Flow cytometric determination of breast tumor heterogeneity.

Flow cytometric analysis was done on the DNA content of nuclei obtained from different sites of small breast tumors. Although specimens for analysis were obtained within a few millimeters of each other, dramatic differences were occasionally observed in the DNA histograms. In a limited study involving 141 consecutive breast specimens submitted for flow cytometry, 52% (74) were found to have at least one DNA aneuploid population. In 18% of DNA aneuploid tumors, one or more specimens from areas grossly identified as tumor had no DNA aneuploid population. Because of the proposed correlation of aneuploidy with a poorer prognosis and possible responsiveness to chemotherapy, multiple sites should be assayed when flow cytometric DNA analysis is done.     

Characterization of bladder papilloma by two-parameter DNA-RNA flow cytometry

Two-parameter flow cytometry (FCM) studies of 0.9% NaCl solution bladder irrigation specimens were performed on 48 patients with histologically orderly or atypical papilloma of the urinary bladder in order to assess the value of RNA as a possible second parameter, along with DNA, in the detection of bladder tumors. DNA, RNA, and nuclear diameter measurements were obtained for each of 5000 cells/sample, and analyses were based on the distributions of those values. With the use of DNA content alone, 22 cases (46%) were classified positive by FCM. With RNA content as an additional parameter, 40 cases (83%) were positive. Two cases were suspicious, and 6 cases were normal by both parameters. Of 28 patients with papillomas showing histological atypia, 16 patients had positive DNA histograms, including 3 patients with aneuploid stemlines, but 24 of the 28 patients had positive RNA histograms. Of 20 patients with orderly papillomas, 6 patients had positive DNA histograms, including 3 patients with aneuploid DNA stem cell lines, but 16 of the 20 patients had positive RNA histograms. Thus, the probability of positive DNA histograms is higher in atypical papillomas (57%) than in orderly papillomas (30%), whereas elevated (positive) RNA is more characteristic of all papillomas without distinction between those that are histologically atypical (86% positive) or orderly (80% positive). For patients at risk of developing papillary bladder tumors, two-parameter DNA-RNA FCM appears to offer greater diagnostic sensitivity than does FCM based on DNA content alone.     

Flow cytometric analysis of DNA content in human bladder tumors and irrigation fluids

Flow cytometry (FCM) was used to study the DNA distribution of 99 tumor biopsy specimens and 41 bladder irrigation samples from patients with transitional cell carcinoma of the bladder. For tumor biopsy and cystectomy specimens, the frequency of aneuploidy increased with advancing tumor stage and grade. All T0 tumors were diploid. Twenty-seven percent of T1, 71.4% of T2, and 75% of T3 and T4 tumors were aneuploid. All Grade I tumors were diploid. Thirty percent of Grade II and 76.9% of Grade III tumors were aneuploid. The frequency of aneuploidy of tumors in the early stages (Ta, T1) is similar to the incidence of subsequent progression by these tumors described in the literature. For irrigation fluids, the relationship between grade and stage and the frequency of aneuploidy was similar to the relationship seen with tumor specimens. All four patients with only carcinoma in situ had aneuploid cells in their irrigations. The comparison of FCM data of bladder biopsy and bladder irrigation from the same cystoscopic evaluation suggests adequate representation of tumor cells in the irrigation fluids for almost all cases. The authors conclude that DNA ploidy analysis by FCM appears useful in a clinically important group of patients with aneuploid superficial tumors of moderate or high grade. Bladder irrigation analysis appears useful in the follow-up of patients with a history of carcinoma in situ and those with aneuploid tumors.     

DNA content flow cytometry as a prognostic factor for node-positive breast cancer. The role of multiparameter ploidy analysis and specimen sonication

The DNA content was analyzed in paraffin-embedded material from 167 patients with node-positive breast cancer to learn whether specimen sonication and multiparameter ploidy analysis (MPPA) (using DNA content and light scatter) could improve the strength of ploidy as a prognostic variable. Sonicated specimens were found to have fewer aggregates, a lower percentage of cells in S-phase (%S) and G2M phase than the corresponding nonsonicated specimens. The results using MPPA predicted the prognosis better because they allowed detection of small aneuploid peaks in histograms classified as diploid or tetraploid using DNA content alone. Ploidy was a significant univariate factor, and patients with tetraploid tumors had the best survival. In the multivariate analysis, if other routine factors were examined preferentially, ploidy and %S did not provide additional prognostic information for survival. This study of paraffin-embedded breast cancers suggested that sonication and MPPA may improve the ploidy analysis in certain cases and that tetraploidy may be a favorable ploidy pattern in this group.     

