Prognostic and predictive value of cathepsins D and L in operable breast cancer patients.

None of the established prognostic factors in breast cancer (BC) is able to determine the final outcome with certainity. Tumor biological factors involved in tumor invasion and metastasis, such as cathepsins and proteins of u-PA system, have been put forward in the recent literature as strong novel prognostic factors in BC. We therefore evaluated prognostic and predictive value of cathepsin-D (CD) and cathepsin-L (CL) in 715 operable BC patients. CD and CL were determined in tumor extracts using immunoradiometric and ELISA assays, respectively. During follow-up (median 37 months), 151 (21%) patients relapsed. In a multivariate analysis of disease-free survival (DFS), CL (p=0.04), nodal status (p<0.001) and hormone receptor status (p<0.001) were the only independent significant prognostic factors. CL thus provided independent prognostic information on DFS and could also predict a response to adjuvant chemotherapy (ChT), while CD had no significant prognostic and predictive impact.

Prognostic and predictive value of the urokinase-type plasminogen activator (uPA) and its inhibitors PAI-1 and PAI-2 in operable breast cancer.

The present study on the prognostic and predictive value of serine proteases was conducted in 460 early breast cancer patients mostly treated with some kind of adjuvant systemic therapy: 156 received chemotherapy, 141 hormone therapy and 111 a combination of both. Already in univariate analysis PAI-1 was the only proteolytic factor with a significant impact on DFS, which was retained in multivariate analysis (p = 0.020); PAI-2 showed borderline significance in univariate analysis (p = 0.0503) and uPA did not present as a significant prognostic factor for DFS in our patient series. In a separate univariate analysis of DFS on patient subgroups defined by adjuvant systemic therapy, a higher risk of relapse associated with higher uPA and PAI-1 levels was found in the subgroup of patients who did not receive any treatment; this difference did not reach the level of significance, probably due to the small number (n = 52) of patients in this group (HR 1.37; p = 0.71 and HR 2.14; p = 0.321, respectively). A higher risk of relapse was also found in the subgroup of patients treated with adjuvant chemotherapy (HR 1.44; p = 0.381 and HR 2.48; p = 0.003, respectively). In contrast, the bad prognostic impact of high uPA and PAI-1 levels was lost in the subgroup of patients treated with adjuvant hormone therapy (HR 0.79; p = 0.693 and HR 0.26; p = 0.204, respectively). The same observations were made for the uPA/PAI-1 combination. Our study confirmed the prognostic value of serine proteases in early breast cancer. In addition, it pointed to a possible predictive value of these tumor markers for response to adjuvant hormone therapy with tamoxifen, which should be confirmed in further studies.

Prognostic value of plasminogen activator inhibitors in breast cancer.

The prognosis of cancer is primarily dependent on its potential to invade and metastasize. Data from both preclinical and clinical studies strongly suggest that serine proteases, as well as their inhibitors and receptor, play a central role in the processes leading to metastasis. We therefore investigated the prognostic value of plasminogen activator inhibitors type 1 (PAI-1) and type 2 (PAI-2) and the combination of both inhibitors in 332 patients with operable breast cancer. PAI-1 and PAI-2 content was measured in the primary tumor cytosols using an enzyme-linked immunosorbent assay. For PAI-1 the median value (3.9 ng/mg protein) was used as cutoff, while the optimized cutoff for PAI-2 (6.5 ng/mg protein) was obtained using the log-rank statistic. After a median follow-up of 46 months 96 (29%) patients relapsed. In univariate analysis patients with a high PAI-1 or a low PAI-2 content had an increased risk of relapse. The difference was statistically significant for PAI-1 (p<0.0001) and almost statistically significant for PAI-2 (p=0.057). Stage, tumor size, differentiation grade, lymph node status and hormone receptor status also showed significant univariate impact on disease-free survival (DFS). In multivariate analysis (Cox model) PAI-1 (p<0.0001, RR=2.78), PAI-2 (p=0.0075, RR=2.17), UICC stage (p=0.0014, RR=2.2), differentiation grade (p=0.0097, RR=1.91) and nodal status (p<0.0001, RR=2.9) retained their significance. When both inhibitors were combined the worst prognosis was observed in patients with simultaneous high PAI-1 and low PAI-2 levels, whereas low PAI-1 in combination with high PAI-2 values indicated a very favorable prognosis. In conclusion, our study showed that both PAI-1 and PAI-2 had independent prognostic value in breast cancer. Combination of both inhibitors further improved the differentiation of patients with respect to prognosis.

