Prognostic impact of ploidy level in carcinoma of the cervix

Ploidy and Proliferation Evaluated by Flow Cytometry. An Overview of Techniques and Impact in Oncology

Flow cytometric methods for the assessment of nuclear and chromosomal DNA content and of cell proliferation (including methods based on pulse-chase of bromodeoxyuridine and on monoclonal antibodies against nuclear oncoproteins and proliferation-associated antigens) are illustrated by examples and analyzed critically. The impact of most of these techniques for the study of human solid tumors, with exception of nuclear DNA content evaluation, appears still limited. In particular, new studies of cell lines and clinical material from human tumors using new proliferation markers and multiparameter flow cytometry are necessary to solve a considerable number of methodologic and scientific problems.

How mitotic errors contribute to karyotypic diversity in cancer

Aneuploidy is a common feature of cancer cells, and is believed to play a critical role in tumorigenesis and cancer progression. Most cancer cells also exhibit high rates of mitotic chromosome mis-segregation, a phenomenon known as chromosomal instability, which leads to high variability of the karyotype. Here, we describe the nature, nuances, and implications of cancer karyotypic diversity. Moreover, we summarize recent studies aimed at identifying the mitotic defects that may be responsible for inducing chromosome mis-segregation in cancer cells. These include kinetochore attachment errors, spindle assembly checkpoint dysfunction, mitotic spindle defects, and other cell division inaccuracies. Finally, we discuss how such mitotic errors generate karyotypic diversity in cancer cells.

DNA Ploidy is Stronger Than Lymph Node Metastasis as Prognostic Factor in Cervical Carcinoma: 10-Year Results of a Prospective Study

Introduction:

To improve the outcome of patients with cervical cancer, a more accurate prognostic assessment is essential. The aim of this study was to evaluate the role of tumor DNA ploidy as an independent prognostic factor in cervical carcinoma. Furthermore, we investigated whether the presence of lymph node metastasis may have a different clinical impact according to ploidy status.

Methods:

In a long-term prospective study, DNA ploidy was evaluated by flow cytometry from fresh tumor samples from 136 patients with cervical cancer who underwent surgery. Ploidy, lymph node metastasis, and other classical parameters were analyzed in relation to the length of disease-specific survival. Treatment modalities did not differ between patients with diploid tumors and patients with aneuploid tumors.

Results:

DNA aneuploidy was found in 52 patients (38.2%). Patients with DNA-aneuploid tumors had a significantly reduced disease-specific survival (P= 0.003). Overall, the 10-year survival probability was 54% for patients with DNA-aneuploid tumors and 80% for patients with DNA-diploid tumors. Among 64 patients with International Federation of Gynecologists and Obstetricians stage I disease, the 10-year survival rates were 38.7% for the patients with DNA-aneuploid tumors and 86.3% for those with DNA-diploid tumors (P= 0.003). Overall, diploid tumors with lymph node metastasis did significantly better than aneuploid tumors with lymph node metastasis (P= 0.05). Among the patients with International Federation of Gynecologists and Obstetricians stage I disease, there was a highly significant difference between patients with diploid node-positive tumors and patients with aneuploid node-positive tumors, with no deaths from the disease in the former group in contrast with the worst outcome in the latter group (P= 0.005). By multivariate analysis, pathologic tumor stage, lymph vascular invasion, and tumor ploidy were significant and independent parameters, whereas lymph node metastasis yielded no independent information.

Conclusions:

DNA ploidy was an independent prognostic factor in cervical carcinoma. Presence of lymph node metastasis may not always have the same impact on survival but may vary according to DNA ploidy of the primary tumor.

The prognostic value of a histologic grading system, DNA profile, and MIB-1 expression in early stages of cervical squamous cell carcinomas

This study evaluated the prognostic importance of a new grading system focusing on the invasive tumor front, DNA profile, and the proliferation marker MIB-1. A complete geographic series of 172 women treated with radical hysterectomy (Wertheim-Meigs) for FIGO stage I-II cervical carcinomas was the target population. The analyses were performed on 141 (82%) squamous cell carcinomas of the complete series. During the period of observation (mean 222 months), 17 recurrences (12.1%) were encountered. Prognostic factors for disease-free survival were lymph node status (P < 0.000001), radical surgical margins (P = 0.00004), and tumor size (P = 0.002). The complete score of the invasive front grading system (IFG), and the individual scores of two variables-pattern of invasion and host response-were all significantly (P = 0.002, P = 0.007, P = 0.0001) associated with pelvic lymph node metastases. Host response was the single most important factor in the IFG system, and it was superior to the complete score in predicting lymph node metastases. The total IFG score was also a significant (P = 0.003) prognostic factor for disease-free survival. DNA ploidy, S-phase fraction, and MIB-1 expression were nonsignificant factors in predicting pelvic lymph node metastases and disease-free survival of the patient. The IFG in the original or modified versions could predict low- and high-risk groups of tumors and therefore be of value in treatment planning for these patients.

The role of radical surgery followed by adjuvant therapy for high-risk early-stage cervical carcinoma patients with pelvic lymph node metastasis

OBJECTIVES

To identify a subgroup of high-risk node-positive patients in early-stage cervical cancers and to determine the role of radical hysterectomy followed by adjuvant therapy to these patients.

STUDY DESIGN

We conducted a retrospective review of 482 surgically-treated patients of clinical stage Ib and IIa cervical carcinoma from July 1986 to December 1994 at Kaohsiung Chang Gung Memorial Hospital. Of these, 96 patients had pelvic lymph node metastases. Clinicopathological variables, including the level of pretreatment squamous cell carcinoma antigen (SCC-Ag), DNA flow cytometry analysis, and the use of different adjuvant therapies were studied.

RESULTS

Disease-free survival was significantly worse among patients with S-phase fraction greater than 20% and pretreatment SCC-Ag level above 5 ng/ml. Utilizing these significant variables, we identified two distinct risk groups. Those patients without any of the risk variables were categorized as the low-risk group. Those patients with either one or both risk variables were categorized as the high-risk group. Five-year disease-free survival rates were 74% in the low-risk group and 43% in the high-risk group, (P=0.034). Disease recurred in 30.2% of the low-risk patients and 45. 3% of the high-risk patients. No survival advantages were found by using different adjuvant therapies.

CONCLUSIONS

Radical hysterectomy should not be attempted if either the pretreatment SCC-Ag level is above 5 ng/ml or S-phase fraction of the tumor greater than 20% due to its limited value despite applying aggressive postoperative adjuvant therapy.

