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The retention of circulating Walker-256 cells by Walker-256 tumours.

When Walker-256 cancer cells are injected into the portal veins of rats bearing Walker-256 tumours in their livers, the retention of the injected cancer cells by the tumours is considerably less than in the surrounding liver. After applying defined general criteria for "homing" phenomena to the data, it is concluded that compared with the liver, they demonstrate "antihoming". The observations are explained in terms of a deficient arrest process within the tumours.

Animals↗

Successful treatment of intraoperative pulmonary tumor embolism from renal cell carcinoma.

During left nephrectomy in a 35-year-old woman with a left renal cell carcinoma extending into the inferior vena cava (IVC) and right atrium, cardiac arrest occurred. Immediate transesophageal echocardiography demonstrated that the event was caused by a pulmonary tumor embolism. Emergent cardiopulmonary bypass (CPB) was established and the tumors in the pulmonary arteries were successfully removed. The left nephrectomy was completed. The patient recovered in the intensive care unit without any neurological deficit. A postoperative pulmonary perfusion scintigram showed no defect in the pulmonary circulation. Transesophageal echocardiography was useful for making a rapid diagnosis of an intraoperative pulmonary embolism originating from a tumor of the IVC or right atrium.

Adult↗

Intravasation-related metastatic factors in colorectal cancer.

Alterations in adhesion molecules, angiogenesis, and matrix metalloproteinases have been associated with metastasis and intravasation. The present study investigated the role of these metastatic factors in the context of primary colorectal tumor. Intravasated colorectal epithelial cells were detected by an RT-PCR assay, and the expression of E-cadherin, alpha-catenin, or beta-catenin as well as the vascularity of tumor were assessed by immunohistochemical staining. Activity of matrix metalloproteinase was assessed by gelatin zymography. The tumor venous blood was positive for guanylyl cyclase C (GCC) mRNA expression in 40 of 68 patients, but alteration in expression of E-cadherin, alpha-catenin, or beta-catenin was not significantly associated with the presence of colorectal epithelial cells in paired portal venous blood. Further, matrix metalloproteinase activity did not correlate with the presence of intravasated colorectal epithelial cells. Multivariate analysis demonstrated that the only factor associated with intravasated colorectal tumor cells was the vascularity of the tumor. Thus, metastasis of colon cancer may result from passive entry into the circulation secondary to angiogenic factors and does not appear to involve other metastatic factors studied in our experiments.

Adult↗

Quantitative RT-PCR assessment of melanoma cells in peripheral blood during immunotherapy for metastatic melanoma.

Circulating malignant cells in peripheral blood are thought to be precursors and surrogate markers of distant metastases and hence markers of a poor clinical outcome. In this study, we used the detection of MART-1 and tyrosinase (TYR) mRNA with a quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay to identify circulating melanoma cells. Blood samples were obtained from 35 patients with metastatic melanoma before, during and after treatment with interleukin-2, interferon-alpha and cisplatin. In addition, MART-1 and TYR protein was identified by immunohistochemistry in consecutive biopsies from 15 of the patients. Analysis of three daily blood samples for 3 days demonstrated that four out of 11 patients examined were negative for both markers on all occasions, and two patients were positive for both markers on all occasions but one. The remaining five patients showed sporadic low positive results for one or the other of the two markers. By comparing the immunohistochemistry results from consecutive biopsies with the RT-PCR results, we demonstrated that patients with MART-1 and TYR protein in their tumour cells had circulating MART-1 and TYR mRNA in 77% and 54% of the cases, respectively. During treatment, the majority of patients who were positive for MART-1 and TYR mRNA converted to being negative. However, these conversions did not significantly correlate with objective response. The presence of TYR mRNA in one of the first two samples showed a trend towards being an independent prognostic factor for poor survival.

Adult↗

Fibrinolytic activity of carcinoma of the colorectum.

Twenty patients with carcinoma, mostly of the colorectum, and five without malignant tumors who were used as controls, have been investigated to elucidate the relationship between tumor fibrinolytic activity and the release of circulating malignant cells. The nature of the tumor fibrinolytic activity has been considered. The most significant fibrinolytic activity was seen in blood draining from the tumors and was evident in 80 per cent. Circulating malignant cells were recovered from half the patients, and in those with significant blood fibrinolysis, recovery from the draining vein reached 89 per cent. The most undifferentiated tumors appeared to be more active and released more cells. Fibrinolytic activity of tumor tissue derives from inflammatory cells, dead tumor cells, avascular areas of the tumor and vascular endothelium and is probably proteolytic as well as purely fibrinolytic.

