SM047 immunoreactivity in peritoneal fluids

SM047 is a recently developed monoclonal antibody generated against an ovarian adenocarcinoma cell line. A recent immunohistochemical study has shown that SM047 is strongly expressed in tissue sections of most ovarian serous adenocarcinomas. This study aimed to ascertain whether SM047 staining is of value in cytological preparations of peritoneal fluid. A total of 206 consecutive peritoneal fluids were stained immunocytochemically with SM047, CA125, monoclonal carcinoembryonic antigen (mCEA), Ber-EP4 and cytokeratins (CK7 and 20). SM047 positivity was present in reactive mesothelial cells in 117 of 141 (83%) benign cases in which these were present. SM047 positive tumour cells were present in 22 of 23 (96%) ovarian serous adenocarcinomas and in small numbers of gastric adenocarcinomas (two of three), mesotheliomas (one of two) and pancreatic adenocarcinomas (one of one). All six colorectal and two breast adenocarcinomas were negative with SM047. Reactive mesothelial cells in all cases were positive with CK7 and in most cases with CA125. They were negative with CEA, Ber-EP4 and CK20. All adenocarcinomas were positive with Ber-EP4 and mesothelial cells were always negative. All colorectal adenocarcinomas were positive with CK20. This study shows that SM047 staining may be of value in the diagnosis of an ovarian serous adenocarcinoma in peritoneal fluids. Negative staining helps to exclude a primary ovarian serous adenocarcinoma and is characteristic of colorectal adenocarcinoma. The small numbers of other malignancies in the study precludes a judgement of the value of SM047 staining in these neoplasms. SM047 staining may be useful, as part of a larger panel, in the work up of patients with peritoneal effusions.     

Tumor markers in patients with chronic renal failure.

In order to evaluate the specificity of tumor markers in chronic renal failure, we have determined serum levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19.9 (CA 19.9), carbohydrate antigen 50 (CA 50), alphafetoprotein (AFP), neuron-specific enolase (NSE), prostatic acid phosphatase (PAP), prostatic specific antigen (PSA), squamous cell carcinoma antigen (SCC), carbohydrate antigen 15.3 (CA 15.3) and carbohydrate antigen 125 (CA 125) in 30 patients with chronic renal failure and in 36 hemodialyzed patients without clinical evidence of neoplasia. CEA, CA 50, NSE and SCC frequently show increased serum levels, suggesting a renal metabolism, while others remain, generally, within the normal levels.     

Proteomics in prostate cancer biomarker discovery

Despite advances in molecular medicine, genomics, proteomics and translational research, prostate cancer remains the second most common cause of cancer-related mortality for men in the Western world. Clearly, early detection, targeted treatment and post-treatment monitoring are vital tools to combat this disease. Tumor markers can be useful for diagnosis and early detection of cancer, assessment of prognosis, prediction of therapeutic effect and treatment monitoring. Such tumor markers include prostate-specific antigen (prostate), cancer antigen (CA)15.3 (breast), CA125 (ovarian), CA19.9 (gastrointestinal) and serum α-fetoprotein (testicular cancer). However, all of these biomarkers lack sensitivity and specificity and, therefore, there is a large drive towards proteomic biomarker discovery. Current research efforts are directed towards discovering biosignatures from biological samples using novel proteomic technologies that provide high-throughput, in-depth analysis and quantification of the proteome. Several of these studies have revealed promising biomarkers for use in diagnosis, assessment of prognosis, and targeting treatment of prostate cancer. This review focuses on prostate cancer proteomic biomarker discovery and its future potential.     

Immunophenotyping of human HT29 colon cancer cell primary tumours and their metastases in severe combined immunodeficient mice

The immunophenotype of HT29 human colon cancer cells implanted into severe combined immunodeficient mice was assessed in primary tumours and their metastases in the lungs using an indirect immunohistochemical method. After primary tumours were surgically removed, the metastases were given time to develop, thus paralleling the clinical situation. While vimentin was negative in both primary and secondary tumours, E-cadherin was present as membrane-bound labelling in the primary tumours only. Whereas the markers p53, MIB1, PCNA and CEA were consistently positive in both primary and metastatic tumours, CD44 variant 6 and CA125 were negative in metastases but positive in the primary tumours. There was a significant increase in the percentage of cells labelled for p53 in the primary tumours compared with the metastases. For the proliferation markers, there was no significant difference in labelling between primary tumours and metastases for MIB1. Of the cytokeratins examined, CK 20 gave the strongest and most consistent reaction in both primary and secondary tumours. The results indicate that, for certain immunohistochemical markers, results are the same in both primary tumours and metastases. Hence, in these cases, antigens that are expressed on the primary tumour as well as on the metastases can serve as target molecules for immunologically based forms of treatment of metastases. This revised version was published online in November 2006 with corrections to the Cover Date.     