Tumour cell kinetics as a prognostic factor in squamous cell carcinoma of the cervix treated with radiotherapy

PURPOSE

Proliferative rate and DNA ploidy status were evaluated by flow cytometry in cervical cancer patients, prior to radiotherapy, to assess their importance as prognostic factors to predict survival rates.

MATERIAL AND METHODS

Between 1987 and 1995, a total of 260 patients with squamous cell carcinoma (SCC) of the cervix, FIGO stages IB-IIIB were analysed. Tumour samples were incubated with bromodeoxyuridine (BrdUrd) in vitro to measure their total labelling index (totLI) and LI (totLI for diploid and anLI for aneuploid tumours). Proliferation was also assessed by S-phase fraction (SPF) analysis of the DNA profile. Patients had intracavitary therapy (three applications, each of 16 Gy to point A) and XRT of 40-50 Gy given over 4-5 weeks.

RESULTS

The cervical tumours were characterized by a high proliferation rate which varied within each clinical stage of disease. The totLI ranged from 1.1 to 33.1% with median value of 9.6% whilst the LI ranged from 1.1 to 37.1% with a median value of 10.9%. Univariate analysis identified patient's age (cut-offpoint < or = 50&greater; years) and to a lesser extent proliferation (cut-off point, median totLI=9.6%) as significant prognostic factors for 5-year survival. The median survival time for younger patients ( < or = 50 years) with tumours of low proliferation (totLI < or = 9.6%) tumours was 17.5 months compared with 56 months in the faster proliferating tumours (P=0.0354). In the older patient sub-group, proliferation rate had no influence on survival. The median LI value was not a useful parameter in survival. Cox multivariate analysis showed that patient age ( < or = 50 years) and low proliferation of the tumour cells (totLI < or = 9.6) were unfavourable prognostic factors for cervical cancers treated with radiotherapy. DNA ploidy was not significant in this series.

CONCLUSIONS

These data suggest that further improvements in therapy might be gained by selection of alternative treatments strategies such as neoadjuvant chemotherapy or radiation sensitizers in younger patients with more slowly proliferating tumours.

Leiomyosarcoma of the uterus: A clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 49 cases

AIM

The authors analyzed in a retrospective manner the prognostic significance of p53 and mdm-2 expression, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathological prognostic factors in patients with uterine leiomyosarcomas.

MATERIAL

Forty-nine patients were diagnosed with uterine leiomyosarcoma (25 stage I, 4 stage II, 8 stage III, and 12 stage IV). DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors.

RESULTS

Of the 49 patients, 35 (71%) died of disease and 2 died of intercurrent disease. The 5-year survival rate was 33%. FIGO surgical stage, DNA ploidy, SPF, mitotic index, cellular atypia, and tumor grade obtained significance (P < 0.05) in a univariate survival analysis of the leiomyosarcomas. In a multivariate analysis with survival as the end point, stage was found to be the most important factor (P = 0.007); DNA ploidy (P = 0. 045) and SPF (P = 0.041) also had independent prognostic significance. For FIGO stage I tumors, DNA ploidy (P = 0.04) and tumor grade (P = 0.01) were statistically significant in a univariate analysis, while only grade had independent prognostic significance (P = 0.01) in a multivariate analysis. In a univariate analysis including only FIGO stage I and II tumors with disease-free survival as the end point, p53 overexpression (P = 0.0016), DNA ploidy (P = 0.042), and tumor grade (P = 0.008) obtained significance. In a multivariate analysis, only p53 had independent statistical significance (P = 0.01). All p53 immunopositive stage I-II tumors recurred within 28 months from diagnosis.

CONCLUSION

This study found that stage represents the most important prognostic factor for uterine leiomyosarcomas. DNA ploidy and SPF had independent prognostic value. DNA flow cytometry is useful in gaining additional prognostic information. In stage I patients, tumor grade gives significant information regarding clinical outcome. In addition, p53 overexpression may predict a higher risk of recurrence in early stage leiomyosarcomas.

Malignant mixed Müllerian tumors of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 44 cases

AIM

The authors retrospectively analyzed the prognostic significance of p53, mdm-2, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathologic factors in patients with malignant mixed Müllerian tumors (MMMT) of the uterus.

METHODS

Between 1970 and 1995, 44 uterine tumors were diagnosed as MMMT (21 stage I, 2 stage II, 10 stage III, and 11 stage IV). Thirty-two were homologous type and 12 were heterologous type. DNA flow cytometry and immunohistochemical analysis for p53 and mdm-2 overexpression were performed on paraffin-embedded archival tissue.

RESULTS

68% of the tumors were nondiploid and 61% had an SPF greater than 10%. Sixty-one percent overexpressed p53 and 25% were mdm-2-positive. Furthermore, 91% of the tumors had a mitotic count greater than 10/10 hpf and 95% had high-grade cytologic atypia. Twenty-seven (61%) patients died of tumor and 6 (14%) died of intercurrent disease. Eleven (25%) patients are alive with no evidence of disease. The median follow-up for patients still alive was 59 months (range, 28-178 months). The overall 5-year survival rate was 38%. In a univariate analysis that included stage, histologic type, DNA ploidy, SPF, p53, mdm-2, mitotic index, and age, and with survival as the end point, only stage reached statistically prognostic significance.

CONCLUSION

The majority of the tumors had obvious signs of aggressiveness such as high grade, high mitotic count, nondiploid pattern, high SPF, and overexpression of p53. This study found that stage is the most important prognostic factor for survival in MMMTs of the uterus.

Female genital tract malignancies during puberty. Uterine and cervical malignancies

Malignancies of the uterine corpus are extremely rare. Diagnostic and therapeutic procedures should be performed according to oncological principles with individually adapted treatment regimes. Clinical cancer of the cervix is rare in adolescence; the treatment is radical surgery. Preclinical stages, that is, CIN III (severe dysplasia, carcinoma in situ) and microinvasive cancer (stages Ia1, Ia2), are important, also because of their frequency. Diagnosis is based on colposcopy, cytology, direct biopsy, histological examination, and conization. In addition, virology (HPV) and DNA cytometry may become prognostic factors. Treatment consists of conization with an exact histological examination in serial sections as a basis for preserving the uterus. The sarcoma botryoides is localized in the cervix in adolescence, whereas it is in the vagina in infants and children.

