Prognostic value of carcinoma-associated antigen MK-1 in urinary bladder carcinoma

BACKGROUND: The present study has been performed to evaluate the expression of MK-1 in schistosomiasis-associated squamous cell carcinoma of the urinary bladder and to correlate this new marker with the conventional histopathological parameters. PATIENTS AND METHODS: Paraffin sections of 5-microm thickness from 81 cases were prepared for hematoxylin and eosin staining and immunohistochemical analysis of MK-1 expression was carried out. RESULTS: Forty-six cases (56.8%) were positive for MK-1 protein expression. Significant correlations between MK-1 expression and tumor grade (p=0.004), schistosoma (p=0.031), DNA ploidy (p=0.001), and tumor recurrence (p<0.001) were observed. MK-1, sex, tumor grade, stage, schistosoma, DNA ploidy, and recurrence were evaluated in relation to outcome. Univariate and multivariate analysis of survival were performed. The overall 5-year survival was 51.85%. In univariate analysis, MK-1 expression, tumor grade, DNA ploidy, and recurrence had a significant impact on the survival of these patients. In a Cox proportional hazards model, recurrence maintained its significant impact on survival. CONCLUSIONS: These findings suggest that MK-1 is a prognostic marker for recurrence: 34 (87.2%) of 39 recurrent cases were positive for MK-1 expression. However, only recurrence was an independent prognostic factor in patients with schistosomiasis- associated squamous cell carcinoma of the bladder.     

Superficial bladder cancer therapy

Bladder cancer treatment remains a challenge despite significant improvements in preventing disease progression and improving survival. Intravesical therapy has been used in the management of superficial transitional cell carcinoma (TCC) of the urinary bladder (i.e. Ta, T1, and carcinoma in situ) with specific objectives which include treating existing or residual tumor, preventing recurrence of tumor, preventing disease progression, and prolonging survival. The initial clinical stage and grade remain the main determinant factors in survival regardless of the treatment. Prostatic urethral mucosal involvement with bladder cancer can be effectively treated with Bacillus Calmette-Guerin (BCG) intravesical immunotherapy. Intravesical chemotherapy reduces short-term tumor recurrence by about 20%, and long-term recurrence by about 7%, but has not reduced progression or mortality. Presently, BCG immunotherapy remains the most effective treatment and prophylaxis for TCC (Ta, T1, CIS) and reduces tumor recurrence, disease progression, and mortality. Interferons, Keyhole-limpet hemocyanin (KLH), bropirimine and Photofrin-Photodynamic Therapy (PDT) are under investigation in the management of TCC and early results are encouraging. This review highlights and summarizes the recent advances in therapy for superficial TCC.     

Immunocytochemistry of collagenase expression in transitional cell carcinoma of the bladder

OBJECTIVE: To evaluate the usefulness of collagenase immunocytochemistry as well as its immunohistochemistry in assessing the correlation with prognostic factors in transitional cell carcinoma (TCC) of the urinary bladder. STUDY DESIGN: We investigated the expression of collagenase in catheterized urine and histologic specimens from 38 patients with TCC and 20 cases with benign lesions of the urinary tract. RESULTS: Thirteen (34.2%) and 17 (44.7%) patients with TCC showed positive expression of collagenase on cytologic and histologic specimens, respectively, whereas in no cases with benign lesions was such expression found (P < .01). Invasive and nonpapillary TCC had higher positive rates than noninvasive and papillary TCC. Grade 3 TCC was positive at a higher rate than was grade 2, whereas there were no positive cases with grade 1. Collagenase expression did not correlate significantly with stage. CONCLUSION: Collagenase expression in urinary TCC correlated well with tumor growth pattern, pathologic grade and invasiveness of the carcinoma; all are known to be prognostic factors. The application of collagenase immunostaining to urinary cytology is very useful for assessing prognosis in TCC.     

p53 protein expression and proliferative activity in imprints of superficial transitional cell carcinoma of the bladder

