Flow cytometric analysis of localized adenocarcinoma of the prostate: the use of archival DNA analysis in conjunction with pathological grading to predict clinical outcome following radical retropubic prostatectomy

Elimination Kinetics of Prostate-Specific Antigen Serum and Urine

The serum half-life of prostate-specific antigen (PSA) was calculated in 66 patients subsequent to radical prostatectomy. Comparing serum half-life to disease outcome in 37 patients after a minimum follow-up of two years, it was found that PSA serum half-life identifies patients with residual disease earlier and more reliably than the presence or absence of detectable PSA levels postoperatively. It is suggested that residual tumor affects the half-life by contributing to the serum level of PSA. When PSA serum half-life was calculated solely in potentially cured patients, we found a half-life of 1.6 days, which is considerably shorter than in previous reports based on patient populations regardless of the outcome of disease in the follow-up.

To elucidate the route of PSA elimination, serial urine PSA levels were determined before and after radical prostatectomy, revealing strong evidence for the assumption that PSA is not eliminated by the kidneys in its unchanged form.

[Cell ploidy: predictive factor of locally advanced prostate cancer]

OBJECTIVE

This study was designed to demonstrate that the study of cell ploidy on biopsies of clinically localized prostate cancers can contribute to the diagnosis of a tumour extending beyond the prostatic capsule and can complete imaging for local staging.

METHODS

Analysis of the histological results of 140 patients operated for clinically localized prostate cancer distinguished two groups of patients in whom the initial tumour was Gleason score 6 or 7. The first group was composed of 33 patients whose tumour was classified as pT3 and the second group was composed of 24 patients whose tumour was classified as pT2. The cell ploidy study was performed on biopsies and operative specimens in the two groups.

RESULTS

In the pT3N0M0 group, 72% of tumours presented an aneuploid contingent versus 16% of tumours of the pT2N0M0 group. A strong correlation was demonstrated between cell ploidy and tumour stage (p = 0.0002) and a highly significant correlation was observed between tumour stage and the presence of a tumour contingent with ploidy greater than 5C (p = 0.0009).

CONCLUSION

The presence of an aneuploid contingent on biopsies of clinically localized prostate cancer significantly increases the risk of a more advanced tumour. This technique could therefore constitute a simple complementary tool in the staging of prostate cancer in combination with transrectal MRI, but this needs to be confirmed by other studies.

Pathologic assessment of the surgical specimen

Despite the wealth of information obtained by conventional histology, long-term studies are needed to provide novel information on the correlation of pathologic findings with prognosis. Findings need to be correlated not only with PSA progression but with the more clinically important parameters of distant metastases and survival. Although conventional histology still will have a role in the evaluation of prostate cancer at radical prostatectomy and its correlation with outcome, it undoubtedly will be augmented by newer techniques. These developments must be approached critically and rationally to determine whether they provide additional prognostic information beyond that currently available using more conventional parameters.

Fluorescence in situ hybridization evaluation of c-myc and androgen receptor gene amplification and chromosomal anomalies in prostate cancer in Japanese patients

BACKGROUND

Oncogene amplification and chromosomal anomalies are found in many solid tumors and are often associated with aggressiveness of cancer. We evaluated the frequency and the association of c-myc and androgen receptor (AR) gene amplification and gain of chromosome 8 or X in prostate cancer in Japanese patients.

METHODS

We examined a total of 42 prostate cancer specimens, using fluorescence in situ hybridization (FISH). Dual-labeling hybridization with a directly labeled centromere probe for chromosome 8 or X together with a probe for the c-myc or AR locus was performed.

RESULTS

Gain of chromosome 8 was identified in 54.8% of specimens and was associated with Gleason sum and nuclear anaplasia in untreated prostate cancers. c-myc gene amplification was found in 14.3% of specimens. Gain of chromosome X was identified in 42.9% of specimens. AR gene amplification was detected in 0 of 37 untreated prostate cancers, but in 1 of 5 hormone-refractory prostate cancers.

CONCLUSIONS

Our results suggest that c-myc and AR gene amplification and gain of chromosome 8 or X may be associated with the development and progression of prostate cancers. These results obtained in Japanese cases are consistent with the results observed in prostate cancer in Western countries.