Factors influencing tumor cell kinetics in cervical cancer

Fresh tumor tissues instead of paraffin-embedded sections were used to study the clinical significance of the tumor cell kinetics in cervical carcinomas by flow cytometry. We analyzed specimens from 153 women with cervical cancer, and DNA aneuploidy was found in 61 cases (39.9%). The mean age of patients with aneuploid tumors was significantly higher than the age of patients with diploid tumors (P < 0.001). The mean proliferation index for aneuploid tumors was significantly higher than those for diploid tumors. There was a significant correlation between the proliferation index and age. However, tumor cell kinetics is not related to the status of human papillomavirus, herpes simplex virsuses I and II, lymph nodes, histology or tumor size. The mean age and S-phase fraction for stage-II tumors were significantly higher than those for stage-I tumors (P < 0.01). The tumors of menopausal patients exhibited a relatively higher rate of lymph node metastasis, and significantly higher aneuploidy rate and proliferation index than tumors of premenopausal patients. In summary, age and, what is more important, menopausal status may significantly influence DNA ploidy and cell kinetics of tumors, and subsequently influence clinical stage and lymph node metastasis. However, tumor cell kinetics is of limited value in the prediction of lymph node metastasis and prognosis.

Changes in S-phase fraction and micronucleus frequency as prognostic factors in radiotherapy of cervical carcinoma

Twenty-five patients with cervical carcinoma were treated with combined external beam and high dose rate afterloading radiotherapy. Biopsies obtained at different time points in the course of therapy were analysed with respect to cell proliferation and cytogenetic damage. The fraction of cells with an S-phase DNA-content as well as the frequency of micronuclei were determined. These two parameters were then related to treatment outcome, in particular patient survival. Neither S-phase fraction nor the micronucleus frequency before radiotherapy were predictive of treatment outcome in this small group of patients. However, when changes in response to therapy were considered, patients whose S-phase fraction decreased and patients whose micronucleus frequency increased tended to have a better prognosis. Although statistical significance was not achieved with either criterion alone, when applied together the combination predicted patient survival quite reliably; the 5-year survival rate of those patients who showed a decrease in S-phase fraction as well as an increase in micronucleus frequency was about 90% in contrast to less than 30% for the non-responders (p < 0.03).

The role of flow cytometry in non-resected cervical carcinoma

Flow cytometry (FCM) has a prognostic value for many malignant neoplasms in terms of treatment response rate and survival. However, its role in non-resected cervical carcinoma remains uncertain. We have collected 96 paraffin-embedded specimens taken from non-resected cervical cancer patients treated by radiotherapy (RT) alone between 1984 and 1986. Our data revealed that FCM has little correlation with patients' age, pathological grade and clinical stage. Ploidy pattern and clinical stage correlate significantly with complete remission (CR) rate (p = 0.001 and 0.03). Most diploid or low-stage tumours (IB to IIA) obtained CR after RT alone. The application of an intravaginal extension electron cone (IVEC) (p = 0.019) and CR status (p = 0.0001) yield significant better overall survival (OS) rates than their alternative groups. The Cox regression model has confirmed these two variables as having an independent influence on OS. We thus conclude that both ploidy pattern and S-phase fraction (SPF) predict neither pre-treatment biological behaviour of the tumours nor overall survival. However, ploidy pattern has an independent influence on CR rate.

Schauta-Amreich vaginal hysterectomy and Wertheim-Meigs abdominal hysterectomy in the treatment of cervical cancer: a retrospective analysis

OBJECTIVE

The aim of the current study was to determine the effectiveness of Schauta's vaginal hysterectomy in the treatment of stage IB or IIA cervical carcinoma.

STUDY DESIGN

In a retrospective analysis the results of Schauta's operation have been compared with those of Meigs' operation in 793 consecutive cases of stage IB or IIA cervical carcinoma. In 201 of them adjuvant radiotherapy was given. A total of 356 patients with stage IB and 76 with stage IIA underwent Schauta's operation, whereas 288 and 64 patients with stage IB and IIA, respectively, were operated on with Meigs' procedure. For statistical analysis the Mantel-Haenszel test was used.

RESULTS

In stage IB the 5-year survival (Kaplan and Meier method) was 81% in the Schauta group and 75% in the Meigs group (p < 0.05). The results for stage IIA were 68% and 64%, respectively (difference not significant). In a separate analysis for stage IB and treatment by surgery alone, 5-year survival rates for the 283 in the Schauta group and the 175 in the Meigs group were 83% and 78%, respectively (difference not significant).

CONCLUSION

Schauta's vaginal hysterectomy showed a high rate of cure for stage IB or IIA cervical cancer. Therefore we conclude that it can be used as an alternative to the Meigs operation in the presence of obesity or elevated surgical risk.

Prediction of lymph node metastases in patients with early squamous cell carcinoma of the cervix uteri by histopathological grading and flow cytometry

The present study comprises a retrospective investigation of 126 patients with stage IB squamous cell carcinoma of the cervix, and a similar prospective investigation of 53 patients with stage IB and 6 patients with stage IIA disease. Tumour biopsies from these patients were analysed by means of flow cytometry and a semiquantitative histological grading system. The study showed that a combination of a low tumour cell DNA index and a low score value of the grading system indicated a very low risk of regional lymph node metastases (0% lymph node metastases in patients with low scores vs. 24-46% metastases in patients with high scores, P < 0.001). In order to study the reproducibility of the histological grading 20 randomly selected cases were studied blindly by three of the participating pathologists and after discussion of the grading criteria. A kappa coefficient of 722 demonstrated a substantial agreement between the observers. These results suggest that by combining flow cytometry with semiquantitative histological grading, a subgroup of patients with early squamous cell cancer of the cervix uteri may be selected that could be sufficiently treated with simple hysterectomy instead of radical hysterectomy including lymphadenectomy, which, in many oncology centres, is the standard treatment of this patient category.

Prognostic factors in invasive cervical carcinomas associated with human papillomavirus (HPV). Quantitative data and cytokeratin expression

As a part of a larger programme to search for the prognostic factors in cervical cancer, quantitative morphometry, demonstration of AgNORs and expression of different cytokeratin polypeptides (SK2-27, SK1, A 53-B/A2) were used to study a series of 85 cervical squamous cell carcinomas, previously analysed for the presence of human papillomavirus (HPV) DNA by in situ hybridization and polymerase chain reaction (PCR). The following nuclear profile parameters were calculated: nuclear area, perimeter, maximum diameter, ellipsoidity (form Ell), regularity (form Ar) and roundness (form Pe). In each case, the number of small (< 3 microns), large (> 3 microns), the total number and the ratio large/small AgNORs were registered. The cancer cell density and the lymphoid cell density were assessed. In the survival analysis, neither the expression of different cytokeratin polypeptides or the pattern of cytokeratin staining proved to be an independent variable. Similarly, none of the nuclear profile parameters analysed possessed an independent prognostic value in the survival analysis. The ratio of large/small AgNORs proved to be a significant independent prognostic predictor (p = 0.0104), second only to the lymphoid cell density. Also the total number of AgNORs was a prognostic indicator. This suggests that AgNOR size and ratio reflect tumor proliferation also in cervical squamous cell carcinoma, as shown in other human malignancies. Similarly, the density of cancer cell nuclei proved to be an independent prognostic predictor (p = 0.0601) in that the tumours in patients with longer survival showed lower density of the nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA cytometry in postirradiation cervical-vaginal smears