Prognostic value of the urokinase-type plasminogen activator, and its inhibitors and receptor in breast cancer patients.

Urokinase-type plasminogen activator (uPA), its inhibitors (PAI-1 and PAI-2), and its receptor (uPAR) play a key role in tumor invasion and metastasis. This study was designed to evaluate the prognostic impact of uPA, PAI-1, PAI-2, and uPAR and the combination of these factors in a group of 460 primary breast cancer patients. Concentrations of all 4 components of the uPA system were measured in tumor extracts using enzyme-linked immunosorbent assays (American Diagnostica, Inc, Greenwich, CT). After a median follow-up of 33 months, 18.5% of the patients had relapsed. The Cox proportional hazards model was applied for both univariate and multivariate analyses of disease-free survival (DFS). PAI-1 and PAI-2 were shown to provide independent prognostic information in breast cancer. Patients with either low levels of PAI-1 or high levels of PAI-2 were found to have better DFS (relative risk was 2.08 and 1.78, respectively). The prognostic value could be even further improved by a combination of both inhibitors. Aside from the uPA inhibitors, only nodal status and hormonal receptor status retained independent prognostic value. The other 2 invasion markers, uPA and uPAR, showed no statistically significant impact on DFS. In our patients, who were mostly treated with adjuvant therapy, uPA was not found to be an independent prognostic marker for DFS; this could be a consequence of the predictive value of uPA for response to adjuvant therapy and should be further investigated.

Prognostic significance of plasminogen activator inhibitor-1 in breast cancer, with special emphasis on locoregional recurrence-free survival.

The independent prognostic value of protease uPA and its inhibitor PAI-1 for survival in breast cancer patients is firmly established. However, there is very little data on the prognostic value of serine proteases and their inhibitors for locoregional recurrence in breast cancer. The prognostic value of PAI-1 for local control in a group of 766 patients treated at our institute with either breast conserving treatment or modified radical mastectomy was evaluated. The locoregional recurrence-free survival (LRFS) of patients with PAI-1 values above the median value was significantly worse than that of patients with PAI-1 values below the median value (log-rank; p=0.0078). In multivariate analysis PAI-1 levels proved to be of independent statistical significance for LRFS (p=0.0401, relative risk 2.28, 95% confidence interval 1.04-5.02). The independent prognostic value of PAI-1 for metastasis-free survival and overall survival was also confirmed. In addition, our data suggest that PAI-1 antigen levels in tumor tissue might be of prognostic value for survival after locoregional recurrence (log-rank; p=0.0618). According to our findings, PAI-1 levels could be used as a biological marker that could facilitate the identifation of patients with a higher risk of local relapse already at the time of primary treatment. These patients should then be offered more aggressive treatment.

Glutathione and glutathione S-transferases as early markers for ovarian carcinomas: case series.

AIM: To determine the activity of glutathione (GSH) and concentrations of glutathione S-transferases (GST), urokinase type plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI-1), and to evaluate their diagnostic and prognostic value and possible correlation with clinical and histopathological prognostic factors for ovarian carcinomas. METHODS: The concentrations of GSH, uPA, PAI-1, and activity of GST were analyzed in 35 tissue samples taken from 10 normal ovaries, 10 benign, 10 primary malignant, and 5 metastatic ovarian tumors. The GSH level and GST activity were determined by spectrophotometric methods, and uPA and PAI-1 concentrations by ELISA commercial kits. RESULTS: GSH concentrations were significantly higher in primary malignant (126.3+/-12.8 nmol/mg protein) and metastatic (160.5+/-24.3 nmol/mg protein) ovarian tumor specimens than in normal ovarian tissue (48.9+/-8.1 nmol/mg protein, p<0.003 for both carcinoma groups) or benign ovarian tumor samples (35.2+/-5.0 nmol/mg protein, p=0.001). The GST activity was significantly higher in primary malignant (245.8+/-22.7 nmol/min/mg protein) and metastatic (303.7+/-48.8 nmol/min/mg protein) ovarian tumor tissues than in benign tumor specimens (105.9+/-16.2 nmol/min/mg protein, p<0.004 for both carcinoma groups) or normal ovarian tissue samples (133.2+/-32.0 nmol/min/mg protein, p<0.044 for both carcinoma groups). There were no statistical differences in uPA and PAI-1 concentrations between normal, benign, and malignant tumor samples. Concentrations of GSH, uPA and PAI-1, and activity of GST were independent from histopathological and clinical prognostic factors. CONCLUSION: Increased GSH concentration and GST activity found in primary malignant and metastatic ovarian tumor samples were independent of histopathological and clinical prognostic factors, suggesting that they could be early markers for ovarian carcinomas.

