Epirubicin combined with estramustine phosphate in hormone-resistant prostate cancer: a phase II study

Twenty-four assessable patients with hormone-resistant prostate cancer (HRPC) were to receive daily doses of oral estramustine phosphate (EMP), 10 mg kg(-1), and intravenous epirubicin (EPR) infusions, 100 mg m(-2), every third week up to a cumulative dose of 500 mg m(-2). Biochemical response [> or = 50% reduction in pretreatment serum prostate-specific antigen (PSA) after three cycles of > or = 3 weeks' duration] was demonstrated in 13 of 24 patients included (54%). No objective response (WHO criteria) was observed, although seven of nine evaluable patients achieved a > or = 50% serum PSA reduction. Subjective improvement (pain score, performance status) occurred in 7 of 24 patients, whereas nine patients progressed subjectively. There was no correlation between subjective and biochemical response. Biochemical progression (> or = 50% increase of nadir PSA) occurred after a median of 12 weeks. All but two patients were alive after a median follow-up time of 8.7 months for surviving patients (range 3.3-13.2). Eight patients experienced grade 3/4 leucopenia, with no indication of cumulative myelosuppression. Cardiovascular toxicity was experienced by four patients. Two patients developed angioedema twice, in one patient requiring hospitalization at the intensive ward. Based on this limited series, the combination of EPR and EMP in patients with HRPC is tolerable and appears to be effective in terms of significant PSA reduction. The results warrant further investigations of the two drugs and, in particular, of the clinical significance of > or = 50% PSA decrease in patients with HRPC.

Pharmacokinetics of reboxetine in healthy volunteers. Single against repeated oral doses and lack of enzymatic alterations

The pharmacokinetics of reboxetine have been investigated in 12 healthy male volunteers after a single 2 mg dose of reboxetine and at steady state, following the last administration of a multiple-dose regimen (2mg twice a day for 5 1/2 d). Reboxetine was analysed in plasma and urine samples collected up to 72 h post-dosing using an HPLC method with UV detection. The urinary excretion rate of 6-beta-hydroxycortisol, used as a marker for cytochrome P450IIIA activity, was also tested, and any possible alteration was correlated to reboxetine plasma levels. The dosing regimen was well tolerated by all subjects. Reboxetine pharmacokinetic parameters, calculated after the single dose using non-compartmental analysis, were in good agreement with those obtained in previous studies. Following the multiple-dosing regimen, no significant deviations from expectation based on linear superposition was observed. The accumulation ratio, based on repeated-dose/single-dose ratios of Cmax, AUC(0-12 h), and C(12 h) was approximately two. A slight rise was recorded for the average excretion rate of 6-beta-hydroxycortisol over 48 h by the end of treatment; however, the difference was not statistically significant and the mean excretion rates were within the normal reference range. Thus a significant induction of P450IIIA was not indicated.

Expression and interconversion of neuron-specific enolase in patient sera and extracts from small-cell lung cancer cells

The isoforms of gamma-enolase were characterized in serum from patients with small-cell lung cancer (SCLC) and in extracts from SCLC cell lines and malignant melanoma tumor tissue. Large variations in the expression of the 3 gamma-isoforms of enolase were observed. These forms probably represent the homodimeric gamma gamma-enolase, the heterodimeric alpha gamma-enolase and the monomeric forms of gamma-enolase. Only the dimeric forms are enzymatically active. The predominant gamma-enolase in the cell lines is the heterodimeric alpha gamma-enolase. The SCLC cell lines can be divided into two groups: one with negligible gamma gamma-enolase expression and considerable amounts of the nonneuronal alpha alpha-enolase and a second group with a large fraction of gamma gamma-enolase concomitant with a low expression of alpha-enolase. Similar patterns are observed in tissue extracts from malignant melanoma. When changing buffer conditions by increasing the ionic strength and decreasing the Mg2+ concentration, interconversions between the isozymes occur. In contrast to the predominant alpha gamma-enolase in extracts from cell lines, the multiple forms of gamma-enolase in serum might be caused by a subunit exchange facilitated by the low Mg2+ concentration in plasma. However, there seems to be a stable equilibrium between the isoforms in undiluted patient serum. The induction of subunit exchange by perturbation in ionic strength and/or Mg2+ concentration indicates a need for caution when choosing diluents for use in assays for neuron-specific enolase.