Benign radiation change (BRC) in cervical-vaginal smears may be difficult to distinguish from postirradiation dysplasia (PRD) or recurrent cervical carcinoma. The utility of DNA analysis in postirradiation smears was evaluated retrospectively in 71 patients. Representative Papanicolaou smears were restained with a Feulgen method and 100 to 250 cells were analyzed for DNA content using the CAS 200 image analysis system. Thirty-three control irradiated patients had negative smears with a minimum 3-year follow-up. Thirty controls (91%) had diploid histograms with a mean coefficient of variation of 8.2% and an average of 6.8% of cells in S and G2/M phase. Three control patients had atypical nondiagnostic histograms. Twenty-three patients had abnormal smears and subsequent local recurrence; 21 (91%) had abnormal histograms, with seven showing polyploidy and 14 showing aneuploidy. The remaining 15 patients had abnormal smears diagnosed as PRD but no evidence of recurrent carcinoma. Five were polyploid, six were aneuploid, one was diploid, and three were atypical but nondiagnostic. Interactive DNA cytometry is useful in differentiating BRC from PRD and recurrent cancer. Aneuploidy is rarely, if ever, seen in negative smears with BRC. However, BRC may be associated with broad diploid peaks and increased proliferating cells. An abnormal histogram can be seen with PRD and does not always correlate with recurrent disease.

Flow-cytometric DNA analysis of stages IB and IIA cervical carcinoma

The prognostic significance of flow-cytometric DNA analysis was assessed in 375 stages IB and IIA squamous cell carcinoma patients treated with radical hysterectomy and lymphadenectomy at the Mayo Clinic between 1956 and 1985. Paraffin-embedded samples containing at least 20% tumor were dewaxed, rehydrated, stained with propidium iodide, and analyzed. Among 344 assessable samples, 136 (40%) were diploid and 208 (60%) were nondiploid (26 tetraploid, 158 aneuploid, and 24 polyploid). Diploid cases were further subclassified: 25 high proliferative phase (HPP) (S+G2M greater than 20%) and 111 low proliferative phase. No significant correlation was noted between DNA diploid patterns and stage, tumor size, grade, or histotype, but HPP diploid tumors had a significantly higher risk of nodal metastasis. With a mean follow-up period of 150 months, 62 patients died of disease. No significant difference was observed in survival rates (SR) between diploid and nondiploid tumors, but the subset of HPP diploid tumors had a prognosis significantly worse than that of any other group (P less than 0.01). Other significant variables included nodal metastases, parametrial extension, age, and clinical stage. While ploidy patterns did not assign additional risk to node-positive lesions, HPP diploid tumors in node-negative patients were associated with a significantly lower SR. Multivariate analyses in node-negative patients demonstrated that stage, histologic subtype, and HPP diploid patterns retained prognostic independence.

Flow cytometric DNA analysis in gynecological oncology

The relevance of flow cytometric DNA analysis in neoplasia of the female genital tract is reviewed. The virtues and limitations of the technique are discussed. There is good evidence, mainly from retrospective studies, that DNA ploidy and/or the tumor S-phase fraction are valuable prognostic indicators in patients with carcinoma of the ovary and endometrium. Further prospective studies are needed, however, to establish the precise value of flow cytometric DNA analysis before it can be used safely for stratification of therapeutic regimes.

Flow cytometric analysis of uterine sarcoma: ploidy and S-phase rate as prognostic indicators

Flow cytometry of various gynecological tumors has shown that aneuploid tumors and a high S-phase rate carry a prognosis worse than that of diploid tumors or tumors with a low S-phase. The aim of this study is to investigate the prognostic importance of DNA ploidy and S-phase rate in relation to mitotic count, tumor stage, tumor grade, and histology in 37 patients with uterine sarcoma stages I-IV (FIGO). Flow cytometry was performed on archival paraffin-embedded tumor tissue and the histologic specimens were reviewed by a single pathologist. Nineteen (51%) of the tumors were classified as DNA aneuploid. The S-phase fraction (SPF) was determined in 33 cases. The mean SPF (+/- SD) was 15.0% (+/- 9.5%). The mean SPF was three times higher in aneuploid tumors than in diploid cases. Both the proportion of aneuploid tumors and the mean SPF were significantly higher in later stage tumors, more poorly differentiated tumors, and tumors with a higher mitotic index. No significant differences were seen between histologic types with respect to the two cytometric variables. The 5-year cancer survival rate was only 11% in aneuploid cases compared with 59% in diploid cases (log rank, P = 0.0002). There was a significantly worse prognosis in cases with a higher SPF (P = 0.0009) and in case with a higher mitotic index (P = 0.0016). In the multivariate survival analysis using the Cox proportional hazards model, DNA ploidy showed a significant prognostic value (P = 0.046) even when adjusted for stage, grade, and mitotic index. When adjusted for stage and grade only, SPF showed significant additional prognostic value.

Comparison between flow cytometry and image cytometry in ploidy distribution assessments in gynecologic cancer

The DNA content in 37 tumors from 34 women with gynecological cancer was measured by flow cytometry (FCM) and interactive image cytometry (ICM). Agreement was obtained in 81% of cases as regards ploidy levels, but seven tumors (19%) showed different ploidies. Of these, five were classified as diploid by FCM but either aneuploid (three cases) or polyploid (two cases) by ICM. Two other tumors were aneuploid by ICM but polyploid (one case) and unclassifiable (one case) by FCM. All tumors classified as aneuploid by FCM were also aneuploid by ICM, and all tumors classified diploid by ICM were also diploid by FCM. Of six patients whose tumors were classified as euploid (five diploid and one polyploid) by FCM but classified as aneuploid by ICM, five relapsed, and three of these have died of disease. On the basis of these findings, it is concluded that ICM must be performed in cases classified as diploid by FCM to ensure that small subpopulations of aneuploid tumor cells are not overlooked.