Comparison of PCNA/cyclin immunohistochemistry with flow cytometric S-phase fraction in breast cancer

Kinetic index determined by enumeration of neoplastic cells positive for proliferative cell nuclear antigen (PCNA) in 70 breast carcinomas (avidin-biotin immunoperoxidase technique) was compared to synthesis-phase fraction (S-phase, or SPF) values obtained by flow cytometry (FCM) using a multiparametric, 2 color method (dual-label propidium iodide/cytokeratin-FITC). The percent PCNA positive tumor cells (12.5% mean, range 1–28%) was significantly greater in aneuploid tumors (14.2% mean, N=35) compared to diploid range tumors (10.7% mean, N=35) (p<0.05), and was correlated with SPF derived from ungated DNA histograms (12.5% mean ± 5.5%, r=0.45, p<0.001). Marginally stronger statistical correlations were observed between the PCNA index and SPF values calculated from cytokeratin-gated (15.8% mean, r=0.53, p<0.001) DNA histograms or from SPF values obtained following linear baseline debris subtraction (mean=8.1%, r=0.48, p<0.001). Significant associations were identified between PCNA index and prognostically important clinicopathologic parameters including nuclear grade (p=0.014), presence of necrosis (p=0.005), and angiolymphatic invasion (p=0.003). We conclude: 1) PCNA index is comparable to FCM SPF and correlates with factors of known prognostic importance in carcinoma of the breast; 2) baseline debris and contaminating events derived from non-epithelial cells both represent significant artifacts in proliferative fraction estimates derived from FCM DNA histograms; and 3) multiparametric analysis may represent one means of improving the specificity and clinical value of FCM SPF determinations.     

Immunocytochemical localization of estrogen and progesterone receptors in imprint preparations of breast carcinomas.

The role of mammography as an effective means of early detection of breast cancer is well established. Needle localization of occult tumors under mammographic guidance has become the principle method of sampling impalpable breast lesions. As a result, the number of clinically inapparent breast carcinomas sampled has increased rapidly. Under these circumstances, as a result of the size and the nature of these "early carcinomas," it may not be possible to assess the hormone receptor expression of these tumors by conventional biochemical assay and/or immunocytochemical analysis. To determine the usefulness of imprint preparation for detecting hormone receptors, 214 examples of primary, recurrent, and metastatic breast cancers were studied. Immunostaining of imprint preparations with monoclonal antibodies against the estrogen (H222SPy) and progesterone receptors (KD68) showed a high degree of concordance with immunocytochemical assay and biochemical analysis done on frozen tissue of the same tumors. This technique can be done easily and is well suited for tumors that are too small and/or ill defined to permit separate sampling for hormone receptor analysis.     

Flow cytometrically determined DNA content of breast carcinoma and benign lesions: correlations with histopathological parameters

The relative DNA content of cellular samples from 54 patients affected by breast carcinomas and 20 affected by benign breast lesions (including 11 fibroadenomas) was measured by flow cytometry. All normal tissue samples and 17/20 (85%) specimens from benign lesions exhibited a cytometrically diploid DNA distribution, 3/20 (15%) benign lesions an abnormal DNA content, and 35/54 (65%) carcinomas at least one aneuploid cell subpopulation. Furthermore, 9/54 (17%) tumors were characterized by the presence of more than one aneuploid cell subpopulation. The results also indicate that flow cytometry can be used to recognize lymph nodes infiltrated by aneuploid cells. Statistically significant correlations were evidenced between the occurrence of aneuploidy or the ploidy level measured as DNA index and the nodal infiltration status. The percentage of S cells can also be extracted from DNA content distribution histograms. Statistically significant differences (p less than 0.01) were also observed for the percentage of S cells between normal tissues (6.2 +/- 3.2 SD) and benign lesions (11.1 +/- 6.6 SD), normal tissues (6.2 +/- 3.2 SD) and aneuploid tumors (19.7 +/- 10.3 SD), benign lesions (11.1 +/- 6.6 SD) and aneuploid tumors (19.7 +/- 10.3 SD), and diploid (7.9 +/- 4.0 SD) and aneuploid tumors (19.7 +/- 10.3 SD).     

