Flow cytometric analysis of estrogen receptor expression in isolated nuclei and cells from mammary cancer tissues.

BACKGROUND: Cellular expression of receptors for the hormones estrogen and progesterone in human mammary tumors is of diagnostic and prognostic value. Ligand binding assays have been replaced by immunohistochemical analysis of receptor expression. However, both of these techniques are slow, and in the ligand-binding assay it is difficult to measure heterogeneity of receptor expression in individual cells. Flow cytometry has been used extensively for monitoring the expression of cellular receptors in hematopoietic tumors but has been of limited value in the analysis of mammary tumors, which are difficult to disaggregate into single cells for flow analysis. Hormone receptors have a predominant nuclear localization, and it is relatively easy to isolate nuclei from paraffin-embedded archival tissues for flow cytometric analysis of receptor expression. METHODS: Thick sections from formalin-fixed paraffin-embedded archival mammary tumors were digested by different enzyme solutions for the isolation of single nuclei. Different fixatives were used to compare the results on subsequent staining of the nuclei for estrogen receptor (ER) expression. Double staining with propidium iodide and fluorescein isothiocyanate labeled secondary antibodies for ER expression was used for multiparametric analysis of ER and DNA content. RESULTS: Digestion of paraffin sections with low concentration of pepsin and detergents was ideal for isolation of single nuclei. Fixation with paraformaldehyde in the presence of Triton X-100 improved staining of the cells. Isolated nuclei had enhanced immunoreactivity compared with the whole cells, and subpopulations differing in reactivity could be identified in the nuclear fractions. Double staining of nuclei for ER expression and DNA content could allow for multiparametric analysis of these two important parameters. CONCLUSIONS: The procedures described can be used for processing of archival paraffin-embedded mammary tumors for monitoring of ER expression and aneuploidy. These two parameters have important diagnostic and prognostic significance in mammary tumors. Laser flow cytometry by providing multiparametric analysis can allow for correlation of these cellular markers with other important cellular and clinical parameters.     

Androgen receptor expression and DNA content of paraffin-embedded archival human prostate tumors

BACKGROUND: Androgen receptors (AR) are expressed in human prostate cells and immunohistochemistry has been used for qualitative analysis of AR expression in prostate tumor cells. Quantitative and multiparametric analysis of receptor expression could be of diagnostic and prognostic value in the management of patients on antiandrogen therapy. Multiparametric flow cytometric methods have been developed for analysis of hormone receptor expression and DNA content in nuclei isolated from formalin-fixed/paraffin-embedded human solid tumors. The present study was undertaken for analysis of AR expression and DNA content in archival human prostate tumors. METHODS: AR expression and DNA content were measured in nuclei isolated by enzyme digestion from thick sections cut from 51 paraffin-embedded human prostate tumors. AR expression in different subpopulations was studied by gated analysis. The relationship among AR activity, DNA content, and histopathological grade was analyzed. RESULTS: Distinct aneuploid populations were observed in 23% of tumors examined. AR activity was observed in all the specimens and the percentage of AR- positive nuclei in the 48 samples analyzed was <10% (n = 4), 11-50% (n = 39), and >51% (n = 5). Tumor subpopulations with aneuploid DNA content had higher AR expression (percent AR-positive cells and mean log fluorescence) than the diploid subpopulations. No strong correlation was seen between AR expression and histopathological grade of the tumors. CONCLUSIONS: Flow cytometric analysis of archival prostate tumor can be used for rapid determination of aneuploid DNA content and AR expression in subpopulations of nuclei isolated from formalin-fixed/paraffin-embedded prostate tumor blocks.     

Immunohistochemical demonstration of estrogen receptors (ER) in formalin-fixed, paraffin-embedded human breast cancer tissue by use of a monoclonal antibody to ER

We describe an immunohistochemical method using a monoclonal antibody to localize estrogen receptors (ER) in formalin-fixed, paraffin-embedded tissue. The avidin-biotin-peroxidase complex method was used, preceded by trypsin treatment to expose antigenic sites. In 111 breast cancer specimens studied simultaneously by a dextran-coated charcoal (DCC) assay and the paraffin section method, agreement on receptor status was found in 101 (91%) specimens. Quantitative staining features showed a high degree of correlation with the results of the steroid binding assay (r = 0.81). Studies on the influence of fixation on ER localization done in rabbit uteri showed that fixatives mainly composed of coagulating reagents (Carnoy's, Zenker's, Bouin's, Lilly's AAF, Helly's, ethanol) precluded ER staining, whereas cross-linking fixatives (formaldehyde, glutaraldehyde) preserved antigenic sites, although the immunoreactivity of the receptor was somewhat decreased. Studies on the effect of enzyme preincubation showed this to increase antigenic expression of ER in formaldehyde-fixed breast tumors and in formaldehyde-, glutaraldehyde-, and Zamboni-fixed rabbit uteri.     