Clinical application of flow cytometry for DNA analysis of solid tumors

Recent developments of flow cytometry (FCM) technology which make multiple correlative biological measurements on normal and neoplastic cells is affecting areas of diagnostic pathology as well as research fields, and a general understanding of FCM techniques is essential for pathologists. Today, FCM DNA measurements of tumors also becomes routine in the clinical and/or pathological laboratory for aid in cancer diagnosis and cancer treatment. It can also contribute to diagnosis of tumors as a supplemental method to conventional histopathology, and DNA ploidy and the percentage of S-phase fraction are considered as complementary prognostic parameters independent of the stage of disease. This article reviews clinical applications of flow cytometry focusing on the DNA measurements of solid tumors, and related practical issues, such as the methodology for nuclear DNA measurement, interpretation of DNA histograms and the relationship of DNA ploidy and S-phase fraction to clinical and pathological features of human solid tumors.

DNA level and stereologic estimates of nuclear volume in squamous cell carcinomas of the uterine cervix. A comparative study with analysis of prognostic impact

Grading of malignancy in squamous cell carcinomas of the uterine cervix is based on qualitative, morphologic examination and suffers from poor reproducibility. Using modern stereology, unbiased estimates of the three-dimensional, volume-weighted mean nuclear volume (nuclear vv), were obtained in pretreatment biopsies from 51 patients treated for cervical cancer in clinical Stages I through III (mean age of 56 years, follow-up period greater than 5 years). In addition, conventional, two-dimensional morphometric estimates of nuclear and mitotic features were obtained. DNA indices (DI) were estimated by flow cytometry. Finally, the semiquantitative malignancy grade score value (MGS) was determined according to previously published methods. Estimates of nuclear vv were on average increased in euploid lesions (2P = 0.01), but the overall relationship between nuclear vv and DI was poor. Different clinical stages of disease did not differ with regard to nuclear vv (2P = 0.99) and DI (2P = 0.56). No relationship was disclosed between MGS and nuclear vv (2P = 0.85). Single-factor analysis showed prognostic impact of clinical stage of disease (2P = 0.0001) and DI (2P = 0.04), whereas estimates of nuclear vv were only of marginal prognostic significance (2P = 0.07). However, Cox multivariate regression analysis showed independent prognostic value of patient age and nuclear vv along with clinical stage and DI. All other investigated variables were rejected from the model. A prognostic index with highly distinguishing capacity between prognostically poor and favorable cases was constructed (2P = 1.9 x 10(-7)). It is concluded that realistic estimates of nuclear volume are independent of nuclear DNA content and are of prognostic value for objective malignancy grading in patients with squamous cell carcinoma of the uterine cervix.

Prognostic value of flow cytophotometric DNA content analysis in single treatment stage IB-IIA squamous cell carcinoma of the cervix

DNA content was measured flow cytometrically in archival tissue from 65 single-treatment stage IB and IIA squamous cell carcinomas of the cervix with at least 5 years of clinical follow-up. Thirty-five cases were treated exclusively by hysterectomy and thirty exclusively by radiation therapy. Tumors were categorized into four groups on the basis of DNA content and cell cycle distribution. DNA content was measured relative to the position of the first resolvable cell peak. G2/M and S-phase fractions were estimated as percentage of cells with DNA contents greater than or equal to relative position 1.70 and percentage of cells with relative positions between 1.20 and 1.70, respectively. The 40 tumors characterized as either aneuploid or nondemonstrably aneuploid with high S-phase fraction estimate had a 5-year recurrence rate significantly higher than that of the 25 tumors categorized as tetraploid or nondemonstrably aneuploid with low S-phase fraction estimate (52 and 4%, respectively; chi 2 = 15.8, P less than 0.001). Similar results were found when radiation and surgically treated tumors were considered independently (chi 2 = 7.95, P less than 0.005 and chi 2 = 5.7, P less than 0.025, respectively). These data suggest that an increased 5-year recurrence rate is associated with both abnormal DNA content and elevated S-phase fraction in stage IB-IIA squamous cell carcinoma of the cervix, and that this relationship is largely independent of treatment method.

Flow cytometric DNA content analysis of paraffin block embedded endometrial carcinomas

Flow cytometry is being used as an aid in planning the treatment of patients with various malignancies. We report our experience with DNA content analysis on paraffin-embedded carcinomas. Hospital, radiation therapy, clinic, and pathology records were reviewed in 139 cases of endometrial carcinoma diagnosed between December 1980 and December 1986. Patients having Stage IV tumors, endometrial sarcomas, dual primary tumors, or incomplete records were eliminated from the analysis, which left 98 evaluable patients. This report outlines our experience with the first 20 patients. Five of 20 (25%) specimens demonstrated DNA content consistent with aneuploidy, median coefficient of variance of 5.3%. The median survival time of these five patients is 55 months, with three dying of cancer and one patient dying of other causes but with metastatic disease. The median %S phase was 3.7% in the 15 patients comprising the DNA content diploid population, median coefficient of variance 5.4%. No patient whose tumor showed S-phase cells below 3.7% died of endometrial cancer. Four of 7 patients developed recurrent cancer with 3 of the 4 patients dying of disease in the high %S phase group. The median patients survival time in the DNA content diploid population was 73 (range: 17-98) months. Patients with 3.7% or below S-phase cells had a median survival time of 75 (range: 40-98) months whereas the median survival time was 48 (range: 17-89) months for patients having a %S phase fraction above 3.7%. Although the number of patients studied is small, it appears that DNA content aneuploid tumors are frequently "upstaged" at surgery. These patients may not benefit from preoperative irradiation. Accurate determination of the %S phase fraction in DNA content diploid tumors may possibly identify patients with a poorer prognosis who may benefit from adjuvant therapy.

Prognostic significance of human papillomavirus (HPV) type and nuclear DNA content in invasive cervical cancer

Eighty-one women treated for an invasive squamous cell carcinoma of the uterine cervix during the period from 1964 to 1987 were studied to assess the prognostic value of human papillomavirus (HPV) types 6,11, 16 and 18, as well as the nuclear DNA ploidy pattern, analyzed using HPV amplification by polymerase chain reaction (PCR) and flow cytometry, respectively. The mean age of the women was 57.7 ± 13.4 years, and the mean follow-up until the patients death or January 1990 was 99 ± 87 months. Altogether, 46 women died; 38 (82.6%) of these deaths were due to cervical cancer. The 5-year survival was significantly correlated with age (P= 0.01), and the FIGO stage of the tumors (P= 0.015), but not with tumor differentiation. Diploid tumor was found in 40 (63.5%) cases, and aneuploid in 23 (36.5%) cases. A DNA index 3= 1.5 was found in 47.8% (11/23) of the cases of aneuploid tumors. The 5-year survival rate in diploid tumors was 60.0% (21/35), as compared to 54.5% (12/22) in aneuploid ones, and in patients with a DNA index of < 1.5, the 5-year survival rate was 58.7% (27/46), as compared to 54.5% (6/11) in those with a DNA index ≥ 1.5. Amplified HPV DNA was found in 30 cases (37.0%) with the pairs of HPV DNA primers for HPV types of 6, 11, 16 and 18. When repeated with the anticontamination primers, only 19 (23.5%) cases remained HPV DNA positive. HPV 16 was the most frequent type present in 57.9% (11/19) of the cases, followed by HPV 18 in 36.8% (7/19). Neither the HPV DNA-positivity nor HPV type proved to be of prognostic significance. The results suggest that despite an intimate association of HPV 16 and 18 in cervical carcinogenesis, the presence of their DNA in cancer biopsies does not seem to have any prognostic value. The most significant prognostic factors are still the age and the FIGO stage at diagnosis. Aneuploid tumors or those with DNA index ≥ 1.5 seem to have a slightly (not statistically significantly) impaired prognosis as compared with the diploid tumors and those with DNA index < 1.5.