Flow cytometric analysis of breast needle aspirates

This study investigated two hypotheses: (1) sufficient cells may be obtained by needle aspiration of breast nodules to produce good flow cytometric DNA profiles; and (2) benign breast lesions do not produce aneuploid G0G1 peaks, and therefore a distinct aneuploid peak is sufficient for a diagnosis of malignancy. Breast specimens received in Surgical Pathology between December 1985 and February 1987 were aspirated, and the cells stained with propidium iodide for flow cytometric DNA analysis. A total of 344 specimens were aspirated, of which 204 (59%) were malignant and 140 (41%) benign. One hundred fifty-three malignant and 111 benign specimens contained sufficient cells for analysis. Cytologic smears were available for 177 malignant and 123 benign specimens. DNA histograms were considered diagnostic of malignancy if an aneuploid peak was present which contained at least 20% of the cells in the distribution, and had a DNA index greater than or equal to 1.2. Using these criteria, 73 of 153 (48%) carcinomas could be identified. None of the benign lesions satisfied these criteria. One fibroadenoma with atypical hyperplasia produced a distinct peak which contained less than 5% of the cells in the histogram, and had a DNA index of 1.25. Flow cytometric analysis provides objective data that complement the subjective cytologic interpretation of fine needle aspirates.     

Prognostic Factors in Locally Advanced Breast Cancer (T3, T4) with Special Reference to Tumor Cell DNA Content

The prognostic value of DNA analysis was studied retrospectively in 91 patients with locally advanced breast cancer (T3, T4) and a follow-up time of 3-7 years. Tumor cell DNA analysis was performed by static cytometry on aspiration biopsy specimens in 42 cases and on tissue sections in 49 cases. The tumors were classified as euploid or aneuploid. Sixty-four percent of the tumors were aneuploid. DNA pattern correlated significantly to histologic grade and axillary perinodal growth and also to survival. DNA pattern, histologic grade and axillary node metastases correlated significantly to disease-free survival (DFS). In this series of patients with locally advanced breast cancer DNA determinations gave important prognostic information.     

DNA Content in Non-Hodgkin's Lymphoma: Comparison between flow cytometry and cytogenetics in fresh and paraffin-embedded tissue

DNA content of 36-non-Hodgkin's lymphomas was analyzed by flow cytometry (FCM) and cytogenetics (CG), 21 in fresh and 15 in paraffin-embedded tissue. The results of both techniques were coincident in 60% of the fresh tissue samples and in 45% of the paraffin-embedded ones, the reason for this difference could be the poor resolution of DNA histograms from paraffin-embedded tissue. All samples judged as aneuploid by FCM were aneuploid also by CG. Some samples with a hyperdiploid population by CG gave a diploid population by FCM with a 'false' high DNA-synthesis (S) fraction. From a technical point of view, CG and FCM have to be performed on the same fresh tissue.     

Detection of p53 Gene Mutations in Aspiration Biopsy Specimens from Suspected Breast Cancers by Polymerase Chain Reaction-Single Strand Conformation Polymorphism Analysis

Genomic DNA was extracted from aspiration biopsy specimens taken from 15 suspected cases of breast cancer, including 7 known cases of breast cancer, and the p53 gene was studied for evidence of mutation by using a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. In 5 of the 15'cases (33%), p53 gene mutation was identified and these tumors were subsequently histologically diagnosed as malignant. Further, DNA flow cytometry of the 15 tumors demonstrated that 6 (40%) were aneuploid and malignant, whereas 9 (60%) were diploid and benign. It was also found that the tumor cells in 5 aspirated cases that showed p53 gene mutations were all aneuploid, the p53 protein expression was positive, and the tumors were proved to be histologically malignant. It was thus concluded that the detection of p53 gene mutation by PCR-SSCP analysis of aspirated biopsy specimens from suspected breast cancers is a helpful method for achieving a more accurate diagnosis.     