Cathepsin B and L and stefin A and B levels as serum tumor markers in squamous cell carcinoma of the head and neck.

Cysteine proteinases cathepsin (Cath) B and L and their endogenous inhibitors stefin (Stef) A and B concentrations were measured using a quantitative immunosorbent assay (ELISA; KRKA d.d., Novo mesto, Slovenia) in serum samples from 35 patients with primary and 7 patients with recurrent squamous cell carcinoma of the head and neck (SCCHN), obtained at diagnosis (Serum no.1) and after therapy (Serum no. 2), and compared to sera from 30 (Stef B, 90) healthy volunteers. A significantly higher Stef A (P = 0.005) and lower Stef B (P < 0.001) concentrations were measured in patients' Serum no.1 than in controls, and the levels of Caths B and L and Stef A were found to be significantly elevated in Serum no.1 as compared to Serum no. 2 (P = 0.045, P = 0.041 and P = 0.024, respectively). The time of Serum no.2 collection did not influence the concentration of either Caths or Stefs in these samples, and no correlation was observed with the established prognostic factors for any of the parameters studied. Patients with subsequently diagnosed recurrent disease had a significantly lower Cath L concentration than those without evidence of relapse during follow up (P = 0.05). The risk of disease recurrence and SCCHN-related death correlated significantly with low Cath L serum levels (P = 0.012, P = 0.006). The serum levels of Cath B, Stef A and Stef B did not influence significantly the probability of survival.

Plasminogen activator inhibitor type 2: potential prognostic factor for endometrial carcinomas.

The clinical determination of proteases which are involved in carcinogenesis, invasion and metastasis may contribute to the detection of the early stage of disease, and to the prognostic assessment of patients with the cancer. The aim of the present study was to determine the level of urokinase plasminogen activator (uPA), plasminogen activator inhibitor type 1 (PAI-1) and plasminogen activator inhibitor type 2 (PAI-2) in normal and malignant tissues of corpus uteri and to evaluate the possible correlation with clinical and histopathological prognostic factors. UPA, PA-I and PAI-2 were determined by the ELISA assay in tissue cytosol of matched pair samples from 27 patients with endometrial carcinoma. Results show that significantly higher levels of these proteins were found in malignant than in normal tissue samples (uPA: 1.266 versus 0.633 ng/mg protein, PAI-1:4.468 versus 1.958 ng/mg protein, and PAI-2:3.428 versus 0.483 ng/ml protein). The levels of uPA and PAI-1 did not correlate with clinical staging or pathohistological grading. However, in tumor tissues with clinical stages II and III, myometrial invasion > 50%, and lymphovascular invasion, increased levels of PAI-2 were determined. Our results indicate that components of the plasminogen activation cascade are up-regulated in endometrial cancer and suggest the role of PAI-2 in determining invasive potential of endometrial carcinomas.

Cathepsin D expression in early cutaneous malignant melanoma.