Immunophenotyping of human HT29 colon cancer cell primary tumours and their metastases in severe combined immunodeficient mice

The immunophenotype of HT29 human colon cancer cells implanted into severe combined immunodeficient mice was assessed in primary tumours and their metastases in the lungs using an indirect immunohistochemical method. After primary tumours were surgically removed, the metastases were given time to develop, thus paralleling the clinical situation. While vimentin was negative in both primary and secondary tumours, E-cadherin was present as membrane-bound labelling in the primary tumours only. Whereas the markers p53, MIB1, PCNA and CEA were consistently positive in both primary and metastatic tumours, CD44 variant 6 and CA125 were negative in metastases but positive in the primary tumours. There was a significant increase in the percentage of cells labelled for p53 in the primary tumours compared with the metastases. For the proliferation markers, there was no significant difference in labelling between primary tumours and metastases for MIB1. Of the cytokeratins examined, CK 20 gave the strongest and most consistent reaction in both primary and secondary tumours. The results indicate that, for certain immunohistochemical markers, results are the same in both primary tumours and metastases. Hence, in these cases, antigens that are expressed on the primary tumour as well as on the metastases can serve as target molecules for immunologically based forms of treatment of metastases. This revised version was published online in November 2006 with corrections to the Cover Date.     

Tumor markers in squamous cell carcinoma of esophagus: immunometric assay in cytosol and membrane fraction

Carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA), ferritin, and the monoclonal antibody-detected tumor-associated antigens CA19.9 and CA50 were measured by radioimmunoassay in tissue fractions of carcinoma and normal esophageal mucosa from 59 patients with untreated primary squamous cell carcinoma of the esophagus. Tumor markers were measured in cytosol (118 samples) and in a membrane-enriched fraction (32 samples). CEA, TPA and ferritin were detected in almost all the cytosol samples evaluated, CA19.9 and CA50 in 66% and 50% of cases respectively. Ferritin was significantly higher in carcinoma than in normal mucosa. The cytosol concentrations of CEA, TPA, CA19.9 and CA50 were not significantly different in carcinoma and normal tissue. Concentrations of CEA, CA19.9 and CA50 in the membrane fraction tended to be higher in normal tissue than in carcinoma, whereas the cytosol-to-membrane ratio was significantly higher in carcinoma. For CEA, CA19.9 and CA50, the phenotypic pattern of the malignant transformation seems to involve a different intracellular distribution rather than a quantitative change. No correlations were found between tissue and serum concentrations of the tumor markers, the former being related to the phenotypic characteristics of the tumor, the latter to the tumor burden.     

Validating a custom multiplex ELISA against individual commercial immunoassays using clinical samples

The measurement of multiple antigens in a single sample poses clinical and methodological challenges. Here we describe the validation of a multiplexed sandwich enzyme-linked immunosorbent assay (ELISA) array (microELISA) of nine antigens. The antigens tested simultaneously were: alpha-fetoprotein (AFP), prostate specific antigen (PSA), carcinoembryonic antigen (CEA), cancer antigen 125 (CA 125), CA 15-3, CA 19-9, beta-human chorionic gonadotropin (beta-hCG), luteinizing hormone (LH), and follicle stimulating hormone (FSH). At least 44 clinical samples were tested for each antigen. microELISA results for the nine antigens were then compared with clinical laboratory results obtained for the same antigens in individual chemiluminescent immunoassays. The microELISA had a coefficient of variation (cv) of 7.3% within an assay and 12.6% for assays run at different times. A statistical comparison of results from the microELISA with results from the clinical laboratory showed that the assays had correlation coefficients ranging from 0.99 to 0.76, and Deming regression demonstrated that four of the nine assays were high-quality assays and not statistically different to the individual assays. To determine if the differences in the assays were due to methodology, the microELISA was also compared with conventional ELISAs using identical antibodies and reagents. Deming regression demonstrated that five of the eight assays were high-quality, indicating that a poor correlation between a microELISA and an individual immunoassay are partly due to antibody differences.     

