Implications of occult metastatic cells for systemic cancer treatment in patients with breast or gastrointestinal cancer

Prediction of early metastatic disease in experimental breast cancer bone metastasis by combining PET/CT and MRI parameters to a Model-Averaged Neural Network

Macrometastases in bone are preceded by bone marrow invasion of disseminated tumor cells. This study combined functional imaging parameters from FDG-PET/CT and MRI in a rat model of breast cancer bone metastases to a Model-averaged Neural Network (avNNet) for the detection of early metastatic disease and prediction of future macrometastases. Metastases were induced in 28 rats by injecting MDA-MB-231 breast cancer cells into the right superficial epigastric artery, resulting in the growth of osseous metastases in the right hind leg of the animals. All animals received FDG-PET/CT and MRI at days 0, 10, 20 and 30 after tumor cell injection. In total, 18/28 rats presented with metastases at days 20 or 30 (64.3%). None of the animals featured morphologic bone lesions during imaging at day 10, and the imaging parameters acquired at day 10 did not differ significantly between animals with metastases at or after day 20 and those without (all p > 0.3). The avNNet trained with the imaging parameters acquired at day 10, however, achieved an accuracy of 85.7% (95% CI 67.3-96.0%) in predicting future macrometastatic disease (ROC_AUC 0.90; 95% CI 0.76-1.00), and significantly outperformed the predictive capacities of all single parameters (all p ≤ 0.02). The integration of functional FDG-PET/CT and MRI parameters into an avNNet can thus be used to predict macrometastatic disease with high accuracy, and their combination might serve as a surrogate marker for bone marrow invasion as an early metastatic process that is commonly missed during conventional staging examinations.

Metastases of malignant neoplasms: Historical, biological, & clinical considerations

The metastasis of neoplastic cells from their site of origin to distant anatomic locations continues to be the principal cause of death from malignant tumors, and that fact has been recognized by physicians for over a century. After the work done by Halsted in the treatment of breast cancer in the 1880s, accepted surgical canon held that metastasis occurred in a linear fashion, with centrifugal "growth in continuity" from the primary neoplasm that first involved regional lymph nodes. Those structures were considered to then be the sources of more distant, visceral metastases. With that premise in mind, radical and "ultra-radical" surgical procedures were devised to remove as many lymph nodes as possible in the treatment of carcinomas and melanomas. However, such interventions were ineffective in altering tumor-related mortality. This review considers the details of the historical material just mentioned. It also reviews currently-held concepts on biological mechanisms of metastasis, the "sentinel" lymph node biopsy technique, and the important topic of metastatic tumor "dormancy" as the cause of surgical treatment failure. Finally, predictive models of tumor behavior are discussed, which are based on gene signatures. These will likely be the key to identifying malignant lesions of low surgical stage that ultimately prove fatal through later manifestation of metastasis.

Significance of occult neoplastic cells on tumor metastasis: a case report of gastric cancer

BACKGROUND

Occult neoplastic cells (ONCs) are the tumor cells floating in the lymph node sinuses, distant from the primary tumor, and supposed to be one of most reliable marker of prognosis.

METHODS

We report here the case of a 52-year-old woman with a gastric cancer associated by numerous ONCs.

RESULTS

Postoperative examination of the stomach disclosed an advanced, poorly differentiated adenocarcinoma with frequent lymph node metastases. In addition to ONCs and occasional micrometastases, focal aggregates of ONCs, one of the possible intermediate lesions between the ONCs and the usual metastases, are also observed.

CONCLUSIONS

In the present case, at least some of ONCs seem to form the microaggregates of tumor cells in lymph nodes, anchor in the sinuses, and grow up to the large tumorous lesion. Even if most of the ONCs were trapped and disappeared under the influence of tumor immunity, the detection of ONCs could be one of the reliable clues to estimate the prognosis.

Primary systemic therapy does not eradicate disseminated tumor cells in breast cancer patients

INTRODUCTION

The presence of disseminated tumor cells in the bone marrow of breast cancer patients has proven to be an independent prognostic factor. The aim of this study was to investigate the status of tumor cell dissemination after primary systemic therapy in relation to therapy response.

METHODS

Bone marrow aspirates were obtained from 120 patients after completion of primary systemic therapy. Disseminated tumor cells were detected by immunocytochemistry using the APAAP method. Bone marrow status was correlated with clinicopathological factors as well as tumor response to primary systemic therapy.

RESULTS

Sixty out of 120 patients had disseminated tumor cells in their bone marrow aspirates (50%). Response rates were 18% for pathologic complete remission, 52% for partial remission, 28% for no change and 3% for progression. Despite complete remission, 36% of these patients were bone marrow positive. In the partial remission group, the positivity rate was 48%. About 61% of patients with stable disease had disseminated tumor cells in their bone marrow. A trend to higher positivity rates was observed in the poor responder group compared to responders (61% vs. 38%, P = 0.1).

CONCLUSION

Primary systemic therapy does not completely eradicate disseminated tumor cells in the bone marrow of breast cancer patients. The biological role of persistent disseminated tumor cells needs to be further investigated to optimize current and future therapeutic strategies.

