Abstract P5-08-43: CASCADE study: Longer overall survival in the novo versus recidivant patients with locally advanced/metastatic breast cancer
Authors: Servitja S , Zamora P , Santaballa A , García J , de Paz L , Plata Y , Garau I , Florian J , Chacón I , de la Haba J , García P , San José B , Rodríguez-Villanueva J , Orcajo L , Martínez E , Segui MA 
Published: May 2016

BACKGROUND: Current treatment strategies for locally advanced and/or metastatic breast cancer (LA/MBC) are meant to prolong survival while maintaining or improving the quality of life. Nevertheless, there is a lack of recent data regarding the actual clinical management and its impact on the prognosis of these patients. It is unknown whether prior diagnosis and treatment of early breast cancer (EBC) make any difference in the outcome of the advanced disease. CASCADE is an epidemiological, retrospective, and multicenter study aimed at retrieving this information from a representative cohort of LA/MBC patients treated within the Spanish National Healthcare System.

MATERIALS AND METHODS: Thirteen Spanish public hospitals covering nearly 5'000'000 inhabitants (&gt;10% of the national population) applied several combined systematic strategies to identify patients firstly diagnosed with LA/MBC between 01/2007 and 12/2008. Once identified, patients were followed throughout their metastatic lifetime until death, lost to follow-up, or until December 2013, whichever occurs first. Data collected included demographical, pathological, diagnostic, and therapeutic information for each line of treatment. Descriptive statistics were applied.

RESULTS: We identified 443 LA/MBC patients; median age at diagnosis was 59 years (CI95%: 49.5 - 71.6). Previous history of early BC was reported in 69.3% of them with a median disease-free interval of 38 months. Median Overall Survival (OS) for the whole study population was 33.5 months, while numbers for advanced cases originally diagnosed as EBC or the novo LA/MBC were 31.7 (CI95%: 26.8 - 36.0) and 38.8 months (CI95% 32.8 - 45.3; p = 0.0138) respectively. Main tumor immunohistochemical subtypes for EBC and the novo LA/MBC were: HER2+/HR- 11.3% and 15.3%, HER2+/HR+ 16.2% and 19.1%, HER2-/HR+ 41.2% and 51.1%, and Triple-negative 17.9% and 11.5%, respectively.

At the end of the study follow-up (Dec 2013) 78.2% of the patients had died. Breakdown of the decaying percentage and OS for the entire study population, early-, and the novo diagnosed LA/MBC from the beginning of each line of treatment was:

OS according to the type of diagnosisTreatment line1L2L3L4L5L6L7LWhole pulation Patients (%)95.370.253.538.424.215.19.5Whole pulation OS (months)32.622.616.613.513.312.48.5Early diag. LA/MBC OS (months))30.921.015.612.912.49.17.5The novo diag. LA/MBC OS (months)37.625.921.618.714.016.913.8

CONCLUSION: Our study's OS data supports the hypothesis that highly effective current neo/adjuvant treatment may cure most treatment-sensitive early tumors, allowing only those more aggressive to develop to LA/MBC, which then will fare worse than those of the novo metastatic diagnosis.

Citation Format: Servitja S, Zamora P, Santaballa A, García J, de Paz L, Plata Y, Garau I, Florian J, Chacón I, de la Haba J, García P, San José B, Rodríguez-Villanueva J, Orcajo L, Martínez E, Segui MA. CASCADE study: Longer overall survival in the novo versus recidivant patients with locally advanced/metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-43.