Cytophotometric analysis of corresponding cytological and histological cervical intraepithelial neoplasia grade III specimens

Cytophotometric analysis of cervical intraepithelial neoplasia grade III (CIN III) was performed in 22 cytological smears (CS) and in 22 corresponding cytospin specimens retrieved from selected areas of paraffin-embedded tissues (PEC). The average time interval between cytological and histological diagnosis was 6 weeks. CIN III nuclei in CS and PEC specimen were Thionin-Feulgen stained and digitized. Beside the visual classification of DNA ploidy patterns, the 2.5c and 5c exceeding rates and the specimen mean and standard deviation values of 21 photometric features were also analyzed. It was shown that, although there was a significant correlation between DNA ploidy patterns in corresponding PEC and CS specimen, the DNA patterns were dissimilar in eight of 22 cases. The DNA index, as represented by 2.5c and 5c exceeding rates, was significantly higher in the CS specimen. High-resolution cytophotometric analysis of cell nuclei in CS and PEC specimens showed significant differences for a large number of nuclear photometric features. These findings can possibly be explained by differences in selection of CIN III cells from CS and PEC specimens and by differences between fixation procedures as used for the two techniques. It was concluded that cytophotometric data of CS and PEC specimens representing CIN III lesions should not be regarded as interchangeable.

DNA ploidy level as prognostic factor in low stage carcinoma of the uterine cervix

Flow cytometry was used to measure DNA content of tumor cells in paraffin-embedded archival material from 89 patients with squamous cell carcinoma of the cervix uteri stages IB and IIA. Patients were all treated with radical hysterectomy and transperitoneal lymphadenectomy. Twenty-four percent received radiotherapy postoperatively because of tumor spread into parametria or positive lymph nodes. Ploidy grade was compared to other prognostic factors. DNA-aneuploidy was seen in 44 (49%), DNA-diploidy in 16 (18%) and 29 (33%) of the tumors were DNA-periploid. Sixty-nine (78%) patients were in FIGO stage IB, 20 (22%) in IIA. In 19 (21%) lymph node metastases were found, vasoinvasion in 25 (28%). Overall disease-specific 5-year survival was 80%. There was a significant effect of positive lymph nodes (90% vs 47%) and vasoinvasion (87% vs 64%) on the 5-year survival (resp. P less than 0.01 and P = 0.02). No correlation was found between stage (81% for IB vs 80% for IIA) or DNA-ploidy grade (81% for aneuploidy, 82% for periploidy, 79% for diploidy) and survival (resp. P = 0.9 and P = 0.8). Ploidy grade was equally divided over other prognostic factors. In stepwise Cox regression analysis DNA-ploidy grade showed no independent effect on survival. We conclude that DNA flow cytometry in this material was of no additional prognostic value.

Is radical hysterectomy always necessary in early cervical cancer?

A semiquantitative histopathologic grading system was used in combination with flow cytometric measurements of tumor cell DNA content to predict the risk of lymph node metastases in early cervical cancer. A retrospective study of 126 stage IB patients showed that a group with no risk of lymph node involvement could be identified by the use of both the histopathologic score and the DNA index. The results were confirmed in a prospective investigation of 59 new patients. Simple hysterectomy may be advised in low-risk patients.

Ploidy as a prognostic indicator in end stage squamous cell carcinoma of the head and neck region treated with cisplatinum

We measured tumour cellular DNA in 102 patients entered into two phase III trials of chemotherapy for end stage squamous carcinoma of the head and neck. The median survival of untreated patients with aneuploid tumours was 55 days compared with 224 days for patients treated with cisplatinum. This difference was highly significant. In contrast the median survival of untreated patients with diploid tumours was 74 days compared with 118 days for treated patients. Although this difference is statistically significant, the increased survival of 6 weeks is of no clinical benefit compared with the prolongation of survival of 6 months in patients with aneuploid tumours. Multivariate analysis showed that the significant predictors of survival were Karnofsky status, response to chemotherapy and ploidy.

Low-grade stromal sarcoma: DNA flow cytometric analysis and estrogen progesterone receptor data

DNA flow cytometry (FCM) data and estrogen receptor (ER) and progesterone receptor (PR) status were studied in three cases of low-grade stromal sarcoma (LGSS). One case was a primary presentation and the remaining two were recurrent tumors. DNA FCM showed a DNA index (DI) equal to 1.00, consistent with a diploid cell population, for four of the six specimens studied. The other two showed near-diploid populations. Proliferation indices (PI) were low in two of the patients' tumors (8.0 and 12.7%). These findings are consistent with the clinical history of LGSS and its propensity for indolent growth, long intervals between recurrences, and generally favorable prognosis. In case 2, a patient with several recurrences, the PI was increased to 20.3% in a specimen from the first recurrence. She subsequently recurred within 1 year with a more aggressive tumor, characterized by a mitotic index of greater than 10 mitoses/10 high-power fields (HPF), absence of ER and PR, and an aneuploid population (DI = 1.19). Receptor data, obtained by dextran-coated charcoal assay, showed that all tumors except the aggressive recurrence in case 2 had high ER (average 316 fmole/mg protein) and high PR (average 753 fmole/mg protein) levels. These ER and PR data are similar to the two other reports in the literature and the usual clinical response to progestational therapy was demonstrated. Further studies will help define the possible role of FCM and ER and PR determinations in patients with LGSS. These preliminary data suggest that they may be of prognostic significance.

