Response to 5-fluorouracil in metastatic extramammary Paget disease of the scrotum presenting as pancytopenia and back pain.

Extramammary Paget disease is a rare intraepithelial neoplasm of the vulvar, penoscrotal, or perianal skin. No effective therapies for metastatic disease have been reported, and prognosis for metastatic disease is poor.Here, we report the case of an Asian man who was initially diagnosed with extramammary Paget disease of the scrotum. Three years later, the patient presented to hospital with pancytopenia and back pain. After an extensive work-up, biopsies of liver and bone marrow revealed adenocarcinoma with signet cells and immunohistochemical staining positive for keratin 7, carcinoembryonic antigen, and prolactin-induced protein, but negative for keratin 20, S100, and prostate markers, consistent with his previous biopsyproven Paget disease of the scrotum. The patient was treated with 5-fluorouracil-based therapy in addition to palliative radiotherapy to selected spine levels. A promising palliative response was demonstrated following 5-fluorouracil chemotherapy.A review of the literature on the pathogenesis, diagnosis, treatment options, and outcomes for metastatic extramammary Paget disease is presented.

IGFBP-3 in epithelial ovarian carcinoma and its association with clinico-pathological features and patient survival.

Insulin-like growth factor binding protein-3 (IGFBP-3) regulates the mitogenic and anti-apoptotic actions of insulin-like growth factors (IGFs). To study the role of IGFBP-3 in ovarian cancer progression, we measured IGFBP-3 concentrations in tumour tissues from 147 patients with epithelial ovarian carcinoma and examined its associations with clinicopathological features of disease and patient survival. The average age of the patients was 54.6 years (range 25-88 years) and the median follow-up time was 37 months. IGFBP-3 levels were measured with a commercial immunoassay kit. Low IGFBP-3 levels were significantly associated with unfavourable prognostic features of the disease, including advanced stage (P=0.048), large size of residual tumour (P=0.007), and suboptimal debulking outcome (P=0.007). Low IGFBP-3 levels were also associated with a significantly increased risk for disease progression (RR=1.92; 95% confidence interval (CI) 1.05-3.45; P=0.034), but the association was not sustained when other clinical and pathological variables were adjusted for in the analysis. No significant associations were observed between the IGFBP-3 level and patients' overall survival and response to chemotherapy. Findings of the study indicate that IGFBP-3 may play a role in the progression of epithelial ovarian cancer, but that it has no independent value in predicting either disease prognosis or the response of patients to chemotherapy.

Evidence for a dose-response effect between p53 (but not p21WAF1/Cip1) protein concentrations, survival, and responsiveness in patients with epithelial ovarian cancer treated with platinum-based chemotherapy.

The prognostic values of p53 and of its downstream mediator p21WAF1/Cip1 in patients receiving adjuvant chemotherapy for epithelial ovarian cancer have not been clearly established. Tumor extracts from a series of 120 patients treated postsurgically with cisplatin or carboplatin alone or together with other chemotherapeutics for primary ovarian carcinoma were assayed both for p53 protein by an immunofluorometric assay developed by us and for p21 protein by a commercially available immunoassay. Relative risks (RRs) for cancer relapse and death after 24 months of follow-up were determined by multivariate Cox regression analysis. Disease-free (DFS) and overall survival (OS) probabilities were also examined by the Kaplan-Meier method and log-rank tests. All other procedures were similarly nonparametric and based on two-sided tests of significance. Concentrations of p53 were elevated in patients with advanced stage disease (P = 0.02) or poorly differentiated (P = 0.03), suboptimally debulked tumors (P = 0.02), as well as in patients who failed to respond to chemotherapy (P = 0.03), as assessed by computed tomography scanning, serum CA125 determination, and second-look laparotomy. Statistically significant associations between concentrations of p53 and p21 were not found, nor were relationships demonstrated between concentrations of p21 and other clinicopathological variables or treatment response. Univariate analysis showed that p53 concentrations above the median indicated significantly higher risks for relapse (P = 0.04) and death (P < 0.01) and showed trends for increasing risks for relapse (P = 0.04) and death (P < 0.01) when p53 was considered as a four-level categorical variable. Multivariate analyses adjusted for age, stage, grade, and residual tumor size confirmed these observations (RR = 1.50; P = 0.05 for DFS and RR = 1.92; P = 0.03 for OS) for median-dichotomized p53, but the trends were of borderline significance (P = 0.09 for DFS and P = 0.07 for OS). In contrast, p21 positivity was not a significant predictor of favorable outcome in univariate survival analysis, and use of a three-level variable combining positivity or negativity status for both p53 and p21 did not yield greater separation of patients into risk groups (P = 0.07 for DFS and P = 0.06 for OS) than the use of p53 alone. Assessment of p53 expression may be an independent indicator of poor prognosis in ovarian cancer patients treated with adjuvant chemotherapy. The prognostic value of p21 expression, however, could not be demonstrated in our series of ovarian cancer patients.