Colonic Neoplasms↗

Intraoperative massive pulmonary tumor embolism from clear cell sarcoma in the retroperitoneum: successful treatment using cardiopulmonary bypass.

Malignant neoplasms rarely extend into the inferior vena cava and up to the right side of the heart. Although massive pulmonary tumor embolism occurs relatively rarely, it can be a catastrophic problem. Intraoperative pulmonary tumor embolism and cardiac arrest occurred in a 68-year-old woman while dissecting the inferior vena cava to resect a pararenal tumor extending into the retrohepatic inferior vena cava. Abrupt arterial hypotension, tachycardia, and increased central venous pressure lead to the diagnosis of massive pulmonary tumor embolism. Emergency cardiopulmonary bypass was commenced under profound hypothermia and cardiac arrest. The tumors in the main pulmonary artery were extracted, and fragments of remnant tumor were retrieved by a vascular endoscope, a Fogarty catheter, and milking of the lung. Following embolectomy, the tumor in the retrohepatic to infrarenal inferior vena cava was removed and the primary tumor together with the infrarenal inferior vena cava was resected under hepatic vascular exclusion and partial cardiopulmonary bypass. The inferior vena cava below the renal veins was not reconstructed. The patient recovered with slight retrograde amnesia. A postoperative pulmonary perfusion scintigram showed no defect in the pulmonary circulation. She is well now 8 months after surgery. Safe prevention measures should be accomplished as a part of the perioperative management of patients with inferior vena cava tumor thrombus that may be fragile, and cardiopulmonary bypass should always be stand-by on surgery.

Aged↗

A polymerase chain reaction-based semiquantitative assessment of malignant melanoma cells in peripheral blood.

Malignant melanoma cells can be detected with high sensitivity in peripheral blood of patients using reverse transcription-PCR. The detection of tyrosinase mRNA that is actively expressed only in melanocytes and melanoma cells indicates the presence of melanoma cells in peripheral blood. As shown previously, tyrosinase transcripts can be found in a variety of patients with metastatic malignant melanoma. For semiquantitative analysis of these cells in peripheral blood and evaluation of possible influence of immunotherapy on the amount of circulating cells, we describe an assay combining reverse transcription-PCR and Southern blotting. In this system, the amount of circulating tumor cells was determined by interpolating the amplified tyrosinase signal strength of patient samples to an equivalent tyrosinase signal of diluted SK-mel 28 cells. We found that the amount of circulating tumor cells correlates with the tumor burden. Furthermore, in patients with regression of melanoma metastases after immunotherapy, a decrease of the amount of tumor cells in the peripheral blood was observed. Quantitative estimates of residual disease may be an accurate and sensitive predictor for the clinical course.

Base Sequence↗

The leptomeningeal vein. A site of re-entry of leukemic cells into the systemic circulation.

The possible routes of transvascular migration of leukemic cells were studied in guinea pigs with an L2C lymphoblastic cell-line inoculation leukemia. The leukemic infiltrates were found mostly in and around the superficial leptomeningeal veins, paralleling findings in human leukemia. Reconstructions, based on thin serial sections (Epon blocks), allowed us to conclude: (1) leukemic cells do proliferate under the vascular endothelium; (2) the endothelium when pushed away from its basement membrane degenerates and ultimately disintegrates; (3) junctions between adjacent endothelial cells tend to be preserved, even when the rest of the endothelial cytoplasm has disintegrated; (4) leukemic cells will eventually re-enter the circulation; (5) leukemic cells, either singly or in groups, cross through endothelial pores in otherwise intact endothelial cells, rather than through opened-up junctions. It is concluded that leukemic cells cross the endothelium either through endothelial pores, which they in some way engender, or through large gaps left by disintegrating endothelium, the latter possibly intravasation.

Animals↗

Expression of epithelial cell adhesion molecule in carcinoma cells present in blood and primary and metastatic tumors.

