Flow cytometric analysis of DNA and cell proliferation in ovarian tumors

DNA content in tumor cells from 50 patients with ovarian tumors was analysed by flow cytometry (FCM). Solid tissue samples were processed to obtain monodispersed cells. Staining for DNA analysis was achieved with ethidium bromide and mithramycin. Peripheral blood lymphocytes were used as reference diploid cell population. All benign ovarian tumors exhibited only diploid cells. DNA aneuploid cell lines were found 66.6% of serous carcinomas and in 80% of malignant granulosa cell tumors. The S-phase fraction of DNA diploid cells in benign ovarian tumors (S = 2.4 +/- 1.2%) was smaller than those of malignant tumors (S = 8.2 +/- 5.2%). DNA aneuploid cell populations in serous carcinomas display a higher S-phase fraction (S = 19.2 +/- 9.3%) than DNA diploid cells (S = 11.7 +/- 3.2%). No major differences were obtained between primary ovarian tumors and their metastases, as far as degree of aneuploidy and S-phase fraction are concerned. A high degree of correlation was established between the grade of differentiation of ovarian tumors and the DNA ploidy abnormalities.     

Pretherapeutic flow cytometric DNA investigations in radiotherapy patients with maxillo-facial carcinomas

In order to analyze the possible meaning of cellular DNA content and cell cycle phases for the radiosensitivity and the prognosis of human malignant tumors, flow cytometric measurements have been performed in biopsies of 131 patients with histologically proven squamous cell carcinomas of the maxillo-facial region. In two-thirds of the patients (88/131; 67%), aneuploid tumor cell lines have been found, only 33% (43/131) had a diploid DNA distribution pattern. The average DNA index (DI) of the aneuploid carcinomas was 3.4 +/- 0.6 (normal nonmalignant tissue DI = 2.0). The frequency of S-phase cells, which represents the "proliferative activity", was between 4.8 and 63.2%, regardless of the ploidy stages. The aneuploid carcinomas had about twice as many S-phase cells (mean 23.7 +/- 11.8%) than diploid tumors (mean 12.7 +/- 4.8%). Mean survival for patients with diploid carcinoma and aneuploid carcinoma was 12 and 9.5 months, respectively. Concerning the relationship of S-phase frequency and survival times in our material there was a high negative statistical correlation (Spearman-Rank test) in patients with diploid carcinomas. A high S-phase fraction resulted in short survival times. No correlation was found in the aneuploid carcinomas: patients with tumors in high S-phase values in their biopsies showed no difference in prognosis in comparison to tumors with lower S-phase fractions.     

Flow DNA analysis of primary bone tumors. Relationship between cellular DNA content and histopathologic classification

The cellular DNA content of 15 benign and 34 malignant primary bone tumors was analyzed by means of flow cytophotometry. All benign tumors except one of questionable histologic type exhibited a normal DNA content (diploid), whereas 23 of 34 malignant tumors showed an abnormal DNA content (aneuploid). Closer analysis revealed that all supposedly highly malignant tumors, i.e., 16 osteosarcomas and 1 Ewing sarcoma were aneuploid, while 8 of 13 chondrosarcomas, 2 periosteal osteosarcomas, and 1 of 2 adamantinomas were diploid. Interestingly, these diploid malignant tumors represent tumor entities which are known to include variants of low-grade malignancy. Cell distribution analysis showed that the aneuploid tumors exhibited a higher proportion of S-phase and G2 + M cells than the diploid tumors, indicating differences in proliferative activity. However, no significant difference in this respect could be demonstrated between diploid benign and diploid malignant tumors. The current study clearly shows that flow DNA cytophotometry can be applied to most primary bone tumors despite a substantial content of hard tissue. The results also indicate that DNA determinations as an adjunct to conventional histopathologic assessment may provide objective clinically relevant information with respect to the degree of malignancy. Thus, regardless of histogenetic origin, it appears that benign bone tumors as well as malignant bone tumors of low-grade malignancy in general, are diploid, whereas highly malignant bone tumors in general are aneuploid.     

