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Tumor cell and host properties affecting the implantation and survival of blood-borne metastatic variants of B16 melanoma.

The organ distribution, arrest and survival of [125I]5-iodo-2'-deoxyuridine-labeled B16 melanoma cells with low (B16-F1) or high (B16-F10) metastatic potential were studied in a variety of normal and immunosuppressed syngeneic C57BL/6 mice, allogeneic A mice, and athymic nude NIH Swiss mice and their immunocompetent littermates. In addition, the in vitro aggregation properties of these tumor cells with various host organ cells in suspension were examined. Tumor cell arrest and survival following i.v. injection occurred at significantly higher rates in normal mice than in immune-depressed animals irrespective of strain, and, two weeks later, significantly more tumor colonies were found in the normal animals. In syngeneic or allogeneic animals, B16-F10 cells were arrested, survived and formed significantly more gross pulmonary tumors than B16-F1 cells. B16-F10 cells also aggregated in vitro with purified organ cells in suspension obtained from either syngeneic or allogeneic mice at a greater rate than B16-F1 cells. These results indicate that although host properties can affect the arrest and survival of circulating tumor emboli, they do not diminish or abolish the biological differences between the high and low metastatic variant B16 lines.

Animals↗

Detection of melanocytes from uveal melanoma in peripheral blood using the polymerase chain reaction.

PURPOSE: Uveal melanoma is the most common intraocular malignancy in adults and can cause loss of vision in the affected eye and death from metastasis, usually to the liver. The techniques currently used to detect cellular dissemination from the tumor are inadequate, and lack the sensitivity required for the detection of low levels of melanocytes in the peripheral blood of patients. The detection of circulating melanocytes is important as an early indication of the possibility of metastasis. METHODS: The viability of reverse transcription/polymerase chain reaction amplification of the tyrosinase gene to detect circulating melanocytes was examined as a first sign of dissemination from uveal melanoma. RESULTS: It was shown that it is possible to detect as few as ten circulating melanocytes in 5 ml of blood. Blood-borne dissemination was also detected in three of six patients with uveal melanoma examined. Two of these patients had clinically confirmed widespread metastases. A positive result was also recorded in one patient in whom there was no other evidence for tumor dissemination. Overt metastatic disease developed in this patient 9 months after blood collection. CONCLUSIONS: The success of this technique has important implications for the detection of circulating tumor cells from uveal melanoma, as an early indication of dissemination. This may be important when considering the administration of adjuvant therapy.

Adult↗

Value of the preoperative detection of prostate-specific-antigen-positive circulating cells by nested RT-PCR in patients submitted to radical prostatectomy.

OBJECTIVE: To assess the value of the detection of circulating prostate cells [prostate-specific antigen (PSA) positive] by reverse-transcriptase nested polymerase chain reaction (nested RT-PCR) to improve the staging of clinically localized prostate cancer. METHODS: Nested PCR was performed on blood samples of 29 patients submitted to radical prostatectomy for clinically localized (T1-T2) prostate cancer. Nine patients with various benign urologic diseases comprised the negative control group. Incubation was for 25 cycles for each PCR, using beta 2-microglobulin to test the integrity of RNA samples. Each sample was tested in quadruplicate and analyzed by agarose gel electrophoresis, blotted and hybridized with specific internal primers. Nested PCR results were compared with the pT stage of the prostate specimen, processed according to the Stanford method. RESULTS: In 6 out of 29 patients (20.7%) with clinically localized prostate cancer, circulating prostate cells were detected by nested PCR. There was no relationship between pathologic stage and RT-PCR results. Eleven out of 14 pT2 patients (78.6%) were PCR negative and only 3 out of 15 pT3 patients (20%) were PCR positive. All control samples were PCR negative. CONCLUSIONS: In selected patients with T1-T2 prostate cancer, there was no relationship between pathologic stage and the presence of circulating PSA-positive cells detected by nested PCR. However, in 20.7% of patients with clinically localized prostate cancer, circulating prostate cancer cells were detected. A further follow-up based on PSA is necessary to clarify the clinical relevance of this biologic anomaly.

