammaprint® can discriminate patients with good or poor prognosis and could help us to decide for using chemotherapy, especially in intermediate risk patients with Luminal subtypes. Material and methods: We evaluated with MP 81 consecutive patients (pts) with invasive operable Luminal A or Luminal B breast cancer (pT1-4pN1-3M0) diagnosed from 2008 to December 2009 at Ferrara University Hospital. Treatment decisions were based on clinical-pathological features, regardless of the MP results. Then we retrospectively evaluated the patients clinic-pathological characteristics, focusing especially on nodal status, and their progression free survival in relation to the MP results. Results: Forty-two pts (51.9%) were Luminal A (LA) (ER = 10%, PR = 20% and Mib1 < 20%) and 39 pts (48.1%) were Luminal B (LB) (ER = 10%, PR < 20% or Mib1 = 20%), MP indicated a good prognosis in 27 (64.3%) LA and 14 (35.9%) LB pts and poor prognosis in 15 (35.7%) LA and 25 (64.1%) LB pts. MP results were significantly correlated with proliferative activity (p = 0.002), histological grade (p = 0.002), but not significantly correlated with nodal involvement (p = 0.220) and tumor size (p = 0.426). Between Luminal A pts, 22 (52.4%) were pN0 (15 MP low and 7 MP high risk), 15 (35.7%) with 1 to 3 node metastases (7 MP low and 8 MP high risk) and 5 (11.9%) with more than 3 lymph node metastases (all MP low risk). Considering instead LB pts 15 (38.5%) were pN0 (7 MP low and 8 MP high risk), 15 (38.5%) with 1 to 3 node metastases (7 MP low and 8 MP high risk) and 9 (23.1%) with more tha 3 lymph node metastases (all MP high risk). At a median follow-up of 70.5 months, 6 pts experienced disease recurrence: 1 (2.4%) between 42 LA pts with MP high risk and pN1 stage and 5 (12.8%) between 39 LB pts, 1 with MP low and pN0, and 3 with MP high (1 pN0, 1 pN1 and 1 with more than 3 lymph node metastases). Conclusions: Accurate prediction of recurrence risk is of vital importancefor tailoring adjuvant chemotherapy for each breast cancer patient, but our data confirm the unclear utility of Mammaprint® in our clinical practice in comparison to classical prognostic parameters.