Flow cytometric DNA measurement and cytomorphometric analysis of formalin fixed rat mammary tumours

Archival paraffin embedded material was used to examine whether additional quantitative criteria would be helpful to discriminate between histologically benign and malignant rat mammary tumours. To this end nuclear DNA content expressed as DNA ploidy index (DI) was measured using flow cytometry (FCM). A total of 63 benign and malignant mammary tumours were investigated. Thirteen out of 38 (34%) mammary carcinomas were DNA aneuploid against 0 out of 25 benign mammary tumours. Aneuploidy was not significantly increased in tumours showing histological signs of greater malignancy such as cribriform-comedo type or invasive growth. In addition to DI other quantitative criteria indicative for malignancy, such as mitotic count and nuclear morphometric characteristics, were estimated in 24 benign and malignant tubulopapillary tumours, a category where the histological classification may be difficult. It appeared that five out of nine noninvasive tubulopapillary carcinomas and six out of seven invasive carcinomas had abnormal values for either DI, mitotic count or nuclear area or for a combination of these parameters. Each single parameter however was abnormal only in a minority of the malignant tumours. In this respect our data are in accordance with the fact that rat mammary carcinomas are clinically and histologically less malignant than their human counterparts.     

DNA index and cell cycle analysis of primary breast cancer and synchronous axillary lymph node metastases

The DNA Index (DI) and the percentage of cells in S-phase (S-phase fraction, SPF) were measured by flow cytometry in 80 primary breast carcinomas and in 80 accompanying axillary lymph node metastases. The DI in primary tumors and metastases agreed in 61 cases (76%). Cases with diploid primary tumors revealed more constancy of the DI in comparison to the metastases than the cases with aneuploid primary tumors (91% and 70% respectively). The mean values of the SPF were in close agreement in the primary tumors and in the lymph node metastases (6.1% and 6.0% respectively). Differences between the SPF of the two groups could be detected only by the consideration of case-related data pairs. In 50 cases (62%), the percentage of SPF agreed approximately in primary tumors and in the correspondent metastases. The cases with diploid primary tumors revealed more agreement of the SPF in the primary site and the metastases than did cases with aneuploid primary tumors (78% and 56% respectively). In conclusion, diploid carcinomas and their metastases revealed more constancy of the DI and the percentage of SPF than aneuploid carcinomas. These findings agree well with a better prognosis of diploid mammary carcinomas, as reported in the literature. Comparisons between the DI and the SPF in primary tumors and the corresponding metastases could be a source of valuable information on the biological behaviour and the aggressiveness of mammary carcinomas.     

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).     

Ploidy and proliferation in human bladder tumors as measured by flow-cytofluorometric DNA-analysis and its relations to histopathology and cytology.

Biopsies from bladder tumors of 41 patients were investigated by flow-cytofluorometric DNA analysis and compared with exfoliated cells. The degrees of ploidy and proliferation were determined. Good agreement was found between the degrees of ploidy and proliferation in the biopsies and the exfoliated cell material. Tumors Grade I-II were either euploid or aneuploid. All Grade III tumors were aneuploid. The S-phase fractions were about 6% in the diploid tumors and 17% with large variations in the aneuploid tumors. The histological grading was well correlated to the number of S-phase cells and the occurrence of aneuploidy. When the Grade II tumors were divided into two groups having lesser and more pronounced atypia, the two groups differed significantly with regard to their degrees of proliferation. In addition to aneuploidy as an important criterium for malignancy, the degree of proliferation appears to be of major biological significance.     

DNA flow analysis of soft tissue tumors

The cellular DNA content of 81 soft tissue tumors was determined by means of flow cytometry and related to conventional histologic classification of the same tumors. Comparison of histologic and cytometric analysis showed that all 23 benign tumors were diploid (normal DNA content), whereas the malignant group included both diploid and aneuploid (abnormal DNA content) lesions. There appeared to be a relationship between tumor grade and ploidy level in that 92% of Grade II, 28% of Grade III, and 11% of Grade IV lesions were diploid. Cell distribution analysis, feasible in 51 cases, disclosed that diploid lesions had a low proportion of S and G2 + M cells and most aneuploid lesions a high proportion, indicating a relationship between ploidy level and proliferative activity. The current study shows that solid mesenchymal tumors may be analyzed by DNA flow cytometry. Regardless of histogenetic type, it appears that benign and low-grade tumors are diploid and high-grade tumors, in general, are aneuploid. As to exceptions, DNA analysis may prove to give information beyond that obtained by subjective histologic interpretation. Thus, adequate follow-up might show that high-grade lesions with a diploid DNA content are associated with a better prognosis than expected from histologic classification.     