Specificity and affinity of 26 monoclonal antibodies against the CA 125 antigen: first report from the ISOBM TD-1 workshop. International Society for Oncodevelopmental Biology and Medicine

The specificity of 26 monoclonal antibodies against the CA 125 antigen was investigated in two phases of the ISOBM TD-1 workshop. The binding specificity was studied using CA 125 immunoextracted by specific antibodies immobilized on various solid phases, or on the surface of human cell lines. Immunometric assays using all possible antibody combinations were used to study the topography of antibody binding sites on the antigen. We conclude that the CA 125 antigen carries only two major antigenic domains, which classifies the antibodies as OC125-like (group A) or M11-like (group B). One antibody, OV 197, showed binding specificity related to some of the OC125-like antibodies, but was classified into a separate group C. The OC125-like group of antibodies has four subgroups with different binding specificities. These are A1 = OC 125 and K 95, A2 = K 93, A3 = B43.13, and A4 = ZS 33, B27.1 and CCD 247. Binding of nonlabelled OC 125 or K 95 to CA 125 caused a marked increase in binding of labelled OV 197 to the complex. This conformational change was not observed with any other antibody combinations. Antibody B43.13 could form immunometric assay combinations particularly with antibodies of subgroup A4, indicating that the B43.13 epitope is in the periphery of the binding area of OC125-like antibodies. The M11-like group of antibodies is more homogenous with strong cross-inhibition between most antibodies. Only one antibody, ZR 38, would form an immunoassay combination with other M11-like antibodies and thus represents a distinct subgroup. The main group of M11-like antibodies are M 11, ZR 45, MA602-6, K 91, OV 185, K 101, K 90, K 96, K 97, K 102, CCD 242, 145-9, and 130-22. Antibody OV 197 binds to a domain designated C and is unique, as stated above. Antibody pairs from any two of the three groups may be used in immunometric assays. Three antibodies were not studied by complete cross-inhibition due to low affinity (OV 198 and K 100) or lack of material (MA602-1). OV 198 and K 100 are most likely OC125-like and MA602-1 is M11-like. Antibody affinity was estimated with labelled antigen in solution or with antigen absorbed on microtiter wells. Western blot analysis showed staining both in the stacking gel and corresponding to a molecule of 200 kDa. There was a marked difference between the antibodies in their ability to bind to CA 125 immobilized on a membrane. Strongest binding was observed with the M11-like antibodies, particularly M 11, K 96, K 97, MA602-6, 145-9. Antibodies belonging to the subgroup A4 were the only OC 125-like antibodies which reacted well with CA 125 in Western analysis. Digestion of CA 125 with proteolytic enzymes showed it to be particularly sensitive to trypsin cleavage. However, no low molecular weight fragments with preserved immunoreactivity were found.

Increase of serum prostatic specific antigen and clinical progression in pN + MO prostate cancer

OBJECTIVE

To analyse the increase of serum prostatic specific antigen (PSA) as a means of early detection of progression in hormonally untreated or androgen-deprived patients with T1-T4, pN+ and MO prostate cancer.

PATIENTS AND METHODS

From 1986 to 1992 40 patients with T1-T4 pN+ MO prostate cancer were either deprived of androgen at diagnosis (Group 1, 19 patients) or had no immediate hormone manipulation (Group 2, 21 patients) and were followed at 3-6-monthly intervals when determinations of PSA and routine clinical/radiological examinations were performed. A significant increase in PSA was defined as a > or = 50% increase of the baseline PSA value which was the either the lowest PSA value within 6 months from the start of androgen deprivation (Group 1) or the initial PSA value (Group 2).

