Occult tumor cells in bone marrow of patients with locoregionally restricted ovarian cancer predict early distant metastatic relapse

Prognostic factors and novel nomograms for overall survival and cancer specific survival of malignant ovarian cancer patients with bone metastasis: A SEER-based study

OBJECTIVE

Ovarian cancer (OC) is a frequent and fatal disease in women, and bone metastasis of ovarian cancer (OCBM) leads to a poor survival trend. This study aimed to determine the factors which influence overall survival (OS) and cancer-specific survival (CSS) of OCBM patients and to develop prognostic predictive models.

METHODS

Data of OCBM patients were stratified from the Surveillance, Epidemiology and End Results database from 2010 to 2017 and were randomly divided into training and testing datasets (7:3). Prognostic factors were identified by Cox regression analyses and nomograms were then developed. Nomogram models were examined on the discriminative ability and accuracy by calibration plots, Brier score (BS), and time-dependent receiver operating characteristic (ROC) curves. Decision curve analyses (DCA) was used for estimation of the clinical benefit of nomogram models.

RESULTS

Grade, tumor size, tumor metastasis (liver, lung), primary site surgery, chemotherapy, and systemic therapy were realized as independent prognostic factors for OS and CSS, respectively. Agreement between the actual and predicted outcomes was proved by calibration plots. Nomograms performed well in OS and CSS predictions, as shown by area under the ROC curves (AUCs) and BSs for testing dataset as follows: for OS, 3-/6-/12-month AUCs and BSs were 0.778/0.788/0.822 and 19.0/18.5/15.4, respectively; for CSS, 3-/6-/12-month AUCs and BSs were 0.799/0.806/0.832 and 18.1/18.0/15.4, respectively. DCA suggested an agreeable clinical benefit of both nomograms.

CONCLUSION

The nomograms developed for OCBM patients' survival prediction were proved to be accurate, efficient, and clinically beneficial, which were further deployed as web-based calculators to help in clinical decision making and future studies.

Biomarkers of minimal residual disease and treatment

Minimal residual disease (MRD) has been defined as a very small numbers of cancer cells that remain in the body after curative treatment. Its presence or absence will ultimately determine prognosis. With the introduction of new technologies the presence of MRD in patients with solid tumours can be detected and characterized. As MRD predicts future relapse, be it early or late treatment failure, in an otherwise asymptomatic patient its treatment and when to start treatment remains to be determined. Thus the concepts of personalized medicine using different biomarkers to classify the biological properties of MRD maybe come possible. Based on this determinations it may be possible to use targeted therapies rather than all patients with the same type of cancer receiving a standard treatment. However, it is important to understand the limitations of the different technologies, what these techniques are detecting and how they may help in the treatment of patients with cancer. The majority of published studies are in patients with metastatic cancer and there are few reports in patients with MRD. In this chapter the concept of MRD, the methods used to detect it and what treatments may be effective based on the biological characteristics of the tumour cells as determined by different biomarkers is reviewed. MRD depends on the phenotypic properties of the tumour cells to survive in their new environment and the anti-tumour immune response. This is a dynamic process and changes with time in the wake of immunosuppression caused by the tumour cells and/or the effects of treatment to select resistant tumour cells. With the use of biomarkers to typify the characteristics of MRD and the development of new drugs a personalized treatment can be designed rather than all patients given the same treatment. Patients who are initially negative for MRD may not require further treatment with liquid biopsies used to monitor the patients during follow-up in order to detect those patients who may become MRD positive. The liquid biopsy used during the follow up of MRD positive patients can be used to detect changes in the biological properties of the tumour cells and thus may need treatment changes to overcome tumour cell resistance.

Metastatic Breast Cancer Recurrence after Bone Fractures

Simple Summary

Bone fractures bear potential risk to promote metastatic relapse in breast cancer. We conducted a population-based cohort study of 84,300 breast cancer patients diagnosed between January 2015 and November 2019. Bone fracture after breast cancer diagnosis was associated with an increased metastasis risk. Fractures may pose an increased risk to developing metastasis. Potential clinical implications for cancer patients are in support of fall prevention programs.

Abstract

Experimental studies suggest that bone fractures result in the release of cytokines and cells that might promote metastasis. Obtaining observational data on bone fractures after breast cancer diagnoses related to distant breast cancer recurrence could help to provide first epidemiological evidence for a metastasis-promoting effect of bone fractures. We used data from the largest German statutory health insurance fund (Techniker Krankenkasse, Hamburg, Germany) in a population-based cohort study of breast cancer patients with ICD-10 C50 codes documented between January 2015 and November 2019. The risk of metastasis overall, regional, distant non-bone or bone metastasis related to a fracture was modeled by an adjusted discrete time-to-event analysis with time-dependent exposure. Of 154,000 breast cancer patients, 84,300 fulfilled the inclusion criteria and had a follow-up time of more than half a year. During follow-up, fractures were diagnosed in 13,579 (16.1%) patients. Metastases occurred in 7047 (8.4%) patients; thereof 1544 had affected regional lymph nodes only and 5503 distant metastases. Fractures demonstrated a statistically significant association with subsequent metastasis overall (adjusted HR 1.12, 95% CI 1.04, 1.20). The highest risk for metastasis was observed in patients with subsequent bone metastasis (adjusted HR 1.18, 95% CI 1.05, 1.34), followed by distant non-bone metastasis (adjusted HR 1.16, 95% CI 1.07, 1.26) and lymph node metastasis (adjusted HR 1.08, 95% CI 0.97, 1.21).

Clinical relevance of circulating tumor cells in ovarian, fallopian tube and peritoneal cancer

Purpose

Presence of circulating tumor cells (CTCs) is associated with impaired clinical outcome in several solid cancers. Limited data are available on the significance of CTCs in gynaecological malignancies. The aims of the present study were to evaluate the dynamics of CTCs in patients with ovarian, fallopian tube and peritoneal cancer during chemotherapy and to assess their clinical relevance.

Methods

43 patients with ovarian, fallopian tube and peritoneal cancer were included into this prospective study. Patients received chemotherapy according to national guidelines. CTC analysis was performed using the CellSearch system prior to chemotherapy, after three and six cycles.

Results

In 26% of the patients, ≥ 1CTC per 7.5 ml of blood was detected at baseline (17% of patients with de novo disease, compared to 35% in recurrent patients). Presence of CTCs did not correlate with other factors. After three cycles of therapy, CTC positivity rate declined to 4.8%. After six cycles, no patient showed persistent CTCs. Patients with ≥ 1 CTC at baseline had significantly shorter overall survival and progression-free survival compared to CTC-negative patients (OS: median 3.1 months vs. not reached, p = 0.006, PFS: median 3.1 vs. 23.1 months, p = 0.005). When only the subgroup with newly diagnosed cancer was considered, the association between CTC status and survival was not significant (OS: mean 17.4 vs. 29.0 months, p = 0.192, PFS: 14.3 vs. 26.9 months, p = 0.085). Presence of ≥ 1 CTC after three cycles predicted shorter OS in the entire patient cohort (p < 0.001).

Conclusions

Hematogenous tumor cell dissemination is a common phenomenon in ovarian, fallopian tube and peritoneal cancer. CTC status before start of systemic therapy correlates with clinical outcome. Chemotherapy leads to a rapid decline in CTC counts; further research is needed to evaluate the clinical value of CTC monitoring after therapy.

Circulating tumor cells and cell-free nucleic acids in patients with gynecological malignancies

The ability to detect cancer cells in the blood or in the bone marrow offers invaluable information which potentially impacts early diagnosis, monitoring of treatment, and prognosis. Accessing blood or other body fluids has the additional advantage of being less invasive than biopsy. Consequently, considerable effort has been invested in the last 20 years in optimizing assays which may identify malignant cells at these anatomic sites. Detection of nucleic acids has been applied as alternative approach in this context, first targeting single cancer-associated genes using PCR-based technology, and recently using assays which identify different DNA classes, as well as microRNAs and exosomes. The present review focuses on studies which applied these assays to the detection of cells or cellular components originating from gynecological cancers.

The Predictive Value of Circulating Tumor Cells in Ovarian Cancer: A Meta Analysis

OBJECTIVE

Studies have confirmed that patients with circulating tumor cells (CTCs) in their peripheral blood (PB) or disseminated tumor cells (DTCs) in bone marrow (BM) might have bad prognosis. In this paper, we discuss whether CTCs/DTCs would be an appropriate biomarker to predict the prognosis of ovarian cancer.

METHODS

We systematically searched PubMed, EMBASE, Cochrane library, and Chinese National Knowledge Infrastructure to collect relevant studies published from the time the database were created to February 2014. Studies quality was assessed by Newcastle-Ottawa Scale. The effect size was estimated by hazard ratio (HR) and corresponding 95% confidence interval (95% CI). Meta-analysis was conducted with STATA Version 12.0.