Breast cancer prognostic significance of a single nucleotide polymorphism in the proximal androgen response element of the prostate specific antigen gene promoter.

Prostate Specific Antigen (PSA) expression by breast epithelial cells is associated with favorable breast cancer prognosis. In preliminary studies, we found that a nucleotide variation (G-->A) at position -158 in the androgen response element (ARE-1) of the PSA promoter was present in four out of 9 breast tumors examined and in a breast carcinoma cell line. We have now determined the nucleotide composition at position -158 of DNA extracted from 148 well-characterized breast tumors and compared tumor genotype with that of controls without cancer, with tumor PSA concentration and with clinicopathological variables, overall survival and disease free survival. The G-->A base change at position -158 is a polymorphism. Allelotypes were similarly distributed in breast cancer patients and controls. The Mann-Whitney U Test showed a significantly higher tumor PSA concentration in tumors that presented a homozygous G as opposed to homozygous A genotype. Genotype at position -158 was not associated with clinicopathological variables in contingency table analysis. Univariate Cox regression models showed a 28% reduction in risk for death in patients with homozygous G genotype compared to those with homozygous A genotype (P = 0.03). However, ARE-1 genotype did not significantly add to the prognostic power in the multivariate model of overall survival. In summary, the base change at position -158 is a polymorphism that may affect breast cancer prognosis, but further studies are required to confirm this possibility and to investigate the relevance of this polymorphism in terms of breast cancer susceptibility.

p21WAF1 protein expression determined by quantitative immunoassay in relation to non-small-cell lung cancer aggressiveness.

PURPOSE: p21WAF1, a cyclin-dependent kinase inhibitor, is an important mediator of the cell-cycle arrest and tumor suppression induced by the protein p53. Although alterations of the p53 gene and its overexpression are frequent in most malignancies, including non-small-cell lung cancer (NSCLC), and may be associated with poor patient prognosis, the clinical utility of p21WAF1 expression in NSCLC has not been established. METHODS: We have used a commercial enzyme-linked immunosorbent assay (ELISA) kit for p21WAF1 to test soluble extracts of 54 NSCLC specimens with known clinicopathological properties. RESULTS: There was no correlation between p21WAF1 and p53 concentrations, the latter being determined by a time-resolved immunofluorometric assay developed in-house. Furthermore, p21WAF1 levels were not associated with patient age, tumor/node/metastasis (TNM) stage, lymph node metastasis, histological grade or type, or smoking history, in Mann-Whitney analysis. chi2-tests, based on cutoffs equal to the 25th, 50th, or 75th percentiles of the p21WAF1 distribution, similarly did not reveal any statistically significant associations between p21WAF1 and other clinicopathological variables. Because of the small number of patients and the median follow-up of only 18 months, a meaningful survival analysis could not be performed. CONCLUSION: In summary, this preliminary study suggests that ELISA-quantified p21WAF1 levels in NSCLC extracts are weaker than p53 in terms of prognostic value and do not contribute to the further subclassification of patients.

Expression of a prostate-associated protein, human glandular kallikrein (hK2), in breast tumours and in normal breast secretions.