OBJECTIVE: To investigate p53 protein expression and proliferative activity in imprints of tumor biopsies from superficial transitional cell carcinoma of the bladder in relation to the histologic grade of malignancy and recurrence status. STUDY DESIGN: The study group consisted of 70 cases of superficial transitional cell carcinoma of the bladder. In order to investigate p53 protein expression and Ki-67 expression, an immunocytochemical avidin-extravidin complex technique was performed using monoclonal antibodies p53 D0-7 and proliferating cells correspondingly. RESULTS: Thirty-seven percent of superficial transitional cell carcinoma cases showed positive expression of p53 protein. No correlation was found between p53 protein expression and grade of malignancy (P = .45). p53 Protein expression was statistically correlated with a high Ki-67 labeling index (LI) (P < .001) and recurrence status (P < .001). Forty-seven percent of cases showed a Ki-67 LI > 25%. No correlation was found between a high Ki-67 LI and grade of malignancy (P = .703). A significant difference in high Ki-67 LI between recurrent and nonrecurrent tumors of the same grade (P < .001) and between recurrent and nonrecurrent tumors was found independently of grade (P < .001). CONCLUSION: These results on cytologic material could provide useful information on the biologic behavior of superficial transitional cell carcinoma of the bladder at the time of diagnosis.     

Cytologic grading and DNA image cytometry of breast carcinoma on fine needle aspiration cytology smears

OBJECTIVE: To correlate the cytologic grade of breast carcinoma with DNA image cytometry (ICM) and nuclear area on fine needle aspiration cytology (FNAC) smears. STUDY DESIGN: In this prospective study, FNAC material from 28 breast carcinomas were studied for cytologic grade and DNA ICM. Breast carcinomas were classified as grade 1-3 (low to high). DNA histograms were classified by the modified Auer method. Degree of hyperploidy (DH), ploidy balance (PB) and nuclear area (NA) were measured on Feulgen-stained smears by a CAS 200 image cytometer. Cytologic grade was correlated with DNA ICM findings and NA. RESULTS: There were 3 cytologic grade 1, 13 grade 2 and 12 grade 3 breast carcinomas. Seven of eight cases of hypertetraploid aneuploidy were grade 3 tumors. All cytologic grade 1 tumors were diploid. There were significant differences in DH, PB and NA in different grades of breast carcinoma (one-way ANOVA). CONCLUSION: DNA image cytometry in combination with cytologic grading might offer additional information for the characterization of breast carcinomas diagnosed by FNAC. These observations are of particular interest with the introduction of preoperative chemotherapy.     

Assessment of DNA flow cytometry as a surrogate end point biomarker in a bladder cancer chemoprevention trial

Although conventional cytology represents the most widely performed cytometric analysis of bladder cancer cells, DNA flow cytometry has, over the past decade, been increasingly used to evaluate cell proliferation and DNA ploidy in cells from bladder washings. We have investigated whether DNA flow cytometry and conventional cytology of epithelial cells obtained from bladder washings provide reliable surrogate endpoint biomarkers in clinical chemoprevention trials. We used cytometric and clinical data from a chemoprevention trial of the synthetic retinoid Fenretinide on 99 patients with superficial bladder cancer. A total of 642 bladder washing specimens obtained from the patients at 4 month intervals was analyzed. Intra-individual agreement and correlation of flow cytometric DNA ploidy (diploid vs. aneuploid), DNA Index, Hyper-Diploid-Fraction (proportion of cells with DNA content higher than 2C), and conventional cytologic examination, as assessed by kappa statistics and Spearman's correlation test, were poor from baseline through 24 months. Moreover, no correlation was found between DNA ploidy and cytology at each time point. The same results were obtained when the analyses were stratified by treatment group. In addition, the association between the results of bladder washing (by either DNA flow cytometry or cytology) and concomitant tumor recurrence was significant only for abnormal cytology, while neither biomarker was predictive of tumor recurrence at the subsequent visit. During the time of this study only four patients progressed to muscle-invasive bladder cancer, indicating the "low-risk" features of the patient population. We conclude that DNA flow cytometry and conventional cytology on epithelial cells obtained from bladder washings do not appear to provide suitable surrogate endpoint biomarkers during the early stages of bladder carcinogenesis.     