Prognostic significance of DNA image cytometry in libyan breast cancer

Background: We evaluated the relation of nuclear DNA content and clinicopathological features and prognosis in primary breast cancer of female Libyan patients with variable stage and grade and different treatment regimes. Patients and Methods: Histological samples from 104 patients of breast carcinoma were retrospectively studied by computerized nuclear DNA cytometry. Isolated nuclei from paraffin sections were stained with Feulgen stain and DNA was measured using a computer-assisted image analysis cytometry system. In each case, 200 nuclei were measured and the DNA histograms, S phase fraction (SPF) and number of cells above 5c and 9c were determined. We applied different approaches in the analysis of DNA to compare the DNA histograms with different clinicopathological features and survival. Results: The mean of DNA ploidy mode for all tumors was 3.43; 82.7% of tumors were aneuploid and 17.3% were diploid. The median SPF was 3.5% for DNA diploid and 13.5% for DNA aneuploid tumors. DNA aneuploid tumors and high SPF were associated with advanced stage, distant metastasis, high histological grade and lymph node involvement. The SPF was also associated with large tumor size and with younger patients (<50 years). In the overall population (median follow-up 51 months), patients with aneuploid DNA histograms and high SPF values had shorter survival times than those with diploid DNA histograms and low SPF values (p = 0.001, p < 0.0001, respectively). Also, short survival was associated with a multiploid DNA histogram and with DNA aneuploid cells ≥5 cells (p < 0.0001, p = 0.001, respectively). In a Cox multivariate analysis, DNA ploidy (p = 0.010), age (p = 0.038) and clinical stage (p = 0.001) were independent predictors of overall survival, and DNA ploidy (p = 0.018) and clinical stage (p = 0.001) also proved to be independent predictors of disease-specific survival. The SPF cutoff point of 11% might be applied to separate patients into good and poor prognosis groups. Conclusions: DNA image cytometry with careful analysis of the histograms may provide valuable prognostic information in Libyan breast cancer, with potential clinical implications in patient management, particularly in predicting the patients at high risk for metastasis and recurrence who should be considered as candidates for combined adjuvant therapy.     

Prognostic significance of DNA content in large bowel carcinoma: a retrospective flow cytometric study

Flow cytometric (FCM) determination of DNA content was performed on surgical specimens from 44 patients with previously untreated colonic carcinoma. For each tumor, cell suspensions were prepared from 2-4 40-microns thick sections obtained from formalin-fixed and paraffin embedded tissue samples. Aneuploidy was found in 47.2% of all the tumors and the aneuploid clone had a median DNA index of 1.49 (range: 1.24-1.93). Aneuploidy was found in 26.7% of highly differentiated tumors (WHO histologic classification), in 53.8% of moderately differentiated tumors and in 100% of poorly differentiated tumors (P = 0.04). The 33.3% of stages 1 + 2 (TNM) and the 70.6% of stages 3 + 4 tumors were aneuploid (P = 0.002). Median survival from surgery was 46.4 months for all patients. It was 18.8 months for patients with aneuploid tumors and 85.7 months for those with diploid tumors (P = 0.0002). FCM determination of DNA in colon carcinomas can easily be performed on archival histological material and provides prognostic information.     

DNA flow cytometry applied to fine needle sampling of human breast cancer

Breast cancer cells can be obtained directly from the patient with minimal trauma by fine needle sampling (FNS). A method was developed that enabled us to prepare tumor cell nuclei for ploidy determination by flow cytometry (FCM). Fine needle sampling was performed on 235 patients with clinically suspected malignancy. Two hundred sixteen specimens (92%) produced enough material for assessment; 206 were diagnosed as cytologically malignant. In 41 patients surgical specimens from the same tumors were available. Thirty-eight of these specimens (93%) were classified according to ploidy. No significant correlation was found between aneuploidy and clinical stage (size and lymph node involvement). The comparison of DNA histograms from 21 primary breast tumors and homolateral axillary lymph nodes showed mostly similar patterns. On the contrary, eight of nine synchronous bilateral cancers were shown to have different ploidy. Flow-cytometry-derived DNA histograms of fine needle samples could be a valuable tool in the management of breast cancer.     