BACKGROUND: The aspartic proteinase cathepsin D is believed to be associated with proteolytic processes leading to the invasion and seeding of tumor cells. An association between cathepsin D tissue concentration and aggressiveness of tumors has been detected in different cancer types, as well as in metastatic melanoma. METHODS: The concentration of cathepsin D was measured immunoradiometrically (ELSA-CATH-D kit, CIS Bio International) in the cytosols of 51 primary cutaneous melanomas (with Breslow index < 4 mm) to estimate the tissue concentrations of cathepsin D in early cutaneous melanoma. RESULTS: A significantly elevated concentration of cathepsin D was measured in the tumor cytosols as compared to adjacent normal tissue (44.2 vs. 14.7 pmol/mg of total protein, P < 0.001). CONCLUSIONS: Our results indicate that cathepsin D is expressed at high levels by melanoma cells. The extremely high expression of cathepsin D in two of our patients, with later progression of the disease over a 42-month follow-up period, suggests a possible correlation between the cathepsin D tissue concentration and the prognosis of primary cutaneous malignant melanoma.

Decreased cortisol secretion by adrenal glands perfused with the P-glycoprotein inhibitor valspodar and mitotane or doxorubicin.

The aim of this study was to investigate the role of P-glycoprotein (P-gp) in the adrenal gland. It has been presumed that P-gp, rather than being involved in physiological cortisol secretion, plays a role in protecting the adrenacortical cells from xenobiotics. To explore this a study was performed on perfused bovine adrenal glands. Individual experimental groups were perfused with either a selective P-gp blocker (valspodar) alone, with a xenobiotic (mitotane or doxorubicin) alone or with both valspodar and a xenobiotic. The cumulative amounts of cortisol secreted in each individual group were calculated and the two-sample t-test was used to compare the mean values of cumulative amounts. The mean value of cortisol secreted from the group of adrenals perfused with the P-gp blocker was not significantly different from that of the control group. Treatment with either mitotane or doxorubicin decreased the amount of cortisol secreted but not significantly when compared to the amount of cortisol secreted in basal conditions. However, treatment with the P-gp blocker valspodar in addition to either mitotane or doxorubicin significantly decreased cortisol secreted compared to the amount of cortisol secreted by the glands treated with either mitotane (p=0.009) or doxorubicin (p=0.017) alone. The regressive changes discovered in all experimental groups were most prominent when valspodar was used with either mitotane or doxorubicin. We found that P-gp blockade increases by xenobiotic (mitotane and doxorubicin)-induced damage of adrenocortical cells, which points to a role of P-gp in the protection of adrenal gland from xenobiotics.

Prognostic significance of cysteine proteinases cathepsins B and L and their endogenous inhibitors stefins A and B in patients with squamous cell carcinoma of the head and neck.

Cysteine proteinases cathepsins (Cats) B and L and their endogenous inhibitors stefins (Stefs) A and B are implicated in the processes of local and metastatic tumor spread. They were identified as potential prognosticators in various malignant diseases, particularly in breast cancer. The aim of the present study was to determine the concentrations of Cats B and L and Stefs A and B in the tumor and adjacent normal tissue samples collected from 49 patients (the present group) with squamous cell carcinoma of the head and neck (SCCHN), using quantitative immunosorbent assays (ELISA; KRKA d.d., Novo mesto, Slovenia). Their clinical significance was compared with that from a previous study (the reference group, 45 patients; Budihna et al., Biol. Chem. Hoppe-Seyler, 377: 385-390, 1996). The follow-up of patients from the latter report was updated for this purpose. In the present group, significantly higher concentrations of Cat B (P < 0.0001), Cat L (P < 0.0001) and Stef A (P = 0.006) were found in tumors compared with concentrations in their normal tissue counterparts. Cat concentrations in normal laryngeal tissue were significantly/marginally elevated compared with nonlaryngeal tissue (Cat B, P = 0.02; Cat L, P = 0.06). The tumor concentration of Cat L was found to correlate with pT classification (P = 0.005) and tumor-node-metastasis stage (P = 0.05), whereas the concentrations of Stefs A and B correlated with pN classification (P = 0.007 and P = 0.03, respectively) and tumor-node-metastasis stage of the disease (P = 0.02 and P = 0.03, respectively). There was no statistically significant difference between low and high Cat B or Cat L groups, regarding either disease-free survival or disease-specific survival, using a minimum P approach to determine cutoff concentrations. The risk of disease recurrence and SCCHN-related death was significantly higher in patients with low Stef A (P = 0.0006 and P = 0.0005, respectively) and Stef B (P = 0.0009 and P = 0.0007, respectively) tumors, compared with those with high-Stef A and Stef B tumors. These results remained significant even after Ps were adjusted for a possible bias in the estimated effect on survival. The survival analysis in the reference group also confirmed these findings (Stef A: P = 0.0009 and P = 0.002, respectively; Stef B: P = 0.03 and P = 0.009, respectively). To avoid any possible bias arising from the differences between the laboratories that performed the biochemical analysis, the concentrations of both Stefs in the present group and in the reference group were standardized and coupled together to form a uniform group. In univariate survival analysis, standardized values of Stef A and Stef B correlated inversely with the rate of relapse (P = 0.0000) and mortality rate (P = 0.0000). Multivariate regression analysis showed that the standardized value of Stef A is the strongest independent prognostic factor for both disease-free survival and disease-specific survival. These findings show the specific role of Cats B and L and Stefs A and B in the invasive behavior of SCCHN. Furthermore, Stef A proved to be a reliable prognosticator of the risk of relapse and death in patients with this type of cancer.