Aged↗

Increased expression of apoptosis inhibitor protein XIAP contributes to anoikis resistance of circulating human prostate cancer metastasis precursor cells.

Survival in lymph or blood is an essential prerequisite for metastasis of carcinoma cells to distant organs. Recently, we reported isolation and initial biological characterization of circulating metastatic cells in a fluorescent, orthotopic, metastatic nude-mouse model of human prostate cancer. Here we show that the metastatic human prostate carcinoma cells selected for survival in the circulation have increased resistance to anoikis, which is apoptosis induced by cell detachment. Using gene silencing and gene transfer techniques, we show that increased expression of the apoptosis inhibitory protein XIAP contributes to anoikis resistance of the circulating metastatic human prostate carcinoma cells. We also provide initial preclinical data on the antimetastatic efficacy of recently discovered small-molecule antagonists of XIAP.

Anoikis↗

Auer rod-like inclusions in circulating lymphoma cells.

Circulating malignant lymphocytes from a 55-year-old woman with small cleaved follicular center cell lymphoma contained azurophilic splinter-shaped cytoplasmic inclusions. By light microscopic and ultrastructural criteria, these structures closely resembled Auer rods found in acute myeloid leukemia; however, the authors could not find cytochemical evidence of lysosomal origin (results were negative for myeloperoxidase, Sudan black B, acid phosphatase, and periodic acid-Schiff). Immunostaining and flow cytometric analysis confirmed a monoclonal IgM-kappa immunophenotype of the circulating malignant lymphoid cells. The inclusions did not show specific immunoglobulin staining by light microscopic or electron microscopic immunostaining techniques. The authors conclude that these membrane-bound inclusions probably represent aberrant lysosomes in the malignant cells.

Female↗

Transcriptional complementarity in breast cancer: application to detection of circulating tumor cells.

BACKGROUND: We used a combination of genetic subtraction, silicon DNA microarray analysis, and quantitative PCR to identify tissue- and tumor-specific genes as diagnostic targets for breast cancer. METHODS AND RESULTS: From a large number of candidate antigens, several specific subsets of genes were identified that showed concordant and complementary expression profiles. Whereas transcriptional profiling of mammaglobin resulted in the detection of 70% of tumors in a panel of 46 primary and metastatic breast cancers, the inclusion of three additional markers resulted in detection of all 46 specimens. Immunomagnetic epithelial cell enrichment of circulating tumor cells from the peripheral blood of patients with metastatic breast cancer, coupled with RT-PCR-based amplification of breast tumor-specific transcripts, resulted in the detection of anchorage-independent tumor cells in the majority of patients with breast cancer with known metastatic disease. CONCLUSION: Complementation of mammaglobin with three additional genes in RT-PCR increases the detection of breast cancers in tissue and circulating tumor cells.

Breast Neoplasms↗

Prognostic value of postoperative detection of blood circulating tumor cells in patients with colorectal cancer operated on for cure.

OBJECTIVE: To assess whether postoperative detection of circulating tumor cells in peripheral blood influenced the prognosis of patients with colorectal cancer after radical surgery. SUMMARY BACKGROUND DATA: In a previous study, the authors demonstrated that baseline detection of blood circulating tumor cells does not have prognostic significance in patients with colorectal cancer. However, surgical procedures may increase tumor cell detachment and mobilization. METHODS: Sixty-six patients with histologically confirmed colorectal cancer operated on for cure were included in this study. Circulating tumor cells were detected by means of reverse transcriptase-polymerase chain reaction targeting to carcinoembryonic antigen messenger RNA in peripheral blood samples obtained 24 hours after surgery. Endpoints of the study were tumor recurrence, overall survival, and cancer-related survival. Univariate (Kaplan-Meier method) and multivariate (Cox regression model) analyses were performed. RESULTS: After a median follow-up of 36 months, 15 patients (23%) had tumor relapse and 14 had died (21%), 8 of them from a cancer-related cause. Cox regression analysis identified lymph node metastases and gender as independent predictors of tumor recurrence and cancer-related survival, whereas overall survival was dependent on the degree of differentiation of the primary tumor. More importantly, the presence of circulating tumor cells after surgery had no prognostic influence on tumor recurrence, overall survival, or cancer-related survival. CONCLUSIONS: Postoperative detection of blood circulating tumor cells had no prognostic significance in patients with colorectal cancer operated on for cure.

