Oh why or why are they not looking at the bone marrow?

[Lani]

Sorry to repeat myself but an excellent open access article on the importance of breast cancer cells HIDING in the bone marrow and being the source of both metastases and local recurrence abounds:

plos.org


OPEN ACCESS PEER-REVIEWED
RESEARCH ARTICLE
Disseminated Breast Cancer Cells Acquire a Highly Malignant and Aggressive Metastatic Phenotype during Metastatic Latency in the Bone
Carolyn G. Marsden,

Mary Jo Wright,

Latonya Carrier,

Krzysztof Moroz,

Abstract

Background

Disseminated tumor cells (DTCs) in the bone marrow may exist in a dormant state for extended periods of time, maintaining the ability to proliferate upon activation, engraft at new sites, and form detectable metastases. However, understanding of the behavior and biology of dormant breast cancer cells in the bone marrow niche remains limited, as well as their potential involvement in tumor recurrence and metastasis. Therefore, the purpose of this study was to investigate the tumorigenicity and metastatic potential of dormant disseminated breast cancer cells (prior to activation) in the bone marrow.

Methodology/Principal Findings

Total bone marrow, isolated from mice previously injected with tumorspheres into the mammary fat pad, was injected into the mammary fat pad of NUDE mice. As a negative control, bone marrow isolated from non-injected mice was injected into the mammary fat pad of NUDE mice. The resultant tumors were analyzed by immunohistochemistry for expression of epithelial and mesenchymal markers. Mouse lungs, livers, and kidneys were analyzed by H+E staining to detect metastases. The injection of bone marrow isolated from mice previously injected with tumorspheres into the mammary fat pad, resulted in large tumor formation in the mammary fat pad 2 months post-injection. However, the injection of bone marrow isolated from non-injected mice did not result in tumor formation in the mammary fat pad. The DTC-derived tumors exhibited accelerated development of metastatic lesions within the lung, liver and kidney. The resultant tumors and the majority of metastatic lesions within the lung and liver exhibited a mesenchymal-like phenotype.

Conclusions/Significance

Dormant DTCs within the bone marrow are highly malignant upon injection into the mammary fat pad, with the accelerated development of metastatic lesions within the lung, liver and kidney. These results suggest the acquisition of a more aggressive phenotype of DTCs during metastatic latency within the bone marrow microenvironment.

Citation: Marsden CG, Wright MJ, Carrier L, Moroz K, Rowan BG (2012) Disseminated Breast Cancer Cells Acquire a Highly Malignant and Aggressive Metastatic Phenotype during Metastatic Latency in the Bone. PLoS ONE 7(11): e47587. doi:10.1371/journal.pone.0047587

Editor: Pranela Rameshwar, University of Medicine and Dentistry of New Jersey, United States of America

Received: May 14, 2012; Accepted: September 18, 2012; Published: November 15, 2012

Copyright: © 2012 Marsden et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: CGM was supported by a DOD Breast Cancer Research Program Predoctoral Traineeship Award BC093134. This project was supported, in part, by a seed grant from the Louisiana Cancer Research Consortium (BGR).] The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Once considered the final step during cancer progression, recent evidence implicates metastasis as an early event in breast cancer [1]–[4]. Disseminated tumor cells (DTCs) may be present at distant sites at the time of primary diagnosis of breast cancer in patients that exhibit no outward signs of clinical metastases. As a preferential site of metastasis for breast cancer [5], the detection of DTCs in the bone of breast cancer patients has become an important prognostic tool. It is estimated that DTCs can be detected in the bone marrow for up to 40% of breast cancer patients using the current detection technology [6], [7]. As a strong independent prognosticator, patients with DTCs in the bone marrow have an overall worse prognosis, as well as a higher propensity for local and distant relapse, compared to patients without DTCs in the bone marrow [8]–[10]. Despite the clinical significance of DTCs in the bone marrow, the biological relevance remains controversial [11].

Although DTCs can be detected in the bone marrow of early breast cancer patients, clinical manifestation of bone metastasis and/or recurrence often does not emerge for years or even decades after initial diagnosis [4], [12]. The lag time between detection of DTCs and manifestation of disease indicates the cells have become dormant, persisting as viable but non-proliferating cells [4], [13], [14]. The mechanisms by which the cells enter a dormant state can be intrinsic, a result of genetic and/or epigenetic modifications, or as a consequence of the microenvironment in which the cells reside [15]. Studies have shown significantly less chromosomal aberrations in DTCs in the bone marrow as compared to cells in the primary tumor [1], [3], [16] suggesting DTCs have not acquired the necessary genetic alterations to overcome growth restraints. However, early DTCs have also been shown to be genomically very unstable [17], [18]. These conflicting reports concerning the intrinsic properties of DTCs indicates it is unlikely intrinsic mechanisms alone can account for the long dormancy periods observed by DTCs in the bone marrow. Alternatively, the bone marrow microenvironment has been implicated as a supportive niche for the existence of disseminated breast cancer cells in a dormant state [19], [20]. Breast cancer cells localized close to the endosteum, the interface of bone and marrow which serves as a supportive niche for hematopoietic stem cells and a frequent site of cancer cell dissemination, were shown to have long doubling times suggesting a possible quiescent state [21]. Intercellular communication through gap junctions between breast cancer cells and the bone marrow stroma close to the endosteum has recently been suggested to play a role in the maintenance of a dormant state [22]. Furthermore, in vitro studies have demonstrated an inhibitory effect on proliferation and acquisition of an invasive mesenchymal phenotype of breast cancer cells upon co-culture with bone marrow stroma isolated from breast cancer patients [15]. These findings illustrate the significance of the cellular interactions within the bone marrow microenvironment and the subsequent effects on the phenotype of disseminated breast cancer cells.