The epithelial cell adhesion molecule (EpCAM) is involved in homophilic cell-cell adhesion in normal epithelia and is frequently overexpressed in primary and metastatic adenocarcinomas. It has been postulated that during detachment and dissemination of tumor cells, EpCAM may be down-regulated. Circulating tumor cells (CTC) may demonstrate this phenomenon as they have successfully escaped their local microenvironment and entered the circulation. EpCAM expression of CTC was compared to tumor cells in paraffin-embedded tissue arrays containing various benign diseases and carcinomas. EpCAM expression on CTC was determined by flow cytometry (FCM) and by immunohistochemistry (IHC) in paraffin-embedded tissue. To permit comparison of FCM results to those derived by IHC, EpCAM was quantified on cancer cell lines by FCM and then paraffin-embedded cell-blocks of these lines were used as staining guides for IHC analysis of tissue arrays. By IHC, 97% (384/397) of solid tissues analyzed had detectable EpCAM, with 72% of tissues showing antigen expression levels of > or =400,000 EpCAM molecules per cell. FCM analysis of CTC from 100 metastatic carcinoma patients with > or =2 CTC/90 microl blood showed EpCAM expression ranging from 9,900 to 246,000 (mean 49,700) antigens per cell. EpCAM expression was approximately 10-fold lower on CTC as compared to primary and metastatic tissues, suggesting that EpCAM expression is transient and dependent upon the local micro-environment. This supports the hypothesis that this adhesion molecule is down-regulated on carcinoma cells in the circulation.

Animals↗

Detection and clinical implications of early systemic tumor cell dissemination in breast cancer.

Blood-borne distant metastasis is the leading cause of cancer-related death in breast cancer. The onset of this fundamental process can now be assessed in cancer patients using ultrasensitive immunocytochemical and molecular assays able to detect even single metastatic cells. Analyses of bone marrow (BM) samples show that disseminated cells are present in 20-40% of primary breast cancer patients without any clinical or histopathological signs of metastasis. The common homing of circulating breast cancer cells in BM is indicative for systemic tumor cell spread and predictive for growth of overt metastases in relevant organ sites such as bone, lung, or liver. Recent clinical studies involving more than 3000 breast cancer patients demonstrated that the presence of tumor cells in BM at primary diagnosis is an independent prognostic factor for unfavorable clinical outcome. To date, sampling of BM, however, is not a routine procedure in clinical management of breast cancer patients. Therefore, several research groups have developed sensitive assays for detection of circulating tumor cells in peripheral blood. Studies evaluating the clinical relevance of these blood assays are ongoing. Here, we will review the existing tumor cell assays and discuss their current clinical relevance and perspectives for the clinical management of breast cancer patients.

Antigens, Neoplasm↗

Reverse transcriptase polymerase chain reaction for prostate specific antigen in the management of prostate cancer.

PURPOSE: Polymerase chain reaction is a powerful tool for expanding minute quantities of deoxyribonucleic acid (DNA) for detailed study. Reverse transcriptase polymerase chain reaction (RT-PCR) involves the initial conversion of messenger ribonucleic acid (mRNA) to DNA, followed by the amplification of the DNA product for molecular analysis. The mRNA for prostate specific antigen (PSA) is expressed only by prostatic cells. RT-PCR offers a potentially more sensitive assay for the detection of cells expressing PSA mRNA in peripheral circulation or in extraprostatic tissues. The current status of RT-PCR in the amplification and detection of PSA gene expression in the management of prostate cancer is reviewed. MATERIALS AND METHODS: The literature was reviewed for available data using RT-PCR for detection of prostatic cells outside of the prostate. RESULTS: Amplification of mRNA by RT-PCR represents a highly sensitive method of detection of gene expression. A single cell expressing PSA among 10 to 100 million lymphocytes can be detected by the RT-PCR assay. This assay may detect extraprostatic or circulating prostatic cells in peripheral blood, lymph nodes and bone marrow in many patients with prostate cancer. Various studies have reported sensitivities of detection of PSA expressing cells in the peripheral blood ranging from 0 to 88%. This wide range in the sensitivity may be partly due to tremendous variation between the protocols used in each study. In patients with lymph node metastasis the RT-PCR assay appears more reliable than immunohistochemistry for identification of prostatic tissue in the lymph node. In some series analyses of radical prostatectomy specimens suggest a strong correlation between a positive RT-PCR result and capsular invasion by the tumor, while others do not support its use in determining pathological stage. In the majority of reports the RT-PCR assay was highly specific for detection of extraprostatic PSA expression in prostate cancer patients, and negative for detection in men with benign prostatic hyperplasia and in women. Sources of potential false-positive and false-negative results of this assay are identified and discussed. CONCLUSIONS: RT-PCR can detect PSA expressing cells that are otherwise undetectable by other means in patients with localized and metastatic cancers. This assay is highly specific, since PSA expressing cells were consistently undetectable in the peripheral circulation of patients without prostate cancer in most studies. Limited data to date suggest that this test may have a role in the staging of tumors before radical prostatectomy and in the serial followup of patients after treatment. RT-PCR may improve the detectability of lymph node metastasis over immunohistochemistry. Presently this test should remain a powerful research tool in the study of the biology and behavior of prostate cancer, and it should not be used to guide any clinical decision making. The use of this assay as a prognostic and management tool for prostate cancer is in the earliest stages.

