Abstract P4-07-24: Circulating tumor cells enumeration and Health Related Quality of Life of patients treated with first-line chemotherapy for HER2 negative metastatic breast cancer
Authors: Pierga Jean-Yves , Billa Oumar , Dabakuyo Sandrine , Lemonnier Jérôme , Berger Frédérique , Trédan Olivier , Jacot William , Gonçalves Anthony , Debled Marc , Levy Christelle , Jouannaud Christelle , Mouret-Reynier Marie-Ange , Ferrero Jean-Marc , Dalenc Florence , Toumi Fatima-Zohra , Bonnetain Franck , Bidard Francois-Clement , Renault Shufang 
Published: March 2023

Abstract
Background: In patients with metastatic breast cancer (mBC), Circulating Tumor Cells (CTC) counts have a strong prognostic impact on progression free survival (PFS) and overall survival (OS). Changes 4 weeks after the start of a new line of therapy, inform on treatment efficacy. Despite improvements in systemic treatment, metastatic BC remains mainly uncurable with alteration of health-related quality of life (HRQOL) during the course of the disease. The aim of this work was to assess impact of clinical factors and biological factors as CTC on HRQOL. Methods: The French cohort COMET is a prospective study including first line HER2 negative patients receiving weekly paclitaxel and bevacizumab according to EMA approved combination. The aim of this cohort was to evaluate clinical, biological and radiological parameters associated with patients’ outcome (CTC, CEC, serum markers, ctDNA, pharmacogenomic polymorphisms, metabolomic parameters, visceral fat assessed by initial CTscan, serum estradiol level, and quality of life). HRQOL was assessed at baseline, at every cycle until progression and then every 3 months up to death using the EORTC QLQ-C30 questionnaire and its breast cancer specific module, the EORTC QLQ-BR23. Five dimensions of HRQOL were analyzed for the primary analyses: Global health status (GHS), physical functioning (PF), Emotional functioning (EF), fatigue (FA) and pain (PA). Time until definitive deterioration (TUDD) in HRQOL was defined as the interval between inclusion and the first decrease in HRQOL score ≥ 5 compared to baseline HRQOL score with no further improvement or in case of death. CTC counts were determined using the standard CellSearch system [Menarini Silicon Biosystems]. Results: Out of 510 patients included in COMET study, 432 patients with available HRQOL data were analyzed in this study. At baseline, patients reported a mean score for GHS of 57.6 (SD=22.7), for PF of 75.8 (23.2), for EF of 62.2 (25.8), for FA of 42.2 (29.60) and for PA of 38.1 (31.5). The Median TUDDs for the 5 targeted dimensions was 10.1 months [7.5-16.9] for GHS, 6.1 months [4.1-8.9] for PF, 21.6 [18.7-31.2] for EF, 10.8 [6.2-16.6] for FA and 13.6[10.1-22.5] months for PA. CTC counts were available in 261 patients at base line and in 229 patients after 4 weeks of treatment, before second cycle of chemotherapy. CTC high count was independent of main clinical and biological characteristics except lobular subtype. We confirmed the poor outcome of patients with high CTC count at base line and after one cycle of treatment with the threshold of &gt; 4CTC/7.5 ml of blood. Out of the 5 dimensions of HRQOL, TUDD of EF was significantly correlated with a high CTC level at base line (p=0.0262) and even more with still an elevated count of CTC after one cycle of chemotherapy(p=0.0137). There was no association of CTC with the other dimensions of HRQOL. Conclusion: This is the first study ever reporting an analysis of QoL and CTC. We observed an association of high CTC count with one component of HRQOL scale. This suggests that CTC could be complementary to clinical factors that could influence HRQOL in HER2 negative metastatic BC treated with first line chemotherapy.
Citation Format: Jean-Yves Pierga, Oumar Billa, Sandrine Dabakuyo, Jérôme Lemonnier, Frédérique Berger, Olivier Trédan, William Jacot, Anthony Gonçalves, Marc Debled, Christelle Levy, Christelle Jouannaud, Marie-Ange Mouret-Reynier, Jean-Marc Ferrero, Florence Dalenc, Fatima-Zohra Toumi, Franck Bonnetain, Francois-Clement Bidard, Shufang Renault. Circulating tumor cells enumeration and Health Related Quality of Life of patients treated with first-line chemotherapy for HER2 negative metastatic breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-24.