PS2 in breast cancer--alternative or complementary tool to steroid receptor status? Evaluation of 446 cases.

The oestrogen induced pS2 protein was measured in the cytosol of 446 breast cancer samples by an immunoradiometric assay. The relationships between pS2 and several clinical and biological parameters were evaluated. pS2 was not correlated to age, pT and nodal status, while it was higher in pre- than in peri- and post-menopausal women. A statistically significant positive association was found between pS2 and ER, PgR and cathepsin D. However, the frequency of pS2 negative values in ER+ (25.6%), PgR+ (21.7%) and cathepsin D-(19.0%) cases suggests that pS2 provides information independent of the above parameters in a fairly high percentage of patients. The prognostic role of pS2 was evaluated in 267 cases (follow up time 24-102 months). pS2+ showed longer RFS (P = 0.016) and OS (P = 0.004) than pS2-. pS2+ cases were significantly associated with a better prognosis in N+ but not in N- cases. Multivariate analysis showed that pS2 is an independent prognostic factor being the second most effective indicator for OS after nodal status and the third for RFS after nodal status and cathepsin D. From the present findings, we conclude that pS2 probably provides additional biological information to steroid receptor status and cathepsin D in patients with primary breast cancer.

A new approach to tumour marker assessment by perioperative determination in breast and colorectal cancer.

Preoperative serum tumour markers are currently classified as positive or negative according to a predetermined cut-off point. In the present study we examined the dynamic variation of marker levels after radical surgery of breast and colorectal cancer. CEA and CA15.3 were measured in 93 patients with breast cancer, CEA and CA19.9 in 97 patients with colorectal carcinoma before and 30 days after radical surgery. Any variation higher than 3-fold the analytical coefficient of variation of the assay was considered significant. In patients with negative preoperative marker levels a significant decrease was noted after surgery in 15.6% of cases for CEA and 27.8% for CA15.3 in breast cancer and in 46.8% for CEA and 25.7% for CA19.9 in colorectal cancer. Using both cut-off-based and dynamic criteria, we found an overall positivity rate of 19.6% for CEA and 33.3% for CA15.3 in breast cancer; 60.0% for CEA and 37.1% for CA19.9 in colorectal cancer. From the present findings we conclude that the dynamic study of perioperative variations of tumour markers is a sensitive method additional to cut-off-based criteria for the assessment of the phenotypic expression of the marker by the tumour.

Epidermal growth factor receptor in breast cancer. Comparison with non malignant breast tissue.

Epidermal growth factor receptors were measured using a radioligand binding assay in membrane preparations from 67 cancer and 25 non-malignant tissues. The binding characteristics of EGFr were similar in tumour and normal breast membranes. The concentrations were significantly higher in non-malignant tissue than in cancer. EGFr concentrations were directly correlated with steroid receptors in non-malignant tissue, whereas in cancer an inverse correlation between EGFr and steroid receptors was found.

Cost/effectiveness ratio of carcinoembryonic antigen--importance of adequacy of routine requests of tumor markers.

Since 1987 we have been evaluating the cost/effectiveness ratio of tumor markers using carcinoembryonic antigen (CEA) as a leading indicator. Preliminary to the evaluation of cost/effectiveness ratio we verified the fitness of CEA requests to the proper clinical problems in order to identify any bias of cost due to inadequate CEA use. 2677 CEA orders were evaluated in 1987. The percentage of inadequate requests was very high (43%). Therefore, it seemed not advisable to carry out the evaluation of cost/effectiveness ratio, while educational actions (divulgation of informative material, service of telephone consultation) were addressed to the physicians of the geographic area of laboratory users. In 1991 the adequacy of CEA requests was reevaluated. The percentage of inadequate requests on 2647 orders was 29.4%. This result, although not yet satisfactory, suggests that proper educational programs may probably improve the fitness of tumor marker requests to correct clinical problems. Additional educational actions are mandatory to further reduce the rate of inadequate tumor marker orders.

Tissue polypeptide antigen in breast cancer cytosol: a new effective prognostic indicator.

Since 1982 we have been evaluating oestrogen and progesterone receptors (PgR), cathepsin D and the cytosolic levels of the tumour marker, tissue polypeptide antigen (TPA), in 257 patients radically resected for breast cancer (follow-up 24-81 months). TPA was measured by an immunoradiometric assay previously validated for cytosol. No significant associations were found between cytosolic TPA and age, tumour size, lymph-node status, receptor status and cathepsin D. TPA+ cases showed a significantly longer disease-free survival (DFS) and overall survival (OS) than TPA-patients (log-rank P < 0.0001). The prognostic value of cytosolic TPA was also demonstrated after stratification by nodal status, PgR and cathepsin D. The prognostic value of TPA was independent of the other prognostic indicators, being the most powerful among the evaluated indices (Cox multivariate analysis: chi 2 15.5 for DFS, 11.4 for OS). We conclude that cytosolic TPA is a powerful additional prognostic factor in primary breast cancer. Its prognostic role should therefore be extensively evaluated.

Epidermal growth-factor receptor and erbb2 protein in colorectal tissue - comparison between cancer and normal mucosa.