Comparison of different antibodies for detection of progesterone receptor in breast cancer

Monoclonal antibodies directed against human estrogen receptor (ER) and progesterone receptor (PR) have been used extensively for biochemical and immunohistochemical detection of receptors independent of hormone-binding assays. These antibodies have been valuable both for experimental work and for detection of receptors in clinical breast cancer specimens. The purpose of this study was to characterize the sensitivity and specificity of different antibodies for detection of PR by immunohistochemistry (IHC) of formalin-fixed paraffin breast carcinoma sections. The panel of twelve antibodies included two new ones (PgR636 and PgR1294) produced prospectively to be resistant to formalin fixation and paraffin embedding. Fifty-nine breast carcinomas, having known PR levels by biochemical ligand-binding assay, were used to prepare multitumor paraffin-embedded tissue blocks for characterization of the PR antibodies. Of all the antibodies tested, both PgR636 and PgR1294 stained the highest percentage of breast carcinomas known to be positive by the biochemical assay (95-98%) and they exhibited the highest concordance with the biochemical assay (88-90%). The PgR636 and PgR1294 antibodies, along with one other, PR 88, also gave the highest intensity of nuclear staining, while PgR636 and PgR1294 stained the highest mean percentage of tumor cell nuclei. Antigen retrieval was not necessary for PR immunostaining by PgR636 and PgR1294 in most tumors and other tissues examined, but did slightly increase the staining intensity. The majority of the other antibodies tested were highly dependent on antigen retrieval; only PR 88 and KD 68 antibodies approached the performance of PgR636 and PgR1294 without antigen retrieval. These results indicate that PgR636 and PgR1294 are optimal antibodies for IHC detection of PR in routine paraffin tissue blocks.     

Progesterone receptor detection and quantification in breast tumors by bivariate immunofluorescence/DNA flow cytometry

A method was developed for the detection of progesterone receptors (PgR) by flow cytometry (FCM) in cell suspensions obtained from mechanically dispersed fragments of operated breast cancers. Two monoclonal antibodies were tested for sensitivity and specificity on four breast cancer cell lines of known PgR expression and a calibration curve thus established. A simple procedure was used to calculate the level of PgR expression, taking into account the relative displacement of total cellular fluorescence compared to nonspecific fluorescence for each sample and the average DNA content of the cells derived from the corresponding histograms. The PgR-specific immunofluorescence of the tumor specimens measured in arbitrary units (channels) was then transformed to fmoles/mg DNA by comparison with the calibration curve. The FCM-derived results were compared with those of a conventional immunoenzymatic PgR assay on 30 surgical samples. PgR content ranged from 10 to 22,000 fmoles/mg DNA and linear regression analysis yielded a good correlation (r = 0.86). With a threshold of positivity of 300 fmoles/mg DNA, the two methods concurred for 28 of 30 tumors (93%). Nine specimens were analyzed repeatedly, showing good reproducibility. This method could prove to be more useful than the biochemical assays on homogenates, since it allows the simultaneous analysis of receptor expression in individual cells and of DNA index (ploidy).     

Apoptosis and Bcl-2 expression in relation to age, tumor characteristics and prognosis in breast cancer. South-East Sweden Breast Cancer Group.