RESULTS

By June 1993 22 of the 40 patients had clinically progressed. In 12 patients the progression was preceded by a significant increase in PSA (Group 1, three of four progressing patients; Group 2, nine of 18 progressing patients). A PSA increase of > or = 50% was observed simultaneously with clinical progression in six patients, whereas clinical progression occurred in four patients with no previous or simultaneous significant increase in PSA. In four of nine hormonally untreated patients > or = 1 year elapsed between antecedent PSA increase and clinical progression.

CONCLUSION

In routine clinical practice PSA does not significantly increase (> or = 50% of baseline value and > 10 micrograms/L) before disease progression in about one third of patients with pN+ MO prostate cancer managed with or with no hormone manipulation. Future studies should be carried out to determine whether a lower rate of increase in PSA during follow-up has any clinical significance.

Dual analyte assay based on particle types of different size measured by flow cytometry

Simultaneous flow cytometric assays have been developed for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG), with internal determination of sample related non-specific binding (NSB). The assays use particles of 7.5, 6.5 and 5.5 microns diameter coated with, respectively, monoclonal antibodies specific for AFP, hCG or an epitope normally not present in serum. The different particle types were identified simultaneously by light-scatter measurements as their specific immunofluorometric responses were determined. The NSB in the simultaneous assay of AFP and hCG was increased by approximately 30% compared to corresponding single analyte assays. The working range of the dual analyte assays was 0.6-2000 kIU/l for AFP and 6-10,000 IU/l for hCG. No significant interference from the presence of the other analyte was observed in the measurement of either AFP or hCG. The 95% confidence interval for the ratio of dual over single analyte assay results was [0.81, 1.11] for AFP and [0.88, 1.16] for hCG.

Detection of c-erbB-2 related protein in sera from breast cancer patients. Relationship to ERBB2 gene amplification and c-erbB-2 protein overexpression in tumour

The level of a c-erbB-2 related protein was determined in sera from 168 breast carcinoma patients, 12 females with benign breast disease, and 66 female controls using an ELISA (enzyme linked immunosorbent assay) kit. Elevated c-erbB-2 related protein level was detected in one of 13 preoperative sera (8%), two of 62 postoperative sera from patients without recurrent disease (3%), and 55 of 93 sera collected at recurrent disease (59%). Elevated serum levels were detected significantly more often in patients with distant metastases than in patients with recurrent disease restricted to loco-regional areas (68% versus 19%). Presence of elevated serum level was associated with ERBB2 gene amplification and c-erbB-2 protein overexpression in tumour. None of the patients who had normal ERBB2 gene copy number in tumour had elevated serum levels. Although the usefulness in postoperative prediction of the presence of micrometastases is somewhat questionable, the results suggest c-erbB-2 related protein to represent a novel tumour marker in serum and other body fluids from breast cancer patients at the time of diagnosis and during treatment monitoring.

DNA ploidy, serum prostate specific antigen, histological grade and immunohistochemistry as predictive parameters of lymph node metastases in T1-T3/M0 prostatic adenocarcinoma

OBJECTIVE

To evaluate whether DNA ploidy and immunohistochemistry performed in primary prostatic carcinoma specimens give predictive information on regional lymph node metastasis in addition to T category, histological grade and serum prostate specific antigen (PSA).

PATIENTS AND METHODS

Pre-treatment TURP specimens from 80 patients with prostatic carcinoma T0-T3/M0 disease were retrospectively evaluated by means of DNA ploidy and histological grade, and immunostaining for PSA, prostatic acid phosphatase (PAP), neuron-specific enolase (NSE) and p53 protein. Pelvic lymph node dissection was performed in all patients. Serum PSA was determined in 76 of the 80 patients before pelvic staging lymphadenectomy. Thirty-two (40%) of the 80 patients had pN+ disease.

RESULTS

Thirty-six patients (46%) had serum PSA values below the upper reference limit (< or = 10 micrograms/L). By univariate analysis the pN category correlated with the serum PSA level (P < 0.001), histological grade (P < 0.001), tissue PSA (P < 0.001), tissue PAP (P < 0.04), T category (P < 0.005) and DNA ploidy (P < 0.02). Multivariate analysis revealed that the serum PSA level was the most powerful independent prognosticator, followed by the T category, tissue PAP and tissue PSA. Histological grade and DNA ploidy did not reach the level of significance in the multivariate analysis.