The recent demonstration of human glandular kallikrein (hK2) expression in a breast carcinoma cell line has suggested that this putatively prostate-restricted, steroid hormone-regulated protease may also be expressed in breast epithelium in vivo and secreted into the mammary duct system. Given that the only substrate yet identified for hK2 activity is the precursor of prostate-specific antigen (PSA), the expression of which in breast carcinomas may be associated with favourable prognosis, our purpose was to examine the expression pattern of both hK2 and PSA in breast tumour tissues. Cytosolic extracts of 336 primary breast carcinomas prepared for routine oestrogen receptor (ER) and progesterone receptor (PR) analysis, as well as 31 nipple aspirates from six women with non-diseased mammary glands, were assayed for hK2 and PSA using immunofluorometric assays developed by the authors. In the tumour extracts, measurable hK2 and PSA concentrations were detected in 53% and 73% of cases respectively, and were positively correlated to each other (r = 0.59, P = 0.0001). Higher concentrations of PSA and hK2 were found in tumours expressing steroid hormone receptors (P = 0.0001 for PSA and P = 0.0001 for hK2, by Wilcoxon tests for both ER and PR), and both PSA (r = 0.25, P = 0.0001) and hK2 (r = 0.22, P = 0.0001) correlated directly with PR levels. A negative correlation between patient age and PSA (r = -0.12, P = 0.03) was also found. Both proteins were present in nipple aspirate fluid at relatively high concentrations which were positively correlated (r = 0.53, P = 0.002). The molecular weights of the immunoreactive species quantified by the hK2 and PSA assays were established by high-performance liquid chromatography (HPLC) and were consistent with the known molecular weights of hK2 and PSA. Together these data provide the first evidence, to our knowledge, that both malignant breast tissue and normal breast secretion contain measurable quantities of hK2, and that the degree of hK2 expression or secretion is directly proportional to the expression of PSA and steroid hormone receptors. hK2 expression may therefore be a marker of steroid hormone action in breast tissue.

Enhanced prediction of breast cancer prognosis by evaluating expression of p53 and prostate-specific antigen in combination.

p53 gene mutation is the most common genetic alteration in neoplastic diseases, including breast cancer, for which p53 alteration may indicate poor prognosis. Recent clinical evidence suggests that prostate-specific antigen (PSA) expression may identify breast cancer patients with favourable outcome. Assessment of p53 and PSA in combination, potentially offering improved prediction, has not yet been performed. Extracts from 952 primary breast carcinomas were assayed for PSA and p53 by quantitative enzyme-linked immunosorbent assays (ELISAs) developed by the authors. Concentrations of each marker were classified as negative or positive on the basis of median and 30th percentile cut-off points for p53 and PSA respectively. Patients followed for a median of 6 years having different combinations of negative or positive status for PSA and p53 were compared with respect to the relative risks (RRs) for relapse and death by Cox proportional hazards regression analysis, in which an interaction term was also evaluated, and with respect to disease-free survival (DFS) and overall survival (OS) probabilities by Kaplan-Meier plots and log-rank tests. Multivariate models were adjusted for oestrogen and progesterone receptor status, nodal status, patient age, tumour size, DNA ploidy, S phase fraction and receipt of chemotherapy. Interactions were not found between the status of PSA and p53 in the Cox models, in which PSA-negativity (RR = 1.47, P = 0.020 for DFS, and RR = 1.49, P = 0.023 for OS) and p53-positivity (RR = 1.46, P = 0.017 for DFS, and RR = 1.41, P = 0.033 for OS) were individually associated with prognosis. Evaluation of a combined three-level variable revealed that PSA(-)/p53(+) patients had significantly higher risks for relapse (RR = 2.13, P < 0.001) and death (RR = 2.08, P = 0.001) than PSA(+)/p53(-) patients, and that patients positive or negative for both markers had intermediate risks for the outcome events in the same multivariate analysis (RR = 1.45 for both DFS and OS). The results of our study demonstrate that the assessment of combined PSA and p53 expression status by ELISAs, easily applicable to breast tumour extracts prepared for steroid hormone receptor analyses, may stratify breast cancer patients into groups differing by relapse and death risks of greater magnitude than offered by the assessment of either p53 or PSA alone.

Immunoenzymatically determined pepsinogen C concentration in breast tumor cytosols: an independent favorable prognostic factor in node-positive patients.