Epidermal growth factor receptor (EGFr) and p185neu protein were measured in 55 samples of carcinoma and 55 of normal colorectal mucosa from the same patient, using a ligand binding assay and an ELISA method respectively. The binding characteristics of EGFr were similar in cancer and normal tissue. The concentrations of both EGFr and p185 showed gaussian distribution and were not significantly different between normal and cancer tissue, although a trend toward higher levels of EGFr in normal mucosa was found. Moreover, no significative variations were found in the ratios between cancer and normal tissue after desaturation of the EGFr. No correlations were found between EGFr and p185 and the main clinopathological parameters.

Epidermal growth factor receptor in lung malignancies. Comparison between cancer and normal tissue.

Epidermal growth factor receptors (EGFr) were measured using a radioligand binding assay, in membrane preparations from 51 human non-small cell lung cancers and in normal tissue of the same patients. The binding characteristics of EGFr were similar in tumour and normal lung membranes (range of dissociation constant of high affinity sites: 0.1-0.6 nM). However, the concentrations in tumours (median, 16.4 fmol mg-1 of protein; range, 1.5-176) were significantly higher than in normal tissues (median, 7.4 fmol mg-1 of protein; range, 1.9-13.4). The receptor levels in normal tissue were normally distributed. It was therefore possible to define a normal/pathologic cut-off level (12.9 fmol mg-1 of protein). In 57% of cases EGFr in cancer was higher than the cut-off. No relationships were found between receptor concentrations and positivity rates of EGFr and histology, stage, lymph node positivity and pT. A trend for a direct relation between receptor positivity and grading was found.

The tumour associated antigen CA15.3 in primary breast cancer. Evaluation of 667 cases.

CA15.3 preoperatory serum levels have been determined in 667 patients with primary untreated breast cancer and in 193 controls. The relationships between CA15.3 and several clinical and pathological parameters were evaluated. CA15.3 levels showed a highly significant direct relationship with stage, T, pT, N and the number of positive lymph nodes. The close relationship between CA15.3 and the number of positive lymph nodes was also demonstrated in a subgroup of 406 patients in which more than ten lymph nodes had been examined. CA15.3 levels were correlated with tumour size in patients without axillary metastasis as well as with the number of positive lymph nodes in pT1 tumours. CA15.3 was significantly higher in medullary than in ductal carcinoma. No relationships were found between serum CA15.3 and receptor status. We conclude from the present findings that CA15.3 in primary untreated breast cancer is a marker of tumour burden as well as of the tendency of local invasiveness (relationship between CA15.3 and nodal status in pT1 tumours).

Tumor-associated trypsin inhibitor (TATI) in primary esophageal carcinoma.

Esophageal carcinoma has a catastrophic clinical course with a very low 5 year survival rate of 5%. A circulating tumor marker with good specificity and sensitivity would be useful in the management strategy of the disease. So far, no tumor marker effective in esophageal carcinoma has been identified. Preliminary reports suggest satisfactory positivity rates of tumor-associated trypsin inhibitor (TATI) in esophageal carcinoma. We measured TATI levels in 71 patients with primary squamous cell esophageal carcinoma as well as in 30 tissue samples from both carcinoma and normal esophageal mucosa. Detectable TATI levels were not found in tumor tissue samples. The marker showed significantly higher serum levels in patients than in controls, with an overall positivity rate of 28%. TATI levels were significantly lower in patients with a high number of tumor-positive lymph nodes. No relationship was found between TATI and several other clinical and pathological parameters. High TATI levels correlated with a lower probability of overall survival as well as in cases without clinical evidence of lymph node metastases. TATI did not show any relationship with CEA, TPA, ferritin or SCC. The results of the present study suggest that TATI shows a satisfactory positivity rate in esophageal carcinoma, and TATI levels are related to local disease spread and prognosis.

Comparison between single saturating dose ligand binding assay and enzyme immunoassay for low-salt extractable oestrogen and progesterone receptors in breast cancer: a multicentre study.

An excellent correlation between ligand binding assay (LBA) and enzyme immunoassay (EIA) for both oestrogen (ER) and progesterone (PR) receptors has been reported. Nevertheless, considering that the clinical value of any discrepancy between LBA and EIA probably varies with the receptor level, we undertook a collaborative study in which a single saturating dose (SSD) LBA and EIA were compared in different ER and PR dose ranges. The values of ER measured by EIA were higher in tumours with low or intermediate receptor content, causing a misclassification of ER status in 9% of cases (ER+: 77.5%, EIA, 68.8% SSD). In the case of ER, EIA values tended to be higher than SSD in all centres. For PR, EIA and SSD were generally more comparable (PR+: 66.0% EIA, 72.0% SSD, discordance rate 6%), with EIA showing, however, different trends in different centres. PR concentration was not significantly different in ER SSD-/EIA+ and in ER SSD+/EIA+ cases, suggesting that EIA detects at least in part integer ER. We conclude that although EIA may be a reliable methodological alternative to SSD, the two methods are not interchangeable until effective cut-off levels for clinical decisions are assessed for EIA.