The extent of apoptosis and the expression of Bcl-2 was investigated in tumor samples from 165 women who underwent surgery for primary breast carcinoma between 1989 and 1990 in South-East Sweden. Apoptosis was assessed by a DNA fragmentation assay for flow cytometry. Bcl-2 protein expression was analyzed with immunocytochemistry. Bcl-2 immunoreactivity correlated with estrogen receptor (ER) and progesterone receptor (PgR) positivity and was inversely correlated with p53 accumulation. Apoptosis increased with patient age and a high degree of apoptosis was negatively associated with Bcl-2 immunostaining. Apoptosis showed no significant correlation with any of the other variables studied, including prognosis. The group with Bcl-2-positive tumors tended to have a lower risk of distant recurrence than others, but the association of Bcl-2 with recurrence was different in groups divided by ER and PgR status. Whereas Bcl-2 positivity indicated a low recurrence rate among PgR-negative patients, in the PgR-positive group, those with Bcl-2-positive tumors showed a non significantly higher recurrence rate than Bcl-2-negative cases. In the PgR-positive group, Bcl-2-positive tumors also appeared more frequently to be lymph node positive and DNA aneuploid. The results suggest that hormone receptor status is of importance for the prognostic role of Bcl-2. Likewise, patient age merits consideration when apoptosis is studied in human cancer.     

Comparative studies of nuclear DNA content in benign and malignant thyroid lesions

Currently available data suggest that DNA aneuploidy is associated with aggressive behavior of and unfavorable prognosis in several malignant human tumors as compared with diploid malignancies. However, the diagnostic and prognostic importance of flow cytometric DNA measurements in the case of thyroid neoplasms remains controversial. Therefore, the aim of our study was to evaluate utility of DNA index (DI) and proliferative index (PI) in distinguishing benign from malignant thyroid lesions taking into account the possible influence of intra-tumor heterogeneity and tissue preparation mode on DNA flow-cytometry measurements. A retrospective study was performed on 71 paraffin-embedded specimens from 57 patients with benign and malignant thyroid pathologies: 13 colloid goitres, 12 parenchymatous goitres, 19 adenomas and 13 carcinomas. In 14 of 57 cases two separate specimens taken from different areas of the same lesion were analysed and DNA parameters were compared. Additionally, flow cytometry DNA analysis was parallelly performed on 3 adjacent but differently processed tissue sections (fresh, formalin-fixed and paraffin-embedded) taken from each of 26 surgically excised thyroid lesions. DNA content was also analysed in both fresh and formalin-fixed twin specimens of normal pig thyroid glands (N = 6). We demonstrated that all tumors diagnosed as thyroid carcinomas were associated with abnormal nuclear DNA content although aneuploidy was not found specific to malignant thyroid tumors. Aneuploid samples of benign thyroid lesions exhibited higher proliferative activity, expressed as mean PI values, than diploid ones. In carcinomas the mean PI values were significantly higher than in benign lesions, independently whether they concerned aneuploid or diploid tissues. Considering intra-tumor heterogeneity, the flow cytometric DNA parameters can be assumed as reproducible despite differences in the mode of tissue fixation and preparation for analysis.     

Immunocytochemistry In the Assessment of Ps2 Protein Expression In Fine Needle Aspiration Cytology From Breast Carcinoma

pS2 protein is a cysteine-rich polypeptide, of unknown function, the expression of which is induced in the human cancer cell line MCF-7 by oestrogen. the availability of a murine monoclonal antibody to human pS2 protein has prompted us to evaluate its expression in 47 cases of primary breast carcinoma. Using a double indirect immunoperoxidase technique, we compared the expression of pS2 protein in fine needle aspiration (FNA) cytology smears with that in formalin-fixed, paraffin-embedded sections from subsequently excised tumours from the same patients. We also compared the expression of pS2 protein and oestrogen receptor (ER) status using immunocytochemical assay (ER-ICA) in formalin-fixed, paraffin-embedded sections from 22 primary breast carcinomas. We found the application of immunocytochemistry in the assessment of pS2 protein expression in FNA cytology to be a reliable and cost-effective technique, having a sensitivity of 84% and a specificity of 100%. There was also a good correlation between the expression of pS2 protein and ER status.     