The aim of this study was to determine the concentration and to evaluate the prognostic value of pepsinogen C (PepC) in breast cancer patients. PepC is an aspartic proteinase that is involved in the digestion of proteins in the stomach and is also synthesized by a subset of human breast tumors. PepC concentrations were measured with a highly sensitive immunofluorometric assay, which uses two monoclonal antibodies that are specific for PepC and has a detection limit of 0.1 ng/ml. Breast tumor cytosols from 151 patients (median follow-up, 67 months), stratified according to nodal status, were evaluated. An optimal cutoff value, equal to 1.75 ng/mg of extracted protein, was first defined by statistical analysis. PepC status was then compared with other established prognostic factors, in terms of disease-free survival (DFS) and overall survival (OS). High PepC concentrations were found in small (P = 0.003) and well-differentiated tumors (P = 0.042) as well as in stage I (P = 0.003) and node-negative patients (P = 0.040). Statistically significant associations of PepC concentration with patient age and estrogen receptor and progesterone receptor status were not observed. In univariate Cox regression analysis of the entire cohort of patients, negative PepC proved to be a significant predictor of reduced DFS (P = 0.0086) and OS (P = 0.025). Multivariate analysis in subgroups of patients defined by nodal status indicated that PepC status was a strong predictor of DFS (P = 0.0039) and the strongest factor for predicting OS (P = 0.0046) in node-positive but not in node-negative patients. Our results suggest that PepC may be used as an independent favorable prognostic factor in node-positive breast cancer patients because there were no significant associations between PepC and the other prognostic factors evaluated in this group of patients.

Splenic and hepatic hemozoin in mice after malaria parasite clearance.

Hemozoin (malaria pigment) is found in many tissues during malaria infections. In mice that have self-cured from Plasmodium yoelii and Plasmodium chabaudi infections, liver hemozoin concentration and total content decreased for 6-9 mo after parasite clearance. However, both spleen hemozoin concentration and total hemozoin content increased dramatically during this time period. Thus, hemozoin or hemozoin-laden macrophages continue to accumulate in murine spleens for at least several months after malaria parasitemia becomes undetectable.

Immunofluorometric assay of p53 protein versus sequencing of p53 exons 5 to 9 for the detection of p53 abnormalities in ovarian carcinoma.

p53 alteration, detected as mutation of the p53 gene or as accumulation of mutant p53 protein, is a common feature of most malignancies, including ovarian carcinoma, and may identify patients with unfavorable prognosis and resistance to chemotherapy. Tumor tissues from 55 patients with well or poorly differentiated (grades 1 or 3) primary epithelial ovarian carcinoma were assessed both for p53 protein overexpression by a sensitive time-resolved immunofluorometric assay employing DO-1 and CM-1 antibodies, and for genetic p53 abnormalities by direct sequencing of PCR-amplified exons 5 to 9. Sixteen p53 mutations (29%), including 3 deletions causing frameshifts as well as one nonsense and 12 missense point mutations were found in all exons except exon 9. Overexpression of p53 protein, defined as a concentration exceeding the 75th percentile, was found in 15 cases (27%), 10 of which had missense mutations (P < 0.01). Tumors with nonsense and frameshift mutations were p53-negative by immunoassay. Both p53 mutation (P = 0.04) and p53 protein accumulation (P < 0.01) were associated with stage III-IV disease, while p53 mutation was more closely related to grade 3 lesions (P = 0.04) and serous histotype (P = 0.01). These results indicate that p53 protein accumulation correlates well with missense point mutation in carcinoma of the ovary and, together with other evidence that p53 abnormality may be prognostic of outcome in this disease, suggest that the immunoassay of p53 protein may have clinical value.

Insulin-like growth factor-binding protein-3 and breast cancer survival.

Insulin-like growth factors (IGFs) are potent mitogens involved in the regulation of cell proliferation and apoptosis. The action of IGFs is mediated through a specific cell membrane receptor (IGF-IR), and the interactions between IGFs and this receptor are regulated by IGF-binding proteins (IGFBPs). IGFBP-3 is one such protein which either suppresses or enhances the actions of IGFs. Findings from most in vitro studies suggest that IGFBP-3 inhibits breast cancer cell growth and facilitates apoptosis, but clinical studies have found that high levels of IGFBP-3 in breast cancer tissues are associated with unfavourable prognostic indicators of the disease, such as large tumour size, low levels of steroid hormone receptors, elevated S-phase fraction and DNA aneuploidy. To further examine the role of IGFBP-3 in breast cancer recurrence and survival, we conducted the following nested case-control study. From a cohort of 1,000 women treated surgically for primary breast cancer, we consecutively selected 100 patients who developed recurrent disease after surgery and 100 age- and year of diagnosis-matched patients who had no relapse. Concentrations of IGFBP-3 in breast tissue extracts were determined with an ELISA. Inverse correlations of IGFBP-3 were revealed with estrogen receptor expression and patient age but not with tumour size or S-phase fraction. Levels of IGFBP-3 in breast tissues were slightly higher in the recurrent patients than in controls, but the differences were not statistically significant. No significant association was found between IGFBP-3 and breast cancer recurrence. Survival analysis, however, indicated that the risk of death was increased with higher IGFBP-3 levels, and the association was independent of other prognostic markers. In conclusion, our results demonstrate that high levels of IGFBP-3 are associated with unfavourable prognostic features of breast cancer.