Flow cytometric analysis to assess the malignant potential of phyllodes tumor

To evaluate DNA content as a prognostic indicator in phyllodes tumor of the breast, flow cytometric DNA analyses were performed retrospectively in 13 patients who were selected, based on the availability of paraffin-embedded tumor specimens. All were women with an average age of 41. 9 years and a mean follow-up of 51.2 months. Pathologically, 3 patients (23.0%) had malignant tumor and 10 (77.7%) had benign lesions. The patients with malignant tumors tended to be older and had larger tumors. Aneuploidy was seen in one patient with malignant tumor (7.7%), with the S-phase fraction ranging from 0.8 to 12.6. This patient died of lung metastases 6 months after mastectomy. One benign tumor showing diploid, developed local recurrence 100 months after lumpectomy. DNA stem cell lines were not detected in the only patient with aneuploid tumor. There was no significant correlation between DNA content and local recurrence. In this series, the number of patients was too small to draw the certain conclusions from data. However, it appears that, compared to diploid tumors, aneuploid tumor are more often malignant and have poorer prognosis. Our study indicates that DNA content has little prognostic value, DNA aneuploidy appears to be associated with a poor prognosis.     

Correlation of DNA ploidy and clinical outcome in early gastric carcinomas

The nuclear DNA content was measured in 120 early gastric carcinomas and the results correlated with histologic findings and S-phase fractions measured by in vivo bromodeoxyuridine (BrdU) labeling. Forty-six cases (38%) were diploid and 74 cases were aneuploid. In aneuploid tumors, incidence of submucosal invasion, vascular invasion, and lymph node involvement were significantly higher than that in diploid tumors. In addition, the S-phase fractions in aneuploid tumors were significantly higher than those in diploid tumors. There was no recurrence in diploid tumors; whereas 21% of cases with aneuploid tumors recurred. These results indicate that DNA content may be a prognostic factor in early gastric carcinoma.     

Distinctive chromosomal instability patterns in oral verrucous and squamous cell carcinomas detected by high-resolution DNA flow cytometry

BACKGROUND:

Oral verrucous carcinomas (OVCs) are characterized by better prognosis than oral squamous cell carcinomas (OSCCs). Because chromosomal instability (CIN) in solid tumors is indicative of prognosis, this study investigated whether OVCs and OSCCs were characterized by differences in CIN biomarkers.

METHODS:

Fresh or frozen multiple tissue samples were submitted to high‐resolution DNA flow cytometry (hr DNA‐FCM).

RESULTS:

DNA aneuploid sublines were detected in 6 of 9 OVCs (66.7%) and in 20 of 25 OSCCs (80.0%). Multiple DNA aneuploid sublines were observed, respectively, in 2 of 6 (33.3%) DNA aneuploid OVCs and in 14 of 20 (70%) DNA aneuploid OSCCs (P = .163). OVCs were mainly characterized by DNA Index (DI) values in the near‐diploid region (DI≠1 and DI < 1.4), whereas aneuploid OSCCs carried most frequently multiple aneuploid sublines with high DI values (DI ≥ 1.4). DNA near‐diploid and high aneuploid sublines were, respectively, 87.5% and 12.5% for the OVCs versus 30% and 70% for the OSCCs (P = .004).

CONCLUSIONS:

Present data suggest that OVCs are characterized by a lower degree of CIN and tumor heterogeneity than OSCCs, such that they appear as “frozen” in an early stage of DNA near‐diploid aneuploidy, as previously observed for oral preneoplastic lesions. These DI characteristics, which can easily be obtained by hr DNA‐FCM, appear to reflect the well‐known differences in aggressiveness and prognosis of OVCs and OSCCs. Cancer 2011;. © 2011 American Cancer Society.     

Study of DNA content using a flow cytometry method and steroid hormone receptors in breast cancer

DNA level measured by flow cytometry and estrogen and progesterone receptors assayed in tissue samples obtained from 85 malignant and 16 benign lesions of the breast. All the benign tumors revealed 2c DNA content and most of them were receptor-negative, while 74.1% of breast carcinomas displayed aneuploidy. Three patients (3.5%) had two lines of aneuploid cells. Many aneuploid tumors were receptor-negative. Preoperative radiation treatment (14-20 Gy) did not significantly influence the level of steroid hormone receptors in tumors. Estrogen receptor level was higher in menopausal patients than in premenopausal ones.     