Deoxyribonucleic acid flow cytometric analysis of cervical adenocarcinoma: prognostic significance of deoxyribonucleic acid ploidy and S-phase fraction

Paraffin-embedded tumor samples from 125 patients with cervical adenocarcinoma were analyzed by deoxyribonucleic acid flow cytometry. Thirty-one percent of the tumors were aneuploid. Triploid deoxyribonucleic acid content predominated (51.3%) and one third of the deoxyribonucleic acid aneuploid tumors were tetraploid, whereas near-diploid deoxyribonucleic acid aneuploidy was seen infrequently. Deoxyribonucleic acid aneuploidy was associated with tumor size, histologic grade, clinical stage, and high S-phase fraction. Deoxyribonucleic acid ploidy and S-phase fraction value were independent prognostic parameters, together with the presence of lymph node metastases and tumor size. In conclusion, our results indicate that flow cytometric deoxyribonucleic acid analysis helps to predict the prognosis and may thus influence the choice of treatment.

Ploidy, proliferative activity and prognosis. DNA flow cytometry of solid tumors

Flow cytometric study has been used to measure the cellular DNA content of solid tumors for the last decade, and of paraffin-embedded tumor specimens for the last 5 years. Ploidy and proliferative activity are the two properties commonly measured by DNA content flow cytometric study. The ability to study archival, paraffin-embedded tumors has hastened an appreciation of the prognostic utility of this assay. Either abnormal ploidy or elevated proliferative activity predict a worsened disease-free or overall survival in most common adult malignancies. Both abnormalities are associated with poor outcome in locoregional breast, non-small cell lung, and colorectal cancers, and in all stages of ovarian cancer. Abnormal ploidy is also a dire prognostic indicator for cancers arising from the kidney, bladder, prostate, and endometrium. Clinical management of patients with these diseases may be aided by studying their tumors for these objective markers of biological aggressiveness.

Ploidy level, histopathological differentiation and response to chemotherapy in serious ovarian cancer

The ploidy level was measured in tumour specimens from 64 patients with advanced epithelial ovarian cancer (FIGO stages III and IV) by flow cytometric analysis. The same tumours were histopathologically graded based on a score system considering eight histopathological parameters. The results showed that both the histopathological grading index (HGI) and the DNA index were important to the frequency of complete pathological remission as assessed by second look operation. A combination of the two parameters allowed a division of the patients into three groups with different frequencies of complete pathological remission and survival. It is concluded that flow cytometric analysis and extended histopathological grading may be important adjuncts in the evaluation of malignant epithelial ovarian tumours.

Flow cytometric measurements of DNA and other cell components in human tumors: a critical appraisal

Fundamental principles of flow cytometry with emphasis on DNA measurements and cell cycle analysis in human cells and tissues are summarized. Some of the pitfalls of cell preparation techniques and histogram interpretation are discussed at length. While consensus has been reached for some organs and tumors that DNA quantitation by flow cytometry (or image cytometry) may be of prognostic value, for most cancers studied to date the information remains incomplete. Thoroughly lacking are well-structured prospective studies because retrospective studies, while suggestive, may not necessarily be of the same value. Potential usefulness of other tumor markers is briefly discussed. Many fundamental questions concerning definitions of "diploid" and "aneuploid" tumors have not been satisfactorily settled. While the goal of "objective measurements" is worthy of further pursuit, the interpretation of results is often highly subjective. The biologic reasons for behavioral differences between diploid and aneuploid tumors are still totally obscure.

DNA ploidy, grade, and stage in prognosis of uterine cervical cancer

A retrospective study of 56 cases of uterine cervical squamous carcinoma evaluated DNA content, histological grade, and clinical stage as indicators of prognosis. Minimum survivor follow-up was 24 months. Following standard radiation therapy, there were 40 cures and 16 treatment failures. DNA content was measured by flow cytometry of pretreatment biopsies removed from paraffin. There were 18 diploid cases and 38 aneuploid (67.9%). Aneuploid cases included 6 with very high G2-M peaks (greater than or equal to 15% of the cell sample). DNA ploidy correlation with prognosis was not statistically significant. However, both grading by a multiple parameter method (P less than 0.0133) and staging (P less than 0.0064) were significant prognostic factors. Higher grade and stage correlated with treatment failure.

DNA ploidy patterns in cervical intraepithelial neoplasia grade III, with and without synchronous invasive squamous cell carcinoma. Measurements in nuclei isolated from paraffin-embedded tissue

This study presents the results of cytophotometric (CPM) and flow cytometric (FCM) DNA ploidy measurements in cervical intraepithelial neoplasias grade III (CIN III) with and without synchronous invasive squamous cell carcinoma. Hysterectomy and biopsy material from 21 patients 35 years of age or younger and from 18 patients age 50 years or older was studied. The DNA analysis was performed in nuclei isolated from specific areas of paraffin-embedded tissue. There were significant differences in the distribution of DNA patterns between the two age groups. About 80% of CIN III lesions in women 50 years of age or older, with or without a coexisting invasive cancer were aneuploid. In the group of younger women a diploid DNA pattern was found in about 60% of CIN III with concomitant invasive cancer. In the absence of an invasive cancer, CIN III lesions were mostly polyploid. The DNA pattern of invasive cancers was generally identical with the adjacent CIN, thus suggesting that the two lesions were related. Although the prognostic value of DNA ploidy measurements in cervical intraepithelial lesions in women in these two age groups has to be further evaluated, these results are at considerable variance with previously published data on DNA values in CIN and invasive carcinoma. In four CIN III lesions without invasive cancer, in women of the group of 35 years of age or younger, human papilloma virus common antigen could be demonstrated by immunochemical procedure. In three of these cases a polyploid DNA pattern was present; the fourth case showed a bimodal aneuploid pattern.

Prognostic influence of ploidy level and histopathologic differentiation in cervical carcinoma stage Ib

Flow-cytometric DNA analysis and extended histopathologic grading were performed in specimens from 126 patients with squamous cell carcinoma of the uterine cervix stage Ib. Archival material was used for the measurements and the ploidy level was analysed according to the method described by Hedley with some modifications. The histopathologic grading was based on eight well-defined parameters all scored 1-3. The results showed that the ploidy level held significant prognostic information about the 10 year survival according to a division of DNA indices above and below 1.5. Further prognostic information appeared from a combination of DNA index and histopathologic score value. The combination held its prognostic importance in subgroups of patients with different tumour sizes. It is concluded that flow-cytometric analysis and histopathologic grading can identify subsets of patients who need more aggressive treatment.

Predictive value of flow cytometric DNA-analysis on fresh retinoblastoma tissue

The cellular DNA content and the distribution of tumour cells in different phases of the cell cycles has been analysed in 8 consecutive enucleated eyes with retinoblastoma. All tumours had abnormal ploidy levels. The analysis did not reveal any specific pattern in 2 tumours which had metastasized compared to 6 local tumours. The flow cytometric analysis alone or in combination with histopathology appeared not to improve the classification of large retinoblastomas.