Quantitative analysis of p53 protein in non-small cell lung cancer and its prognostic value.

Accumulation of mutant p53 protein occurs frequently in human malignancies, including 40-60% of non-small cell lung carcinomas. The implications of such p53 over-expression, usually assessed by immunohistochemical techniques, for the prognosis of lung cancer patients remain undetermined. In this study, we used a time-resolved immunofluorometric assay to measure p53 protein concentrations in extracts prepared from 86 primary non-small cell lung tumours and examined the associations between p53 protein levels (corrected for total protein) and other clinico-pathologic variables, including post-surgical disease-free and overall survival. Contingency tables analysed by chi2 tests revealed no significant relationships between p53 status, defined by a median cut-off point, and patient gender, age, disease stage, histologic grade and type, lymph node extension, smoking history and administration of adjuvant chemotherapy or radiation. However, multivariate Cox proportional hazard regression analysis demonstrated a dose-response relationship between p53 concentration, expressed as a 4-level, quartile-divided variable, and increased risk of relapse (p = 0.010) and death (p = 0.016). Patients whose tumours contained p53 concentrations exceeding the median value had over 3-fold higher risk of relapse (p = 0.002) and death (p = 0.007) than those whose tumours had lower p53 concentrations. We also provide evidence suggesting that the impact of p53 on survival is greater in patients with squamous cell carcinoma than in those with adenocarcinoma. Although the latter finding needs confirmation, our results suggest that application of an immunoassay of p53 protein on non-small cell lung tumour extracts may identify patients at increased risk of unfavourable outcome.

Enzyme-linked immunoabsorbent assay-detected p53 protein accumulation: a prognostic factor in a large breast cancer cohort.

PURPOSE: This study was designed to evaluate whether patients with an unfavorable breast cancer prognosis could be identified by p53 protein overexpression detected by a quantitative enzyme-linked immunoabsorbent assay (ELISA). PATIENTS AND METHODS: Extracts from 998 breast carcinomas were assayed for p53 protein by an ELISA that used both DO-1 monoclonal and CM-1 polyclonal antibodies. Relative risks (RRs) for cancer relapse and death after 6 years of follow-up for patients with p53-positive tumors based on different dichotomization criteria were determined by multivariate Cox regression, adjusted for patient age, tumor size, S-phase fraction, estrogen (ER) and progesterone (PR) receptor concentrations, DNA ploidy, and lymph node metastases. Disease-free (DFS) and overall (OS) survival probabilities of p53-positive and p53-negative groups, using a median cutoff, were also estimated by the Kaplan-Meier method and the log-rank test. These analyses were performed for all patients and for subgroups defined by ER status, node status, and primary postoperative treatment. RESULTS: Univariate analysis showed that p53 concentrations that exceeded the median indicated significantly increased risks for relapse (P < .01) and death (P = .02). Multivariate analyses confirmed these observations (RR = 1.40; P = .02 for DFS and RR = 1.50; P < .01 for OS) and showed trends for increasing risks for relapse (P = .02) and death (P = .06) when p53 was considered as a four-level categoric variable, and identified p53 positivity as a significant predictor of outcome in node-positive patients (RR = 1.67; P < .01 and RR = 2.10; P < .01 for DFS and OS, respectively), ER-positive patients (RR = 1.45; P = .02 and RR = 1.50; P = .01 for DFS and OS, respectively), and in patients treated with chemotherapy (RR = 1.73; P = .04 for relapse and RR = 2.04; P = .03 for death). CONCLUSION: Assessment of p53 overexpression by ELISA, easily incorporated into the routine biochemical work-up of breast tumors, may be an independent predictor of reduced survival of breast cancer patients.

Prognostic value of prostate-specific antigen for women with breast cancer: a large United States cohort study.