Ploidy assessment of benign and malignant ovarian tumors by flow cytometry. A clinicopathologic study

In a prospective study, 112 fresh ovarian tumor samples were collected from 83 consecutive patients. Cellular DNA content was measured by flow cytometry. All the benign (n = 24) and semimalignant (n = 6) tumors were diploid. Of 50 malignant tumors, 24 (48%) were diploid and 26 (52%) were aneuploid. Aneuploidy was more frequent in the advanced stages of the disease, in tumors of low degree of differentiation, and in older patients. The patients with aneuploid tumors had smaller primary tumors and more often ascites. The fraction of cells with S-phase DNA content was higher in the aneuploid tumors. No association was seen to the tumor type. Ploidy determination is objective and reproducible. Aneuploidy associates to most negative prognostic factors in ovarian carcinoma and may reflect the aggressiveness of the tumor. The ploidy status may be taken into consideration in the stratification of patients of comparable risk for treatment studies.     

DNA distributions in human normal, precancerous and cancerous breast tissue. II. Differences in heparin mediated changes in DNA distributions

DNA distributions were recorded flow cytometrically (FCM) in human normal, precancerous (P1 characterized by ductal hyperplasia and/or lobular hyperplasia, and P2 characterized by carcinomata lobularia in situ and intraductal carcinoma) and malignant breast tissues. Heparin, a polyanion, mediated two changes: (a) a time-dependent increase in fluorescence intensity (IFI) considered to be inversely proportional to the proliferative activity. IFI was significantly lower in carcinomas than in P2, in normal and in P1 tissues; it identified a highly and a poorly heparin-sensitive subgroup of carcinomas, which differed in respect to histological type and tumor stage distribution; (b) a time-dependent increase in the percentage of recorded DNA aneuploid cells (IAC) at the expense of DNA diploid cells in mixed cell population. IAC is considered to correspond to cell membrane permeability. DNA aneuploid cell populations homogeneous in respect to DNA - index (DI) seem to be heterogeneous in respect to cell membrane function. Duct carcinomas showed significantly higher IAC than lobular carcinomas.     

The prognostic significance of nuclear DNA content in malignant epithelial tumors of the ovary

Recent studies have indicated that the nuclear DNA content of certain malignant neoplasms can be used as an adjunct in predicting their biologic behavior. The DNA content of 99 ovarian carcinomas was determined by flow cytometric analysis of nuclei obtained from paraffin-embedded tissue. Of the 99 tumors, 51 were diploid and 48 showed one or more aneuploid peaks. The 5-year survival for patients with diploid tumors (50%) was significantly higher than for patients with aneuploid tumors (22%) (P less than 0.01). Other factors which significantly affected survival were clinical stage (P less than 0.001), tumor pattern grade (P less than 0.01), DNA index (P less than 0.01), the presence of ascites (P less than 0.001), peritoneal carcinomatosis (P less than 0.0001), and residual tumor at second-look laparotomy (P less than 0.05). Diameter of the primary ovarian tumor, diameter of the largest peritoneal implant before debulking, and the percent S-phase had no significant correlation with survival. Of 16 patients with aneuploid tumors who underwent second-look laparotomy, nine (56%) had residual tumor, compared to six of 22 of patients with diploid tumors (27%). Of seven patients with aneuploid tumors and a negative second-look laparotomy, four (57%) died from recurrent tumor. By comparison, of 16 patients with diploid tumors and a negative second-look laparotomy, only four (25%) died from recurrent tumor. The determination of DNA ploidy in ovarian carcinomas may be used as an adjunct in predicting tumor behavior, response to chemotherapy, and late recurrence of disease.     

The clinical relevance of ploidy and S-phase fraction determination in salivary gland tumors: a flow cytometric study of 97 cases

BACKGROUND: The authors studied a series of 97 consecutive cases of salivary gland tumors to investigate the correlation between the biologic parameters DNA ploidy and S-phase fraction (SPF) and the presumptive behavior of the neoplasms, as well as their potential clinical utility. METHODS: Histopathologic classification and grading of the tumors were evaluated according to 1991 World Health Organization criteria. DNA analysis was performed by flow cytometry in fresh material after propidium iodide staining. Clinical data and follow-up information were obtained from the clinical charts. RESULTS: All the 71 benign salivary tumors showed a DNA diploid pattern. Seven carcinomas (7.2%) exhibited DNA aneuploidy. Eleven (42.3%) of 26 malignant tumors were considered low grade carcinomas, all of them being DNA diploid. Of the remaining 15 tumors, classified as high grade carcinomas, 7 showed DNA aneuploidy. SPF values ranged from 0.6% to 27.7%. A statistically significant difference was found between the mean SPF values of benign and malignant tumors, diploid and aneuploid tumors, and low grade and high grade carcinomas. When a cutoff value of 3% was used to discriminate histopathologic subgroups with prognostic impact, a significant difference was found between benign and malignant salivary tumors, high grade and low grade carcinomas, and high grade and benign tumors (P < 0.001). CONCLUSIONS: The data from this study confirm the low incidence of DNA aneuploidy in salivary gland tumors and suggest the potential utility of SPF estimation in evaluating the clinical behavior of these neoplasms.     