Stage B Prostate Cancer: Correlation of DNA Ploidy Analysis With Histological and Clinical Parameters

BACKGROUND: The ability to accurately predict tumor behavior and patient survival is a problem in managing patients with prostate cancer. Prognostic variables in predicting death from tumor include prostate-specific antigen (PSA) level, histological grade, and clinical stage. Observer subjectivity is inherent in determining grade and stage; thus, criteria that are more objective are needed to identify patients for appropriate treatment. METHODS: The authors correlated flow cytometric nuclear DNA ploidy with Gleason score, PSA level, and recurrence risk in patients who underwent radical retropubic prostatectomy and bilateral pelvic lymphadenectomy between 1987 and 1993 for histopathologic stage B prostate cancer (T2, N0, M0). RESULTS: Of the tumors analyzed, 64% were DNA diploid with a low proliferative fraction, 25% were DNA diploid with a high proliferative fraction, and 11% were DNA aneuploid. DNA aneuploidy was associated with high Gleason grade (7-10). All Gleason grade 10 tumors were DNA aneuploid. Both DNA aneuploidy and high proliferative fraction (S+G2M) were statistically correlated with high Gleason grade and adverse prognosis but not with PSA level or patient age. CONCLUSIONS: A direct relationship is shown between both DNA aneuploidy and a high proliferation index with aggressive biological behavior in stage B prostatic cancer. Objective tumor criteria are needed to choose treatment more selectively for individual patients.

Detection of telomerase activity in prostate needle-biopsy samples

BACKGROUND

Telomerase in an enzyme ribonucleoprotein responsible for cell immortality and oncogenesis. Telomerase activity has been detected in most cancers, including prostate cancer. To verify whether the detection of telomerase in prostate needle biopsy samples could have diagnostic value, we blindly assayed telomerase activity in samples from patients who were clinically suspected of having prostate cancer.

METHODS

A total of 183 prostate biopsy samples was obtained from 63 patients who were suspected of having prostate cancer. Telomerase activity was determined by polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay. An internal telomerase assay standard (ITAS) was used in this study to distinguish false negatives.

RESULTS

Telomerase activity was detected in 17 of 19 (89.5%) patients with prostate cancer (chi(2) test, P < 0.005). In 39 of 42 (92.9%) biopsy samples from these 19 prostate cancer patients, confirmed histologically as prostate cancer, telomerase activity (chi(2) test, P < 0.005) was detected. Meanwhile, we also found one false-positive sample. In contrast, all of 44 normal or benign prostate disease patients (124 biopsy specimens) were telomerase-negative. We also revealed that poorly differentiated prostate cancer often expresses a high level of telomerase activity. The area of cancer tissue in biopsy specimens was not associated with relative telomerase activity.

CONCLUSIONS

This study suggests that determination of telomerase activity in prostate needle-biopsy samples might be a useful tool for detecting prostate cancer.

Comparative analysis of prognostic factors in men undergoing radical prostatectomy for adenocarcinoma of the prostate, including DNA ploidy, surgical tumor stage, prostatic specific antigen, Gleason grade, and age

One hundred consecutive men with adenocarcinoma of the prostate, treated by modified pelvic lymphadenectomy and radical retropubic prostatectomy, were evaluated, comparing DNA ploidy as determined by flow cytometry to surgical tumor stage (pT), preoperative prostatic specific antigen (PSA), Gleason grade, and age at presentation, in an effort to assess the prognostic ability of DNA ploidy. There were 71 (71%) men found to have diploid tumors and 29 (29%) with nondiploid tumors. There was no statistical difference in surgical pathologic stage between these two groups (P = 0.2369). There was no statistical difference when comparing preoperative PSA between these two groups (P = 0.0925). There was no statistical difference when comparing Gleason grade between these two groups (P = 0.5807). Age at presentation was similar in both groups. Based on these findings, it is apparent that longitudinal studies of patient outcome will be necessary to fully assess the prognostic ability of DNA ploidy determined by flow cytometry in men undergoing radical prostatectomy for treatment of adenocarcinoma of the prostate gland.

Prostate specific antigen and prostate specific antigen density. Roles in patient evaluation and management

Prostate specific antigen (PSA) is the most accurate serum marker for prostate cancer. However, sensitivity and specificity are suboptimal, especially at the intermediate levels between 4.1 and 10.0 ng/ml (monoclonal). For intermediate PSA levels, PSA density (PSAD) provides unique information regarding the need for biopsy and the likelihood of prostate cancer. The authors prospectively used PSAD to determine the need for biopsy in 68 patients with PSAD values below 0.150 and normal results from a digital rectal examination. Ten patients have undergone biopsy secondary to a rising serum PSA. Three were found to harbor prostate cancer and have undergone therapy. The remaining 65 patients continue on surveillance. PSAD can predict treatment outcomes for patients with clinically localized prostate cancer treated with radical prostatectomy. PSADs at low values are 90% accurate in predicting operative success. PSADs at high values are 67% accurate in predicting failure. Cancer 1994; 74: 1667-73.