Quantitative microscopy of human DNA topoisomerase II-alpha expression in transitional cell carcinoma of the bladder

OBJECTIVE: To compare the nuclear size of various grades of transitional cell carcinoma (TCC) stained immunohistochemically with the nuclear enzyme topoisomerase II-alpha (topo II-alpha) in bladder urothelial neoplasms. STUDY DESIGN: Histologic sections from 53 consecutive papillary bladder neoplasms were stained immunohistochemically for topo II-alpha expression. There were 18 (33.9%) urothelial neoplasms of low malignant potential (UNLMP), 18 (33.9%) low grade urothelial carcinoma (LGUCa), and 17 (32%) with high grade urothelial carcinoma (HGUCa). The histologic slides were photographed at 400 x magnification and then projected on a screen, and the area with stained nuclei was measured. RESULTS: The cells and nuclei in HGUCa were significantly larger than in LGUCa (P < .05) and UNLMP (P < .01). CONCLUSION: Calculation of the area fraction of nuclei in TCC of the bladder stained with topo II-alpha is an additional method of establishing the grade of these tumors.     

Prediction of recurrence in giant cell bone tumors by DNA cytometry.

The most interesting therapeutic aspect of giant cell bone tumors is which patients can be cured without a risk of recurrence by intralesional surgery (curettage). To find out the suitability of some DNA cytometric and morphometric parameters for showing differences between this group of patients (n = 9) and those with recurrence (n = 12), the parameters mean ploidy, 2cDI (mean square deviation of the tumor cell DNA content from the normal 2c value), mean nuclear area and its variability were calculated from cytologic specimens prepared by a cell separation technique from formalin-fixed, paraffin-embedded tissues, measuring the values of 100 stromal cells per case by a TV image analysis system. Further measurements were performed on 19 cases of different diseases of the bone and on an additional 17 cases of giant cell tumors without follow-up. The 2cDI allowed us to distinguish the two groups of patients, with and without recurrence, without overlap; even the lowest value for patients with recurrence was higher than the highest value for cured ones. Mean ploidy analysis resulted in a less convincing discrimination of the patients. Mean nuclear area and its variability failed to predict recurrence. Single-cell DNA cytometry provided a parameter, 2cDI, that was able to predict recurrence in patients with giant cell bone tumors with high sensitivity.     

DNA aberrations in urinary bladder cancer detected by flow cytometry and FISH: prognostic implications.

We evaluated the genetic changes in bladder cancer biopsy by fluorescence in situ hybridization (FISH) and related them to stage and grade of the tumor, ploidy (FCM) and clinical outcome, to determine a simple method to identify tumors with a poorer prognosis. Using FISH the numerical aberrations of chromosomes 1, 7, 9, 17 in tumor's imprints of 70 patients with transitional cell cancer (TCC) were determined. First of all, the data demonstrated that the sensitivity of FISH in detecting quantitative DNA aberrations exceeds FCM's sensitivity. The frequency of chromosome 1 and 9 aberrations did not show significant differences in diploid and aneuploid tumors in different stage and grade. On the contrary, the chromosome 7 and 17 aneusomy showed greater differences between pT1 and pT2-3 tumors (p<0.032 and p<0.0006, respectively) than between stage pTa and pT1. In our investigation, an increasing number of aberrations was observed in all chromosomes examined in tumors of patients who afterwards underwent cystectomy and/or had recurrent tumors. These results suggest that chromosome 7 and 17 aneusomy could be predictive of adverse outcome in a subgroup of patients with superficial tumors at presentation.     