Urokinase-type plasminogen activator, plasminogen activator inhibitor type 1 and cathepsin D: analysis of their prognostic significance in squamous cell carcinoma of the head and neck.

BACKGROUND: The aim of the study was to evaluate the prognostic significance of tumour and serum concentrations of urokinase-type plasminogen activator (uPA), its type 1 inhibitor (PAI-1) and cathepsin D (Cath D) in patients with squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Determinations of uPA and PAI-1 were made using enzyme-linked immunosorbent assays in tumour and serum samples of 47 and 32/47 patients, respectively. For the determination of tumour (94 patients) and serum (34/94 patients) Cath D concentrations, an immunoradiometric assay was used. RESULTS: In an univariate survival analysis, the risk of disease recurrence and SCCHN-related death was significantly higher in the patients with high uPA (P = 0.046, P = 0.010) tumours, compared to those with low uPA tumours. In addition, the high serum levels of uPA correlated positively with the rate of relapse (P = 0.007), but not with the mortality rate (P = 0.200). There was no statistically significant difference between low and high PAI-1 groups, regarding either tumour or serum concentration of the inhibitor, and between low and high Cath D tumours. Low Cath D serum levels appeared to be related to longer disease-free interval (P = 0.055), but not to disease-specific survival (P = 0.120). CONCLUSIONS: The tumour levels of uPA, as well as serum levels of uPA and Cath D could potentially predict the survival probability of patients with SCCHN. However, the strength of this association remains to be investigated on a larger and more homogeneous group of patients.

Cisplatin resistant glioblastoma cells may have increased concentration of urokinase plasminogen activator and plasminogen activator inhibitor type 1.

Gliomas are the most common form of intrinsic primary brain tumors, that extensively invade the surrounding normal brain tissue. The failure of chemotherapy treatment of these tumors is chiefly attributed to drug-resistance. From human glioblastoma we developed two cell sublines resistant to cisplatin due to acute (AT cells) or continuous (CT cells) treatment with clinically relevant doses of cisplatin. We examined their sensitivity to different cytostatics by colorimetric MTT assay. The concentrations of urokinase plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) were determined by the ELISA assay. The results reveal that both AT and CT cells became resistant to cisplatin and vincristine; AT cells became resistant also to etoposide. Both AT and CT cells did not significantly change their sensitivity to doxorubicin, 5-fluorouracil and chlorambucil. Concentrations of uPA and PAI-1 were increased in CT cells, with no change in AT cells. In the conditioned medium of both, AT and CT cells, the level of uPA were increased. No differences in concentrations of PAI-1 in the conditioned medium of these cells were found. Thus, our results show that drug-resistance of glioblastoma cells may be accompanied with the increased levels of markers for tumor invasion.

Drug resistant tumor cells have increased levels of tumor markers for invasion and metastasis.