Prostate-specific antigen (PSA) is a valuable tumor marker used for diagnosis and management of prostate cancer. Recently, PSA has been found in various female tissues and body fluids. Female breasts, both normal and abnormal, including cancerous tissues, can produce PSA, and this production is regulated by androgens and progestins. Preliminary data suggested that patients with breast tumors positive for PSA may have better prognosis compared to those with PSA-negative breast tumors. This study examines the prognostic value of PSA in a large cohort study of United States patients. Using a PSA assay that has a lower detection limit of 0.001 ng/ml, we measured PSA in tumor cytosolic extracts of 953 women with primary breast cancer. Other information available for this study included age, follow-up time, survival outcome, tumor size, nodal status, steroid hormone receptor levels, DNA analysis by flow cytometry, and postoperative treatment. The median follow-up time was 73 months. During the follow-up, 200 patients relapsed and 188 died. PSA presence was found to be significantly associated with smaller tumors, tumors with low S-phase fraction, diploid tumors, younger patient age, and tumors with lower cellularity. Survival analysis indicated that the relative risks (RRs) for relapse and death were both significantly lower [RR = 0.67 (P = 0.01) for relapse; RR = 0.72 (P = 0.05) for death] in PSA-positive patients (levels higher than the 30th percentile of PSA values) than in PSA-negative patients. The reduced risks for relapse and death remained statistically significant after other clinical and pathological variables were adjusted in the multivariate analysis [RR = 0.68 (P = 0.02) for relapse; RR = 0.65 (P = 0.02) for death]. Our results suggest that the measurement of PSA in breast tumor extracts provides additional information on the prognosis of patients with primary breast cancer.

Immunofluorometrically determined p53 accumulation as a prognostic indicator in Italian breast cancer patients.

The prognostic value of p53 protein accumulation in breast cancer, especially as detected by methods other than immunohistochemistry, has not been established unequivocally. A sensitive immunofluorometric assay of p53 protein employing DO-1 and CM-1 antibodies was used in this study to assay extracts of 171 breast carcinomas from northern Italy. p53 over-expression, demonstrated in 36 (21%) tumours, was associated with lack of oestrogen receptor (ER) expression but was not related to patient age, stage, lymph node status, tumour size, histologic type, grade or progesterone receptor (PR) expression status in contingency tables. An increased risk for cancer relapse of p53-positive patients compared to p53-negative patients was determined using multivariate Cox regression analysis, which also showed that p53 protein over-expression was an independent predictor of reduced disease-free survival in node-positive and ER+ patients but not in node-negative or ER- individuals. The equivalent analysis for assessing the impact of p53 status on overall survival was not statistically significant, possibly reflecting the short patient follow-up. Our results suggest that an immunoassay of p53 protein, applicable to cytosolic extracts prepared for steroid hormone receptor analyses, may provide information for breast cancer prognosis.

Exon 5 of the p53 gene is a target for deletions in ovarian cancer.

Missense point mutations, leading to inactivation of the p53 tumor suppressor gene product, are currently the most frequent alterations in human cancer. Little, however, is known about small intragenic deletions or insertions occurring in this locus of chromosome 17. We have analyzed 56 primary ovarian tumors for the presence of such abnormalities. The analysis was based on multiplex PCR amplification of exons 1 through 11 of the p53 gene and fragment analysis of the generated PCR products. Mutations were detected in 14% (8 of 56) of the tumors. Deletions were much more prevalent than insertions (seven vs one). Six of the deletions and the insertion affected exon 5, and the other deletion was in exon 7. Two deletions and the insertion did not disrupt the reading frame; the protein product was expressed in the tumor at high concentrations in all three cases. The other five deletions generated a frameshift, which is predicted to result in the production of a truncated protein product. In the case of the deletions, a 2-5-bp repeat was present close to the detected deletion, whereas the insertion duplicated the sequence immediately upstream of the insertion site. Overall our findings indicate that small intragenic p53 deletions/insertions are not rare events in ovarian cancer, and that p53 exon 5 is the target in the vast majority (88%) of the cases.

Comparison of immunofluorometry and immunohistochemistry for the detection of p53 protein in lung cancer specimens.