Improved radioimmunodetection of tumours using liposome-entrapped antibody

The discrimination of radioimmunodetection of tumours is reduced by the presence of circulating radiolabelled antibody (primary antibody). We have prepared liposomes containing an antibody to the primary antibody (secondary antibody), with the intention of complexing and delivering to the liver primary antibody which is not associated with the tumour. In mice bearing xenografts of human tumours which secrete the marker carcinoembryonic antigen (CEA), liposomally entrapped secondary antibody was able to reduce the blood levels of 125I-labelled anti-CEA within 2 h, without reducing the amount of anti-CEA bound to the tumour. We therefore suggest that the use of liposomally entrapped secondary antibody would improve the diagnostic potential of radioimmunodetection of tumours and their metastases.     

Relationship of CA 125 and CA 19.9 with lung carcinoma histological subtype: preliminary study

The aim of this work was to study the possible utility of simultaneous determination of CA 125 and CA 19.9 in patients with lung cancer. Serum levels of both markers were studied in 87 patients without metastases (Mo), 72 patients with distant metastases (MT) and 15 cases without clinical evidence of disease after primary treatment (NED). Sixty-five tumors were epidermoid, 34 were adenocarcinomas, 24 were cell undifferentiated carcinomas and 51 were small-cell carcinomas. Sera from 75 healthy subjects and 20 patients with benign lung disease were used as controls. The cut-off values used were 35 and 37 U/ml for CA 125 and CA 19.9, respectively. CA 125 and CA 19.9 serum levels were within normal limits in all control patients. In NED patients these markers were not elevated, except in one with chronic liver disease who showed elevated CA 19.9 (76 U/ml). Twenty-five percent of Mo lung cancer patients and 40.3% of MT cases had CA 19.9 over 37 U/ml. Abnormally high levels of CA 125 were found in 18.7% and 22.9% of Mo and MT patients, respectively. Sixty percent of patients with large cell undifferentiated carcinoma had elevated CA 125 (mean 176 U/ml) compared to 15.4% of patients with all other histological types of tumors combined (54.3 U/ml, p less than 0.01). CA 19.9 serum levels were also more often elevated in patients with large cell undifferentiated carcinomas (50%, 7/14 cases) than in other histological types (30%, 36/120 patients), but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of a new two-site assay for CA125 antigen

As appropriate surgery and chemotherapy can improve both quality of life and survival of patients with ovarian adenocarcinoma, there has been a pressing need for "serodiagnostic" assays to enable close patient monitoring. CA 125 antigen has previously been described as a useful tumor marker of ovarian cancer. This is the first clinical evaluation of a radioimmunoassay using two new monoclonal antibodies, B27.1 and B43.13, that react with separate sites on the glycoprotein marker CA 125. Using the new assay, the majority of patients with clinically or radiologically detectable disease had serum CA 125 antigen levels well above the upper limit seen with random apparently healthy donors, while only three patients who were believed free of disease had elevated levels. Disease progression was associated with increasing values of serum CA 125 antigen, while response to therapy was associated with a steady decline in serum CA 125 antigen levels. Seven patients had steadily rising serum CA 125 antigen levels after initially having normal levels. The mean lead time between rise above normal and clinical or radiological evidence of relapse was 5 months (range 2 to 12 months). The merits of further surgical intervention are illustrated by the serial values of two patients followed after chemotherapy. The assay appears to have value in monitoring response to therapy and in detecting disease relapse at a time when appropriate therapeutic intervention is still possible or likely to be beneficial. Furthermore, monitoring CA 125 antigen was shown to be of benefit in assessing response to chemotherapy in a few patients with metastatic adenocarcinoma of unknown primary, and may be useful in this group of patients in determining those likely to benefit from aggressive chemotherapy.     

Immunohistochemistry of CA 125. Unusual expression in normal tissues, distribution in the human fetus and questions around its application in diagnostic pathology

CA 125 is known as the marker that is most strongly associated with epithelial gynecological tumors. Compared to the number of publications on its use in serum assays, the application in immunohistochemistry is still limited. The availability of many good antibodies that perform well in formalin-fixed paraffin-embedded tissue opens good possibilities for a wider use. Outside the gynecological tract several other structures may react positive for CA 125. Among these are the lung and breast but also the epithelial cells of the conjunctiva and to some extent prostate glandular epithelium. In the fetus reactions can be found in the serosal linings of body cavities but also in the esophagus and skin. In diagnostic pathology CA 125 plays a role in identifying the primary locations of metastatic carcinoma of unknown origin. It is recommended to use CA 125 antibodies not in a solitary setting but in combination with CEA, BRST-2 and Vimentin to discriminate best between the most frequent sites of origin of metastatic carcinoma. Regular analysis of sensitivity/specificity ratios in a balanced population, representing the composition of the patient population seen in daily practice, should be performed to evaluate the position of CA 125 in diagnostic immunohistochemistry.     