Aged↗

Molecular markers in blood as surrogate prognostic indicators of melanoma recurrence.

Improvement is needed in the ability to evaluate the prognosis of melanoma patients who are clinically disease-free but likely to develop recurrent metastatic disease. The detection of circulating melanoma cells in blood is a potential surrogate marker of subclinical residual disease. We assessed the prognostic clinical utility of a multimarker melanoma reverse transcriptase-PCR (RT-PCR) assay using blood of 46 patients who were clinically disease-free. All patients were followed up for more than 4 years for disease recurrence. There was a significant correlation between number of RT-PCR markers present in blood and American Joint Committee on Cancer stage (P = 0.009). The number of RT-PCR markers detected in blood was an independent prediction factor of disease recurrence in a Cox proportional hazard model (P = 0.02). A risk factor model using American Joint Committee on Cancer stage and number of positive RT-PCR markers significantly predicted disease recurrence in 2, 3, and 4 years of follow-up. These studies demonstrate that molecular detection of circulating melanoma cells may be of significant prognostic value in determining early disease recurrence and may be useful for stratifying patients for adjuvant therapy.

Biomarkers, Tumor↗

Detection of circulating tumor cells in colorectal cancer by immunobead-PCR is a sensitive prognostic marker for relapse of disease.

BACKGROUND: Recurrent and metastatic carcinoma of the colorectum remains a major problem, with survival at 5 years post curative resection still only about 50%. Moreover, up to 30% of patients who present with early stage disease also relapse and die within 5 years, suggesting the presence of micrometastatic disease at diagnosis. One route of metastatic spread is via the blood stream, hence the detection of tumor cells in blood is likely to provide an important predictive tool with respect to relapse of disease. We have developed a sensitive molecular technique to identify tumor cells in blood using mutations in codon 12 of the K-ras gene as a marker. MATERIALS AND METHODS: Twenty-seven patients whose tumor carried a mutation in codon 12 of K-ras were studied for the presence of tumor cells in perioperative peripheral blood samples. Immunomagnetic beads, labeled with an epithelial-specific antibody, were used to harvest epithelial cells from blood. K-ras mutations were identified in this selected population using a polymerase chain reaction (PCR)-based analysis (immunobead-PCR). RESULTS: Circulating K-ras mutant cells were detected in 9 or 27 patients; seven of these nine patients have since died due to recurrent or metastatic disease. Mutant cells were not detected in 18 patients, and 16 or 18 have remained disease free (median follow-up: 16 months; range: 7-42 months). Kaplan-Meier analysis showed that detection of K-ras mutant cells in bloods was associated with significantly reduced disease-free survival (p = 0.0001). CONCLUSION: This study indicates that detection of circulating tumor cells perioperatively by immunobead-PCR provides a sensitive prognostic marker for recurrent and metastatic colorectal cancer.

Aged↗

Biological behavior of malignant melanoma cells correlated to their survival in vivo.