Use of an enzymeimmunoassay (EIA) for quantitation of cytosolic and nuclear estrogen receptor, and correlation with progesterone receptor in human breast cancer

We have adapted a commercially available enzyme immunoassay for ER (ER-EIA) for use with nuclear extracts of breast carcinoma specimens, and have examined the data obtained in relation to the results from cytosolic ER-EIA and radioligand (DCC) assays and from DCC assays for PgR. In a series of 139 carcinoma specimens, we observed a very significant correlation between the cytosolic ER concentration as measured by the EIA and DCC methods, and also between the log10 of the concentration of ER in the cytosolic and nuclear fractions assayed by the ER-EIA method. The correlation between nuclear ER and cytosolic PgR was also highly significant, but not as close as for cytosolic ER. If 130 fmol ER/mg DNA was used as a "cut-off" point to discriminate between specimens "positive" and "negative" for ERN, there was 87% concordance in receptor status between ERN and cytosolic ER, and 79% concordance between ERN and cytosolic PgR. Forty-one percent of specimens were positive or borderline for both ERN and cytosolic PgR, and it is suggested that this receptor combination may be a valuable predictive factor in prognosis and response to hormonal treatment.     

Insulin-like growth factor II (IGF-II) immunohistochemistry in breast cancer: relationship with the most important morphological and biochemical prognostic parameters

Recent in situ hybridization experiments have shown a high content of IGF-II mRNA in breast cancer stroma. The aim of this study was to examine the relationship between IGF-II protein expression and several prognostic parameters in 75 infiltrating ductal carcinomas (IDC) of the breast. Tissue sections were evaluated for proliferative activity, IGF-II protein, ER, PgR, p53, and p21 expression using immunohistochemical procedures. The degree of stromal proliferation was assessed. Menopausal status, axillary lymph node involvement and nuclear grade were known. Thirty-five patients (44.3%) were premenopausal and 47 (62.6%) had lymph node metastases. Marked stromal proliferation was found in 34 (45.3%) specimens and high nuclear grade in 20 (26.5%). Eighteen tumors (24%) showed no IGF-II immunostaining. In the positive cases, IGF-II was detected both in the tumor stroma and in the cytoplasm of epithelial cancer cells: a high IGF-II content was found in 12 specimens (16.0%), a low content in 14 (18.7%) and a moderate content in 31 (41.3%). Twenty-four tumors (32.0%) showed high proliferative activity. Both ER and PgR were expressed in the nucleus of cancer cells: 49 tumors (65.3%) were ER positive (ER+) and 34 (45.3%) PgR positive (PgR+). p21 protein was detected in 37 tumors (49.6%) and p53 in 12 (16%). IGF-II protein was not correlated with menopausal status, lymph node metastases, nuclear grade, proliferative activity, ER or p53. In contrast, IGF-II correlated strongly with stromal proliferation (p=0.008), PgR (p=0.03) and p21 (p=0.01). This study demonstrates that in IDC of the breast IGF-II protein is expressed in the epithelium and stroma of the majority of tumors and is correlated with stromal amount, PgR and p21 expression. These preliminary results indicate that IGF-II expression in breast cancer is connected with two important regulators of breast cancer growth and differentiation.     

MUC3 and MCA serum levels and steroid receptor content in breast cancer

Mucins are an important class of complex glycoproteins expressed by many epithelial cells and their malignant counterparts. The aim of this study was to determine the serum levels of MUC3 and mucin-like carcinoma-associated antigen (MCA) in patients with primary breast cancer and to analyze the possible relationships between these two mucins and the steroid receptor status. The preoperative basal serum levels of MUC3 (ELISA assay with monoclonal antibody 1143/B7) and MCA (EIA assay with anti-MCA mouse monoclonal antibody b-12) were determined in 44 patients with breast cancer while estrogen receptor (ER) and progesterone receptor (PgR) levels were measured by the dextran-coated charcoal method in the cytosol of neoplastic tissue. MUC3 was expressed in 43/44 serum samples while high MCA serum levels were found in 16/44 only; the mean values of both markers did not correlate with menopausal status, tumor size, nodal involvement or ER. The only significant difference observed was a lower median value of MCA in patients with small tumors (T1-T2). No statistically significant correlation between MUC3 and MCA, MUC3 and ER or MCA and ER was observed; a statistically significant direct correlation between MUC3 and PgR+ status and a statistically significant inverse correlation between MCA and PgR+ were observed. Our results suggest that further investigations are necessary to establish whether progesterone can modulate MUC3 and MCA expression in breast cancer.     

Flow cytometric DNA analysis using cytokeratin labeling for identification of tumor cells in carcinomas of the breast and the female genital tract.