RESULTS

Eight studies of 1184 patients were included in the final analysis. In the PB group, it showed that patients with positive CTCs had significantly shorter overall survival and disease-free survival than patients with negative CTCs (HR, 2.09; CI, 1.13-3.88 and HR, 1.72; CI, 1.32-2.25, respectively). The same result was shown with DTCs in the BM group (HR, 1.61; CI, 1.27-2.04 and HR, 1.44; CI, 1.15-1.80, respectively). We also discussed the influence of CTCs/DTCs on International Federation of Gynecology and Obstetrics stage, pathological grade with odds ratio and 95% CI. However, it did not show any statistical significance.

CONCLUSIONS

The CTCs/DTCs might be a new biomarker to predict the prognosis of ovarian cancer. Future studies are needed to confirm this consequence.

Analysis of disseminated tumor cells before and after platinum based chemotherapy in primary ovarian cancer. Do stem cell like cells predict prognosis?

BACKGROUND

We recently reported that the presence of disseminated tumor cells (DTCs) in the bone marrow (BM) of primary ovarian cancer patients (POC pts) correlated with reduced progression free survival (PFS) and overall survival (OS). Here we analyzed whether the negative prognostic influence was related to DTC persistence after platinum based chemotherapy and/or due to DTCs associated with stem cell character.

RESULTS

DTCs were detected in 33/79 pts (42%) before and in 32/79 pts (41%) AT. Persistent DTCs were found in 13 pts, 20 pts were only positive BT, 19 pts AT and 27 pts had no DTCs. Whereas the presence of DTCs BT significantly correlated with reduced OS (p = 0.02), pts initially DTCneg BT but DTCpos AT had a significantly shorter PFS (p = 0.03). DTC persistence resulted in a shorter PFS and OS reaching borderline significance (p = 0.06; p = 0.07). LIN-28-and SOX-2 positive cells were detected in all eight pts AT.

PATIENTS AND METHODS

79 POC pts were studied for DTCs before therapy (BT) and after therapy (AT) using immunocytochemistry. Eight pts harboring at least five DTCs AT were further analyzed on two additional slides by four-fold immunofluorescence staining for DAPI, Cytokeratin (CK), SOX-2 or LIN-28, CD45 and CD34 (Cy5). A stem-like tumor cell was classified as Dapipos, CD45neg, CD34neg, SOX-2pos/LIN-28pos and CKpos or CKneg.

CONCLUSIONS

Stem cell associated proteins are expressed in DTCs that are present AT and their presence seem to be correlated with a worse outcome. Additional therapeutic regimens may be necessary to eliminate these cells.

Circulating tumor cells in the differential diagnosis of adnexal masses

The aim of this study was to evaluate circulating tumor cell (CTC) detection in the differential diagnosis of adnexal masses. A total of 87 preoperative women with an indeterminate adnexal mass were prospectively enrolled. Preoperative diagnostic modalities including CTC detection, risk of ovarian malignancy algorithm, risk of malignancy index, and computed tomography or magnetic resonance imaging were compared. Forty-three (49.4%) benign tumors, 13 (14.9%) borderline malignant masses, and 31 (35.7%) cancers were pathologically confirmed. Forty-nine (56.3%) cases were positive for CTCs: 19/43 (44.2%) benign, 10/10 (100%) early-stage, and 14/21 (66.7%) advanced-stage cancer. CTC detection had sensitivities of 77.4%, 100%, and 100% for benign vs. all stage cancer (n = 74), benign vs. stage I–II cancer (n = 53), and benign vs. stage I cancer (n = 49), respectively. CTC detection had a specificity of 55.8% across all comparisons. The sensitivities of the other modalities assayed were decreased in stage I–II cancer and stage I cancer vs. benign masses. Receiver operating characteristic curves showed that CTCs, of which the area under the curve was modest in all stage cancer (0.655), had the widest area under the curve among the evaluated modalities in stage I–II cancer and stage I cancer (0.768 for both). In conclusion, our study findings suggest that preoperative CTCs could have a substantial role in differentiating early stage cancer from benign tumors for adnexal masses.

O-GlcNAcylation promotes migration and invasion in human ovarian cancer cells via the RhoA/ROCK/MLC pathway

O-GlcNAcylation is a dynamic and reversible post-translational modification associated with the regulation of multiple cellular functions. The addition and removal of O-Linked β-N-acetylglucosamine (O-GlcNAc) on target proteins is catalyzed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. Accumulating evidence suggests that O-GlcNAcylation is associated with the malignancy of several types of human cancer. To investigate the effect of O-GlcNAcylation on ovarian cancer phenotypes, global O-GlcNAc levels were decreased by OGT silencing through RNA interference and increased by inhibiting OGA activity with Thiamet-G. Transwell assay results demonstrated that OGT silencing inhibited the migration and invasion of SKOV3 and 59M ovarian cells in vitro, while Thiamet-G treatment promoted migration and invasion. Furthermore, a pull-down assay and western blot analysis demonstrated that Thiamet-G treatment enhanced RhoA activity and the phosphorylation of the Rho-associated protein kinase (ROCK) substrate, myosin light chain (MLC), while OGT silencing attenuated RhoA activity and MLC phosphorylation. In addition, RhoA silencing via RNA interference and inhibition of ROCK activity with Y-27632 prevented Thiamet-G-induced increases in cell migration and invasion. These data suggest that O-GlcNAcylation augments the motility of ovarian cancer cells via the RhoA/ROCK/MLC signaling pathway. Therefore, O-GlcNAcylation may be a potential target for the diagnosis and treatment of ovarian cancer.

Aspirin and P2Y12 inhibition attenuate platelet-induced ovarian cancer cell invasion

BACKGROUND

Platelet-cancer cell interactions play a key role in successful haematogenous metastasis. Disseminated malignancy is the leading cause of death among ovarian cancer patients. It is unknown why different ovarian cancers have different metastatic phenotypes. To investigate if platelet-cancer cell interactions play a role, we characterized the response of ovarian cancer cell lines to platelets both functionally and at a molecular level.

METHODS

Cell lines 59 M and SK-OV-3 were used as in vitro model systems of metastatic ovarian cancer. Platelet cloaking of each cell line was quantified by flow cytometry. Matrigel invasion chamber assays were used to assess the invasive capacity of the cell lines. The induction of an EMT was assessed by morphology analysis and by gene expression analysis of a panel of 11 EMT markers using TaqMan RT-PCR.

RESULTS

SK-OV-3 cells adhered to and activated more platelets than 59 M cells (p = 0.0333). Platelets significantly promoted the ability of only SK-OV-3 cells to invade (p ≤ 0.0001). Morphology and transcritpome analysis indicated that platelets induce an epithelial-to-mesenchymal transition phenotype in both cells lines, with a more exaggerated response in SK-OV-3 cells. Next, we investigated if antiplatelet agents could abrogate the platelet-induced aggressive phenotype in SK-OV-3 cells. Both aspirin (p ≤ 0.05) and 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (P2Y12 inhibitor; p ≤ 0.01) significantly decreased their invasion capacity, and effectively reverted invasion to levels comparable to SK-OV-3 cells alone.

CONCLUSION

While there is increasing evidence for the cancer-protective effect of aspirin, this study suggests P2Y12 inhibition may also play a role. Understanding these complex interactions between platelets and cancer cells could ultimately allow the establishment of therapies tailored to inhibiting metastasis, thus significantly reducing cancer morbidity.

Effect of lymphovascular space invasion on survival of stage I epithelial ovarian cancer

OBJECTIVE

To evaluate the effect of lymphovascular space invasion on survival of patients with early-stage epithelial ovarian cancer.

METHODS

A multicenter retrospective study was conducted for patients with stage IA-C epithelial ovarian cancer who underwent primary comprehensive surgery including lymphadenectomy. Histopathology slides for ovarian tumors were examined by gynecologic pathologists for the presence or absence of lymphovascular space invasion. Survival analysis was performed examining tumoral factors.

RESULTS

A total of 434 patients were included in the analysis. Lymphovascular space invasion was detected in 76 (17.5%) patients associated with histology (P=.042) and stage (P=.044). Lymphovascular space invasion was significantly associated with decreased survival outcomes (disease-free survival, 5-year rate 78.4% compared with 90.7%, P=.024 and overall survival, 84.9% compared with 93.2%, P=.031) in univariate analysis. In multivariate analysis, lymphovascular space invasion did not remain a significant variable for disease-free survival (hazard ratio [HR] 1.98, 95% confidence interval [CI] 0.97-3.97, P=.059) or overall survival (HR 2.41, 95% CI 0.99-5.85, P=.052). Lymphovascular space invasion was associated with increased risk of hematogenous and lymphatic metastasis (HR 4.79, 95% CI 1.75-13.2, P=.002) but not peritoneal metastasis (P=.33) in multivariate analysis. Among lymphovascular space invasion-expressing tumors, patients who received fewer than six cycles of postoperative chemotherapy had significantly poorer disease-free survival than those who received six or more cycles (HR 4.59, 95% CI 1.20-17.5, P=.015).