Changes in the expression of serum markers CA242, CA199, CA125, CEA, TNF-α and TSGF after cryosurgery in pancreatic cancer patients

The presence of serum tumor markers, carbohydrate antigen 242 (CA242), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), tumor-supplied group of factors (TSGF) and tumor necrosis factor-α (TNF-α), is closely associated with invasion and metastasis of many malignancies. The expression of these markers were measured in serum taken from 37 pancreatic cancer patients prior to treatment. Levels of CA242, CA199, CA125, CEA and TNF-α expression correlated with tumor size, clinical stage, tumor differentiation, lymph node and liver metastasis (P < 0.05). One month after cryosurgery, serum levels of these markers were significantly reduced compared with levels prior to cryosurgery (P < 0.05), whereas there was no significant difference was found between serum levels before and after chemotherapy (P > 0.05). Thus, cryosurgery is more effective than chemotherapy for decreasing CA242, CA199, CA125, CEA, TSGF and TNF-α serum levels in these patients.     

Serum tumor markers may precede instrumental response to chemotherapy in patients with metastatic cancer

PURPOSE: Although serum tumor markers (STMs) are widely used in clinical practice, their predictive role for the response to anticancer treatment is still controversial. The correlation of CEA, CA 15.3, CA 19.9, CA 125 (only with peritoneal involvement) and NSE levels with imaging response and clinical benefit was investigated in 60 non-selected patients with metastatic epithelial cancers treated by single-agent docetaxel chemotherapy. METHODS: STM measurement was performed at baseline and subsequently every three to four weeks. We applied the WHO criteria to evaluate both STM and instrumental responses. Concordance analysis was performed by the Cohen Kw index, and the significance of the results was established using the Fleiss, Cohen & Everitt test. Qualitative interpretation of data was obtained with the Landis & Koch scale. Correlations of STM response with clinical benefit (PS or pain improvement) were evaluated by the chi-square test. RESULTS: The primary tumors included breast cancers (38 patients), gastrointestinal non-colorectal cancers (12 patients), and lung cancers (10 patients). An overall significant good degree of agreement was observed between STM and instrumental response (p < 0.0005). The degree of agreement for each marker was as follows: excellent for CEA (p < 0.0005) and CA 125 (p = 0.006), good for CA 15.3 (p < 0.0005) and CA 19.9 (p = 0.011). Restricted analysis for the correlation of each marker with primary tumor origin showed good prediction of radiological response for CA 15.3 and CEA in breast cancer patients (p<0.0005 for both), for CEA and CA 19.9 in gastrointestinal cancer patients (p = 0.01 and 0.04, respectively), and for CEA+NSE in lung cancer patients (p = 0.01). Conversely, STM response did not correlate significantly with the clinical benefit for the patients, both in terms of PS and pain improvement (p = 0.24 and p=0.42, respectively). CONCLUSION: This study showed STMs to be good predictors of tumor response. Although STMs cannot replace diagnostic imaging, in metastatic cancer they might be useful to optimize the timing of radiological re-evaluation in the palliative setting.     

The value of calretinin and cytokeratin 5/6 as markers for mesothelioma in cell block preparations of serous effusions

