208P - Treatment outcomes in early breast cancer patients undergoing neoadjuvant chemotherapy in a multidisciplinary setting. An analysis of 273 patients

Background

Pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC) has been proposed as a surrogate endpoint for of long-term clinical benefit, in early breast cancer (BC). A pCR is dependent on clinical-pathological characteristics and molecular subtypes.

Methods

The aim of the study was to evaluate real-world treatment outcomes managing early breast cancer patients. We retrospectively analyzed data of 273 pts undergoing taxane and/or anthracycline, +/- trastuzumab based NAC. Luminal A was documented in 12 pts, Luminal B in 55 pts, Her-2⁺ in 44 pts and triple negative breast cancers (TNBC) in 162 pts. Pathological complete response was defined as the complete disappearance of the invasive cancer in the breast and absence of tumour in the axillary lymph nodes.

Results

The pCR rate of the entire cohort was 48%. At 4 years 96% of pts who attained a pCR were disease free compared to 74% of pts who did not attain a pCR (log rank test Chi² =19.78, p < 0.0000). On univariate analysis factors associated with higher pCR included molecular subtype (TNBC 60%, Her-2⁺ 61%, Luminal A - none and Luminal B 15%, Chi² =48, p<0.00000), primary tumour size (T1=66% vs. T2=49% vs. T3=19% vs. T4=27%, Chi²=19,70, p<0.0002), nodal disease (N0=56% vs. N1=40%, Chi²=7.05, p<0.007), age (< than 50 years = 55% vs. ≥ 50 years = 43%, Chi² = 3.75, p<0.05) ER receptor status (negative=61% vs. positive=26%, Chi²=31.56 p<0.00000), PR receptor status (negative=59% vs. positive=19%, Chi²=33.95 p<0.00000), Ki67 (≥40=60% vs.14-39=41% vs. ≤14=5%,Chi²=27.11 p<0.00001) and Stage (I= 77% vs. IIA=55% vs. IIB=40% vs. III=24%, Chi²=23.89 p<0.00003). Menopausal status, ethnicity, extra-nodal spread and lympho-vascular invasion were not associated with a higher pCR rate. In a logistic regression model Ki-67 as a continuous variable (p<0.007) and biological subtype (p<0.0002) retained its significance; while tumour size, stage of disease, nodal status, ER and PR loss significance.

Conclusions

This data highlights the importance of breast care multidisciplinary management in early disease. TNBC and HER-2+ subsets were associated with a higher pCR rate. Our results are similar to those reported in a clinical trial setting.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.