Recent reports have presented data supporting the bi-directional flow of DTCs, demonstrating targeted homing of DTCs to tumors present in the mammary fat pad and accelerated tumor progression upon colonization by the DTCs [23], [24]. The early detection and persistence of DTCs in the bone marrow of breast cancer patients signifies the bone marrow microenvironment may function as a reservoir for DTCs [11]. It is highly probable that cancer cells within the bone marrow microenvironment will re-enter the circulation, disseminating to other organs or back to the primary site of tumor formation. Therefore DTCs in the bone marrow not only pose a threat to the development of metastatic lesions in the bone, but may also contribute to the development of metastases at other sites as well as tumor progression and/or recurrence at the primary site.

Although implicated in recurrence at the primary site of tumor formation and the development of metastatic disease, the malignant potential of dormant breast cancer cells residing in the bone marrow remains undetermined. We previously reported detection of early disseminated human breast cancer cells by measuring human DNA in the bone marrow of mice that harbored mammary fat pad tumors derived from injection with primary tumorspheres isolated from patient core biopsies. These early disseminated breast cancer cells were detected prior to the development of metastatic lesions that were detected by H+E staining for up to 12 months post-injections [25]. These findings prompted further investigation into the tumorigenicity and metastatic potential of DTCs within the bone marrow. Herein, we demonstrate a malignant and aggressive metastatic phenotype of dormant breast cancer cells isolated from the bone marrow of mice. These data offer compelling evidence that supports the crucial role of the bone marrow microenvironment in both the maintenance of dormancy and the conversion of breast cancer cells to a more aggressive and rapid growth phenotype once cells have exited the bone microenvironment...

Type the title of the article into google to get to PLOS site of article and read on!

[Cathya]

Lani;

I am thinking seriously of asking my oncologist to test my bone marrow but have a question. If it comes back positive for DTC's what treatment options would I have? Or would this be a situation of having the certain knowledge that eventually my breast cancer will return so be vigilant with testing? I appreciate your comments.

Cathy

[Ellie F]

Cathay
I think you've asked an excellent question. What needs to happen if these cells are detected in bone marrow? Is more chemo/ targeted treatments necessary to eradicate them? Should every bc patient have a bone marrow biopsy? If a bone marrow shows no cells present how predictive is it of future mets or local recurrence ?

Lani, your wisdom and insight would be very welcome.

Ellie

[Lani]

I don't think you can "get " the oncologist to test your bone marrow as it is not standard of care.

There are German studies showing those who had residual cells in the bone marrow after chemotherapy were at exceedingly greater risk of recurring

The problem is that most hospitals are not geared toward the correct processing of the bone marrow samples. Clarient is from what I understand and I believe they are now using the services of Biocept to phenotype the positive DTC) ie, tell if they are ER+,PR+ her2+ and look for other biomarkers in order to help guide further treatment

Until more trials are done, they will not develop the expertise in bone marrow processing and testing and confirming efficacy/need of different/additional treatments

But unless they look, this will never move forward and people will continue to get excessive/ wrong/ insufficient treatment and have to wait years to find out
at which point treatment is much less likely to be successful

CTCs sound great as a substitute for DTC testing , but have not panned out yet, and may not ever do so--too many technologies, may not reflect those cells which can actually start macrometastases, very heterogenous group of cells found, etc

[Cathya]

Lani;

From your comments I think the only thing that would be helpful at this time is to join a clinical trial if there were any available. Unless you have other suggestions. Thank you.

Cathy

[AlaskaAngel]

At time of diagnosis and treatment planning, I asked my onc that question over 10 years ago. At that time he said it was a viable question some oncologists were interested in too.

I understand the procedure is painful, although not prohibitively so. I don't know if that is part of the reason it hasn't "gone further", or not. I don't know what the infection rate or other complications might be for having it done. ???

A.A.

[Lani]

An ex-neighbor of mine in her 70s volunteered for a study which required a bone marrow biopsy (she is healthy with no known disease) and paid her $100.

She describes truly minimal "soreness" that lasted less than a day and hers was done by a nurse practitioner, rather than a doctor.

I have known many who have had the biopsy with minimal, transient complaints and "a tiny bit of soreness" for a day or two. Even though these are usually done in outpatient clinics rather than hospital operating rooms (unless a concurrent surgery is planned) infection rates are listed as "extremely rare" as are bleeding complications even though bone marrow aspirates and biopsies are done most commonly for those with hematologic abnormalities which might include not having enough functioning white blood cells or platelets.

[Lani]

Cathy--you ask what you can do.

I answer both what you can do for yourself and what you can do for others.My suggestion is to advocate by opening your mouth, writing emails, perhaps "getting in their face" The status quo is not finding cures/ transformation into treatable chronic disease fast enough

Susan Love foundation has an "army of women" giving samples, but not bone marrows. Let your doctors know that you would be willing to have one done if it might clear up whether or not a positive marrow meant one had minimal residual disease and thus were prone to recur and also willing to see if additional treatment/different treatment could clear the dtcs and if this prolonged survival.