CONCLUSION

Lymphovascular space invasion is an important histologic feature to identify a subgroup of patients with increased risk of recurrence in stage I epithelial ovarian cancer.

LEVEL OF EVIDENCE

III.

Clinical outcome with correlation to disseminated tumor cell (DTC) status after DTC-guided secondary adjuvant treatment with docetaxel in early breast cancer

PURPOSE

The presence of disseminated tumor cells (DTCs) in bone marrow (BM) predicts survival in early breast cancer. This study explores the use of DTCs for identification of patients insufficiently treated with adjuvant therapy so they can be offered secondary adjuvant treatment and the subsequent surrogate marker potential of DTCs for outcome determination.

PATIENTS AND METHODS

Patients with early breast cancer who had completed six cycles of adjuvant fluorouracil, epirubicin, and cyclophosphamide (FEC) chemotherapy underwent BM aspiration 2 to 3 months (BM1) and 8 to 9 months (BM2) after FEC. Presence of DTCs in BM was determined by immunocytochemistry using pan-cytokeratin monoclonal antibodies. If one or more DTCs were present at BM2, six cycles of docetaxel (100 mg/m(2), once every 3 weeks) were administered, followed by DTC analysis 1 and 13 months after the last docetaxel infusion (after treatment). Cox regression analysis was used to evaluate disease-free interval (DFI).

RESULTS

Of 1,066 patients with a DTC result at BM2 and available follow-up information (median follow-up, 71.9 months from the time of BM2), 7.2% were DTC positive. Of 72 docetaxel-treated patients analyzed for DTCs after treatment, 15 (20.8%) had persistent DTCs. Patients with remaining DTCs had markedly reduced DFI (46.7% experienced relapse) compared with patients with no DTCs after treatment (adjusted hazard ratio, 7.58; 95% CI, 2.3 to 24.7). The docetaxel-treated patients with no DTCs after treatment had comparable DFI (8.8% experienced relapse) compared with those with no DTCs both at BM1 and BM2 (12.7% experienced relapse; P = .377, log-rank test).

CONCLUSION

DTC status identifies high-risk patients after FEC chemotherapy, and DTC monitoring status after secondary treatment with docetaxel correlated strongly with survival. This emphasizes the potential for DTC analysis as a surrogate marker for adjuvant treatment effect in breast cancer.

Prevalence and prognostic value of disseminated tumor cells in primary endometrial, cervical and vulvar cancer patients

AIMS

Disseminated tumor cell (DTC) detection in bone marrow (BM) of primary breast cancer patients predicts poor prognosis. This study investigates the prevalence of DTCs and their prognostic significance in primary gynecologic malignancies.

PATIENTS & METHODS

DTCs from BM aspirates of 603 patients with endometrial (311), cervical (228) and vulvar cancer (64) were identified by the pancytokeratin antibody A45B/B3.

RESULTS

DTCs were detected in 18% of BM aspirates (21, 16 and 16% in endometrial, cervical and vulvar cancer, respectively). In cervical cancer, DTCs were associated with International Federation of Gynecology and Obstetrics stage, nodal status and lymphangiosis. There was no association between BM status and prognosis.

CONCLUSION

Tumor cell dissemination is common in gynecological cancer. In contrast to breast cancer, DTCs that derive from cervical, endometrial or vulvar cancer have less potential to initiate metastatic regrow. The molecular mechanisms underlying this observation warrant further investigation.

Circulating and disseminated tumor cells in ovarian cancer: a systematic review

OBJECTIVES

Detecting circulating tumor cells (CTCs) in the peripheral blood and disseminated tumor cells (DTCs) in the bone marrow of cancer patients has proven feasible and of prognostic value in different neoplasms. However, the clinical significance of CTCs and DTCs in ovarian cancer and its association with outcome remains unclear.

METHODS

A literature search in PubMed was performed from January 2000 to December 2013 for studies evaluating CTCs and/or DTCs and its association with clinicopathological characteristics and clinical outcome in ovarian cancer. The main outcome measures were progression-free survival (PFS) and overall survival (OS).

RESULTS

Fourteen studies met the inclusion criteria. Median study size was 84 patients (range 43-216). Median follow-up was 19months (range 5-52). Most studies were small case series (n<100; studies; 71%). The majority of studies used an immunophenotyping approach to identify CTCs and/or DTCs, but only 3 studies (21%) used the FDA-approved Cell Search method. Despite the differences in methodology among studies the presence of CTCs and DTCs tended to be associated with higher baseline CA-125 serum levels, higher odds of residual disease after surgery, and worse survival in ovarian cancer across studies. No consistent intra-patient correlation was observed between DTCs detected in the bone marrow and CTCs detected in the blood.

CONCLUSIONS

The presence of CTCs and DTCs is associated with adverse clinicopathological characteristics and poor clinical outcomes in ovarian cancer patients. Its implementation as a valuable prognostic tool in the clinical setting requires uniform methodology and prospective validation.

Pooled analysis of the prognostic relevance of disseminated tumor cells in the bone marrow of patients with ovarian cancer

OBJECTIVE

Detection of disseminated tumor cells (DTCs) in the bone marrow (BM) of patients with breast cancer is associated with poor outcomes. Recent studies demonstrated that DTCs may serve as a prognostic factor in ovarian cancer. The aim of this 3-center study was to evaluate the impact of BM status on survival in a large cohort of patients with ovarian cancer.

MATERIALS AND METHODS

Four hundred ninety-five patients with primary ovarian cancer were included in this 3-center prospective study. Bone marrow aspirates were collected intraoperatively from the iliac crest. Disseminated tumor cells were identified by antibody staining and by cytomorphology. Clinical outcome was correlated with the presence of DTCs.

RESULTS

Disseminated tumor cells were detected in 27% of all BM aspirates. The number of cytokeratin-positive cells ranged from 1 to 42 per 2 × 10⁶ mononuclear cells. Disseminated tumor cell status did correlate with histologic subtype but not with any of the other established clinicopathologic factors. The overall survival was significantly shorter among DTC-positive patients compared to DTC-negative patients (51 months; 95% confidence interval, 37-65 months vs 33 months; 95% confidence interval, 23-43 months; P = 0.023). In the multivariate analysis, BM status, International Federation of Gynecology and Obstetrics stage, nodal status, resection status, and age were independent predictors of reduced overall survival, whereas only BM status, International Federation of Gynecology and Obstetrics stage, and resection status independently predicted progression-free survival.

CONCLUSIONS

Tumor cell dissemination into the BM is a common phenomenon in ovarian cancer. Disseminated tumor cell detection has the potential to become an important biomarker for prognostication and disease monitoring in patients with ovarian cancer.

Multiple MAGE-A genes as surveillance marker for the detection of circulating tumor cells in patients with ovarian cancer

Ovarian cancer is a leading cause of death among gynecologic malignancies. In this study, we reported the expression of melanoma-associated antigens A (MAGE-A) genes in peripheral blood from 80 patients with ovarian cancer and 30 healthy donors. MAGE-As expression was associated with the factors indicating poor prognosis. The expressions of MAGE-As and each individual MAGE-A genes were also associated with low overall survival of patients with ovarian cancer. Our results suggested MAGE-A genes may have the potential to be surveillance markers for the detection of circulating tumor cells and represent a poor prognosis for patients with ovarian cancer.

Presence of disseminated tumor cells in bone marrow correlates with tumor stage and nodal involvement in cervical cancer patients

Detection of disseminated tumor cells (DTCs) in the bone marrow (BM) of breast cancer patients is associated with poor outcome. The aim of our study was to evaluate the impact of BM status on survival in a large cohort of cervical cancer patients. Three hundred twenty-five patients with cervical cancer were included into this prospective two-center study (University Hospitals Tuebingen, Munich, Germany). BM was collected preoperatively. DTCs were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3. DTCs were detected in 22% of all BM aspirates. The number of CK-positive cells ranged from 1 to 93 per 2 × 10(6) mononuclear cells. Eighteen percent of patients with T1 stage presented with DTCs in BM compared to 30% in T2 and 45% in T3/4 patients. Among nodal negative patients, 18% had tumor cells in BM compared to 32% of nodal positive patients. Positive DTC status was associated with tumor size (p = 0.007) and nodal status (p = 0.009) but not with grading (p = 0.426). DTC status did not correlate with overall or disease-free survival. In the univariate analysis, tumor stage, nodal status, resection status and grading correlated with OS and DFS. In the multivariate analysis, only tumor stage and nodal status were independent predictors of OS and tumor stage, nodal status and grading of DFS. Tumor cell dissemination into BM is thus a common phenomenon in cervical cancer and correlates with higher tumor load but lacks prognostic relevance. Alternative detection methods may be needed to establish prognostic potential.