Transrectal fine needle aspiration biopsy of the prostate combining cytomorphologic, DNA ploidy status and cell cycle distribution studies

Fine needle aspiration (FNA) cytology of the prostate is becoming a common diagnostic procedure, and DNA flow cytometry (FCM) data have been shown to correlate with the pattern of evolution of prostatic carcinoma, thus emphasizing the importance of assessing both parameters together. The aim of the present paper is to analyze the presence of DNA aneuploidy, cell cycle distribution and their relationship with the cytologic grade in transrectal fine needle aspiration prostate biopsies from 78 consecutive patients. Herein we studied the DNA ploidy status, the cell cycle distribution and their relationship with cytologic grade in transrectal FNA biopsies of the prostate from 78 consecutive patients -47 benign hyperplasias and 31 carcinomas- as analyzed by a reproducible FCM method for single cell suspension preparations, data acquisition and analysis. The presence of DNA aneuploidy was detected in 39% of the carcinomas and it was found to be a specific marker for prostatic carcinoma since all benign hyperplasia cases were diploid. Moreover, the incidence of DNA aneuploidy increased progressively from well-differentiated to moderately-differentiated and poorly-differentiated carcinomas (p = 0.005). Regarding cell cycle distribution, carcinomas displayed a higher proportion of both S-phase (p = 0.0003) and G2/M-phase (p = 0.0006) cells with respect to benign hyperplasias. Aneuploid cases also showed a greater proliferation rate as compared to the diploid carcinomas, regardless of their cytopathologic grade (p = 0.00001). Despite the fore-mentioned results, these correlations were far from being absolute, suggesting that combined assessment of these parameters should give additional information for the clinical management of prostatic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic value of deoxyribonucleic acid content in prostate cancer: a review of current results

A total of 115 articles on prostate cancer were reviewed for data on the prognostic value of DNA content in the tumor cells. In 44 series, data pertinent to this review were found. There was no consensus in the literature with respect to methods of analysis of DNA content or definitions of subclasses of DNA content such as categories of ploidy. The DNA content of prostate cancer cells was strongly related to tumor grade and stage. When analyzed as a single parameter in univariate analyses, the DNA content had a prognostic value with respect to overall or disease-specific survival. In multivariate analyses the additional prognostic value of the DNA content was less convincing when analysed with tumor grade and stage. The prognostic data from univariate and multivariate analyses available in the literature were mainly derived from patients with advanced disease and data on localized, potentially curable disease were scanty and conflicting.

Predictive value of prostate-specific antigen density for the presence of micrometastatic carcinoma of the prostate

OBJECTIVE

To examine the efficacy of prostate-specific antigen (PSA) density (PSAD; serum PSA/prostate volume) as a predictor of clinical outcome of patients undergoing radical retropubic prostatectomy for clinically confined prostate cancer, and its ability to determine the presence of micrometastatic disease.

METHODS

A retrospective analysis of patient outcome as reflected by surgical stage and postoperative PSA was performed with respect to PSAD as determined by preoperative PSA and pathologic prostate gland volume. The findings for 107 consecutive patients who underwent radical prostatectomy are reported.

RESULTS

PSAD at low values was found to be 90 percent accurate in predicting operative success or absence of micrometastatic disease. PSAD at high values was shown to be 70 percent accurate in predicting failure.

CONCLUSIONS

PSAD appears to be useful in selecting patients for radical prostatectomy and may be capable of identifying patients with micrometastatic disease.

