Abstract P1-15-10: A prospective multicenter real-world study on neoadjuvant treatment and clinical outcome in TNBC patients

Introduction

Controversy exists with regards to the optimal regimen for neoadjuvant chemotherapy (NAC) of TNBC. Platinum-based regimens seem to be more active in TNBC improving pCR rates significantly. But adding platinum to an anthracycline/taxane chemotherapy regime comes at the expense of greater toxicity. Its impact on survival and long-term-outcomes remains undetermined. Practical guidelines vary across leading international professional societies. In this real-world multicenter study neoadjuvant regimens, pCR rates and survival were evaluated.

Material and methods

This study was conducted from 2012-2017 in six certified breast cancer centers in the region of Hanover, Germany, including rural and urban populations by using a personal questionnaire and data from the medical records. All patients with primary TNBC (ER<1%, PR<1%, Her2/neu 0, 1+ or 2+ FISH/CISH negative) and no evidence of distant disease were eligible.

Results

143/217 patients (66%) received NAC and 74/217patients (34%) adjuvant chemotherapy. 63/143 (44%) patients achieved pCR. 23/63 (35%) received platinum-based NAC and 40/63 (65%) received chemotherapy without platinum. In 80 patients pCR was not achieved. 12/80 patients received platinum and 68/80 non platinum-based NAC. pCR was significantly higher among patients with platinum-based chemotherapy (chi-square, p < 0.003). 20/23 patients who achieved pCR received NAC containing anthracycline/taxane/carboplatin, 3/23 patients received a taxane/carboplatin-based regime. Treatment discontinuation was seen in 12/35 (34%) patients receiving platinum-based NAC vs 15/108 (14%) in non-platinum-based NAC. Mean follow up was 17 months (1-70months). A significant difference in OS (p=0.007) and DFS (p=0.001) was seen for patients with a pCR.

Conclusion

Our trial confirms that platinum based NAC achieves significantly higher rates of pCR in patients with TNBC. pCR was associated with significantly longer DFS and OS. The CALBG protocol (CALBG 40603) was the preferred choice of treatment regimen followed by the GeparSixto protocol. In our study the pCR rate was comparable to that of both trials in which pCR rates of 60% (CALBG 40603) and 53% (GeparSixto) were achieved. However, in our trial 34% of the patients discontinued treatment due to toxicity. Therefore these protocols should be used in carefully selected patients. In a real world setting less toxic chemotherapy regimens achieved a pCR rate of 37%. In terms of toxicity and adherence to chemotherapy, these regimens are reasonable alternative options. In daily care close monitoring of treatment response is essential during NAC. In patients who have a rapid clinical response to platinum-free NAC the benefit of adding platinum is questionable. In contrast, the addition of platinum seems to be appropriate in those patients who show only limited response under NAC.

Citation Format: Kuehnle E, Kaur P, Siggelkow W, Luebbe K, Schrader I, Uleer C, Noeding S, Noeding K-H, Noesselt T, Arfsten M, Busch C, Krentel N, Hillemanns P, Dörk T, Park-Simon T-W. A prospective multicenter real-world study on neoadjuvant treatment and clinical outcome in TNBC patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-10.