CONCLUSION

These data suggest that tissue PAP and tissue PSA predict the pN status in patients with T0-T3/M0 prostate carcinoma, in addition to serum PSA and T category. Neuroendocrine differentiation and p53 protein seem to have no predictive ability.

[Tumor marker analyses--valuable tools if used correctly]

The tumour marker assays in routine use today are not cancer-specific. Most markers are normal products of epithelial tissues, usually excreted from the intact organ. The infiltrating malignant growth allows release directly into lymph and blood, where the product is measured as a "tumour marker". Many tumour markers are glycoproteins depending on the liver function for their catabolism. These mechanisms explain the slight to moderate increases in tumour marker values found in various non-malignant diseases. Therefore, in general, such assays are of no use for screening healthy populations, and a normal value does not exclude cancer. Their main use is in the primary staging of patients known to have cancer, to evaluate the completeness of primary surgery, to follow-up patients for early detection of relapses, and to monitor the effect of cytotoxic or radiation therapy of advanced disease. In all these applications, good clinical judgement is the necessary basis for using these assays.

Reduction of serum prostate-specific antigen during endocrine or cytotoxic treatment of hormone-resistant cancer of the prostate. A preliminary report

During the years 1988-1991 sequential serum prostate-specific antigen (PSA) determinations were performed during systemic treatment of hormone-resistant prostate cancer. The following drugs were used: prednisone (5 mg 4 times per os daily, 8 patients); flutamide (250 mg 3 times per os daily, 13 patients); estramustine phosphate (280 mg 2-3 times per os daily, 12 patients), and epirubicin (100 mg/m2 i.v. every 3rd week, 18 patients). In 3, 3, 4 and 6 patients, respectively, a PSA reduction of > or = 50% was observed during treatment, which in 12 patients was combined with pain relief and improvement in the performance status. Though the exact mechanism of PSA reduction and its clinical significance are not completely understood, the findings suggest that hormone-resistant prostate cancer still contains hormone-sensitive tumor cells. The 4 drugs used in this study seem to be equally effective in achieving a PSA reduction of > or = 50%.

Homogeneous immunofluorometric assays of alpha-fetoprotein with macroporous, monosized particles and flow cytometry

We evaluated two homogeneous immunofluorometric assays (IFMAs) of alpha-fetoprotein (AFP) based on new macroporous acrylate particles combined with flow cytometry. The standard IFMA, requiring 1 h of incubation, provided a working range from 1.8 to > 900 kIU/L (CV < 10%) and a detection limit of 0.6 kIU/L. Use of overnight incubation and a lower particle concentration extended the working range by 1 decade in the lower end. Analytical recoveries for the standard IFMA varied between 97% and 108%. The slope and y-intercept of the regression line correlating measurements by the standard IFMA and a routine immunoradiometric assay were not significantly different from 1 and 0, respectively (P > 0.5), and the correlation coefficient was 0.996. High precision and warning of spuriously high measurements were obtained by including in each sample separate particle types for detecting instrument instability and measuring nonspecific binding only.

Homogeneous immunofluorometric assays of alpha-fetoprotein with macroporous, monosized particles and flow cytometry

We evaluated two homogeneous immunofluorometric assays (IFMAs) of alpha-fetoprotein (AFP) based on new macroporous acrylate particles combined with flow cytometry. The standard IFMA, requiring 1 h of incubation, provided a working range from 1.8 to &gt; 900 kIU/L (CV &lt; 10%) and a detection limit of 0.6 kIU/L. Use of overnight incubation and a lower particle concentration extended the working range by 1 decade in the lower end. Analytical recoveries for the standard IFMA varied between 97% and 108%. The slope and y-intercept of the regression line correlating measurements by the standard IFMA and a routine immunoradiometric assay were not significantly different from 1 and 0, respectively (P &gt; 0.5), and the correlation coefficient was 0.996. High precision and warning of spuriously high measurements were obtained by including in each sample separate particle types for detecting instrument instability and measuring nonspecific binding only.

