Disseminated tumor cells in the bone marrow of patients with ductal carcinoma in situ

Abstract

Detection of disseminated tumor cells (DTCs) in bone marrow is an independent prognostic factor in primary breast cancer. Here, we conducted a proof-of-principle study to evaluate whether this tumor cell spread occurs already in patients with ductal carcinoma in situ (DCIS). After preoperative screening by stereotactic core biopsy, 30 consecutive women with DCIS were included. Bone marrow aspirates, taken at the time of primary surgery, were subjected to DTC detection by a standardized immunoassay using the established monoclonal anti-cytokeratin antibodies A45-B/B3 and AE1/AE3. DTCs were detected in 4 of 19 cases of pure DCIS (21.1%) and in four of seven cases of DCIS with microinvasion (57.1%). After a median follow-up time of 22 months, two initially DTC-positive patients suffered from contralateral carcinoma and contralateral DCIS at months 12 and 30, respectively, whereas the remaining patients were relapse free. Thus, hematogenous tumor cell dissemination into bone marrow is an early event in breast cancer development.Breast cancer is the most common malignant disease in women. According to a meta-analysis including 4,703 Stage I-III breast cancer patients, the detection of disseminated tumor cells (DTCs) in bone marrow is associated with poor prognosis.1,2 Interestingly, DTC detection is seen in small primary carcinomas and is not only a predictor for metastatic relapse in bone and other organs but also for local relapse, 2 supporting recent experimental data that breast tumor cells may recirculate from bone marrow back to the primary site where they might contribute to local relapse and even primary tumor growth.3 Thus, bone marrow might be a reservoir for breast tumor cells in which they may survive for an extended period of time. 4,5 Thus far, the time point of the onset of breast tumor cell spread is unclear. A DCIS is a nonobligate precursor of invasive breast cancer. However, 1-2% of all primary DCIS patients present positive axillary lymph node metastases. 6 Indeed, classification of DCIS is based on histopathological criteria and on the growth dimensions. 7,8 Remarkably, DCIS patients may relapse with invasive breast cancer, whereas patients with large, high-grade DCIS with necrosis are at higher risk of developing recurrence. Furthermore, DCIS patients with poorly differentiated histological types are associated with higher rates of distant metastases and death within a long follow-up period. 9 The rate of metastases increases after invasive local recurrence.10 Free surgical margins and postoperative radiotherapy are the most important and significant prognostic factors for local disease control, 11 but none of them can reliably predict the risk of invasive recurrence. 12,13 Material and MethodsOur proof-of-principle investigation focused on the search for DTC in bone marrow aspirates from 30 patients who were treated with the suspicion of DCIS at the Goethe-University hospital and the Diakonie Medical Center, Frankfurt, Germany. Written informed consent was provided by all patients, and the stud...

The biology of circulating tumor cells

“…24 However, at present, it is unknown whether these early disseminating cells are indeed capable of forming clinically manifest metastases. In ductal carcinoma in situ, metastatic relapse is very rare, while DTCs are detected in 20-30% of patients, 20,23 suggesting that early DTCs rarely transform into metastasis-initiator cells. Hence, although CTCs may enter the circulation throughout the disease course, it may be that later, disseminating cells have better conditions for forming metastases.…”

“…Nevertheless, the assumption that tumor cells can disseminate early even before primary tumors become overtly invasive is supported by experimental [20][21][22] and clinical observations in patients with pre-invasive lesions such as ductal carcinoma in situ. 23 Further evidence for early dissemination comes from studies using intravital flow cytometry to count rare CTCs (o 1 CTC per ml) in vivo. After injection of tumor-specific fluorescent ligands, multiphoton intravital microscopy allows observation of CTCs as they flow through the peripheral vasculature.…”

Comparison of molecular and immunocytochemical methods for detection of disseminated tumor cells in bone marrow from early breast cancer patients

“…Furthermore, the detection of tumor cells in the BM does not always lead to disease relapse. Many patients with positive DTC status do not relapse, and DTCs can be detected in patients with ductal carcinoma in situ [6]. The mechanisms behind tumor dormancy and the possibility of tumor cell re-awakening are poorly understood.…”

The Biology of Bone Metastasis

“…While metastasis is typically characterized as the final step of primary tumor growth, this study demonstrates that primary tumors and metastatic lesions can develop in parallel rather than in sequence; a hypothesis that is further supported by the fact that DTC status is not correlated to tumor size (Hüsemann et al 2008). This finding was clinically validated by the detection of DTCs in the bone marrow of patients diagnosed only with breast ductal carcinoma in situ (DCIS) (Sänger et al 2011; Banys et al 2012) or localized Prostate cancer (Melchior et al 1997). …”