Imprint immunocytochemistry of estrogen receptors in breast carcinoma

To clarify the accuracy of immunocytochemical detection of estrogen receptors (ER) in breast carcinomas using cytological materials, imprint specimens from tumor tissue were compared with frozen tissue sections and tumors analyzed by the dextran coated charcoal (DCC) method and enzyme immunoassay (EIA). Out of 50 cases examined by imprint immunocytochemistry, there were 39 ER positive cases (78.0% positivity). The positivity in the imprint materials agreed with that of the DCC in 36 out of 40 cases (85.0%), with 100% sensitivity and 60.0% specificity. The two methods statistically correlated with each other in their positivity and grade (p less than 0.001). The positivity and grades of imprint and frozen immunocytochemistry as well as those of imprint immunocytochemistry and the EIA agreed almost perfectly with each other. As a result of the present study, we concluded that immunocytochemical detection of ER is indeed reliable, as accurate as other procedures. We recommend that aspiration biopsy cytology (ABC) be used for morphological examination and ER immunocytochemistry when adequate materials are available and that imprint materials be used when ABC materials are inadequate and fresh tissue is available at the time of surgery.     

Flow cytometric analysis of deparaffinized nuclei in urinary bladder carcinoma. Comparison with cytogenetic analysis

Both cytogenetic analysis and flow cytometry (FCM) have prognostic efficacy in the analysis of transitional cell carcinoma (TCC) of urinary bladder. To correlate results of the two methods, we studied a unique group of patients whose tumors had undergone prospective conventional cytogenetic analysis. Paraffin blocks of these tumors were processed for FMC, then analyzed for nuclear DNA content. Of the 34 tumors processed, 30 (88%) yielded interpretable DNA histograms. In 26 (87%) of these, there was good correlation between the two methods with respect to the presence or absence of a hyperdiploid cell line. Discrepancies may have resulted from sampling error or from interpretation of a tetraploid peak as a prominent G2M region. Retrospective FCM analysis of paraffinized TCC tissue correlates well with conventional, prospective cytogenetic analysis and is applicable to the majority of urinary bladder transitional cell carcinomas.     

Assessment of methods for the cytogenetic analysis of human solid tumors

A comparative study was undertaken to evaluate the effectiveness of various procedures (e.g., direct harvest vs. short-term culture) for the cytogenetic analysis of human solid tumors. A total of 51 specimens (38 primary tumors, 13 effusions) were examined from 45 patients with tumors of the ovary, lung, breast, colon, and testicles. Sufficient numbers (greater than or equal to 3) of metaphase cells to be useful for karyotypic analysis were obtained in 42 of 51 (82.3%) specimens. More than 10 analyzable metaphases were found in each of 32 specimens (62.7%), but in some cases it was necessary to examine many slide preparations to achieve this number. The rate of successful chromosome preparations was markedly better for short-term cultures than for specimens harvested directly. Short-term cultures generally showed a mitotic peak after about 3 days of growth in vitro. Generally, the quality of metaphase cells was better in specimens disaggregated enzymatically with collagenase than in those dissociated mechanically. Exposure to ethidium bromide (EB) for the final 2 hours of culture yielded more cells with elongated chromosomes than cultures harvested by conventional methods without EB. Overall, the findings indicate that successful karyotypic analysis can be performed in a high percentage of human solid tumors with the use of techniques that can be readily applied in most cytogenetics laboratories. However, further methodological advances in tissue culture are warranted to routinely provide large numbers of mitotic cells for karyotypic analysis.     