Optimalized in vivo production of monoclonal antibodies in mouse ascitic fluid

The note contains a brief summary of the method in use at the National Institute of Public Health for the production of monoclonal antibodies in mouse ascitic fluid. This method of obtaining large amounts of monoclonal antibodies is widely used. Refining the in vivo method and increasing the yield from each mouse could result in a reduction of the number of animals used.

Increased serum creatine kinase BB and neuron specific enolase following head injury indicates brain damage

The aim of this study was to examine whether an increase in the serum concentrations of the two brain enzymes creatine kinase BB (CK-BB) and neuron specific enolase (NSE) can be demonstrated in patients with acute head injury and whether such an increase reflects release from damaged brain tissue. In 60 patients who had suffered minor to severe head injury, serial blood samples were drawn during the first hours after impact, and CK-BB and NSE were measured by radioimmunoassay. Computed tomography (CT) was also performed shortly after admission to hospital, and was repeated 1-3 days later in selected patients. Increased serum concentrations of both CK-BB and NSE were found in 88% of the patients with moderate to severe head injury (group 1, n = 18) and in 23% of the patients with minor head injury (group 2, n = 42), whereas CT showed contusion in only 41% and 2% of the group 1 and 2 patients, respectively. The following findings suggest that the enzymes had been released from brain tissue: 1) The maximum concentrations of CK-BB and NSE correlated with the severity of injury as assessed clinically and with the volume of contusion as estimated from CT (r = 0.79 with CK-BB, r = 0.72 with NSE). 2) The maximum concentrations of CK-BB and NSE were closely correlated (r = 0.87).(ABSTRACT TRUNCATED AT 250 WORDS)

89Strontium in bone metastases from hormone resistant prostate cancer: palliation effect and biochemical changes

Hematological and biochemical parameters were evaluated in 31 patients receiving 150 MBq 89Strontium (89Sr) intravenously due to painful skeletal metastases from hormone resistant prostate cancer. Two and 3 months after the injection prostate specific antigen (PSA) had increased by a median of 36% and 100%, respectively, as compared to the pretreatment value whereas alkaline phosphatase (APHOS) had decreased by about 20% (median). The leucocyte and platelet counts were reduced by about 20-35%, without reaching grade greater than or equal to 2 toxicity. Pain relief was reported in 14 of 29 evaluable patients at 2 months and in 11 of 23 patients at 3 months. It is concluded that 89Sr represents a worthwhile therapeutic modality in the palliation treatment of patients with hormone resistant prostate cancer, though the biological significance of frequently increasing PSA and decreasing APHOS is not yet completely understood.

The prognostic significance of prostate specific antigen in metastatic hormone-resistant prostate cancer

Twenty-seven of 152 patients (18%) with progressing hormone resistant prostate cancer had normal serum levels of prostate specific antigen (PSA less than or equal to 10 micrograms l-1), when referred for secondary treatment. PSA was significantly correlated with the extent of skeletal metastases (R: 0.35) and the levels of hemoglobin (R: -0.19) and serum alkaline phosphatase (R: 0.30). In a multivariate Cox regression analysis the survival of the 152 patients was not correlated with the PSA level but with the patients performance status, the level of hemoglobin, and the time between primary hormone treatment and relapse. The lack of serum PSA to predict survival may be explained by a heterogenous composition of hormone resistant prostate cancer as regards differentiated and/or PSA producing vs undifferentiated and/or PSA non-producing cells.

Prostate-specific Antigen and other Prognostic Factors in Patients with Hormone-resistant Prostatic Cancer Undergoing Experimental Treatment

In 58 patients with progressive hormone-resistant metastatic cancer of the prostate, prostate-specific antigen (PSA) greater than 100 micrograms/l, haemoglobin less than 12.0 g/dl and pronounced fatigue were found to be independent adverse prognostic factors. These risk factors distinguished a subgroup of patients with a median survival of 9 months (none or only 1 risk factor present) from a subgroup with a median survival of 4 months (greater than or equal to 2 risk factors present). The clinician should be reluctant to enter patients from the second group into complicated and resource-demanding clinical studies, particularly if such trials require frequent and inconvenient follow-up examinations.