Flow cytometric assessment of DNA-ploidy and S-phase fraction in malignant tumors is compromised by the heterogeneity of cell subpopulations derived from the malignant and surrounding connective tissue, e.g., tumor, stromal and inflammatory cells. To evaluate the effect on quality of DNA cell cycle analysis and determination of DNA ploidy, cytokeratin labeling of epithelial cells was used for tumor cell enrichment in breast, ovarian, cervical and endometrial cancer prior to DNA analysis. In a prospective study, tumor cell subpopulations of 620 malignant tumors were labeled by a FITC-conjugated cytokeratin antibody (CK 5, 6, CK18 and CK 5, 6, 8 and CK 17, respectively) prior to flow cytometric cell cycle analysis. Compared to total cell analysis, detection rate of DNA-aneuploid tumors following cytokeratin labeling was increased from 62% to 76.5% in breast cancer, from 68% to 77% in ovarian cancer, from 60% to 80% in cervical cancer and from 30% to 53% in endometrial cancer. Predominantly in DNA-diploid tumors, a significantly improved detection of S-phase fraction of the tumor cells was shown due to the elimination of contaminating nonproliferating "normal cells". S-phase fraction following tumor cell enrichment was increased by 10% (mean) following cytokeratin staining in ovarian and endometrial cancer, by 30% in breast cancer and even by 70% in cervical cancer compared to total cell analysis. Thus, diagnostic accuracy of DNA-analysis was enhanced by cytokeratin labeling of tumor cells for all tumor entities investigated.     

Alterations of estrogen receptors, progesterone receptors and c-erbB2 oncogene protein expression in ductal carcinomas of the breast

Estrogens are important for stimulating the growth of a large proportion of breast cancers. Progesterone plays critical roles in breast development and tumorigenesis. The c-erbB2 gene (HER-2/neu) is a proto-oncogene expressed in 10-34% of breast cancers. Its expression is associated with poor clinical outcome. The hypothesis that the progression of in situ ductal carcinoma of breast to invasive ductal carcinoma is associated with alterations of ER, PgR and HER-2/neu protein expression was tested. Of 100 mastectomy specimens examined, all contained both ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDC) not otherwise specified (NOS). The status of ER, PgR and HER-2/neu proteins was examined by immunochemistry. ER and PgR protein expression was scored as the mean value of positively stained cells. HER-2/neu protein expression was evaluated on ts staining pattern (0, 1+, 2+ and 3+). We found variations between DCIS and IDC with significant decrease of the mean values of ER and PgR positively stained cells in high-grade (Grade 3) IDC (ER: 49.2+/-10.3 vs. 30.8+/-5.5 and PgR: 40.0+/-10.0 vs. 22.3+/-5.1 in DCIS and IDC, respectively, P<0.05). Invasive carcinomas with lymph node metastases or lymphovascular invasion or both had lower mean values of ER and PgR positively stained cells compared to those without these features. In IDC (Grade 3), HER-2/neu protein expression values (1.2+/-0.2) were significantly high compared to DCIS (0.7+/-0.3, P<0.05). In addition, HER-2/neu protein expression values were significantly higher (P<0.05) in IDC with lymph node metastases or lymphovascular invasion (1.5+/-0.3) than those without these features (0.8+/-0.2). A significantly high mean (P<0.05) of ER and PgR positively stained cells was observed in postmenopausal females compared to premenopausal women. In contrast, high HER-2/neu expression values were seen only in premenopausal females. A significant positive correlation was observed between ER and PgR receptor expression (r=0.81). A low degree inverse correlation (r=-0.24, P<0.012) was found between ER+/PgR+ tumors and HER-2/neu expression. These findings substantiate the notion that breast cancer progression is often associated with alterations of ER, PgR and HER-2/neu expression. The underlying mechanisms of these alterations are open for further investigation.     