Evaluation of tumor heterogeneity of prostate carcinoma by flow- and image DNA cytometry and histopathological grading.

BACKGROUND: Heterogeneity of prostate carcinoma is one of the reasons for pretreatment underestimation of tumor aggressiveness. We studied tumor heterogeneity and the probability of finding the highest tumor grade and DNA aneuploidy with relation to the number of biopsies. MATERIAL AND METHODS: Specimens simulating core biopsies from five randomly selected tumor areas from each of 16 B?cking's grade II and 23 grade III prostate carcinomas were analyzed for tumor grade and DNA ploidy by flow- and fluorescence image cytometry (FCM, FICM). Cell cycle composition was measured by FCM. RESULTS: By determination of ploidy and cell cycle composition, morphologically defined tumors can further be subdivided. Heterogeneity of tumor grade and DNA ploidy (FCM) was 54% and 50%. Coexistence of diploid tumor cells in aneuploid specimens represents another form of tumor heterogeneity. The proportion of diploid tumor cells decreased significantly with tumor grade and with increase in the fraction of proliferating cell of the aneuploid tumor part. The probability of estimating the highest tumor grade or aneuploidy increased from 40% for one biopsy to 95% for 5 biopsies studied. By combining the tumor grade with DNA ploidy, the probability of detecting a highly aggressive tumor increased from 40% to 70% and 90% for one and two biopsies, respectively. CONCLUSION: Specimens of the size of core biopsies can be used for evaluation of DNA ploidy and cell cycle composition. Underestimation of aggressiveness of prostate carcinoma due to tumor heterogeneity is minimized by simultaneous study of the tumor grade and DNA ploidy more than by increasing the number of biopsies. The biological significance of coexistent diploid tumor cell in aneuploid lesions remains to be evaluated.     

DNA quantitation of distal bile duct carcinoma measured by image and flow cytometry

OBJECTIVE: To evaluate discrepancies between flow cytometry (FCM) and image cytometry (ICM), ploidy incidence and relation between DNA ploidies and survival in distal bile duct carcinomas (DBDCs). STUDY DESIGN: Forty-four archival tumor samples from patients with DBDC who underwent subtotal pancreatoduodenectomy from 1985 to 1996 were examined for DNA ploidy using FCM and ICM. RESULTS: Overall, 59% (26/44) of the tumors were aneuploid by at least one of the two techniques. We detected more cases of aneuploidy with ICM than FCM in formalin-fixed, paraffin-embedded DBDCs, 62% (21/34) versus 33% (13/40), respectively. When results could be compared, moderate strength of agreement (kappa = .45) was demonstrated. No correlation was found between DNA ploidy by FCM, ICM or combined FCM-ICM and survival time (P = .80, P = .35, and P = .54, respectively). CONCLUSION: Approximately 59% of DNA histograms contained aneuploid cell populations. Although ICM, as compared to FCM, is more sensitive in assessing the ploidy status of DBDC, both methods were complementary. Most discrepancies between FCM and ICM were due to the dilution of aneuploid populations by non-neoplastic diploid cells. DNA ploidy assessment in DBDC did not offer the possibility of improving the ability to predict survival.     

Characterization of ploidy level in bladder tumors and selected site specimens by flow cytometry

The histopathological grade of atypia was compared with the ploidy level in biopsy specimens from bladder tumors and six grossly normal areas (selected sites). The study included investigation of 303 specimens from 45 patients. The results demonstrated a high correlation between the grade of atypia and the occurrence of aneuploid cell populations. The selected site specimens were diploid in patients with low grade malignant tumors, while high grade malignant tumors were associated with aneuploid selected site specimens in 20% of the cases. The divergence of ploidy level in the tumor and selected site specimens found in some cases clearly demonstrated that the carcinogenic process in the bladder may lead to clonal heterogeneity. Flow cytometric analysis seems suited for mapping of the ploidy levels in different parts of the bladder. The possible importance of the additional information is discussed.     