Successive B16 melanoma tumor lines were selected for their ability to form pulmonary tumor nodules. This was accomplished by injecting tumor cells i.v. into syngeneic C57BL/6 mice and 2 to 3 weeks later collecting the secondary tumor growths and placing them into tissue culture. These tumor cells were then injected i.v. into new syngeneic mice and the process was repeated several times. With each successive tumor line the number of experimental lung tumor nodules was significantly increased. The B16 lines were found to be stable in their metastatic properties even after many subculturings in vitro. These studies demonstrated that tumor cells that succeed in forming pulmonary tumor colonies also had increased invasive properties into normal tissues when implanted s.c. In addition, the tumor cell lines were prelabeled in vitro with [125-I]-5-iodo-2'-deoxyuridine and suspensions of labeled cells were injected i.v. into normal syngeneic hosts. Animals were killed at intervals afterwards, and the lungs and blood were processed and monitored for radioactivity. At any time interval, the lungs of mice treated by injections of cells of high metastatic yield contained more tumor cells. The differences in tumor cell numbers in the lungs were most pronounced immediately following i.v. injection. These results suggest that an increased initial arrest of highly metastatic cells in a capillary bed may be a major factor in their increased survival. Low numbers of normal lymphocytes or lymphocytes from syngeneic mice immunized to the B16 melanoma, when mixed in vitro with the tumor cells, lead to the formation of multitumor cell-lymphocyte clumps. The degree of clumping was related to both the type of the metastatic tumor line and/or the syngeneic lymphocyte. These results support the hypothesis that the survival of invasive and/or circulating malignant tumor cells is not a random phenomenon; rather it appears that malignant cells possess unique qualities which allow for their survival.

Animals↗

Discordance between K-ras mutations in bone marrow micrometastases and the primary tumor in colorectal cancer.

PURPOSE: To study bone marrow micrometastases from colorectal cancer patients for the presence of K-ras mutations and to compare their genotype with that of the corresponding primary tumor. PATIENTS AND METHODS: Bilateral iliac crest aspiration was performed in 51 patients undergoing surgery for colorectal cancer, and bone marrow micrometastases were detected by immunohistochemistry. The presence of K-ras mutations was determined by single-strand conformation polymorphism analysis on both primary tumors and paired bone marrow samples and was confirmed by sequencing. RESULTS: In six patients with primary tumor mutations, it was possible to amplify a mutated K-ras gene also from the bone marrow sample. In three of those patients the pattern of K-ras mutations differed between both samples, in two patients the mutation was identical between the bone marrow and its primary tumor, and in one patient the same mutation plus a different one were found. Fifteen of 17 K-ras mutations found in primary tumors were located in codon 12, whereas in bone marrow, five of seven mutations were found in codon 13 (P =.003). CONCLUSION: Our results demonstrate that, at least for K-ras mutations, disseminated epithelial cells are not always clonal with the primary tumor and they question the malignant genotype of bone marrow micrometastases. They also indicate that different tumoral clones may be circulating simultaneously or sequentially in the same patient. Analysis of the type of mutations suggests that cell dissemination might be an early event in colorectal carcinogenesis.

Aged↗

Peripheral blood tumor cell load reflects the clinical activity of the disease in patients with carcinoma of the breast.

Peripheral blood was examined for the presence of tumor cells at multiple time points over a one-year period in 45 patients with a history of surgical resection of breast carcinoma. The number of circulating epithelial cells in 8 of 8 patients with clinically active disease concurred or preceded changes in the disease activity. In 12 of 37 patients with no evidence of disease epithelial cells were found at least at one time point at a frequency larger than the control group. One patient had a recurrence of the breast cancer 4 weeks after circulating epithelial cells were detected in the blood.

Antineoplastic Agents↗

Acute neoplastic arterial embolism after pneumonectomy.

Intra-arterial tumour embolism after pneumonectomy is a known but rare complication. It arises because of tumour involvement of pulmonary veins. Usual outcome of this complication is grave when embolism is to a major vessel. If embolism occurs in a peripheral circulation, timely intervention can avoid significant morbidity. We report a case where embolisation occurred in both the femoral arteries. Emergency embolectomy was done successfully avoiding major complication.

Acute Disease↗

Bioassay for quantitating circulating tumor cells in a syngeneic mouse tumor system.