Neuron-specific enolase--a serum tumour marker in seminoma?

The clinical significance of neuron-specific enolase (NSE) as a tumour marker was evaluated in 54 patients with seminoma. Before orchiectomy NSE was elevated in six out of 21 patients with stage I seminoma and 11 out of 16 patients with metastases. After orchiectomy NSE normalised in all evaluated stage I cases, but was still elevated in six out of 12 patients with metastatic disease. NSE monitored the effect of cisplatin-based chemotherapy in patients with metastases. In some patients, increased serum NSE was found together with raised levels of human choriogonadotropin (HCG) and lactate dehydrogenase (LDH), while in others only NSE was elevated. No false positive NSE values were observed. NSE seems to be a clinically worthwhile serum tumour marker for monitoring seminoma patients, with a sensitivity and specificity of the same order as HCG.

Neuron-specific enolase as a prognostic factor in metastatic malignant melanoma

Serum neuron-specific enolase (NSE) was measured in 63 patients with metastatic malignant melanoma. 20 patients (32%) had elevated serum NSE (> 10 micrograms/l) before the start of treatment. Another 13 patients (21%) developed pathological NSE values during the course of the disease. In many patients, elevated NSE was related to a large tumour burden, and a gradual rise in serum NSE indicated disease progression. Patients with elevated pretreatment NSE had a median survival time of 3 months compared with 12 months for those with normal pretreatment NSE values. NSE thus proved to be a useful prognostic factor in metastatic malignant melanoma.

Prediction of pelvic lymph node metastases by a prostate-specific antigen and prostatic acid phosphatase in clinical T3/T4M0 prostatic cancer

Prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) were determined in the serum of 69 patients with clinical T3/T4M0 prostatic cancer before staging lymphadenectomy. In principle, high-dose radiotherapy was given only to patients of pathological N0 category. Seventeen patients had a prelymphadenectomy PSA level below the normal upper reference limit (10 micrograms/l) and only 3 of them had pelvic lymph node metastases. Fifteen of 52 patients with a preoperative PSA level > or = 10 micrograms/l were of N0 category. Only 8 of the 41 evaluable patients had PAP values above the normal range, and 6 of these 8 patients had pelvic lymph node metastases. Preoperative PSA values, but not preoperative PAP levels, assist the clinician in predicting regional lymph node metastases in patients with clinical T3/T4M0 prostatic cancer. Two-thirds of the patients with T3/T4 tumours and PSA values between 10 and 50 micrograms/l have regional lymph node metastases. About 80% of the patients with PSA levels < 10 micrograms/l belong to the N0 category. About 75% of the patients with PSA > 50 micrograms/l have N+ disease. Taking into account the individual preoperative PSA values, the indication for preradiotherapy staging lymphadenectomy should be balanced between the chance of demonstrating N+ disease, the expected postoperative morbidity and the benefit for the patient found to be of N0 category.

Flutamide in hormone-resistant prostatic cancer

Flutamide (250 mg. orally 3 times daily) yielded a subjective response in 5 of 25 fully evaluable patients with hormone-resistant prostatic cancer. Four additional patients had early progression. A 40% or greater decrease in the pre-treatment prostate specific antigen level was observed in 7 of 24 patients and this finding was correlated with improved survival. Toxicity was mainly gastrointestinal and resulted in permanent discontinuation of flutamide in 5 patients. Flutamide or similar antiandrogens may have a role in the management of hormone-resistant prostatic cancer when relief of subjective symptoms should be an important treatment goal together with improvement of survival. However, before the drug should be used routinely in the management of hormone-resistant prostatic cancer phase 3 studies must confirm its effectiveness, especially in comparison to less expensive drugs.