Polymorphic methyl group metabolism genes in patients with transitional cell carcinoma of the urinary bladder.

Because polymorphisms in the methyl group metabolism genes methylene-tetrahydrofolate reductase (MTHFR), methionine synthase (MS), and cystathione beta-synthetase (CBS) affect plasma homocysteine levels and intracellular concentrations of S-adenosylmethionine (SAM), they modify the susceptibility to cardiovascular diseases and cancer. Specifically, genome-wide decreased DNA methylation ('hypomethylation') in human cancers might be a consequence of decreased SAM levels. Because hypomethylation is particularly prevalent in transitional cell carcinoma of the urinary bladder (TCC), the genotype distributions for the two each most prevalent MTHFR, MS, and CBS alleles were compared between 165 TCC patients and 150 population controls. The distributions of the MTHFR 677A/V and the MS 919G/D alleles were not significantly different between cancer patients and controls, even after stratification according to age, gender, tumor stage or grade. The CBS 844INS68 allele was slightly less frequent in TCC patients than in controls (q=0.07 versus 0.10), but was rarer among males in both groups. Among the TCC patients, this gender difference was highly significant (Mantel-Haenszel and chi(2)-test P=0.007). No significant difference between TCC patients and controls was found for any combined genotype. Likewise, the extent of DNA hypomethylation determined in 62 carcinoma specimens was not related to the respective genotypes. Thus, on their own, the MTHFR, MS and CBS genotypes do not appear to act upon susceptibility to TCC or influence the extent of DNA hypomethylation in this cancer.     

Prognostic significance of DNA ploidy determined by high-resolution flow cytometry in breast carcinoma

OBJECTIVE: To assess the prognostic value of DNA ploidy in breast carcinoma and its relation to other established prognostic factors. STUDY DESIGN: We evaluated DNA ploidy in 303 breast carcinoma patients with a median follow-up of 63 months. Flow cytometry was performed on frozen tumor material, yielding histograms with narrow peaks (median coefficient of variation of 2.08). DNA ploidy pattern was classified as either diploid versus nondiploid, euploid (diploid and tetraploid) versus aneuploid or diploid/near-diploid (DNA index < 1.2) versus other, and correlated with relapse-free (RFS) and cancer-specific survival (CSS) along with tumor size, histologic grade and type, axillary lymph node involvement, menopausal and steroid receptor status, age and type of treatment. RESULTS: Seventy-one percent of tumors were DNA nondiploid (14% tetraploid and 57% aneuploid). There was a strong association between DNA ploidy and histologic grade. Histologic grade, lymph node status, tumor size and DNA ploidy (regardless of the classification used) were all significantly associated with RFS and CSS in multivariate analysis. CONCLUSION: These results suggest that DNA ploidy, at least when determined from frozen tumor tissue, is an independent prognostic factor in breast carcinoma; however, its prognostic power seems to be inferior to that of histologic grade, with which it strongly correlates.     

Diagnostic value of cytology of voided urine

Cytologic examination of the sediment of voided urine is the only noninvasive method of detection, diagnosis and follow-up of tumors of the bladder and other anatomic components of the lower urinary tract. In order to assess the value of cytology of voided urine, we analyzed the diagnostic yield in 203 episodes, each composed of three sediments of voided urine obtained on consecutive days. For each one of these episodes, histologic material was available and was reviewed. Of special interest were 181 instances of primary or recurrent bladder tumors; in 37 of these patients, random biopsies of the bladder were also available for review. The concept of intraurothelial neoplasia (IUN), graded I, II or III, was introduced to describe degrees of atypia in flat urothelium, with IUN grade III corresponding to nonpapillary carcinoma in situ. The results documented that cytology of voided urine is highly reliable in the diagnosis of high-grade tumors, with a sensitivity of 94.2%. In primary flat carcinoma in situ (IUN III), the sensitivity was 100%. The method failed in the recognition of grade I papillary tumors and in about one-third of grade II tumors. There were no false-positive results in this study. In the 151 positive cases, the cytologic diagnosis was established on the first specimen in 79%, on the second specimen in an additional 14% and on the third specimen in 7% of cases. These results justify the use of three consecutive daily urine specimens for optimal diagnostic results. There is a remarkable similarity between the presence of cancer cells in voided urine and the DNA ploidy of bladder tumors, as established by Tribukait. The observations reported herein suggest that positive urine cytologies may correspond to aneuploid tumors and hence be not only of diagnostic but also of prognostic value. A direct proof of this hypothesis is under investigation; the results of this study justify the need for a field trial of an automated image analysis diagnostic system that was developed in this department.     