Prognostic value of the flow cytometric DNA index in human ovarian carcinoma

Flow cytometric measurements were done on 51 ovarian carcinoma specimens collected from consecutive patients in a prospective study. The ploidy status was related to the course of the disease. The tumors from 26 (52%) of 50 evaluable patients had DNA aneuploidy. Patients with diploid tumors were more often considered disease-free after initial operation (P less than 0.01). Patients with aneuploid tumors had a more aggressive course of the disease in all respects of comparison. The median survival of patients with diploid tumors was 18 months as compared to 8 months for those with aneuploid tumors (P less than 0.0005). Flow cytometric DNA measurements give important prognostic information and such analyses should be included in future clinical trials. Through the development of high-speed instrumentation they also may become feasible in routine clinical work.

Cervical carcinoma DNA content, S-fraction, and malignancy grading. II. Comparison with clinical staging

In an attempt to achieve more biologically meaningful subclassification of squamous cell cervical cancers and ultimately more reliable prediction of tumor behavior, we have studied the tumor pretreatment DNA content (i.e., DNA index), cell-cycle S-fraction, and histomorphologic malignancy grading properties for tumors having similar and different clinical staging. The tumor DNA index, %S-phase cells, and average malignancy grades were statistically tested against known clinical predictive variables for 90 primary squamous cell carcinomas of the uterine cervix studied prior to radiotherapy. We observed that the biological and morphological tumor properties of cervical cancers broadly overlapped between different stages of disease and for other clinical criteria including the gross morphology, lymph node status, and intravenous positivity. No significant differences were detected in the DNA indices, %S, or malignancy grades between the stages of disease or the other clinical criteria. It was concluded that: the gross clinical staging criteria inadequately reflected the tumor biological properties; and that the possibility exists for refining prognosis by use of the biological and morphological noncodependent tumor parameters to supplement staging criteria; and the use of cell-cycle cytokinetic and malignancy grading criteria in addition to tumor DNA index is superior to DNA index (or DNA content) alone for identifying biologically different cervical cancers.

Cervical carcinoma DNA content, S-fraction, and malignancy grading. I. Interrelationships

The flow cytometric measured DNA content (i.e., DNA index), S-fractions, and histopathologic malignancy grades were studied for ninety uterine cervical squamous cell carcinomas using tissue biopsies taken prior to radiotherapy. The DNA aneuploidy frequency for low S-phase tumors (%S less than 14) was only 9/29 (31%) compared to 22/30 (73%) for intermediate (%S 15-23) and 30/31 (97%) for high (%S greater than 24) tumors. An overall mean %S of 20 +/- 7 (range 2-45%) was observed for these cervical cancers, with the S-fraction significantly increasing (P = less than 0.01) from 12 +/- 5, to 18 +/- 8, and 26 +/- 7 for diploid/near diploid, low-degree DNA aneuploidy, and high-degree DNA aneuploidy tumors, respectively. Broad heterogeneity was observed for the microscopic scored malignancy grades within DNA index and the cell-cycle S-fraction subgroups. Generally, multifactorial histopathology scoring was not significantly correlated with either the tumor DNA index or %S variables. Based on statistical analysis, the malignancy grades more closely reflected the tumor proliferative activity than the DNA index, with nuclear polymorphism, mitotic frequency, and the invasion pattern showing the lowest P values (which were not significant at P = 0.05). High tumor S-fraction was associated with high malignancy grade, as evidenced by 19/25 (75%) of high S-fraction, high degree DNA aneuploidy tumors having greater than average malignancy grade compared to only 2/14 (14%) low to moderate S-fraction tumors having similar DNA index. The results indicate that more reliable identification of biologically different cervical cancers can be achieved by evaluating the tumor DNA index in relationship to the cell-cycle %S and malignancy grading.

Flow cytometric deoxyribonucleic acid index: a prognostic factor in endometrial carcinoma

In a prospective study, flow cytometric deoxyribonucleic acid analyses were performed on cell samples from benign and malignant tumors of the endometrium and benign endometrium. No ploidy aberrations were found in normal endometrium. Of 52 cases with adenocarcinomas, 38 (73%) were diploid and 14 (27%) aneuploid. Both the frequency and the degree of aneuploidy were correlated to histologic tumor grade but not to other prognostic variables such as International Federation of Gynecologists and Obstetricians stage, depth of myometrial invasion, or patient age. Patients with aneuploid tumors had a higher recurrence rate and shorter disease-free intervals as compared to those with diploid tumors. Similarly, death rates were higher and the median survival was shorter in the aneuploid group. Flow cytometric ploidy determination may therefore serve as an important prognostic parameter.

Accuracy and reliability of flow cytometric DNA analysis using a simple, one-step ethidium bromide staining protocol

Sources of variation and error were investigated for a simple flow cytometric analysis of DNA content of detergent-isolated nuclei stained with ethidium bromide. Using the ploidy classes of mouse liver nuclei, deviations from linearity were assessed for three different instruments. In more extreme settings, the maximum deviations for a FACS instrument were up to 6 to 9%, but in general deviations were around 1% or lower for all instruments. As biological DNA standards, human peripheral lymphocytes and trout erythrocytes appeared to be suitable and easy to store frozen. The erythrocytes had dye-binding characteristics similar to those of human lymphocytes and a 20% lower fluorescence, thus being well suited as an internal standard, as was demonstrated in tumor ploidy analyses performed with varied tissue concentration. Staining homogeneity was improved when staining time was extended to 24 h, at which time male and female lymphocytes were completely separated with an average difference in DNA content of 1.9%. A small difference in fluorescence between mitogen-stimulated and unstimulated lymphocytes was reduced to less than 1% after 24 h of staining. In general, the manipulations of the conditions for the analysis resulted in maximum variations of around 1%, indicating the robustness and reliability of the technique.

DNA aneuploidy in colorectal adenomas

The frequency of DNA aneuploidy was investigated by flow cytometry in 156 colorectal adenomas including 56 associated with 36 synchronous adenocarcinomas. Nine of 156 adenomas (6%) were DNA aneuploid. DNA aneuploidy correlated with increasing size (P less than 0.005) and histopathological type P less than 0.05) but not with dysplasia. Adenomas in associated with a synchronous adenocarcinoma did not have an increased incidence of DNA aneuploidy. Adenocarcinomas found in association with adenomas tend to have a lower incidence of DNA aneuploidy then the generality of colorectal cancers.