Objective: To determine the value of calretinin and cytokeratin (CK) 5/6 in discriminating mesothelioma from adenocarcinoma in serous effusion specimens. Methods: A total of 101 recent, histologically or clinically confirmed malignant effusions with immunostained cell block preparations were reviewed. The cases consisted of 34 mesotheliomas and 67 adenocarcinomas. This included 17 ascitic fluid and 84 pleural fluid samples. The adenocarcinomas included metastatic carcinomas from the breast (12), lung (19), stomach (3), colon (1), pancreas (2), ovary (6) endometrium (1) and 23 histologically confirmed metastases from unknown primary sites. The cases were assessed as negative or positive (>5% of cells stained). The staining pattern was recorded as cytoplasmic, cell membrane, nuclear or cytoplasmic and nuclear staining. Results: Calretinin staining was present in 97% (33/34) of the mesothelioma cases with a majority of them showing both cytoplasmic and nuclear staining (29/33). Only 3% (2/67) of adenocarcinomas were positive for calretinin, one being a lung adenocarcinoma and the other an adenocarcinoma of unknown primary site in an ascitic fluid. Cytokeratin 5/6 staining was also present in 33/34 (97%) of mesothelioma cases. Six (9%) adenocarcinomas were positive, including metastases from the lung (1), breast (1), ovary (2) and unknown primary site (2). Four of the six adenocarcinoma cases positive for CK5/6 were in ascitic fluids. No cases of mesothelioma were negative for both calretinin and CK5/6. Only one adenocarcinoma case, (which was from unknown primary site in an ascitic fluid sample), was positive for both markers. Conclusions: The results confirm that calretinin and CK 5/6 are useful markers for mesothelioma in effusion specimens. CK5/6 staining may be less useful for peritoneal fluid specimens where metastatic adenocarcinomas may be more likely to express the antigen. Further study of ascitic/peritoneal specimens is warranted. However, positive staining, particularly for both antigens, is highly indicative of a mesothelial origin for cells. The two markers make a useful addition to EMA and the panel of adenocarcinoma markers routinely applied to effusion specimens.     

A novel multi-array immunoassay device for tumor markers based on insert-plug model of piezoelectric immunosensor

A novel multi-array immunoassay device based on the insert-plug model of piezoelectric (Pz) immunosensor fabricated with the screw clamp apparatus has been developed for quantitative detection of tumor markers such as alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), prostate specific antigen (PSA), and carcinoma antigen 125 (CA125) in serum, in which single immunosensor can oscillate independently with the frequency stability of +/-1 Hz (hertz) in air phase and +/-2 Hz in liquid phase. These response characteristics of Pz tumor marker multi-array immunoassay device such as time-cost, reproducibility and specificity, etc. were also investigated, respectively. The detection range for AFP, CEA, PSA and CA125 obtained by multi-array Pz immunosensor were 20-640 ng/ml, 1.5-30 microg/ml, 1.5-40 ng/ml and 5-150 IU/ml, respectively, with the coefficient of variance (CV) less than 5% and no cross-reactivates with other tumor markers in serum were observed. Application of the multi-array immunosensor to clinical samples demonstrated that results were in good agreement with chemiluminescence immunoassay (CLIA). Moreover, the multi-array Pz immunosensor could be regenerated to be reused for three cycles without appreciable loss of response activity. Therefore, the proposed multi-array immunoassay device based on Pz immunosensor provides a rapid, sensitive, specific, reusable, convenient and reliable alternative for the detection of tumor markers in clinical laboratory.     

Clinical evaluation of the simultaneous determination of CA 15-3, CA 125 and sHER2 in breast cancer

Objective We investigated serum levels of CA 15-3, sHER2 and CA 125, and their usefulness in the detection of metastatic disease in breast cancer patients.

Methods The levels of CA 15-3, sHER2 and CA 125 tumour markers were determined in 60 patients, 40 with localized and 20 with metastatic breast carcinoma. The control group consisted of 10 healthy women.

Results We found that, at the time of diagnosis, serum levels of all three tumour markers were elevated in patients with distant metastases, but of minute importance in the detection of any breast cancer. When the data for the individual markers were combined the overall sensitivity of metastases detection with all three markers improved. In this regard, 90% of patients with distant metastases had an increase in serum level of at least one of tested tumour markers. Similar results were obtained using receiver operating characteristic curve (ROC). Moreover, using ROC we defined cut-off values for metastasis detection for each of the tested markers.

Conclusion Our findings indicate that measurement of CA 15-3 serum values in conjunction with sHER2 and CA 15-3 can increase sensitivity in metastasis detection.     

Localisation of tumour deposits by external scanning after injection of radiolabelled anti-carcinoembryonic antigen.

Sheep IgG antibody to carcinoembryonic antigen (CEA) was radiolabelled with 131I and used to identify human gastrointestinal tumours by external subtraction imaging. 99Tc-pertechnetate and 99Tc-human serum albumin were used to identify tissue spaces. In 13 patients with tumours four out of five primary sites and eight out of 11 secondary sites were successfully shown. Two patients with benign disease had negative scans. Comparison with conventional methods of scanning showed good correlation. The success of this pilot study should encourage the search for more tumour-specific antigens and further study of the implications for treatment.     