Deoxyribonucleic acid cytometric analysis of prostate core biopsy specimens: relationship to serum prostate specific antigen and prostatic acid phosphatase, clinical stage and histopathology

We describe a sampling method of obtaining fresh prostate cells that yields adequate numbers of cells for flow cytometric deoxyribonucleic acid (DNA) analysis and produces histograms of good resolution. Exfoliated cells from 204 prostate biopsy wash specimens obtained by agitation of biopsy cores in saline were fixed and stained for DNA analysis. The mean percentage of hyperdiploid cells was statistically different between the pathologically benign and malignant specimens (p < 0.0001). Hyperdiploid cells of 22% or more exhibited a high degree of specificity for the malignant specimens with only a 1.4% (1 of 69 benign specimens) false-positive rate. However, sensitivity was only 41% (25 of 59 malignant specimens were associated with a flow cytometry analysis of 22% or greater hyperdiploid cells) because of the high false-negative rate (59%, 35 of 59). The percentage of hyperdiploid cells correlated statistically with increasing prostate specific antigen (PSA) levels and approached significance with Gleason grade but did not correlate with prostatic acid phosphatase or clinical stage. When the amount of hyperdiploid cells was 22% or more and serum PSA level was greater than 4.0 ng./ml. a 95% chance of a malignant biopsy was predicted. This result was greater than that predicted by a PSA elevation alone. Only a 5% chance of a malignant biopsy was present for patients with less than 22% hyperdiploid cells and 4.0 ng./ml. or less serum PSA, a decrease over either method separately. This method of DNA assessment permits prospective categorization of tumors by ploidy without interfering with histological assessment. The prognostic importance of ploidy analysis awaits further clinical followup.

Cytogenetics of primary prostatic adenocarcinoma. Clonality and chromosome instability

We have examined 62 prostatic adenocarcinomas by conventional cytogenetic analysis. Most were primary cultures harvested in 14 days or less. The most consistent finding was a normal male diploid karyotype, found in 87% of all cells analyzed, and as the exclusive finding in 19 tumors. Nonrandom chromosomal changes included gain of chromosome 7 and loss of the Y chromosome. In addition, clonal gains of chromosomes 8, 12, and 18, and clonal losses of chromosomes 14 and 19 were noted in individual cases. Two structural clonal aberrations, a 9p+ in one case and a t(Y;22) (q11.2;p12) in another, were also seen. Ten of 62 cultures demonstrated chromosome instability, defined herein as nonclonal gain or loss of chromosomes in more than 10% of the metaphases examined from that culture. In those cases with nonclonal numerical aberrations, loss of chromosomes was more common than gain. The distribution of apparently random numeric abnormalities was similar to that of the clonal abnormalities in that the most frequent nonclonal gain was of chromosome 7 and the most frequent nonclonal loss was of the Y chromosome. Apparently random structural aberrations were observed in less than 1% of all analyzed cells. These included a 4p-,del(3)(q13), and t(1;11). The extent of apparently random aneuploidy suggests that chromosome instability characterizes cultured prostatic adenocarcinomas. An increase in the frequency of nonclonal aberrations may be an indicator of tumor origin in a predominantly diploid cell population. The coexistence of clonally aberrant, nonclonally aberrant, and normal diploid cells in culture may reflect heterogeneity of prostate tumors in vivo.

Methodologic sources of errors in image and flow cytometric DNA assessments of the malignancy potential of prostatic carcinoma

Considerable controversy exists about the value of using cytometric assessments of nuclear DNA ploidy patterns from neoplastic parenchymal cells of prostatic carcinomas as a supplement to conventional clinicopathologic data in an assessment of malignancy potential in neoplastic disease. To a great extent, the controversy is of methodologic origin. By revealing common pitfalls in this kind of DNA cytometry and by suggesting means to avoid or at least to reduce them, a realistic assessment can ultimately be made of the prognostic values of this technique: (1) the results of DNA assessments using flow cytometry and image cytometry should be combined (advantages and disadvantages with the two techniques outbalance each other); (2) the cytometric DNA ploidy pattern must always be correlated with results of histopathologic assessments and clinical data; (3) a standardization of DNA histograms obtained by means of both flow DNA cytometry and image DNA cytometry must be made with precise definitions of "diploidy," "tetraploidy," and "aneuploidy"; (4) the subjective component in classifying DNA histograms can be reduced by means of a computerized evaluation technique; (5) the degree of intratumoral variation in DNA ploidy patterns of neoplastic cell nuclei must be established by means of assessments of multiple biopsy specimens from widely different parts of a carcinoma; and (6) foci of a previously poor recognized neuroendocrine phenotype of neoplastic parenchymal cells are ubiquitous in prostatic carcinomas, particularly in anaplastic adenocarcinomas. Today, the DNA ploidy pattern of this phenotype can be assessed by means of a new image DNA cytometry technique.