Tissue polypeptide antigen in tumor cytosol: a new prognostic indicator in primary breast cancer.

The assessment of the risk of relapse is a critical need in the management strategy of breast cancer patients. To date, the most reliable prognostic factor is axillary nodal status. Several other pathological and biological parameters are currently under evaluation. Since 1982 we have been studying the prognostic role of several tumor markers in breast cancer cytosol. Elevated cytosol concentrations of tissue polypeptide antigen (TPA) have been found to have a highly significant direct correlation with both prolonged relapse-free interval (RFI) and higher survival rate. The information provided by cytosol TPA was independent of both axillary nodal status and steroid receptor content. In patients with a low risk of relapse (no axillary metastases, estrogen and progesterone receptor positive), cytosol TPA was still a significant prognostic indicator.

Is tissue polypeptide antigen still a useful tumor marker in breast carcinoma? Comparison with CA15.3 and MCA.

Serum levels of tissue polypeptide antigen (TPA) are related to the proliferative activity and to the mass of the malignancy, differently from any other available tumor marker. We therefore evaluated TPA in comparison with CA15.3 and MCA (mucinous-like carcinoma-associated antigen) in patients with primary breast cancer. TPA was measured in tumor cytosol and in serum. Cytosol and serum TPA levels were not significantly correlated. Serum TPA was higher in patients with locally more advanced disease and in receptor-negative cases. The relation between TPA and disease spread was not directly dependent on tumor bulk, whereas CA15.3 and MCA were highly correlated to the number of positive lymph nodes and tumor size. No correlations were found between TPA and CA15.3 or MCA, and the positivity concordance rate between TPA and CA15.3 or MCA was very low. Patients with higher TPA serum levels showed a worse prognosis in cases with and in those without axillary metastases. From our data we conclude that TPA provides information different from that obtained with breast-specific tumor markers and could therefore be useful in association with CA15.3 and/or MCA in the management of patients with breast cancer.

Radioligand binding assay of epidermal growth factor receptor: causes of variability and standardization of the assay.

Although experimental evidence indicates a probable role of epidermal growth factor receptor (EGFr) in clinical oncology, no standardized method for its determination has been yet described, and discrepant results have been reported in clinical studies. In standardizing a radioligand binding assay for EGFr, we evaluated the causes of variability in each step of the assay. Entrapment of EGFr in the nuclear fraction and contamination of the crude membrane fraction by cytosol protein were eliminated through preliminary purification steps. Both Scatchard and Rosenthal analysis of the saturation reaction of the membrane fraction with a wide range of concentrations of 125I-labeled EGF revealed a double class of binding sites. Study of the saturation reaction showed a partial exchange of 125I-labeled EGF with endogenous EGF within 20 h. The present method--incubation of partly purified membrane fraction with 125I-labeled EGF, 0.5 nmol/L, with and without 100-fold excess of cold EGF, for 20 h at 26 degrees C, followed by centrifugation at 5000 x g for 30 min to separate membrane-bound 125I-labeled EGF--shows good sensitivity, precision, and accuracy; is reasonably simple; and may be suitable for routine clinical use.

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.

A mucinous-like carcinoma-associated antigen (MCA) in the tissue and blood of patients with primary breast cancer.

The monoclonal antibody (MAb) b12 raised against human breast cancer cell lines was found to identify an epitope of a mucinous-like carcinoma associated antigen (MCA) that is strongly represented on breast tumor cells. The b12 MAb was used to develop an enzyme immunoassay (EIA) kit. MCA levels were measured with the EIA method in the cytosol of both breast cancer and normal breast tissue as well as in the blood of 147 patients with primary breast cancer and 92 healthy subjects. MCA cytosol levels were significantly higher in carcinoma than in normal breast tissue cytosol samples. Higher MCA levels were found in the cytosol of tumor without lymph nodal involvement. The 95th percentile of the MCA value distribution in the healthy control group (11.0 U/ml) was chosen as negative/positive cut-off level. The overall positivity rate in breast cancer group was 26.5% with MCA showing a trend toward higher levels in patients with more advanced disease. Significantly higher levels were found in patients with a higher number of positive lymph nodes.

Tumor marker radioimmunoassays in gastric juice. Methodologic drawbacks due to pH variations.

Conflicting data have been reported on tumor marker determination in gastric juice. In the present study the effect of pH variations on both antibody-antigen binding and the immunologic stability of the antigen were evaluated for the radioimmunoassay of carcinoembryonic antigen, CA19-9, tissue polypeptide antigen, and ferritin. A significant inhibition of antibody-antigen binding was constantly found in acidic conditions. Antigen concentration was lower in acidified than in untreated samples, possibly due to the carryover of acidity in the incubation mixture. Neutralization of acidified samples partly improved recovery of carcinoembryonic antigen and CA19-9. Tissue polypeptide antigen and ferritin were not recovered by neutralization in samples with pH less than 4.5, suggesting an irreversible damage of the immunologic characteristics of the two antigens. From the present data we conclude that an accurate validation of methods and a rigorous standardization of sample collection are mandatory for tumor marker determination by radioimmunoassay in gastric juice.