The association between drug-resistance and three markers for invasive capacity: cathepsin D (Cath D), urokinase type plasminogen activator (uPA) and inhibitor of plasminogen activator type 1 (PAI-1) was examined in nine cervical and laryngeal carcinoma cell lines resistant to different cytostatics. The level of Cath D was measured by solid phase two-site immunoradiometric assay, while uPA and PAI-1 concentrations were determined by use of ELISA. All drug resistant cell lines had increased concentration of cathepsin D. uPA levels were similar in parental and drug resistant cervical carcinoma cells, but significantly higher in all examined drug resistant laryngeal carcinoma cells. In cervical carcinoma cells, PAI-1 concentrations were similar in parental and cisplatin resistant, but significantly higher in doxorubicin resistant cells. In laryngeal carcinoma cells, no increase in concentrations of PAI-1 was determined in the three from five resistant cell lines. There was no uPA in conditioned medium of parental or drug resistant cells. PAI-1 was detected in conditioned medium. Its levels were significantly increased in the medium of two cervical and three laryngeal drug resistant carcinoma cells. Thus, our results suggest that drug-resistance may be accompanied by increased levels of tumor associated proteases and/or its inhibitor.

Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) in tissue and serum of head and neck squamous cell carcinoma patients.

The aim of this study was to determine urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) concentrations in tumour and adjacent normal tissue samples from 58 patients, and in serum samples from 40 of 58 patients with squamous cell carcinoma of the head and neck obtained at diagnosis and after completion of therapy. uPA and PAI-1 serum concentrations were also measured in 28 healthy volunteers who served as controls. Measurements were made using enzyme-linked immunosorbent assay (ELISA) techniques. For both uPA and PAI-1, significantly elevated concentrations were measured in tumour tissue as compared with normal tissue (uPA: 8.89 versus 0.41 ng/mg total protein (mgp), P < 0.0001; PAI-1: 23.9 versus 1.47 ng/mgp, P < 0.0001). A statistically significant difference in uPA concentrations was found between normal laryngeal and nonlaryngeal tissue (0.52 versus 0.3 ng/mgp, P = 0.008), and in PAI-1 concentrations between T1 + 2 and T3 + 4 stage of disease (17.32 versus 35.63 ng/mgp, P = 0.04). The uPA concentrations positively correlated with those of PAI-1 measured in both tumour (Rs = 0.62, P < 0.0001) and normal tissue (Rs = 0.30, P = 0.02). In serum samples, lower concentrations of PAI-1 were measured in the control group than in patients with cancer (412.0 versus 680.5 ng/ml serum (mls), P = 0.0006). The time of collection of the serum sample did not influence uPA and PAI-1 concentrations, and no association was observed between their concentrations and any clinical and histopathological prognostic factors tested. Our results indicate that both uPA and PAI-1 may play a specific role in the process of invasion and metastasis, and might also be of prognostic value in squamous cell carcinoma of the head and neck.

Cathepsin D in tissue and serum of patients with squamous cell carcinoma of the head and neck.

Aspartic proteinase cathepsin D (CD) is believed to be associated with proteolytic processes leading to local invasion and seeding of tumour cells. To estimate a potential prognostic value of cathepsin D in squamous cell carcinoma of the head and neck, its total concentration was measured immunoradiometrically (ELSA-CATH-D kit, CIS bio international) in cytosols of tumour and adjacent normal tissue samples from 111 patients; in 42/111 patients, the CD concentration was determined in serum samples obtained at diagnosis (serum no. 1) and after the therapy (serum no. 2) from each of these patients. Sera of 15 healthy volunteers served as controls. A significantly elevated concentration of CD was measured in tumour cytosols as compared to normal tissue cytosols (31.1 versus 12.6 pmol/mgp, P < 0.0001) and in cytosols of normal laryngeal tissue than of the oral cavity or pharynx (13.3 versus 11.2 pmol/mgp, P = 0.03). The higher CD tumour concentration correlated with the age of the patients (< or =60 versus >60 years, 28.8 versus 32.8 pmol/mgp, P = 0.045) and histopathological tumour grade (G1+2 versus G3, 32.6 versus 24.4 pmol/mgp, P = 0.02). In serum samples, a lower concentration of CD was measured in the control group than in the patients (3.6 versus 4.1 pmol/mls, P = 0.045) and in serum no. 1 than in serum no. 2 (4.1 versus 5.1 pmol/ mls. P = 0.05). The CD concentration in sera obtained at diagnosis was stage-dependent (S(I-III) versus S(IV), 3.9 versus 4.7 pmol/ mls. P = 0.09); there was a trend towards lower CD concentrations with an increasing time delay in serum no. 2 sampling (Rs = -0.20, P = 0.21). No correlation was observed between cytosolic and serum concentrations of CD. We conclude that our results confirm a specific role of CD in the process of invasion and metastasis of squamous cell carcinoma of the head and neck, which might also be of prognostic value in this particular cancer type.