Prognostic significance of DNA cytometry in carcinoma of the uterine cervix FIGO stage IB and II.

OBJECTIVE: To assess the prognostic value of DNA-image cytometry in cervical carcinoma of the uterus and its relation to other established prognostic factors. STUDY DESIGN: The study included 116 cases of cervical carcinoma FIGO stages IB and II which were treated with radical abdominal hysterectomy. The median follow-up was 55 months (range 1-162 months). DNA image cytometry was performed on cytologic specimens prepared by enzymatic cell separation from formalin-fixed, paraffin-embedded tissues. DNA stemline ploidy, DNA stemline aneuploidy, 5c exceeding rate, 9c exceeding rate, 2c deviation index, and DNA malignancy grade were computed. DNA-variables as well as various clinical and histological variables were related to survival rates. RESULTS: In multivariate statistical analysis DNA stemline ploidy using 2.2c as a cut-off value and FIGO stage showed to be statistically significant available presurgery predictors of survival, whereas the postsurgical parameters lymphonodal status, tumor size and parametrial involvement were significantly correlated with survival. The synopsis of all parameters in a multivariate Cox model indicated that - with declining relevance - the number of positive pelvic lymph nodes, DNA stemline ploidy using a cut-off level at a modal value of 2.2c, largest pelvic lymph node, 5c exceeding rate, and ratio of carcinoma area to cervix area, were of predictive value for survival. CONCLUSIONS: Our results suggest that prognostic information deducted from classical staging parameters is successfully complemented by DNA image cytometry which can be applied pretherapeutically.     

Comparative image analysis of cells in voided and catheterized urine

OBJECTIVE: To objectively evaluate the difference in cytologic findings between specimens of voided and catheterized urine by using a comparative image analysis device, CAS200. STUDY DESIGN: Cells in voided and catheterized urine from 13 patients with transitional cell carcinoma (TCC), including 3 with grade 1, 6 with grade 2 and 4 with grade 3, were compared cytologically. The cellular area, nuclear area, nuclear/cytoplasmic ratio and nuclear density of both types of cytologic specimen were measured using CAS200. RESULTS: Cell area and nuclear area of grade 1 TCCs were significantly greater in voided urine than in catheterized urine. In contrast, cell area and nuclear area of grade 3 TCCs were significantly smaller in voided urine than in catheterized urine (P < .01), and nuclear density of grade 3 TCCs was higher in the latter than in the former. CONCLUSION: The cellular findings in voided urine were different from those in catheterized urine from the same patient. Thus, the method selected for obtaining urine specimens will affect the findings in urinary cytology.     

Nasopharyngeal carcinoma heterogeneity of DNA content identified on cytologic preparations.

