Neoadjuvant chemotherapy (NCT) in 466 patients for operable breast cancer: Predictive factors for pathological response.

Abstract

648 Background: In a new database harbouringthe patients of several prospective phase II neoadjuvant trials (fec 50-100, net, tncf, taxotere/tncf, taxotere alone), the predictive value of tumour factors (SBR grade, RH, Her2, Ki-67 and cycline D1) was studied in 466 women with stage II-III operable breast cancer treated between 1991 and 2006. Methods: Median age of the patients was 48 years [27-76]. Median diameter of the invasive tumour was 40 mm [10-130]. 382 (82%) patients had a canalar, 57 (12.2%) a lobular, 14 (3%) a mixed or invasive carcinoma, 3 (0.6%) neoplasic cells only and 10 (2.2%) another carcinoma. Before chemotherapy, 32.8% were grade III SBR, 60% were RH+ and 10% were Her2+. For 36% of the tumours, the Ki-67 was ≤ 20% and for 16% of the tumours, the cyclin D1 was ≤ 20%. The median number of NCT courses was 6 [1-8] followed by a surgery for 98%, a radiotherapy for 93%, an adjuvant chemotherapy (20%) and/or a hormonotherapy (56%). Results: Overall response rate was 71% (17% complete). The complete pathological response (pCR) rate was 16.7% according to Chevallier's classification. On 455 patients operated, 324 (71%) had a conservative surgery. On 390 patients with an axillary dissection, 195 (50%) had involved nodes (median number :2 [1-20]). After a median follow-up of 121 months, DFS and actuarial survival at 120 months were 61.9% and 69.7%, respectively. Concerning the predictive value of the tumour factors, the pCR according to Chevallier's classification was threefold more frequent for Her-2-positive patients (p=1.7.10−3) and for RH negative patients (p=10−7) ; and elevenfold more frequent for SBR III patients (p=5.4.10− 7). Moreover, the pCR was twofold more frequent when Ki-67 was > 20% (p=0.012). There was no significant correlation between the cyclin D1 and the pCR. Using a multivariate analysis, these four factors remain predictive in the following order (from stongest to weakest): RH, Her2, SBR grade and Ki-67. Conclusions: SBR grade, RH, Her2 and Ki-67 were strong predictive factors of the pathological complete response. No significant financial relationships to disclose.