Platelet adhesion and degranulation induce pro-survival and pro-angiogenic signalling in ovarian cancer cells

Thrombosis is common in ovarian cancer. However, the interaction of platelets with ovarian cancer cells has not been critically examined. To address this, we investigated platelet interactions in a range of ovarian cancer cell lines with different metastatic potentials [HIO-80, 59M, SK-OV-3, A2780, A2780cis]. Platelets adhered to ovarian cancer cells with the most significant adhesion to the 59M cell line. Ovarian cancer cells induced platelet activation [P-selectin expression] in a dose dependent manner, with the most significant activation seen in response to the 59M cell line. The platelet antagonists [cangrelor, MRS2179, and apyrase] inhibited 59M cell induced activation suggesting a P2Y12 and P2Y1 receptor mediated mechanism of platelet activation dependent on the release of ADP by 59M cells. A2780 and 59M cells potentiated PAR-1, PAR-4, and TxA2 receptor mediated platelet activation, but had no effect on ADP, epinephrine, or collagen induced activation. Analysis of gene expression changes in ovarian cancer cells following treatment with washed platelets or platelet releasate showed a subtle but valid upregulation of anti-apoptotic, anti-autophagy pro-angiogenic, pro-cell cycle and metabolic genes. Thus, ovarian cancer cells with different metastatic potential adhere and activate platelets differentially while both platelets and platelet releasate mediate pro-survival and pro-angiogenic signals in ovarian cancer cells.

Loss of heterozygosity proximal to the M6P/IGF2R locus is predictive for the presence of disseminated tumor cells in the bone marrow of ovarian cancer patients before and after chemotherapy

Disseminated tumor cells (DTC) in the bone marrow (BM) are present in about 35% of ovarian cancers before surgery and after chemotherapy and are associated with worse prognosis. A molecular biomarker in the primary tumor predicting tumor cell spread would be highly desirable. The purpose of the study was to investigate loss of heterozygosity (LOH) in primary ovarian tumors at four ovarian cancer-relevant chromosomal loci involved in apoptosis, platinum sensitivity, or DNA-repair, to assess the prognostic value of LOH and to correlate LOH with DTC occurrence before surgery and after chemotherapy. Primary tumor DNA of 88 patients was analyzed for LOH at four polymorphic microsatellite markers using PCR-based fluorescence microsatellite analysis. BM aspirates were analyzed for DTC by immunocytochemistry using the pan-cytokeratin antibody A45-B/B3. LOH at the entire marker set correlated with tumor grading (P = 0.0001) and histology (P = 0.004). LOH at marker D10S1765 correlated with FIGO stage (P = 0.046) and grading (P = 0.05), whereas LOH at D17S855 significantly associated with grading (P = 0.023) and histology (P = 0.012), respectively. DTC were detected in 49% of patients before surgery and in 50% of patients after chemotherapy. Interestingly, LOH proximal to D6S1581 significantly correlated with DTC presence before surgery (P = 0.05) and after chemotherapy (P = 0.022). Conclusively, our data suggest that allelic loss at D6S1581 (proximal to M6P/IGF2R locus) serves as a molecular biomarker for the presence of DTC in the BM before and after chemotherapy.

Impact of platinum-based chemotherapy on circulating nucleic acid levels, protease activities in blood and disseminated tumor cells in bone marrow of ovarian cancer patients

There is an unmet need for biomarkers for the prediction and monitoring of anticancer therapies. Here, we measured the concentrations of nucleosomes and DNA, protease and caspase activities in serum of 62 patients with ovarian cancer before and after first-line carboplatin/taxane-based chemotherapy and of 28 healthy individuals by Cell Death Detection ELISA, PicoGreen, Protease Fluorescent Detection Kit and Caspase-Glo3/7 Assay, respectively. By immunocytochemistry, we analyzed bone marrow (BM) aspirates for disseminated tumor cells (DTCs) using the monoclonal antibody A45-B/B3. The measurements in blood and BM were correlated to clinical outcome (median follow-up time: 18 months). Significant correlations between circulating nucleosome and DNA concentrations (p = 0.0001), nucleosome concentrations and caspase activities (p = 0.031) and circulating DNA concentrations and protease activities (p = 0.0001) were detected. Before therapy, the occurrence of DTCs correlated with increasing serum protease activities (p = 0.030) and higher tumor stages (p = 0.029), and after therapy, it correlated with a higher risk of relapse (p = 0.040). Higher protease activities in serum were associated with advanced tumor stages (p = 0.045). We observed a significant relationship between residual tumor load of >1 cm after primary surgery and serum DNA levels (p = 0.0001), and both parameters were associated with a higher risk of relapse (p = 0.0001 and p = 0.020, respectively) and a poorer overall survival (p = 0.021 and p = 0.010, respectively). These findings suggest that the residual tumor load might contribute to elevated DNA levels in blood. Serum DNA levels together with BM status for DTCs have the potential to become suitable biomarkers to predict the prognosis of ovarian cancer patients undergoing platinum-based chemotherapy.

Enrichment of circulating tumor cells from a large blood volume using leukapheresis and elutriation: proof of concept

BACKGROUND

The aim of this study was to determine the applicability of a sequential process using leukapheresis, elutriation, and fluorescence-activated cell sorting (FACS) to enrich and isolate circulating tumor cells from a large blood volume to allow further molecular analysis.

METHODS

Mononuclear cells were collected from 10 L of blood by leukapheresis, to which carboxyfluorescein succinimidyl ester prelabeled CaOV-3 tumor cells were spiked at a ratio of 26 to 10⁶ leukocytes. Elutriation separated the spiked leukapheresates primarily by cell size into distinct fractions, and leukocytes and tumor cells, characterized as carboxyfluorescein succinimidyl ester positive, EpCAM positive and CD45 negative events, were quantified by flow cytometry. Tumor cells were isolated from the last fraction using FACS or anti-EpCAM coupled immunomagnetic beads, and their recovery and purity determined by fluorescent microscopy and real-time PCR.

RESULTS

Leukapheresis collected 13.5 x 10⁹ mononuclear cells with 87% efficiency. In total, 53 to 78% of spiked tumor cells were pre-enriched in the last elutriation fraction among 1.6 x 10⁹ monocytes. Flow cytometry predicted a circulating tumor cell purity of ~90% giving an enrichment of 100,000-fold following leukapheresis, elutriation, and FACS, where CaOV-3 cells were identified as EpCAM positive and CD45 negative events. FACS confirmed this purity. Alternatively, immunomagnetic bead adsorption recovered 10% of tumor cells with a median purity of 3.5%.

CONCLUSIONS

This proof of concept study demonstrated that elutriation and FACS following leukapheresis are able to enrich and isolate tumor cells from a large blood volume for molecular characterization.

CCL25-CCR9 interaction modulates ovarian cancer cell migration, metalloproteinase expression, and invasion

BACKGROUND

Ovarian carcinoma (OvCa) is the most lethal gynecological malignancy among women and its poor prognosis is mainly due to metastasis. Chemokine receptor CCR9 is primarily expressed by a small subset of immune cells and its only natural ligand, CCL25, is largely expressed in the thymus, which involutes with age. Other than the thymus, CCL25 is expressed by the small bowel. Interactions between CCL25 and CCR9 have been implicated in leukocyte trafficking to the small bowel, a frequent metastatic site for OvCa cells. The current study shows OvCa tissue and cells significantly express CCR9, which interacts with CCL25 to support carcinoma cell migration and invasion.

METHODS

RT-PCR and flow cytometry techniques were used to quantify the expression CCR9 by OvCa cells. OvCa tissue microarrays (TMA) was used to confirm CCR9 expression in clinical samples. The Aperio ScanScope scanning system was used to quantify immunohistochemical staining. Cell invasion and migration assays were performed using cell migration and matrigel invasion chambers. Matrix metalloproteinase (MMP) mRNAs were quantified by RT-PCR and active MMPs were quantified by ELISA.

RESULTS

Our results show significantly (p<0.001) higher expression of CCR9 by mucinous adenocarcinoma, papillary serous carcinoma, and endometriod ovarian carcinoma cases, than compared to non-neoplastic ovarian tissue. Furthermore, CCR9 expression was significantly elevated in OvCa cell lines (OVCAR-3 and CAOV-3) in comparison to normal adult ovarian epithelial cell mRNA. OvCa cells showed higher migratory and invasive potential towards chemotactic gradients of CCL25, which was inhibited by anti-CCR9 antibodies. Expression of collagenases (MMP-1, -8, and -13), gelatinases (MMP-2 and -9), and stromelysins (MMP-3, -10, and -11) by OvCa cells were modulated by CCL25 in a CCR9-dependent fashion.