Clinical Trials as Topic↗

Low dose daily rhGM-CSF application activates monocytes and dendritic cells in vivo.

Granulocyte macrophage colony stimulating factor (GM-CSF) is a powerful cytokine with multiple actions. We investigated the effects of low dose daily rhGM-CSF application on monocytes and peripheral circulating dendritic cells (DC) in malignant melanoma patients in vivo. Twenty patients were included; rhGM-CSF was given as daily subcutaneous injections for 14 days. A significant increase was noted in monocytes and granulocytes, starting on the 5th day. Expression of CD95 (Apo-1/Fas) and CD45RO on monocytes increased significantly on the 5th day, and CD4 expression on monocytes increased significantly on the 14th day. Peripheral circulating dendritic cells which were 0.94% in the beginning, increased to 1.35% (P<0.04) and to 1.96% (P<0.001) on days 5 and 14, respectively.

Adult↗

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.

Antineoplastic Combined Chemotherapy Protocols↗

Detection of neuroblastoma cells in blood by reverse transcriptase-polymerase chain reaction.

OBJECTIVE: To determine whether circulating tumor cells are present in patients with localized or disseminated neuroblastoma (NB). METHODS: Sixteen pediatric malignant tumor cell lines, including 10 NB, 4 primitive neuroectodermal tumor (PENT), 2 Wilms' tumor and 39 samples (tumor tissue, bone marrow and peripheral blood) from 8 patients with NB, were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) using two markers: neuroendocrine protein gene products 9.5 (PGP 9.5) and tyrosine hydroxylase (TH). RESULTS: Analysis of RT-PCR products by agarose electrophoresis demonstrated that in culture cell lines the specificity for NB was highest in TH (9/10 with NB, 3/4 with PNET, 0/2 with Wilms' tumor) and the sensitivity was highest in PGP 9.5 10(-7). PGP 9.5 and TH mRNA were undetectable in the peripheral blood mononuclear cells (PBMNC) from normal children. Expression of these markers in 8 patients with NB at diagnosis and during treatment was found positive in 5 out of 8, all had been proved paralleling with their disease status. Two of the 5 became negative after further treatment. CONCLUSIONS: These systems allow the detection of circulating NB cells with higher sensitivity and specificity. When RT-PCR is clinically used for the detection of NB cells in blood, that both PGP 9.5 and TH should be selected is recommended. The assessment of bone marrow alone might not be used as a single index of tumor dissemination.

Biomarkers, Tumor↗

Circulating tumor cells in patients with breast cancer: possible predictor of micro-metastasis in bone marrow but not in sentinel lymph nodes.