Comparison of fresh, ethanol-preserved, and paraffin-embedded samples in DNA flow cytometry

Fresh, ethanol-preserved, and formalin-fixed and paraffin-embedded samples taken from the same part of 15 human tumors, and from one normal spleen and one pancreas were analyzed for nuclear DNA content by flow cytometry. The coefficient of variation (CV) values of the G1 peaks were smaller in the fresh than in the other samples (P less than 0.001). The DNA ploidy of the tumors was the same in all types of samples. The DNA indices (DIs) measured from either ethanol-preserved or formalin-fixed tissue correlated strongly with those obtained from fresh tissue (P less than 0.001), although they tended to be somewhat smaller in the fresh samples. The S-phase fractions measured from all types of samples were of the same order of magnitude in most cases (P less than 0.001). Uninterpretable histograms were most often obtained from fresh samples. Identical DI values and rather constant S-phase fractions were obtained from ethanol-preserved samples stored at 4 degrees C for up to 5 months. It is concluded that all three types of samples are suitable for the determination of DNA ploidy, DI, and S-phase fraction and that 50% ethanol is suitable for long-term preservation of flow cytometric samples.     

Estrogen and progesterone receptors in colorectal cancer and surrounding mucosa

In this prospective study we have quantified by means of ELISA-methods the cytosolic content of estrogen (ER) and progesterone receptors (PgR) in tumoral tissue and paired normal mucosa from 163 patients with resectable colorectal cancer. Survival analysis was performed in a subgroup of 120 patients and the mean follow-up period was 24.9 months. The cutoff for ER and PgR levels was set at 1 fmol/mg protein. On the basis of this cutoff 20.9% of the cancers were ER positive and 25.8% were PgR positive; normal adjacent tissue presented ER in 18.4% and PgR in 24.5%. Our results did not show any significant correlation between ER and PgR levels in neoplastic tissues. Howewer, a correlation was found in normal mucosa samples (p=0.02). Statistical analysis showed that there was no correlation between tumor ER and PgR content and patient age or sex, tumor location, Dukes' stage, histological differentiation, DNA ploidy status and S-phase fraction. Furthermore, the results did not show any statistical differences in relapse-free and overall survival curves calculated for patients classified according to the hormone receptor content of their tumors. ER and PgR were detected at low levels in normal and neoplastic colorectal tissues without any significant relationship to either clinicopathological tumor characteristics or patient outcome. Their possible role in colorectal cancer remains to be elucidated.     

Flow cytometric analysis of DNA content and keratins by using CK7, CK8, CK18, CK19, and KL1 monoclonal antibodies in benign and malignant human breast tumors.

We have used a double-labelling flow cytometry analysis of keratin (CK) and DNA in breast cancer. Five monoclonal anti-keratin antibodies were tested: KL1 recognizing Mr 55,000-57,000 keratins, and "anti-glandular epithelia," LE41, RGE-53, and LP2K specific for CK n. 7, 8, 18, and 19 of Moll's classification, respectively. Flow cytometric (DNA-CK) analysis was performed on 10 benign and 19 malignant human breast tumors. All the benign tumors were diploid and 63% of the malignant tumors were aneuploid. This technique permits the analysis of DNA in the epithelial fraction alone. In aneuploid tumors, gating the DNA-keratin-positive population allowed accurate DNA analysis without interference due to debris background and non-epithelial cells. Moreover, double-labelling using the CK19 antibody gave a better identification of near-diploid tumors. An enhancement of keratin expression in malignant tumors was observed with CK 19 (P less than 0.001), KL1 (P less than 0.01), CK 8 (P less than 0.05), and CK18 (n.s.) compared to benign tumors. The comparison of keratin expression in aneuploid and diploid malignant tumors revealed reduced CK8, CK18, and CK19 in the former.     

Immunohistochemical detection of proliferating cells in vivo

Incorporation of the thymidine analogue 5-bromo-2'-deoxyuridine (BrUdR) into newly synthesized DNA provides the basis of a simple technique for identifying proliferating cells. BrUdR was administered to C57BL/6 mice by continuous infusion for 1-7 days, or by intraperitoneal injection for shorter intervals. Various tissue types, including gut, kidney, and liver, were excised, fixed in neutral buffered formalin, and paraffin-embedded for sectioning. De-paraffinized 4-micron tissue sections and bone marrow samples were incubated with an anti-BrUdR antibody and cells that had traversed S-phase during the BrUdR exposure period were identified immunohistochemically. Proliferation and migration of intestinal epithelial cells were identified by antibody staining after continuous in vivo exposure to BrUdR for 1-4 days, and BrUdR incorporation into proliferating marrow cells was detected within 30 min. Tissues such as normal liver, known to have low levels of proliferation, remained unstained after 3 days' exposure to BrUdR. After we established that normal proliferating cells could be identified using this technique, BrUdR was administered to mice bearing B16 melanomas. Again, proliferating tumor cells were clearly identified in histological sections. The nuclei from these paraffin-embedded tumors were also collected for flow cytometric analysis after de-waxing, rehydration, and pepsin treatment. This combination of techniques made possible the comparison in adjacent tissue sections of labeling index, obtained from stained sections, with percentage S-phase, measured using DNA flow cytometry. The % S-phase was consistently higher than the labeling index obtained with immunocytochemistry, and two-parameter DNA vs BrUdR flow cytometry showed that this difference could be accounted for by a population of unlabeled cells with an S-phase DNA content.     

