Abstract 2384: Assessment of PITX2, BMP4, FGF4, ERalpha, ERbeta promoter methylation in the circulating tumor cells (CTCs) can predict metastasis and survival in primary invasive duct carcinoma (PIDC) patients

Abstract

Abstract Recent studies have focused on hematogenous tumor cell dissemination as predictive factors of breast cancer metastasis and several methods for detecting circulating tumor cells (CTCs) in peripheral blood were described. However, in early-stage breast cancer, molecular characterization of CTCs and their prognostic value is not well established. We previously found a significant correlation between DNA promotor methylation (PM) of PITX2, BMP4, FGF4, ERalpha, ERbeta and breast cancer recurrence and metastasis (unpublished data). Therefore, we sought to compare the frequency of PM of these genes in the CTC and the primary breast tumors (PBT) in relation to recurrence, progression free and overall survival rates (DFS& OS) CTCs were collected from the 10 cm peripheral blood of 80 primary invasive duct carcinoma (PIDC) patients by immunomagnetic beads separation. The number of CTCs was determined by flow cytometry (FCM) and RT-PCR (using CK-19, mammaglobin and CD44) for confirmation and comparison. Patients were first tested for CTC counts immediately before surgery, prior to therapy, at first follow-up (4-6 weeks later) and after 6 months. PM of PITX2, BMP4, FGF4, ERalpha, ERbeta was assessed by methylation specific PCR (MSP) in PBTs and CTCs and correlated with metastasis and survival. The number of CTCs ranged from 0-500/10 ml blood. The concordance between FCM and RT-PCR was 98% (p=0.01). At first assessment, 56 patients have β10 CTCs/10 ml blood and exhibited a significantly shorter progression-free survival (PFS) (12.7 months versus 20.6 months) and overall survival (OS) (28.1 months versus 49.5 months) than women with 10 CTCs was 16.1 months, compared to greater than 36 months in the cohort with <10 CTCs. PM of PITX2, BMP4, FGF4, ERalpha and ERbeta, was reported in 42.90%, 50.00%, 51.20%, 63.10% and 46.40% compared to 63.15%, 73.75%, 62.5%, 81.2% and 78.75% in CTCs. PM of BMP4, and ERbeta was associated with reduced OS and PFS. Conclusions: 1) The presence of CTCs in the blood of PIDC patients can impact standard treatment and future research, 2) FCM provides a simple and accurate technique for enumerating CTCs in peripheral blood, 3) the significant increase in PM frequency of all studied genes except FGF4, suggests that aberrant PM may contribute to increased aggression and more liability to metastasis. More studies are still needed to assess the impact of CTCs in PIDC patients and how they might contribute to improving individualized cancer therapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2384. doi:1538-7445.AM2012-2384