Although immunohistochemical techniques are widely used to demonstrate the presence of mutant p53 protein in a wide variety of malignant tissues, quantitative enzyme-linked immunosorbent assay (ELISA)-type immunoassays offer some advantages. In this study we compared immunohistochemistry, performed on formalin-fixed, paraffin-embedded sections of 91 primary lung tumor tissues, with a highly sensitive quantitative two-site immunofluorometric assay, on extracts of fresh-frozen specimens from adjacent regions of the same tissues. Monoclonal DO-7 antibody, and the related monoclonal DO-1 with polyclonal CM-1 antibodies, were used for immunostaining and ELISA, respectively. Concentrations of p53 were expressed relative to total protein, while an immunostaining score reflected the proportion of stained malignant cells, intensity of staining, and tumor cellularity. Strong concordance was shown between the two methods by Spearman correlation (P < .001), Wilcoxon rank sum (P < .001), and contingency table (P < .001) analyses. The use of ELISA-type assays for p53 quantification in lung tumor tissues may be an alternative to the more labor-intensive histologic techniques.

p53 protein is absent from the serum of patients with lung cancer.

p53 protein, which accumulates intracellularly in over half of all human tumours, has also been reported to be present in the sera of patients with various malignancies, including lung cancer. Using a quantitative immunoassay, we measured p53 protein concentrations in 216 sera from 114 lung cancer patients of whom 75 provided matched lung tumour tissues, which were also assayed for p53 protein. p53 protein levels above the detection limit of 0.04 ng ml-1 were detected in only two sera from lung cancer patients (0.14 ng ml-1 and 0.27 ng ml-1), but not in any of 13 sera from non-malignant lung disease patients or in 100 sera from normal non-diseased individuals. The presence of these apparent traces of serum p53 protein concentrations could not be related either to the p53 protein expression status of the primary lung tumours or to the tumour stage, grade or histological type. By pretreating these two sera with anti-p53 antibody linked to solid phase, and by the addition of mouse serum to neutralise possible heterophilic antibodies, the signals arising from these sera were shown to be non-specific and possibly caused by heterophilic antibodies. We conclude that our data do not support previous reports of p53 protein in the sera of lung cancer patients. Since immunoassays are subject to numerous sources of interference in serum, including heterophilic antibodies, we suggest that the results of p53 protein analysis of serum specimens should be interpreted with caution.

Associations between insulin-like growth factors and their binding proteins and other prognostic indicators in breast cancer.

Recent studies have suggested that insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) may be implicated in the development and progression of breast cancer. Prostate-specific antigen (PSA), a serine protease, may play a role in the regulation of IGFs' function through cleavage of IGFBP-3, resulting in release of active IGFs from IGFBP-3. As IGFs, IGFBPs and PSA are all present in breast cancer, possible associations among these proteins were speculated. In this study, we have measured PSA, IGF-I, IGF-II, IGFBP-1 and IGFBP-3 in tumour tissue cytosols from 200 women with primary breast cancer, and have examined relationships between IGFs or IGFBPs and PSA along with other markers, including p53 protein, steroid hormone receptors (oestrogen and progesterone), cathepsin-D, epidermal growth factor receptor, Her-2/neu protein, S-phase fraction and DNA ploidy. Correlations or associations between PSA and IGF-I, IGF-II, IGFBP-1 or IGFBP-3 were not observed. IGF-II was positively correlated with both IGFBP-3 and IGFBP-1. IGF-I was not associated with either of the two binding proteins, nor with IGF-II. Both IGF-II and IGFBP-3 were inversely associated with the oestrogen receptor, and IGFBP-3 was also positively associated with S-phase fraction. Our finding of IGF-II and IGFBP-3 in association with unfavourable prognostic indicators of breast cancer suggests that IGFs may be involved in the progression of breast cancer.

Time-resolved immunofluorometric assay of p53 protein.

A common feature of human tumor tissue is mutant p53 protein accumulation. Here we evaluate a new "sandwich" immunoassay for p53 protein incorporating modifications to a previously reported method, including the use of microtiter plates coated directly with the anti-p53 monoclonal antibody DO-1, a detergent- and mouse serum-containing sample diluent, and a labeled secondary antibody diluent containing goat serum. The use of CM-1 antiserum to probe the immunocaptured p53 and the detection of bound complexes by a labeled secondary antibody allows coupling to a time-resolved fluorescence detection system. The new assay yielded p53 concentrations comparable with those by the previous assay for breast tumor cytosols (n = 198), nondiseased breast tissues (n = 70), and five transformed cell lines, but showed differences in p53 values measured in sera from patients without cancer (n = 78). These serum differences were found to reflect nonspecific interferences affecting the original method, which implies that the new immunoassay has improved specificity for serum p53 quantification.