Flow cytometric DNA index in the prognosis of colorectal cancer

The authors investigated the relationship between flow cytometric DNA index (DI, defined as the ratio of the DNA content of malignant cells to that of normal cells) and other prognostic factors (grade and stage, anatomical site, age and sex) with the survival of 115 patients with colorectal cancer. Multiple biopsy specimens from 62 patients were taken during colonoscopy before surgery. Additional samples from 53 patients were obtained from paraffin-embedded material. All patients were treated with surgery only. Fresh-frozen material gave higher incidence of DNA aneuploidy than paraffin-embedded material (79% versus 41%). The patients with DNA diploid tumors (DI = 1) had a better overall survival than those with DNA aneuploid tumors (DI = 1). Among DNA aneuploid tumors, those with DI greater than 1.2 (excluding DI = 2) were worse than those with DI = 1.2 (excluding DI = 1) and DI = 2. Cox's regression analysis showed that pathologic stage was more important for prognosis than DNA index, whereas age, sex, histologic grade, and anatomic site were removed from the analysis as not relevant for prognosis. Relative risk of death (RR), in reference to patients with DI = 1 and Stages A + B (RR = 1), were RR = 1.8 for patients with carcinomas with Stage C. RR = 2.7 for patients with carcinomas with DNA near-diploid and DNA tetraploid tumors. RR = 3.5 for those with DI greater than 1.2 (excluding DI = 2), and RR = 8.0 for those with Stage D. These data indicate that flow cytometrically evaluated DI values have a relevant independent power for predicting the clinical outcome of colorectal cancer patients.     

Progression of diploid tumor cells in aneuploid head and neck squamous cell carcinomas

The development of aneuploid clones from diploid progenitor cells is a regular characteristic of head and neck squamous cell carcinoma progression. While the significance of aneuploidy formation for the acquisition of invasive and metastatic behavior is well documented, little is known about the contribution of diploid tumor cells after aneuploid clones have emerged. To distinguish diploid cells of epithelial origin from benign cellular components, we applied multiparameter flow cytometry of DNA content and cytokeratin (CK) expression to 36 primary tumors. Twenty-seven carcinomas accommodated aneuploid cell lines that stained positive for CK. All diploid cell populations obtained from aneuploid carcinomas contained CK-positive subpopulations as did all of nine tumors that consisted exclusively of diploid cells. The proportions of CK-positive diploid cells ranged between 6% and 80%, independent of whether they were achieved from entirely diploid or from aneuploid carcinomas. CK-gated diploid and aneuploid cell populations showed largely identical S-phase fractions. These results emphasize that diploid tumor cells regularly persist after the development of aneuploid clones and significantly contribute to local tumor progression. Despite the presence of diploid epithelial cells in aneuploid primary tumors, exclusively the aneuploid clones of eight corresponding lymph node metastases were CK-positive. This provides further evidence of a largely reduced metastatic potential of diploid tumor cells.     

A flow cytometric analysis of DNA content in primary and metastatic lesions of esophageal squamous cell carcinoma.

BACKGROUND. DNA content of malignant tumors has been considered a significant prognostic factor, but intratumor variations in DNA content and differences in DNA content between primary and metastatic lesions have been found in various tumors. METHODS. DNA indexes of multiple samples obtained from different sites in each tumor were determined by flow cytometry (FCM) in 27 esophageal squamous cell carcinomas. RESULTS. Intratumor variation in DNA indexes in primary lesions was found in 10 (37%) of the 27 specimens. Of the rest, all DNA indexes were diploid in 5 and all identically aneuploid in 12 samples. A DNA index differing from that of the metastatic lesion was found in four (50%) of eight primary lesions; however, a component of the DNA index identical to that of metastatic lesion was found in seven (88%) of eight primary lesions. CONCLUSIONS. Recurrence after a "curative" operation was frequent in patients with a tumor that had an aneuploid DNA index, with or without a variation in DNA indexes. There was no recurrence in the five patients with tumors that had only a diploid DNA index. These results suggest that differences in DNA content between primary and metastatic lesions reflect intratumor variation in DNA content in the primary lesions. The presence of a tumor cell population with an aneuploid DNA content, even when the DNA content varied in the primary lesion, may indicate an aggressive clinical course in patients with esophageal squamous cell carcinoma.