BACKGROUND: Blood and lymphatic circulation are the major routes during metastatic spread of breast cancer cells. Despite the predictive and prognostic value of bone marrow (BM) micro-metastasis, repeated and frequent BM aspirations may not be easily accepted by patients. We try to establish the role of circulating tumor cells as a predictor for micro-metastasis in BM and sentinel lymph node (SLN) as well as to identify the association between micro-metastasis in blood and lymphatic circulation. We prospectively studied 47 breast cancer patients without overt metastasis. Bilateral BM samples and blood samples were obtained before surgery and subsequently handled using magnetic-activated cell separation (MACS) followed by immunocytochemistry (ICC). SLN was examined by hematoxylin and eosin (H and E) staining and ICC. RESULTS: Blood and BM micro-metastasis were detected in 16 (35%) and 25 (54%) of 47 patients. SLN micro-metastasis were detected in 13 (27.7%) and 22 (46.8%) patients using H and E and ICC, respectively. All the patients with circulating tumor cells had micro-metastasis in BM, whereas 9 of 25 (36%) patients with micro-metastasis in BM had no circulating tumor cells (P < 0.001). On the other hand, there is no correlation between circulating tumor cells and micro-metastasis in SLNs detected by either H and E (P = 0.52) or ICC (P = 0.36). We found that the presence of circulating tumor cells might predict BM micro-metastasis but not SLN micro-metastasis. It is also interesting to find that the presence of SLN micro-metastasis does not necessarily correlate with the presence of micro-metastasis in BM and blood.

Adult↗

Evaluation of a panel of tumor markers for molecular detection of circulating cancer cells in women with suspected breast cancer.

PURPOSE: We examined the feasibility of using molecular characterization of circulating tumor cells as a method for early detection of breast cancer. RESEARCH DESIGN: Women without a prior history of cancer who had a breast abnormality detected on imaging followed by a breast biopsy were enrolled in this study. Density gradient centrifugation and immunomagnetic capture were used to enrich for epithelial cells from approximately 20 mL of blood. Real-time reverse transcription-PCR was used to quantitate the expression levels of the highly breast-specific genes, mammaglobin, gamma-aminobutyric acid type A receptor pi subunit (GABA A(pi)), B305D-C, and B726P in the epithelial cell-enriched samples. RESULTS: The assay was technically feasible in 154 of 199 accrued patients. From their clinical assessment, 100 patients had benign breast disease, 10 patients had ductal carcinoma in situ, and 44 patients had invasive breast cancer. We constructed a diagnostic test that classified patients with mammaglobin levels of at least 32.2 copies/pg beta-actin (units) in their circulating epithelial cells as positive for invasive breast cancer. This resulted in a sensitivity and specificity of 63.3% and 75.0%, respectively. A diagnostic test that classified patients as positive for invasive breast cancer when either mammaglobin levels were >46.3 units or B305D-C levels were >11.6 units increased the sensitivity and specificity to 70.5% and 81.0%, respectively. In the latter test, 12 of the 14 node-positive breast cancer patients were correctly identified. Including GABA A(pi) and B726P in the test did not increase its diagnostic potential. CONCLUSIONS: These results suggest that molecular characterization of circulating epithelial cells using mammaglobin and B305D-C offers potential for early detection of invasive breast cancer.

Adult↗

Metastatic inefficiency in mice bearing B16 melanomas.

When injected i.v. into mice, the F10 subline of B16 melanoma cells produced significantly more lung tumours over a 3-week period than cells of the F101.r-6 subline. However, in animals bearing intramuscular tumours produced by these sublines, the high pulmonary-colonization potential of the F10 cells was not realized, and no significant differences in natural pulmonary metastasis formation were observed in animals with untreated primary cancers, even when they progressed to the moribund state. Massage of i.m. tumours derived from the two sublines produced no change in metastasis and no changes in the numbers of cancer cells in the blood detectable by bioassay. In contrast, massage increased metastasis from tumours derived from an invasive BL6 subline and B16 wild-type cells and, in the case of the wild-type, the numbers of circulating cancer cells. In vitro experiments show that blood cells from non-tumour-bearing animals are toxic to both sublines; but less to F10 than to F101.r-6. In addition, after i.v. injection of radiolabelled cells, more of the F10 subline were retained in the lungs of recipients than the F101.r-6. In spite of these apparent metastatic advantages of the F10 subline following intravasation, the incidence of natural metastases from i.m. F10 and F101.r-6 tumours was similar, suggesting that substantially fewer F10 than F101.r-6 cells gained access to the circulation. Thus, the higher colonization potential of the F10 cells was not matched by its intravasation potential, since metastatic efficiency is determined by the least efficient step in the metastatic process.

Animals↗