CONCLUSIONS

These results demonstrate both biological significance and clinical relevance of CCL25 and CCR9 interactions in OvCa cell metastasis.

Disseminated tumor cells in bone marrow may affect prognosis of patients with gynecologic malignancies

INTRODUCTION

The presence of disseminated tumor cells (DTC) in the bone marrow (BM) of breast cancer patients is associated with poor prognosis. Several studies demonstrated that tumor cell dissemination may occur in gynecologic cancer and affect clinical outcome. The aim of our study was to evaluate the incidence of DTC and to assess their prognostic significance in patients with gynecologic malignancies.

METHODS

Bone marrow aspirates from 377 patients with primary ovarian (112), endometrial (141), cervical (102), and vulvar cancer (22) undergoing surgery at the Department of Gynecology and Obstetrics, University Hospital, Tuebingen, Germany between November 2001 and November 2007, were included into the study. Disseminated tumor cells were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3 and by cytomorphology.

RESULTS

Disseminated tumor cells were detected in 19% of BM aspirates from patients with gynecological malignancies. Incidences of DTC in ovarian, endometrial, cervical, and vulvar cancer were 25%, 16%, 19%, and 5%, respectively. For patients with ovarian and endometrial cancer, no correlation with established clinicopathological factors was observed. In case of cervical cancer, BM positivity was correlated with International Federation of Gynecology and Obstetrics stage, tumor size, and nodal involvement. Bone marrow positivity of ovarian cancer patients was correlated with significantly shorter disease-free survival (P = 0.035). For other tumor entities, no association between BM status and clinical outcome could be observed.

CONCLUSIONS

We conclude that up to 25% of patients with loco-regionally restricted gynecologic malignancies present with DTC at the time of diagnosis. For ovarian cancer patients, BM status affected clinical outcome.

The urokinase receptor (u-PAR)--a link between tumor cell dormancy and minimal residual disease in bone marrow?

Minimal residual disease (MRD) is hypothesized to be the major cause of tumor recurrence and metastasis even years and decades after primary cancer diagnosis and curative solid tumor resection. In these patients disseminated tumor cells reflecting MRD can be detected in the bone marrow years after treatment. It is to be assumed that genetic determinants and a complex interplay between the disseminated tumor cells and their microenvironment in the bone marrow are responsible for tumor cell dormancy and the final reactivation towards metastasis. The urokinase receptor (u-PAR), a critical regulator of invasion, intravasation, and metastasis, is found to be a key player in regulating the shift between single cell tumor dormancy and proliferation. This has mainly been attributed to a regulation by u-PAR of integrins, and the ability of the latter to propagate signals from fibronectin through the EGF-receptor, ERK, and p38 signaling. Interestingly, u-PAR is found in disseminated tumor cells in the bone marrow of solid cancer patients, and is associated with the expansion of these cells and clinical prognosis. Here we summarize and discuss findings on disseminated tumor cells in the bone marrow, MRD and the role of u-PAR in tumor biology, especially focusing on its specific role in providing a switch between tumor cell proliferation and dormancy. Finally, we discuss the hypothesis that u-PAR might be an essential molecule in bone marrow disseminated tumor cells for long-term survival during dormancy, and/or reactivation of their proliferation years after primary treatment.

Clinical significance of circulating tumor cells detected by an invasion assay in peripheral blood of patients with ovarian cancer

OBJECTIVES

The invasive growth of circulating tumor cells (CTCs) propagates cancer metastasis. The aims of this study were to evaluate the association of invasive CTCs, detected by a novel cell invasion assay, with disease stage, CA-125 level and patient survival.

METHODS

Peripheral blood samples from 71 patients undergoing evaluation for ovarian malignancy were assessed for the presence of invasive CTCs using a cell invasion assay that enriches and identifies tumor cells with a cell adhesion matrix (CAM). Invasive CTCs were identified as cells exhibiting CAM invasion (CAM+) and expressing standard epithelial markers (Epi+).

RESULTS

43 (60.6%) patients had detectable CTCs: 0/5 benign patients, 1/10 (10%) early stage, 39/52 (73.1%) late stage and 3/4 (75%) unstaged patients (p-value <0.001). CTC counts ranged from 0-149 CTCs/ml with stage III/IV patients exhibiting significantly higher mean counts (41.3 CTCs/ml) than stage I/II patients (6.0 CTCs/ml) and benign patients (0 CTCs/ml, p-value=0.001). A positive correlation between CTC count and CA-125 level was observed (Spearman correlation coefficient r=0.309, p-value=0.035). Kaplan-Meier curves revealed a significant decrease in disease-free survival in patients with detectable CTCs (median survival 15.0 months vs. 35.0 months, log-rank p-value=0.042). Tumor grade and tumor histology did not influence CTC detection.

CONCLUSIONS

Invasive CTCs can be detected in a majority of epithelial ovarian cancer patients and may predict shorter disease-free survival. Furthermore, higher CTC counts may reflect later stage disease and higher CA-125 levels.

Prognostic impact of KI67, p53, human epithelial growth factor receptor 2, topoisomerase IIα, epidermal growth factor receptor, and nm23 expression of ovarian carcinomas and disseminated tumor cells in the bone marrow

Examination of tumor biological factors for prognostic and predictive indicators is not part of routine testing in ovarian cancer. As in other tumors, the detection of hematogenous tumor spread could help to estimate the risk of metastatic disease. We examined the expression of p53, KI67, topoisomerase IIα (Top IIa), epidermal growth factor receptor (EGFR), human epithelial growth factor receptor 2 (HER2) and nm23 in tumor tissues from 90 patients with ovarian cancer. All underwent bone marrow (BM) aspiration and screening for disseminated tumor cells in the bone marrow (DTC-BM) at primary diagnosis. BM aspiration, cytospin preparation, and immunocytochemical staining with the anticytokeratin antibody (A45-B/B3) were done following a standardized protocol. The expression of p53, KI67, Top IIa, EGFR, HER2, and nm23 was evaluated by immunohistochemistry on paraffin-embedded tissue samples and classified by percentage of stained cells or immunoreactive score (IRS). The prognostic impact of the individual factors together with standard histologic parameters was calculated by univariate and multivariate analyses. Expression rates for HER2 (2+/3+: 34.5%), KI67 (median 30%), p53 (median IRS 5), and Top IIa (median IRS 4) were relatively high, whereas nm23 (median IRS 2) and EGFR (IRS 0: 61%) showed weak staining. In 21/90 patients (23.3%), DTC-BM (≥1/2 × 106 cells) could be detected. The presence of DTC-BM was inversely related to nodal status (P= .015) but not to the other factors examined. Tumor stage (P= .02), lymph node involvement (P= .003), grade (P= .046), postoperative tumor residue (P <.001), peritoneal seeding (P= .02), and KI67 (P= .046) significantly correlated with overall survival (OS) after a median observation time of 28 months (2–105). The finding of ascites was borderline significant (P= .050). The presence of DTC-BM (P= .04) and KI67 positivity (P= .02) predicted reduced distant disease-free survival. By multivariate analysis, postoperative tumor residue remained an independent factor for OS (P= .02, relative risk = 4.6). As a primarily locoregional disease, tumor stage and postoperative tumor residue are the main determinants of prognosis in patients with ovarian cancer. However, even in advanced stages, examination of tumor biological factors could help to stratify subgroups of patients and establish targeted therapies.

Recent advances in the detection of bone marrow micrometastases: A promising area for research or just another false hope? A review of the literature

The presence of early disseminated tumor cells (DTC), otherwise termed micrometastases or minimal residual disease, in the bone marrow (BM), or other secondary compartments, such as the blood and the lymph nodes, is the main reason for recurrence of patients with early stage epithelial cancers after "curative" resection of the primary tumor. There is increasing evidence, that the detection of DTC in BM aspirates may provide additional and independent prognostic information and aid in the stratification of these patients for adjuvant clinical treatment. However, the clinical relevance of micrometastases has not yet been firmly established. In addition, the molecular events and interactions that prevail in early metastatic disease and determine the formation or not of overt metastases remain poorly understood. The methods currently used for the detection of micrometastatic cells include extremely sensitive immunocytochemical and molecular assays, often in conjunction with enrichment techniques for the purification of tumor cells and additional increase of their sensitivity. Nevertheless, the specificity of these methods is mostly inadequate. After the impressive advances of molecular cytogenetics, a highly accurate and global assessment of the genetic status of tumors is now possible. Therefore, the greatest challenge of our time is the application of these novel technologies for the clarification of the key molecular events that initiate metastatic spread. This will further enable us to identify the highly specific and sensitive diagnostic and prognostic markers as well as the therapeutic targets which are so urgently needed.

