Abstract P3-11-07: Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry
Authors: Huober J , Fasching PA , Taran F-A , Volz B , Overkamp F , Kolberg HC , Hadji P , Tesch H , Haeberle L , Ettl J , Hartkopf AD , Lux MP , Lueftner D , Wallwiener M , Mueller V , Beckmann MW , Belleville E , Wimberger P , Hielscher C , Geberth M , Fersis N , Abenhardt W , Kurbacher C , Wuerstlein R , Thomssen C , Untch M , Janni W , Wallwiener D , Brucker SY , Schneeweiss A , Fehm TN 
Published: February 2018

Abstract
Background
For breast cancer patients with metastases which are not life threatening national and international guidelines recommend the exhaustion of all antihormonal therapeutic options before recommending chemotherapy. In Germany up to now only everolimus was an additional option to overcome endocrine resistance. CDK4/6 inhibitors recently became available in Germany (Nov 2011). Aim of this analysis was the identification of predictors for a decision against an antihormonal treatment.
Methods
The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for metastatic breast cancer patients. Besides biomarker research the description of real-world treatment data was one of the main study aims. This analysis was restricted to first line metastatic patients who were hormone receptor (HR) positive and HER2 negative. First, predictors were identified with a multiple logistic regression model. Then patients, who received chemo or not ,were compared with regard to overall survival using Cox regression analysis with the predictors for chemotherapy from above and additionally chemo status (yes/no)
Results
A total of 389 HR-positive and HER2-negative patients with detailed treatment information were included during the 1st line therapy into PRAEGNANT. Of those 173 (44.5%) received a chemotherapy, 190 an antihormone therapy (AHT) (48.8%), and 26 (6.7%) everolimus+AHT. In the multiple logistic regression model, older patients, lower graded tumors, bone only disease and previous adjuvant chemotherapy were associated with a lower rate of first line chemotherapies. BMI and number of concomitant diseases had no influence on the choice of first line metastatic therapy. In patients with visceral metastases 58.1% were treated with a 1st line chemo, while in patients with brain metastases or bone only metastases these numbers were 55.6% and 26.9%. Grading had an influence with patients having a G1, G2 and G3 tumor receiving 1st line chemo in 28.0%, 38.4% and 63.2% of the cases respectively. Patients who received chemo seemed to have a worse overall survival than patients who did not receive chemo (adjusted HR 1.58; 95% CI, 0.89 to 2.18). However, this result was not signifcant (p = 0.12). Overall survival was primarily influenced by ECOG and location of metastasis
Conclusion
The usage of chemotherapy can be predicted with age, metastasis pattern, grading and previous use of chemotherapy. However, we could not show that patients benefited from chemotherapy. On contrary, there was a tendency that patients treated with chemotherapy had poorer overall survival. Further studies with larger sample sizes are needed to confirm this claim.
Citation Format: Huober J, Fasching PA, Taran F-A, Volz B, Overkamp F, Kolberg HC, Hadji P, Tesch H, Haeberle L, Ettl J, Hartkopf AD, Lux MP, Lueftner D, Wallwiener M, Mueller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Fersis N, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Wallwiener D, Brucker SY, Schneeweiss A, Fehm TN. Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-07.