A bioassay is described for the quantitation of tumor cells in blood specimens in a syngeneic mouse tumor system (Sarcoma 1 in A/J mice). The procedure involved i.m. injection of blood containing tumor cells into each thigh of normal recipient mice and, 14 days later, examination of the sites of injection for evidence of tumor growth. For each specimen, a tumor index was calculated based on the number of tumor takes and the size of the tumors. The number of tumor cells was determined by comparison with tumor indices from standard specimens with known number of tumor cells. Optimal conditions for this assay were investigated. We have used this bioassay to quantitate tumor cells in the venous blood of tumor-bearing animals under various treatments and manipulations. At the same time, the incidence of regional node metastasis was obtained by direct histological examination. Surgical removal of a well-established primary tumor enhanced the dissemination of the tumor, as evidenced by an increased incidence in regional node metastasis and an increase in the number of tumor cells reaching the venous circulation. Similar results were obtained when the tumor-bearing feet were ligated to produce ischemia of the primary tumor. Repeated physical trauma to the primary tumor resulted in increased dissemination of tumor cells into the venous circulation, but it did not increase the incidence of regional node metastasis. Immunosuppression of the tumor-bearing animals increased the dissemination of tumor cells, whereas immunostimulation decreased the dissemination.

Animals↗

Detection and quantification of circulating tumor cells in patients with esophageal cancer by real-time polymerase chain reaction.

Polymerase chain reaction (PCR) amplification was used for detecting circulating tumor cells. However, PCR was so sensitive that it detected a very low level of mRNA with no relevance to tumor cells. We analyzed the degree of micro-tumor spread in esophageal cancer patients using quantitative PCR. Samples were collected from 28 patients and 35 controls. Real-time quantitative PCR (LightCycler) was employed for the detection of carcinoembryonic antigen (CEA) and cytokeratin 20 (CK-20). In the CEA and CK-20 mRNA assays, 7 and 3 out of 28 patients, respectively, showed higher mRNA levels in peripheral blood than the normal range based on values of controls (mean+/-2SD). Eleven out of 19, 4 out of 14, and 2 out of 5 patients showed higher CEA mRNA levels in the samples from tumor drainage vein, costal bone marrow, and thoracic duct lymph, respectively. One of the 7 patients who showed higher CEA mRNA levels in pretreatment peripheral blood is currently free from disease. These findings reveal that quantitative PCR can discriminate high levels of cancer-specific expression from low levels of illegitimate expression in blood. They also suggest that the identification of circulating tumor cells by the CEA mRNA assay is a reliable means of predicting early recurrence.

Aged↗

Frequency and significance of tumor thrombi in esophageal varices in hepatocellular carcinoma associated with cirrhosis.

Histological examination of the wall of the stomach and esophagus in patients with hepatocellular carcinoma associated with cirrhosis demonstrated intravariceal tumor thrombi in 13 (23.6%) of 55 cases studied. There were distant hematogenous metastases in 31 of them, of whom 12 (38.7%) had variceal tumor thrombi. Tumor thrombi were of varying sizes, and tumor cells appeared either intact, degenerated or necrotic. In seven cases, there was a firm adhesion of thrombi onto the vascular wall suggesting possible mural infiltration, but no extravascular metastases were noted grossly. These findings suggest a possibility of metastasis of hepatocellular carcinoma to the stomach and esophagus via the portal vein. It is also suggested that the degree of varices is not increased by tumor thrombus formation per se, and that both varices and tumor thrombi are due to extensive hepatofugal collateral circulation. Considering that 12 of 13 cases of intravariceal tumor thrombi had lung metastases, a portal vein-varices-lung route is possible for lung metastasis beside the established route through the hepatic vein in hepatocellular carcinoma.

Adult↗

The prognostic significance of circulating tumour cells: a five-year follow-up study of patients with cancer of the breast.

One hundred and sixteen patients with proved cancer of the breast were followed up for five years to detect circulating tumour cells. Such cells were found in 61 patients, but, irrespective of the stage of the disease, the five-year survival rate in these was not significantly different from those in whom no tumour cells were found. The higher incidence of patients without circulating tumour cells in Stage I was not sufficient to influence the survival rate of the whole group. While the validity of the identification of these cells is questionable, the results of this study indicate that the presence or absence of tumour cells in the blood is of no prognostic significance.

Breast Neoplasms↗