Image analysis systems for the detection of disseminated breast cancer cells on bone-marrow cytospins

We assessed the accuracy of automated cell imaging systems when compared to manual evaluation of cytospin slides in determining the presence of cytokeratin-positive, disseminated breast cancer cells in bone marrow aspirates. A total of 298 cytospin slides of bone marrow aspirates were first evaluated by individual screening by one expert immunocytologist. Subsequently, all 298 slides were evaluated by the Automated Cell Imaging System (ACIS) by ChromaVisiontrade mark. Two separate analysis cycles were performed using ACIS. The results of the two ACIS analysis cycles were almost identical: in 293 out of 298 samples (98.3%), identical numbers of disseminated breast cancer cells were detected. In the remaining five samples (1.7%), the result of the two ACIS analysis cycles differed by only one tumor cell. By using the manual technique, 120 cytospin samples were found to be positive. ACIS was able to detect additional tumor cells in 64 cases. Not once did ACIS miss tumor cells when compared to the manual technique. Using ACIS, we were able to determine the bone marrow status of patients with nonmetastatic breast cancer faster, with greater accuracy, and with greater reproducibility than with the manual technique.

Evidence-based principles and practices in pathology: selected problem areas

Contrary to the intuitive impression of most pathologists, there are still many areas in laboratory medicine where evidence-based medicine (EBM) principles are not applied. These include aspects of both anatomic and clinical pathology. Some non-EBM practices are perpetuated by clinical "consumers" of laboratory services, because of inadequate education, habit, or over-reliance on empirical factors. Other faulty procedures are pathologist-driven, with similar underpinnings. This overview considers several exemplary problem areas representing non-EBM practices in the hospital laboratory. Such examples include ideas and techniques centering on metastatic malignancies, "targeted" oncological therapy, analysis of surgical margins in the excision of neoplasms, general laboratory testing and data utilization, evaluation of selected coagulation defects, administration of blood products, and analysis of hepatic iron-overload syndromes. The concepts illustrating departures from EBM are discussed for each of those topics.

Relevance of disseminated tumour cells in blood and bone marrow of patients with solid epithelial tumours in perspective

Currently-used systems to predict prognosis in patients with solid epithelial tumours after surgical resection of the tumour do not give any guarantees for the individual patient. In this respect the clinical relevance of the presence of disseminated tumour cells in blood and bone marrow has been frequently studied. Because of growing awareness that information on merely the presence of disseminated tumour cells is not sufficient for prognostic and therapeutic purposes, attention for characterization of disseminated tumour cells has increased. Numerous reviews have already been published on the detection and clinical relevance of disseminated tumour cells. Therefore, this paper will mainly focus on the biological significance of these cells and discusses the (in)efficiency of the metastatic process, the genotypic and phenotypic characteristics of disseminated tumour cells, and their structure of appearance. Despite the fact that information gained on the several individual aspects is substantial, it did not render any solid solutions for individual patient management yet. Hence, a combined approach of several aspects of disseminated tumour cells together with characteristics and behaviour of the primary tumour is needed to substantially improve our knowledge on the role of disseminated tumour cells in the complex process of tumour metastasis.

Antigenic profiles of disseminated breast tumour cells and microenvironment in bone marrow

AIMS

Thirty per cent of breast cancer patients with axillary lymph node negative at primary surgery will relapse within 10 years. This may be caused by disseminated tumour cells from the primary tumour. This study report the phenotypic profiles of disseminated tumour cells and microenvironmental characteristics in bone marrow of breast cancer.

METHODS

We detected the biologic markers on the disseminated tumour cells with immunocytochemical staining, analysed the immunological changes through flow-cytometry, and investigated the u- PA activity in the plasma of bone marrow.

RESULTS

With the immunocytochemical staining of EMA and CK19, we detected micrometastasis in thirty out of 72 (41.67%) breast cancer patients. Compared with the primary tumours, disseminated tumour cells expressed low protein cyclin D1, P53, Ki-67, EGFR, and high protein P21. The percentage of memory CD4+ T cells was significantly higher in the micrometastasis-positive group than in the micrometastasis-negative group. Tumour size and axillary lymph node status were found to be significantly correlated with the u- PA activity level.

CONCLUSIONS

Immunophenotypic profiles of disseminated tumour cells could be measured by immunocytochemical staining and microenvironment can be analysed by flow cytometry.

Comparison of two density gradient centrifugation systems for the enrichment of disseminated tumor cells in blood

BACKGROUND

The detection of disseminated tumor cells in peripheral blood is limited by the presence of very few tumor cells within a large number of blood cells. Therefore, tumor cell detection calls for enrichment systems with effective depletion of blood cells and high tumor cell recovery.

METHODS

We compared the new density gradient centrifugation method OncoQuick with the standard method of Ficoll. The enriched cell fractions were quantified. Tumor cell spiking experiments examined the recovery of tumor cells as detected by immunocytochemistry and cytokeratin-20 reverse transcriptase-polymerase chain reaction (RT-PCR). Clinical application of OncoQuick was evaluated in 37 peripheral blood samples of patients with gastrointestinal carcinomas.

RESULTS

The depletion of mononuclear cells (MNCs) in the enriched cell fraction after OncoQuick centrifugation was 632-fold, with an average cell number of 9.5 x 10(4), compared with Ficoll, with a depletion factor of 3.8 and a mean number of 1.6 x 10(7) MNCs. The mean tumor cell recovery rates were 87% for OncoQuick and 84% for Ficoll. The increased depletion of MNCs with OncoQuick centrifugation further simplified immunocytochemical evaluation by reducing the number of cytospins and increasing the tumor cell density. Due to the reduced number of co-enriched MNCs by OncoQuick, the blood volume, which could be analyzed in one RT-PCR reaction, was increased up to 30 ml. Examination of peripheral blood samples from 37 patients with gastrointestinal tumors showed a cytokeratin-20 detection rate of 30% and a significant correlation with the presence of distant metastases (P < 0.02).

CONCLUSIONS

OncoQuick significantly reduced the co-enriched number of MNCs, with a high tumor cell recovery rate. Processing blood from tumor patients with OncoQuick increased the chance of detecting circulating tumor cells.