Abstract P5-15-07: First and further line choices of treatment for HER2-VE metastatic breast cancer (MBC) according to adjuvant treatment and biological subtype. Preliminary results of the observational “GIM-13 – AMBRA” Italian study

Abstract

Abstract Frequency of CHT regimens according to biological subtypes and Setting of treatmentLuminal TumoursSettingRegimenAdj (%)1st-line (%)2nd-line (%)3rd-line (%)anthra-based (w/o Taxanes)44.27.15.19.9Anthra-Taxanes30.52.60.50CMF-like17.50.61.02.1Taxane mono/combo*6.319.314.521.5Pacliataxel + Bevacizumab020.24.33.7Platinum-based03.61.70.8Capecitabine +/- Vinorelbine019.122.217.4Eribuline002.312.4 TNBCSettingRegimenAdj (%)1st-line (%)2nd-line (%)3rd-line (%)Anthra-based (w/o Taxanes)25.73.15.116.2Anthra-Taxanes36.11.100CMF-like8.22.15.10Taxane mono/combo*6.318.417.810.8Paclitaxel + Bevacizumab024.71.70Platinum-based020.622.42.7Capecitabine +/- Vinorelbine025.720.610.8Eribuline003.429.7**Irrespectively of biological subtype, nab-paclitaxel was used in 3.6%, 15.3% and 16.4% of cases in 1st, 2nd and 3rd line, respectively BACKGROUND Breast Cancer prognosis improved in the last years due both to early diagnosis and Adj treatments. The choice of CHT regimens should consider previous Adj treatments, pattern of relapse and biological subtype. There are few information on the treatment of MBC in the clinical practice outside controlled trials, last study has been published 15 yrs ago in Italy. PATIENTS AND METHODS The GIM13-AMBRA Study is a multicenter longitudinal cohort study, describing the choice of first and subsequent lines of treatment for MBC in HER2-ve pts. We are collecting data of 30 consecutive pts from 42 Italian Centres who developed the first relapse in the years 2012-2015 and were treated with CHT, (+/- previous endocrine treatments (HT)) for MBC. One of the secondary aims is to evaluate the Time to Treatment Change (TTC) (time between treatment start and its change for any reason) as surrogate endpoint for Time To Progression outside clinical trials. The present report is focused on the choice of treatments in any line and TTC, according to biological subtypes. . RESULTS For the present analysis, 683 pts are evaluable. Pts with Luminal A and B tumours received CHT and HT in 65.3% (Adjuvant), 21.7% (1st line), 7.1% (2nd line) and 7% (3rd line) of the cases. The most used regimens according to tumour subtype and line of treatment are shown in Table 1. Median TTC from 1st to 2nd line was 8.1 and 17.9 months in TNBC and Luminal tumours, respectively, whereas TTC from 2nd to 3rd line was 3.1 and 12.9 months, respectively. CONCLUSION Preliminary results of the AMBRA-GIM13 Italian observational study confirm that in most cases treatment for MBC is strongly related to the type of the Adj regimen, being the use of anthracyclines marginal in MBC, whereas taxanes are widely used in any line. In 1st line the most used regimens are Taxane and Bevacizumab or Capecitabine/Vinorelbine combinations. The last one remains the most used CHT in 2nd and 3rd lines. No difference have been observed according to biological subtype, except for Platinum-based regimens in TNBC. HT alone remains the preferred choice in 1st and 2nd line in Luminal cases. TTC seems to be a reliable surrogate for PFS in the “real world” practice . CHT still plays a crucial role in the treatment of MBC HER2-ve pts. Citation Format: Mustacchi G, Cazzaniga ME, Biganzoli L, De Laurentiis M, Del Mastro L, De Placido S, Donadio M, Garrone O, Giordano M, Latini L, Livi L, Marchetti P, Michelotti A, Montemurro F, Natoli C, Pronzato P, Riccardi F, Turletti A. First and further line choices of treatment for HER2-VE metastatic breast cancer (MBC) according to adjuvant treatment and biological subtype. Preliminary results of the observational “GIM-13 – AMBRA” Italian study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-15-07.