Detection of disseminated tumor cells in patients with gynecological cancers

OBJECTIVES

The presence of disseminated tumor cells (DTC) in breast cancer patients is associated with poor prognosis. However, there are limited data about the prevalence and prognostic impact of DTC in patients with gynecological tumors. The aim of this study was to evaluate the presence of DTC in the bone marrow (BM) of patients with gynecological cancers and to correlate their presence with established prognostic factors.

METHODS

BM aspirates of 201 patients with primary ovarian (n=69), cervical (n=54) and endometrial cancer (n=78), undergoing surgery at the Department of Gynecology and Obstetrics, University Hospital, Tuebingen, Germany between 1/2002 and 01/2006, were included into the study. Cytokeratin (CK)-positive cells were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3.

RESULTS

The bone marrow positivity rate was 36% in ovarian, 26% in cervical and 17% in endometrial cancer, respectively. Presence of DTC was significantly correlated with FIGO (International Federation of Gynecology and Obstetrics) tumor stage (p<0.05). The recurrence rate was 14% in patients with CK-positive cells compared to 8% in CK-negative patients (p=0.2). There was no correlation between DTC and other established prognostic factors including nodal status or grading except for cervical cancer. Patients with positive lymph node status were more likely to be bone marrow positive compared to those with negative lymph node status (p<0.05).

CONCLUSIONS

Disseminated tumor cells seem to be a general phenomenon in epithelial tumors even though their clinical impact remains to be evaluated. The hypothesis that bone marrow is the homing site of disseminated tumor cells is further supported by these data since gynecological tumors only rarely metastasize to the skeletal system.

Minimal residual disease in ovarian cancer as a target for complement-mediated mAb immunotherapy

Ovarian cancer is potentially well suited for local monoclonal antibody (mAb) immunotherapy, because it remains within the peritoneal cavity for a long period of time before giving rise to distant metastases. At the stage of minimal residual disease, the cells appear to be in a state of dormancy (G(0)) or at least have lower rates of tumour cell proliferation. They should be a promising target for immunotherapy. Here we first examined the cell-cycle expression of CD59 and decay-accelerating factor (DAF; CD55) on four different ovarian carcinoma cell lines, using simultaneous flow cytometric analysis of DNA content or the cell-cycle-specific nuclear proliferation protein Ki67 and CD59 or DAF surface expression. We found that CD59 and DAF are stably expressed throughout the cell cycle. The polyvalent approach to target-independent antigens to improve the efficiency of mAb complement (C)-mediated damages was promising, and tumour cells become sensitive to C damage, when incubated with cross-linked mAb against different tumour-associated antigens. Although, such immune complex-mediated C activation was rather ineffective in killing the cells, it could be potentiated by the addition of blocking mAb against CD59 and DAF. Our results suggest that the activities of intrinsic C regulators must be neutralized to make minimal residual disease a promising target for antibody therapy.

Fate and characterization of circulating tumor cells in a NOD/SCID mouse model of human hepatocellular carcinoma

There is much debate about the way in which epithelial tumors metastasize. It has been proposed that the bone marrow (BM) acts as a tumor cell reservoir. We injected human hepatocellular carcinoma (HCC) cells (Mahlavu cell line) into the livers, circulation or BM of NOD/SCID mice and circulating tumor cells were quantified. When injected under the Glisson capsule, a primary tumor developed and continuously yielded circulating tumor cells. Liver tumor removal led to a very low level of Mahlavu cells both in blood and BM 30 days later. When Mahlavu cells (cultured or from BM of primary mice femurs) were intravenously injected into mice, the number of cells in the bloodstream (BS) steadily decreased, whereas the BM was not significantly colonized. When Mahlavu cells were directly injected into one femur, the controlateral femur was not colonized. Microscopic analysis and a sensitive PCR assay (<1 Mahlavu cell/nuclear cells) both failed to detect human tumor cells in other organs regardless of injection route. In conclusion, our model strongly supports the hypothesis that HCCs continuously release cells into the BS. However, in sharp contrast with the current hypothesis, the BM is not specifically colonized by tumor cells but could store them at a very low level.

Detection and molecular characterisation of disseminated tumour cells: Implications for anti-cancer therapy

Haematogenous distant metastasis is the leading cause of cancer-related death in solid tumours. By applying sensitive immunocytochemical and molecular assays, disseminated tumour cells (DTC) in bone marrow (BM) can be detected in 20-40% of cancer patients without any clinical or even histopathological signs of metastasis, and the presence of these DTC at primary diagnosis predicts the subsequent occurrence of overt metastases in bone and other organs. The detection and characterisation of DTC in BM may lead to a better understanding of the biology initiating metastatic spread in cancer patients and will eventually contribute to the development of more effective strategies to eliminate DTC. In this review, we will therefore discuss the detection and characterisation of DTC in the light of new therapeutic strategies targeting tumour-associated molecules and signalling pathways.

Circulating tumor cells in breast cancer: correlation to bone marrow micrometastases, heterogeneous response to systemic therapy and low proliferative activity

PURPOSE

The incidence and biological characteristics of circulating tumor cells in the blood of patients with breast cancer were examined and subgroups were evaluated in the context of systemic treatment and the presence of disseminated tumor cells in bone marrow.

EXPERIMENTAL DESIGN

Circulating tumor cells were isolated from the peripheral blood of patients with breast cancer using a gradient system designed for the enrichment of circulating tumor cells (OncoQuick). Circulating tumor cells were identified with the anti-cytokeratin antibody, A45-B/B3. In subsets of patients, expression of the proliferation-associated Ki-67 antigen in circulating tumor cells and the concomitant presence of micrometastases in bone marrow were examined.

RESULTS

In patients with primary breast cancer (stage M(0)), circulating tumor cells were detected in 5 of 60 patients (8.3%) after surgery and before initiation of adjuvant chemotherapy; a positive correlation to the presence of disseminated tumor cells in bone marrow was observed (P = 0.030, n = 53). During the course of adjuvant chemotherapy, repeated analysis of 20 M(0) patients revealed the occurrence of circulating tumor cells in 7 of 16 patients that were initially negative. Patients with metastatic disease (stage M(1)) showed circulating tumor cells in 25 of 63 cases (39.7%, P < 0.0001 as compared with M(0) patients), and a positive finding was correlated with elevated concentrations of the serum tumor marker CA15.3 (P = 0.0093). Performing repeated analysis in a subgroup of 25 M(1) patients, circulating tumor cells were found more frequently in patients with progressive disease than in patients with stable disease or remission (87.5% versus 43.8% of patients with circulating tumor cells, respectively; P = 0.047). Independent of the disease-stage, none of the 47 patients examined for the proliferative status of their circulating tumor cells showed coexpression of Ki-67.

CONCLUSIONS

Circulating tumor cells seem to be nonproliferating cells that persist during chemotherapy. Circulating tumor cell detection is linked to disease progression and elevated tumor marker concentrations in patients with metastatic breast cancer.

Detection of Micrometastatic Disease in Bone Marrow: Is It Ready for Prime Time?

Minimal residual disease (MRD), or isolated tumor cells (ITCs) in bone marrow, may be the source of potentially fatal overt distant metastases in solid tumors even years after primary treatment. MRD can be detected by immunohistochemical methods using antibodies directed against cytokeratins or cell-surface markers or molecular, polymerase chain reaction-based techniques. Among solid tumors, the clinical relevance of MRD has been most extensively studied in breast cancer patients. Recently, the highest level of evidence for the prognostic impact of MRD in primary breast cancer was reached by a pooled analysis comprising more than 4,000 patients, showing poor outcome in patients with MRD at primary therapy. Yet the clinical application of MRD detection is hampered by the lack of a standardized detection assay. Moreover, clinical trial results demonstrating the benefit of a therapeutic intervention determined by bone marrow status are still absent. Recent results suggest that, in addition to its prognostic impact, MRD can be used for therapy monitoring or as a potential therapeutic target after phenotyping of the tumor cells. Persistent MRD after primary treatment may lead to an indication for extended adjuvant therapy. However, until clinically relevant data regarding successful therapy of MRD are available, treatment interventions on the basis of MRD should only be performed within clinical trials.