Flow and image cytometric DNA ploidy,including 5c exceeding cells,of serous borderline malignant ovarian tumors. Correlation with clinicopathologic characteristics

OBJECTIVE: To analyze DNA ploidy of serous borderline ovarian tumors by flow cytometry (FCM) and image cytometry (ICM), with 5c exceeding cells also analyzed, and to evaluate their correlation with clinicopathologic characteristics of patients and tumors. STUDY DESIGN: Cell suspensions were prepared according to a modified Hedley method from formalin-fixed, paraffin-embedded tissue blocks of 43 tumors. One part of the suspension was used for flow cytometric measurement; from the other part, filter slides were prepared for ICM. RESULTS: FCM and ICM found 2 aneuploid (peridiploid) serous borderline ovarian tumors, and FCM found 1. ICM found 3 tumors with 5c exceeding cells and 2 tumors with octaploid cells. There was no correlation between DNA aneuploidy and presence of 5c exceeding cells with tumor size, International Federation of Gynecology and Obstetrics stage or survival. CONCLUSION: The results confirm a good correlation between FCM and ICM DNA ploidy and the ability of ICM to detect 5c exceeding cells. The prognostic value of DNA ploidy and 5c exceeding cells in serous borderline malignant ovarian tumors warrant further evaluation.     

Technical and statistical improvements for flow cytometric DNA analysis of paraffin-embedded tissue

Flow cytometric DNA analysis of paraffin-embedded solid tumors has permitted review of large series of archival tissue in attempts to relate abnormal DNA content to prognosis. Limitations of the technique include: 1) a laborious, time-consuming procedure; 2) variation in technique between laboratories; and 3) lack of an objective method of computing DNA indices. Critical evaluation of our technique has shortened the time involved in dewaxing and rehydration, selectively utilized patient's own normal tissue as the internal standard, proved reproducibility of stored specimens, standardized DNA index computation, and developed a statistical analysis to confirm aneuploidy. These technical improvements and the development of a statistical analysis provide a way to shorten the procedure time and standardize the data generated from flow cytometric DNA analysis so as to improve the quality of retrospective reviews of paraffin-embedded tumors and accelerate the definition of flow cytometry's role as a prognostic indicator.     

p53 protein expression and oestrogen and progesterone receptor status in invasive ductal breast carcinomas

p53 protein expression and oestrogen and progesterone receptor status in invasive ductal breast carcinomas The p53 protein expression and oestrogen and progesterone receptors status was investigated in correlation to the grade of malignancy of primary breast carcinomas. Our material constituted imprints from surgical biopsies of 75 invasive ductal breast cancer cases. The p53 protein expression was investigated immunocytologically using the monoclonal antibody p53 DO-7 (DAKO). A biochemical DCC method was applied for the detection of oestrogen and progesterone receptors for all tumours. Fifty-one percent of breast cancer cases were p53 protein positive. A statistically significant association of p53 protein expression and high tumour grade was found (chi2=23.72, d.f.=2, P < 0.001). A statistically significant association was also found between oestrogen and progesterone receptor positive cases and the grade of malignancy (P < 0.001). A negative association between p53 protein expression and oestrogen (ER) and progesterone receptors (PgR) positivity was found. From our results it appears that it is possible to distinguish from grade II tumours two subgroups of cases, one with low malignancy potential and p53 (-), ER (+), PgR (+), and another subgroup with high malignancy potential and phenotype p53 (+), ER (-), PgR (-). The last subset of patients could actually benefit from adjuvant therapy.