Image and flow DNA cytometry of small cell carcinoma of the lung

Both image and flow DNA cytometry were performed in isolated nuclei from paraffin-embedded tumor tissue of patients with small cell carcinoma of the lung (SCCL). In 14 patients tissue was obtained by surgery from the primary tumor. From 14 patients tissue was taken by autopsy. From two patients tissue obtained by both surgery and later autopsy were available. From the autopsy patients tissue was taken only from the primary tumor (n = 6), from a metastasis (n = 1) and from the primary tumor and distant metastases (n = 7). Twelve of the tumors obtained by surgery were diploid, and two multiploid (two stem lines present). This was found both with image and flow cytometry. The group of patients could clearly be subdivided in short survivors (less than 9 months, n = 6) and long survivors (greater than 16 months, n = 8); since in both groups one multiploid and the remainder diploid cases were present, ploidy did not seem to be a good prognosticator for survival. In most (n = 26) of the tissues measured from the autopsy patients, again, a good correlation between image and flow DNA cytometry was obtained, the histograms being either (near) diploid or multiploid. In six cases, however, flow cytometry showed multiploidy whereas image showed aneuploidy (one single peak clearly deviating from diploidy). This discrepancy is caused because normal diploid (nonneoplastic) cells in the preparations could not be discarded from the flow cytometry measurements. Using the image cytometry data of the primary tumors, five diploid, three aneuploid, and four multiploid tumors were found. In five of the seven patients of whom tissue was obtained from the primary tumor and multiple metastases, differences between the histograms were found, mostly showing two malignant cell populations in one tissue and only one of them in another. Of one of the two patients of whom tissue was obtained by surgery and later autopsy, a change in histogram pattern was observed. It is concluded that although there is a high similarity between image and flow DNA cytometry, for an optimal interpretation of the histogram pattern, image measurements are more reliable. Ploidy determination does not seem to be of use in prediction of survival, and care should be taken in interpreting DNA histograms of metastases in SCCL patients because of the variability in histogram pattern.     

Cyclin-D1 expression in node-positive (N+) and node-negative (N-) infiltrating human mammary carcinomas

Cyclin-D1 (CD1) expression was analyzed in human mammary carcinomas by immunohistochemical (IHC) and flow-cytometry (FCM) methods: 52.5% and 50% of cases were strong expressors of CD1 by IHC and FCM analysis respectively. The percentage of CD1-positive cells was especially high in node-negative (N-) estrogen-receptor-positive (ER+) tumors, probably as a consequence of CD1 induction by estrogens in steroid-responsive tissues. However, CD1 expression was not related to ER positivity in node-positive tumors (N+). An interesting relationship between CD1 expression and H3-thymidine labelling index (H3Td-LI) was also found: CD1 and H3Td-LI were unrelated in N- tumors, while high CD1 expression was observed in N+ tumors with high DNA synthesis, as assessed by H3Td-LI. The combined measurement of DNA and CD1 showed that 27 specimens were aneuploid, 19 of them (19/27; 70%) strongly expressing CD1. Further studies are needed to clarify the role of CD1 in DNA abnormality of breast tumors. However, we cannot exclude that the CD1 may be differently de-regulated in the last phase of tumor progression, and that CD1 over-expression may contribute to the aneuploidy of mammary carcinomas.     

Evaluation of a modeling system for S-phase estimation in breast cancer by flow cytometry

Using software programs provided by Coulter Electronics, we have developed an analysis system that would address problems encountered in DNA flow cytometric analysis of heterogeneous solid tumor populations, especially where the G2-M phase of the diploid population contaminates the S-phase of the aneuploid population, causing an overestimation of cells in S phase. We used the PARA 1 and PARA 2 programs in concert and developed three analysis models: (a) for euploid tumors; (b) for hyperdiploid tumors with overlapping populations; and (c) for near-diploid aneuploid tumors. Our purpose in this paper is to determine the limits and reproducibility of this analysis system with an emphasis on tumors with overlapping populations. Aliquots of frozen, pulverized breast tumor tissue (50 to 100 mg), routinely used in the steroid receptor assay, were used for routine flow cytometric measurement of the DNA index and S-phase fraction. To determine the accuracy of the analysis when overlapping populations were present, we mixed an aneuploid breast cancer cell line with human blood lymphocytes in varying ratios. A 10% mixture of aneuploid cells, the lowest mixture tested, still allowed analysis results within 95% confidence limits. Reproducibility of the system was assessed on frozen breast tumor tissue by intra- and interassay variation studies measuring cell cycle parameters and coefficient of variation of the G0-G1 peak width. Within any sample the amount of variation (+/- 2 SD) for the G0-G1 value was +/- 4.40 for intraassay and +/- 4.60 for interassay, and the amount of variation for S phase was +/- 3.0 and +/- 3.2 for intraassay and interassay, respectively. There was no difference in the variation of estimates for G2-M (+/- 2.6 for both intra- and interassay). In this study, the coefficient of variation of the G0-G1 peak greater than 5% was defined as unacceptable for accurate analysis, with the conclusion that S-phase fractions in aneuploid tumors can be routinely analyzed in human breast tumor biopsies despite tumor cell heterogeneity.