Bi-specific immunomagnetic enrichment of micrometastatic tumour cell clusters from bone marrow of cancer patients

Metastasis-the spread of tumour cells from a primary lesion to distant organs-is the main cause of cancer-related death, and bone marrow (BM) is a frequent site for the settlement of disseminated tumour cells. Many BM samples harbour isolated tumour cells, whereas tumour cell clusters, as the potential precursors of solid distant metastases, are rarely detected after current enrichment procedures. We have analysed BM samples from 43 patients with carcinomas of the breast, colon and ovaries; 41 of these patients had no clinical signs of overt metastases (stage M0). Tumour cells in BM were enriched with immunomagnetic beads coupled to monoclonal antibodies against both EpCAM and HER2/neu. After enrichment, tumour cells were identified by immunostaining with the anti-cytokeratin antibody A45-B/B3. In total, 886 CK-positive cells were detected in 16 (35%) samples after immunomagnetic enrichment as compared to 34 cells in 9 (21%) samples using Ficoll density centrifugation previously used as the standard enrichment technique. Most remarkably, clusters of 2 to 10 CK-positive cells were found in 75% of CK-positive samples enriched by immunobeads, whereas no CK-positive cell clusters were detected after Ficoll enrichment. The method described offers an excellent tool for the enrichment of micrometastatic tumour cell clusters; these clusters may represent the initial stage of development from a single disseminated tumour cell towards an overt metastasis.

Transmigration of human ovarian adenocarcinoma cells through endothelial extracellular matrix involves alphav integrins and the participation of MMP2

The growth of ovarian carcinoma is dependent upon their vascularistion, but the interaction of ovarian cancer cells with the endothelium and their invasion through an endothelial environment remain poorly understood at the molecular level. To investigate adhesive events underlying this process with focusing on the role of alphav integrins and MT1MMP-MMP2 proteinases, we used in vitro models of cocultures of human ovarian adenocarcinoma cell lines (IGROV1 and SKOV3) with human umbilical vein endothelial cells (HUVECs). Immunostaining of HUVECs revealed the network organisation of fibrillar fibronectin (Fn) and pericellular vitronectin (Vn). During coculture, IGROV1 and SKOV3 cells gain access to subendothelial basement membrane of HUVECs and dislocated endothelial Fn without affecting endothelial Vn. Transmigration assays revealed that tumour cells invade Vn and, with an higher efficiency, Fn. Our data also highlighted that ovarian carcinoma cells migrated through the Fn-rich HUVEC-ECM. The expression of MMP2 and MT1-MMP was revealed in tumour cells within an endothelial environment. Furthermore, we found that cell migration through the endothelial ECM was almost totally dependent on alphav integrin function, whereas beta1 integrins were not solicited. In addition, inhibitors of MMP2 activity (alone or combined with anti-alphav integrin MAb) or TSRI265 (which blocks MMP2-alphavbeta3 association) were found to impede this process. Finally, alphav integrins, MT1-MMP and MMP2 were found in ovarian carcinoma cells within the 3-dimensional architecture of intraperitoneal tumour nodes collected from nude mice xenografted with IGROV1 or SKOV3 cell lines or within human tumour tissues. alphav integrins therefore appear as essential to the migration properties of human ovarian carcinoma cells, especially in an endothelial environment, with MMP2 participating to this process.

Correlation of tumor- and stromal-derived MT1-MMP expression with progression of human ovarian tumors in SCID mice

OBJECTIVE

Human ovarian carcinoma samples were orthotopically implanted into SCID mice to investigate the contribution of matrix metalloproteases (MMPs) to the spread of ovarian tumors.

METHODS

Mice were inoculated with patient tumor samples, and developed ovarian tumors over a 16-week period with metastasis occurring in some mice. Species-specific quantitative RT-PCR was used to identify the source of tumor-associated MMPs.

RESULTS

Membrane-type (MT)1-MMP mRNA was significantly increased in high-grade tumors, tumors with evidence of serosal involvement, and tumors in which distant metastases were detected. The increase in MT1-MMP expression was predominantly from the human tumor cells, with a minor contribution from the mouse ovarian stroma. Neither human nor mouse MT2-MMP were correlated with tumor progression and MT3-MMP levels were negligible. While tumor cells did not produce significant amounts of MMP-2 or MMP-9, the presence of tumor was associated with increased levels of MMP-2 expression by mouse ovarian stroma. Stromal-derived MT1-MMP was greater in large tumors and was associated with stromal MMP-2 expression but neither was significantly linked with metastasis.

CONCLUSIONS

These studies indicate that tumor-derived MT1-MMP, more so than other gelatinolytic MMPs, is strongly linked to aggressive tumor behavior. This orthotopic model of human ovarian carcinoma is appropriate for studying ovarian tumor progression, and will be valuable in the further investigation of the metastatic process.

BM micrometastases and circulating tumor cells in breast cancer patients: where have we been, where are we now and where does the future lie?

Over the past 15 years early tumor cell dissemination has been detected in patients with breast cancer using sensitive immunocytochemical and molecular assays based on the use of MAb and PCR, respectively. Clinical studies involving more than 4,000 breast cancer patients have now demonstrated that the presence of disseminated tumor cells in BM identified with immuncytochemical assays at primary diagnosis is a strong and independent prognostic factor. The published studies for the detection of disseminated tumor cells in BM fulfill the highest level of evidence as prognostic markers in primary breast cancer. In addition, various assays for the detection of circulating tumor cells in the peripheral blood have been developed recently and some studies suggest a potential clinical relevance of this parameter as a prognostic and predictive factor. Comparative analyzes indicate that the prognostic information derived from BM and blood screening seems to be complementary and not redundant. Advanced methods for molecular characterization of single tumor cells and the surrounding environment have been developed lately, and this approach allows new insights into the metastatic cascade and characterization of targets for therapeutic approaches. Taken together, these findings provide the basis for the implementation of disseminated tumor cells in BM or blood as markers for stratification and assessment of therapies in prospective clinical trials. The valuable information derived from these trials should help to improve future treatment of breast cancer patients.

Reliable and sensitive identification of occult tumor cells using the improved rare event imaging system

PURPOSE

The purpose of this study was to assess the feasibility of using rare event imaging system (REIS)-assisted analysis to detect occult tumor cells (OTCs) in peripheral blood (PB). The study also sought to determine whether REIS-assisted OTC detection presents a clinically viable alternative to manual microscopic detection to establish the true significance of OTC from solid epithelial tumors.

EXPERIMENTAL DESIGN

We recently demonstrated proof of concept using a fluorescence-based automated microscope system, REIS, for OTC detection from the PB. For this study, the prototype of the system was adopted for high-throughput and high-content cellular analysis.

RESULTS

The performance of the improved REIS was examined using normal blood (n = 10), normal blood added to cancer cells (n = 20), and blood samples obtained from cancer patients (n = 80). Data from the screening of 80 clinical slides from breast and lung cancer patients, by manual microscopy and by the REIS, revealed that as many as 14 of 35 positive slides (40%) were missed by manual screening but positively identified by REIS. In addition, REIS-assisted scanning reliably and reproducibly quantified the total number of cells analyzed in the assay and categorized positive cells based on their marker expression profile.

CONCLUSIONS

REIS-assisted analysis provides excellent sensitivity and reproducibility for OTC detection. This approach may enable an improved method for screening of PB samples and for obtaining novel information about disease staging and about risk evaluation in cancer patients.

A relevant immunomagnetic assay to detect and characterize epithelial cell adhesion molecule-positive cells in bone marrow from patients with breast carcinoma: immunomagnetic purification of micrometastases

BACKGROUND

The efficient detection and characterization of micrometastatic cells in the bone marrow of patients with breast carcinoma are of prognostic and therapeutic importance. The technique used must overcome the challenges that result from the small number of target cells (1 per 1 million hematopoietic cells) and the heterogeneous expression of micrometastatic cell markers. In this study, the authors assessed and improved the current methods for purifying and characterizing rare disseminated carcinoma cells.

METHODS

The authors developed a single-step assay that does not require density-gradient separation. This assay can be performed directly on crude human bone marrow aspirates and is based on the use of immunomagnetic beads coated with an antibody that recognizes an epithelial cell-surface epitope, the epithelial cell adhesion molecule (EpCAM). To determine the specificity of the assay, the authors evaluated bone marrow specimens from 46 control patients.

RESULTS

The novel method was highly reproducible and was capable of detecting as few as 10 carcinoma cells among 50 million hematopoietic cells. The yield was nearly 100%, with only 0.01% nonspecific cell draining. The authors found that 68 +/- 51 cells were trapped per 50 million cells in control crude aspirates and that density-gradient separation increased this number by 2-fold to 29-fold. These trapped cells expressed EpCAM, represented 1.4 x 10(-4) % of the sample, and were characterized as of hematopoietic cell origin (CD45 positive) or progenitor cell origin (CD34 positive).

CONCLUSIONS

The authors developed a highly efficient and reproducible, single-step immunomagnetic assay that may be performed directly on crude human bone marrow aspirates. The authors believe the current study is the first to demonstrate that some rare bone marrow cells (CD45-positive or CD34-positive cells) may express EpCAM and, to some extent, may contaminate the purified micrometastatic cell fraction. Thus, a universal marker for micrometastatic cells remains to be discovered.

Effect of laparoscopy versus laparotomy on circulating tumor cells using isolation by size of epithelial tumor cells

AIM

To assess the effect of laparoscopy on circulating tumor cell (CTC) detection in case of carcinosis.