Clinical evaluation of the simultaneous determination of CA 15-3, CA 125 and sHER2 in breast cancer

Objective We investigated serum levels of CA 15-3, sHER2 and CA 125, and their usefulness in the detection of metastatic disease in breast cancer patients.

Methods The levels of CA 15-3, sHER2 and CA 125 tumour markers were determined in 60 patients, 40 with localized and 20 with metastatic breast carcinoma. The control group consisted of 10 healthy women.

Results We found that, at the time of diagnosis, serum levels of all three tumour markers were elevated in patients with distant metastases, but of minute importance in the detection of any breast cancer. When the data for the individual markers were combined the overall sensitivity of metastases detection with all three markers improved. In this regard, 90% of patients with distant metastases had an increase in serum level of at least one of tested tumour markers. Similar results were obtained using receiver operating characteristic curve (ROC). Moreover, using ROC we defined cut-off values for metastasis detection for each of the tested markers.

Conclusion Our findings indicate that measurement of CA 15-3 serum values in conjunction with sHER2 and CA 15-3 can increase sensitivity in metastasis detection.     

Elevated CEA and CA19-9 serum levels independently predict advanced pancreatic cancer at diagnosis

Abstract

Purpose: It is suggested that tumour markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) could be used to predict the stage of pancreatic cancer. However, optimal cut-off values for CEA and CA19-9 are disputable. This study aimed to assess the value of CEA and CA19-9 serum levels at diagnosis of pancreatic ductal adenocarcinoma (PDAC) as predictors for the advanced stage of PDAC in patients discussed at pancreatic multidisciplinary team (MDT) meetings.

Methods: Patients with suspected PDAC discussed at MDT meetings from 2013 to 2017 were reviewed, in order to determine optimal cut-off values of both CEA and CA19-9.

Results: In total, 375 patients were included. Optimal cut-off values for predicting advanced PDAC were 7.0?ng/ml for CEA and 305.0?U/ml for CA19-9, resulting in positive predictive values of 83.3%, 73.6%, and 91.4% for CEA, CA19-9 and combined, respectively. Both tumour markers were independent predictors of advanced PDAC, demonstrated by an odds ratio of 4.21 (95% CI:1.85–9.56; p?=?0.001) for CEA and 2.58 for CA19-9 (95% CI:1.30–5.14; p?=?0.007).

Conclusions: CEA appears to be a more robust predictor of advanced PDAC than CA19-9. Implementing CEA and CA19-9 serum levels during MDT meetings as an additional tool for establishing tumour resectability is worthwhile for tailored diagnostics.     

Circulating macrophage colony stimulating factor as a marker of tumour progression

Tumour expression of the macrophage colony stimulating factor (CSF-1 or MCSF) has been associated with an adverse prognosis in breast cancer, through an effect on the promotion of metastasis. The aim of the present study was to evaluate the clinical relevance of high circulating CSF-1 levels in patients with newly diagnosed breast tumours and correlate CSF-1 with clinico-pathological parameters. A secondary aim was to also measure CSF-1 in patients with other tumour types and at different stages of disease. Using a commercially available ELISA, pre-treatment plasma levels of CSF-1 were assessed, in 471 consecutive patients diagnosed with breast tumours, in 70 patients with newly diagnosed cancer of the head & neck, in 32 men with prostate cancer metastatic to bone and in 39 women with advanced metastatic breast cancer. Mean CSF-1 levels were significantly higher in patients with locally advanced (p <.015) or metastatic breast tumours (p <.048) and in a group of primary breast cancer patients (n = 26) selected for intensive chemotherapy because of multiple adverse tumour characteristics (p <.0002). Mean CSF-1 was also higher in patients younger than 35 years (p <.02) and in post-menopausal patients (p <.03). There was no significant association with tumour histologic type, grade, or other individual histopathologic parameters. No significant association was found between pre-treatment CSF-1 and overall/relapse free survival. Median CSF-1 levels were dramatically higher in patients with newly diagnosed tumours of the head & neck (604 pg/ml), in men with prostate cancer metastatic to bone (627 pg/ml) and women with advanced metastatic breast cancer (867 pg/ml) than those seen in patients with newly diagnosed breast tumours (334 pg/ml). Our data support the hypothesis that CSF-1 may play a functional role in tumour progression to metastasis as has previously been reported in animal models.