OBJECTIVE: To evaluate tumor heterogeneity of DNA content in nasopharyngeal carcinoma (NPC) performed on cytologic specimens. STUDY DESIGN: Image cytometric analysis of DNA ploidy status of 40 NPCs was performed on nasopharyngeal brushing smears stained with the Feulgen method after hematoxylin eosin staining. If the DNA distribution pattern from the same tumor exhibited diploid, aneuploid or/and tetraploid peaks or some combination of these patterns, the presence of tumor heterogeneity of DNA content was identified. RESULTS: Thirty-four cases (85%) had a nondiploid DNA pattern among the 40 NPCs. Twenty-eight cases exhibited tumor heterogeneity of DNA content (70%). Of the 28 tumors, 13 (46%) had a combination of diploid and tetraploid patterns, 10 (37%) had a combination of diploid and aneuploid patterns, 3 cases (11%) had a combination of tetraploid and aneuploid patterns, and 2 cases had two aneuploid stem lines. The relationship between DNA ploidy pattern and tumor histologic and cytologic morphology was also examined. CONCLUSION: There is a high incidence of DNA content heterogeneity in NPC. The relevance of tumor heterogeneity to the biologic behavior of NPC awaits further study. DNA quantification with image cytometry on destained cytologic preparations is feasible and reliable.     

Evaluation of applying feulgen stain for DNA analysis on destained hematoxylin-eosin-stained cytologic smears

OBJECTIVE: To evaluate the feasibility and reliability of DNA analysis performed on the original hematoxylin-eosin (HE)-stained cytologic specimens by destaining the slides and restaining with the Feulgen method. STUDY DESIGN: Image cytometric analysis of DNA ploidy status was performed in a comparative study on 20 cytologic preparations from 10 nasopharyngeal carcinomas. Ten smears were stained directly by the Feulgen method, and the others were Feulgen stained after HE destaining. RESULTS: There was 90% overall concordance in DNA determination and a good correlation (r = .97, P < .001) between the DNA indices determined by the 2 methods. Discordance was probably due to tumor heterogeneity. CONCLUSION: This study demonstrated that image cytometric DNA analysis on previously routinely HE-stained cytologic preparations is feasible and reliable. This method permits retrospective studies on archival cytologic material from patients with long term follow-up data.     

Proportion of S-phase tumor cells measured by flow cytometry is an independent prognostic factor in meningioma tumors.

Meningiomas are tumors in arachnoid cells which represent up to one fifth of all intracranial tumors and up to a quarter of spinal neoplasias. Although meningiomas have classically been considered to be benign tumors, it has also been well-established that they show a heterogeneous clinical outcome. To the best of our knowledge no study has yet been performed in which the independent prognostic value of both DNA ploidy and cell cycle has been simultaneously assessed in a large series of meningioma tumors. The aim of the present study was to prospectively explore the prognostic value of DNA ploidy status and the proliferative rate of tumor cells in a series of 105 consecutive meningioma patients studied at diagnosis. Both the presence of DNA aneuploidy and the proportion of S-phase tumor cells were analyzed in all cases in fresh tumors obtained during diagnostic surgery. From the technical point of view, we followed the recommendations of the Consensus Conference on Flow Cytometry DNA Analysis held in October 1992. Our results show that meningioma tumors display a relatively low incidence of DNA aneuploidy (14%), and they usually show a low proliferative rate (mean percentage of S-phase cells of 1.3 +/- 0.3%). The presence of DNA aneuploidy was associated with a higher incidence of aggressive histopathologic subtypes (P = 0.045), a greater age (P = 0.009), location at the cerebral convexity (P = 0.004), and a greater proportion of S-phase cells (P = 0.005). In contrast, no significant association between the DNA ploidy status of meningioma patients and their disease-free survival was found (P = 0. 1). Regarding the proliferative activity of neoplastic cells, we found that a high proportion of S-phase cells (>1.8%) was associated with a significantly lower mean age (P = 0.007), aggressive histopathologic subtypes (P = 0.03), a higher incidence of DNA aneuploidy (P = 0.004), and a significantly shorter disease-free survival (P < 0.004). Multivariate analysis of prognostic factors showed that the proportion of S-phase tumor cells was the most powerful independent prognostic factor in meningioma patients (P = 0.02). In summary, we conclude that the proportion of S-phase tumor cells represents the individual parameter with the highest value for predicting disease-free survival in meningioma patients.