MATERIAL AND METHODS

We compared laparoscopy versus laparotomy on tumor cell blood release in an animal model of ovarian carcinosis obtained by intraperitoneal inoculation of IGR-OV1 cells in nude rats. Animals were randomly assigned to one of the following groups: CO(2) laparoscopy (L), gasless laparoscopy (GL), midline laparotomy (ML), or general anesthesia as control (C). A 0.5 ml blood sample was taken in each case before and after experiment and tested with a novel assay, ISET (isolation by size of epithelial tumor cells), which isolates CTC by filtration on account of their size. Statistics were performed with the Fisher's and the Chi-square tests.

RESULTS

Ten rats were included in each group. We did not find any significant difference in CTC prevalence before and after surgery (2/14 versus 3/19, respectively, P = 1). Similarly, the three surgical accesses were equivalent with one post-experiment detection per group: 1/5 for L, 1/7 for ML, 1/7 for GL, and 1/6 for C (P = 0.9).

CONCLUSION

This trial did not show any deleterious effect of laparoscopy on CTC when compared to laparotomy.

Preoperative detection of peripherally circulating cancer cells and its prognostic significance in ovarian cancer☆

OBJECTIVES

Studies in several solid tumors have shown that the presence of occult metastasis in the bone marrow or peripheral blood is highly predictive of decreased disease-free and overall survival. Our objective was to determine the incidence of circulating ovarian or primary peritoneal cancer cells in the peripheral blood at the time of disease diagnosis, or recurrence, and to determine the prognostic significance of these occult metastasis.

METHODS

Peripheral blood was drawn preoperatively from 91 women thought to have newly diagnosed or recurrent epithelial ovarian or primary peritoneal carcinoma. All samples underwent a tumor-enriched immunocytochemical assay.

RESULTS

Sixty-four women were found to have epithelial ovarian or primary peritoneal cancer. Of the 64 women with cancer, 12 had evidence of circulating cancer cells in their peripheral blood (18.7%). Characteristics were compared between those with circulating cancer cells and those without, using Fisher's exact test or the Wilcoxon-Mann-Whitney test, as appropriate. Women with circulating cancer cells had statistically more grade 3 tumors than women without. At a mean follow-up of 18.7 months (SD 6.7 months), analysis using Kaplan-Meier estimation and the log-rank test indicated that survival curves did not differ between patients with and without circulating cancer cells.

CONCLUSIONS

Ovarian and primary peritoneal cancer, which historically has been thought to spread primarily by direct cell seeding throughout the abdominal cavity, can have circulating cancer cells in the peripheral blood. The clinical utility of identifying circulating cancer cells is yet to be defined.

Minimal residual disease in breast cancer and gynecological malignancies: phenotype and clinical relevance

In breast cancer, about 35% of patients without any clinical signs of overt distant metastases already have disseminated tumor cells in bone marrow aspirates at the time of primary therapy. A significant prognostic impact of these disseminated tumor cells has been shown by many international studies: patients with tumor cells in their bone marrow have a significantly worse prognosis than those without them. Even in malignancies where the skeletal system is not a preferred location for distant metastasis, such as ovarian cancer, early presence of minimal residual disease (MRD) is correlated with poor patient outcome. Thus, besides analysis of the primary tumor, detection of MRD can be used for assessment of patient prognosis and for prediction or monitoring of response to systemic therapy. Disseminated tumor cells are also the targets for novel tumor biological therapy approaches such as specific antibody-based therapies against target cell-surface antigens such as HER2, Ep-CAM (17-1A), and uPA-R. In breast cancer, a first antibody-based tumor therapy against HER2 (Herceptin) has already been approved for clinical use in recurrent disease. However, patient selection for such tumor biological therapies becomes rather difficult due to phenotype changes, which may manifest themselves as differences between primary lesion and disseminated tumor cells. Therefore, not only identification of disseminated tumor cells but even more so their characterization at the protein and gene levels have become increasingly important. In conclusion, characterization of tumor biological properties of disseminated tumor cells allows identification of patients with breast cancer or gynecological malignancies at risk for relapse who are likely to benefit from systemic treatment and/or novel tumor biological therapy approaches.

Patterns of disease recurrence influenced by hematogenous tumor cell dissemination in patients with cervical carcinoma of the uterus

BACKGROUND

The presence of isolated tumor cells (ITC) in the bone marrow at the time of primary diagnosis indicates an increased risk for subsequent development of distant metastases in various solid tumors. This study evaluates the prevalence and prognostic significance of ITC in patients with primary carcinoma of the cervix uteri.

METHOD

We immunocytochemically analyzed bone marrow aspirates of 130 patients with newly diagnosed carcinoma of the cervix uteri for the presence of cytokeratin(CK)-positive cells from May 1994 to January 2001. We used a quantitative immunoassay with the monoclonal anti-CK antibody A45-B/B3 and evaluated 2 x 10(6) bone marrow cells per patient. Patients were followed prospectively for a median of 43 (range, 1-85) months.

RESULTS

Isolated tumor cells were found in the bone marrow of 38 patients (29%). The presence of ITC did not correlate with the International Federation of Gynecology and Obstetrics (FIGO) tumor stage (P = 0.61), pelvic and paraaortal lymph node involvement (P = 0.41), histopathologic grading (P = 0.67), the histologic type of the carcinoma (P = 0.93), invasion of lymph nodes (P = 0.93) and blood vessels (P = 0.92), or with menopausal status (P = 0.17). The bone marrow status at the time of primary diagnosis did not correlate with the overall survival as estimated by Kaplan-Meier analysis (P = 0.30). However, distant metastases occurred in 5% of the patients (n = 5) with negative bone marrow status and in 15% of the patients (n = 6) with positive bone marrow status (P = 0.054). The median distant disease-free survival period was 78 months (95% confidence interval 73-82) in patients with negative bone marrow status and 72 months (95% CI 61-82) in patients with positive bone marrow status (P = 0.051). Multivariate analysis revealed the presence of ITC as a significant, independent risk factor for the subsequent development of distant metastases (relative risk 3.6, P = 0.046).

CONCLUSION

Despite the locoregional predominance of cervical carcinoma at the time of primary diagnosis, the presence of ITC in the bone marrow indicates an increased risk for the development of distant metastases. This information may prove useful to stratify patients for systemic treatment.

The Systemic Progression of Human Cancer: A Focus on the Individual Disseminated Cancer Cell—The Unit of Selection

The metastatic progression of solid tumors is discussed controversially. Because metastasis is usually lethal, it appears as an end point of successive cellular changes. This has led to the prevailing interpretation that genetic changes, in addition to those present in the most advanced clone of the primary tumor, are required to initiate invasion, dissemination, and growth at anatomically distant sites. It has become possible to detect and analyze single disseminated cancer cells at ectopic sites long before metastasis can be diagnosed by standard clinical techniques. Because the finding of single disseminated cancer cells correlates with the subsequent development of distant metastasis, these cells have been identified as the precursors of metastasis. Their direct molecular-genetic characterization, however, shows that dissemination occurs very early in the process of accumulation of genetic changes and suggests that metastases may seldom be derived from the dominant clone of the primary tumor. In contrast, it appears that cancer cell evolution explores a multitude of variant cells from which systemic cancer can develop independently. This review integrates data derived by different approaches into a model of systemic cancer progression.

Heterogeneous proliferative potential of occult metastatic cells in bone marrow of patients with solid epithelial tumors

Bone marrow is a major homing site for circulating epithelial tumor cells. The present study was aimed to assess the proliferative capacity of occult metastatic cells in bone marrow of patients with operable solid tumors especially with regard to their clinical outcome. We obtained bone marrow aspirates from 153 patients with carcinomas of the prostate (n = 46), breast (n = 45), colon (n = 33), and kidney (n = 29). Most of the patients (87%) had primary disease with no clinical signs of overt metastases [tumor-node-metastasis (TNM)-stage UICC (Union Internationale Contre le Cancer) I-III]. After bone marrow was cultured for 21-102 days under special cell culture conditions, viable epithelial cells were detected by cytokeratin staining in 124 patients (81%). The cultured epithelial cells harbored Ki-ras2 mutations and numerical chromosomal aberrations. The highest median number of expanded tumor cells was observed in prostate cancer (2,619 per flask). There was a significant positive correlation between the number of expanded tumor cells and the UICC-stage of the patients (P = 0.03) or the presence of overt metastases (P = 0.04). Moreover, a strong expansion of tumor cells was correlated to an increased rate of cancer-related deaths (P = 0.007) and a reduced survival of the patients (P = 0.006). In conclusion, the majority of cancer patients have viable tumor cells in their bone marrow at primary tumor diagnosis, and the proliferative potential of these cells determines the clinical outcome.