Effect of the multidrug resistance modulator valspodar on serum cortisol levels in rabbits.

PURPOSE: To contribute to a better understanding of the physiological role of P-glycoprotein (P-gp) in the adrenal gland, we initiated our studies in rabbits. The aim of our study was to explore the effect of the selective multidrug resistance (MDR) modulator PSC 833 (valspodar) on serum cortisol in rabbits. METHODS: Baseline and corticotropin-stimulated serum cortisol levels were measured before and after valspodar treatment in adult male rabbits. Seven rabbits were treated with 50 mg/kg per dose and seven, with 75 mg/kg per dose of valspodar subcutaneously. Serum cortisol levels were determined by radioimmunoassay adjusted for expected values. RESULTS: Serum cortisol levels (baseline as well as corticotropin-stimulated) increased after both valspodar treatment regimens. The increase was dose-dependent and was higher for the baseline than for the corticotropin-stimulated values. Serum valspodar levels exceeding 1000 ng/ml were achieved in all except one animal in each group. We hypothesize that the increased serum cortisol levels were due to increased adrenocorticotropic hormone (ACTH) secretion after valspodar treatment, but, unfortunately, we could not measure ACTH properly in rabbits by means of the commercially available kits. CONCLUSIONS: Our study indicates that P-gp is not involved in steroid hormone secretion in the adrenal gland. This is evident from observations that serum cortisol levels were found to have increased rather than decreased in rabbits treated with a P-gp blocker and that the treated animals appeared healthy and normal. Since P-gp was found to play an important role in protection against xenobiotics in some other organs, further studies to explore the protective role of P-gp in the adrenal gland are warranted.

Comparison of standardized immunohistochemical and biochemical assays for estrogen and progesterone receptors in breast carcinoma.

The purpose of this study was to determine estrogen receptor (ER) and progesterone receptor (PR) expression assessed by dextran-coated charcoal method (DCC) and standardized immunohistochemical method (IHC) in a prospective series of 557 primary breast carcinomas, to assess the concordance between the two assays, and to evaluate the association between hormone receptor expression and various clinicopathological parameters. For ER, results of both methods were in agreement in 73.6% of the cases (277 positive, 133 negative), 74 tumors (13.3%) where IHC+/DCC- and 73 (13.1%) were IHC-/DCC+. For PR, concordant results were observed in 72.7% of the cases (201 positive and 204 negative), 127 tumors (22.8%) were IHC+/DCC- and 25 (4.5%) were IHC-/DCC+. Irrespective of the method used, ER and PR positivity showed a strong negative association with tumor grade. ER+ tumors were significantly more common among older patients. With IHC, PR+ cases were more common among tumors of lobular and mucinous type and among node positive tumors. The only parameter that was related to the concordance rate of ER determination by the DCC and IHC method was the age of the patients, with agreement being significantly lower in the group of patients younger than 50 years. On the other hand, discordant PR determination was more often observed in tumors of lower grade, node positive tumors and in tumors of lobular and mucinous type.

Prognostic value of cathepsins B, D and steffins A and B in laryngeal carcinoma.

Concentrations of cathepsins A, D and stefins A and B were measured in primary tumor and adjacent normal tissue of 25 patients with laryngeal carcinoma. Median concentrations of both cathepsins and that of stefin B were significantly higher in tumor tissue than in their normal counterparts (cathepsins B and D, P < 0.0001; stefin B, P = 0.01), indicating their possible involvement in the process of tumor spread. Early (T1 and T2) tumors had lower concentrations of stefins A and B than locally advanced (T3 and T4) tumors (P = 0.04). Disease-free and disease-specific survival rates at 45 months were significantly better in patients with tumor concentrations of stefins above or equal to the cut-off values (stefin A, P = 0.001 and P = 0.004; stefin B, P = 0.048 and P = 0.008), indicating that these might be of prognostic value. The concentrations of cathepsins B and D did not correlate with survival.