Proliferative index determination in prostatic carcinoma tissue: is there any additional prognostic value greater than that of Gleason score, ploidy and pathological stage?

Hidden clues in prostate cancer - Lessons learned from clinical and pre-clinical approaches on diagnosis and risk stratification

The heterogeneity of prostate cancer is evident at clinical, morphological and molecular levels. To aid clinical decision making, a three-tiered system for risk stratification is used to designate low-, intermediate-, and high-risk of disease progression. Intermediate-risk prostate cancers are the most frequently diagnosed, and even with common diagnostic features, can exhibit vastly different clinical progression. Thus, improved risk stratification methods are needed to better predict patient outcomes. Here, we provide an overview of the improvements in diagnosis/prognosis arising from advances in pathology reporting of prostate cancer, which can improve risk stratification, especially for patients with intermediate-risk disease. This review discusses updates to pathology reporting of morphological growth patterns, and proposes the utility of integrating prognostic biomarkers or innovative imaging techniques to enhance clinical decision-making. To complement clinical studies, experimental approaches using patient-derived tumors have highlighted important cellular and morphological features associated with aggressive disease that may impact treatment response. The intersection of urology, pathology and scientific disciplines is required to work towards a common goal of understanding disease pathogenesis, improving the stratification of patients with intermediate-risk disease and subsequently defining optimal treatment strategies using precision-based approaches.

Failure of Ploidy and Proliferative Fraction to Predict Long-Term Outcome After Prostatectomy

Background

Historically, ploidy and S phase percentage appeared to be promising predictors for prostate cancer recurrence. Lack of uniformity and consistency hampered their development. We evaluated ploidy and S phase for prostate cancer death in a cohort of patients with long-term follow-up.

Methods

We identified 127 patients that had ploidy and S phase determined at the time of their radical prostatectomy for prostate cancer. With 15 years of follow-up, we determined the risk of biochemical failure and risk of death from prostate cancer. We correlated the S phase and ploidy findings with standard pathology findings.

Results

A total of 107 (84%) had diploid and 20 (16%) had non-diploid cancers. The median S phase was 6.6%. There was no correlation of ploidy (P = 0.472) or S phase with preoperative PSA or Gleason score. On univariate analysis, EPE, margin positivity, seminal vesicle involvement, lymph node involvement, high Gleason score and PSA > 10 ng/mL were all predictive of biochemical failure. Ploidy and S phase were not. For prostate cancer death, only Gleason score was predictive.

Conclusions

With long-term follow-up in our cohort, Gleason score was predictive of prostate cancer death. Ploidy and S phase were not predictive for biochemical failure or prostate cancer mortality.

Insulin-like growth factor (IGF)-I, IGF binding protein-3, and prostate cancer: correlation with Gleason score

Introduction

Non-androgenic growth factors are involved in the growth regulation of prostate cancer (PCa).

Objective

This is the first Brazilian study to correlate, in a population of patients operated for PCa, PSA, total testosterone, insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) with Gleason score and to compare with a control group with benign prostate hyperplasia (BPH).

Materials and Methods

This retrospective single-center study included 49 men with previously diagnosed PCa and 45 with previously diagnosed BPH. PSA, testosterone, IGF-I, IGFBP-3 were determined in both groups.

Results

PSA and IGFBP-3 levels were significantly higher in the PCa group as compared to the BPH group (p<0.001 and p=0.004, respectively). There was a significant difference when we compared the PSA before surgery (p<0.001) and at the inclusion in the study (p<0.001) and IGFBP3 (0.016) among patients with Gleason <7, ≥7 and BPH. In the PCa group, PSA, testosterone, IGF-I and IGFBP-3 levels were comparable between Gleason <7 and ≥7.

Conclusions

Our data suggest that in localized PCa, the quantification of PSA and, not of IGF-1, may provide independent significant information in the aggressiveness. IGFBP-3 could be a biochemical marker of disease control in PCa patients.

Prognostic significance of proliferation activity and neuroendocrine differentiation to predict treatment failure after radical prostatectomy

OBJECTIVES

Neuroendocrine (NE) cells in prostate cancer may influence tumor cell proliferation in a paracrine fashion. The aims of this study were to clarify the prognostic value of tumor cell proliferation and NE tumor cell differentiation in prostate cancer after radical prostatectomy, and to compare these parameters with each other.

MATERIAL AND METHODS

Specimens were pooled from a total of 528 patients treated with radical prostatectomy without neoadjuvant hormonal therapy between 1996 and 2003. NE differentiation (NED) was determined by immunohistochemistry using antibodies directed against chromogranin A (CgA), and was scored as either NE-negative (0-1+) or -positive (2-3+). Tumor cell proliferation was assessed by means of the Ki-67 labeling index (Ki-67 LI). The mean post-surgical follow-up period was 49 months (range 10-116 months). Any subsequent rise in prostate-specific antigen (PSA) level was regarded as reflecting disease progression. The prognostic values of Ki-67 and CgA were comparatively analyzed using multivariate Cox regression.

RESULTS

NED was present in 6.1% of tumors. The mean Ki-67 LI was significantly higher in the CgA-positive group in comparison with CgA-negative specimens (6.6% vs 5.0%; p=0.029). The Ki-67 LI showed the highest correlations with Gleason score and pathological tumor stage (r=0.31 and r=0.3, respectively). NED was found to have the strongest association with pathological tumor stage (r=0.2). Multivariate analysis determined Gleason score > or =7 (4+3) [hazard ratio (HR) 3.04], NED (HR 1.89), lymph node metastases (HR 1.84), preoperative PSA level>20 ng/ml (HR 1.66), and Ki-67 LI > or = 5% (HR 1.62) to be significant predictors of biochemical progression.

CONCLUSION

Our results identify Ki-67 LI and NED as additional prognostic markers after radical prostatectomy.

A Correlation of FTIR Spectra Derived from Prostate Cancer Biopsies with Gleason Grade and Tumour Stage

OBJECTIVES

We introduce biochemistry as a second dimension to Gleason grading, using Fourier transform infrared (FTIR) microspectroscopy. For the first time, we correlate FTIR spectra derived from prostate cancer (pCA) tissue with Gleason score and the clinical stage of the tumour at time of biopsy.

METHODS

Serial sections from paraffin-embedded pCA tissue were collected. One was stained with hematoxylin and eosin and Gleason scored; FTIR spectra were collected from malignant locations using a second unstained section. FTIR spectra, representing different Gleason grades, were used to construct a diagnostic classifier for pCA using linear discriminant analysis (LDA). This model was blind tested using 383 IR spectra from 36 biopsies.

RESULTS

Using a three-band Gleason criteria, we obtained sensitivity of > or =70% for the FTIR-LDA model to predict Gleason <7,=7, and >7, with specificities of > or =81%. Using a threshold of Gleason/FTIR-LDA score of > or =8, we obtained a sensitivity and specificity of 71% and 67%, respectively, for the correlation with metastatic tumours using the FTIR-LDA system and 85% and 63%, respectively, for the correlation of metastatic tumours using the Gleason system.

CONCLUSIONS

There is a correlation between tissue architecture using Gleason score with tissue biochemistry using FTIR-LDA. Both systems are similar in their performance in predicting metastatic behaviour in tumours from individual patients.

Molecular markers in the diagnosis of prostate cancer

The genetic alterations leading to prostate cancer are gradually being discovered. A wide variety of genes have been associated with prostate cancer development as well as tumor progression. Knowledge of gene polymorphisms associated with disease aid in the understanding of important pathways involved in this process and may result in the near future in clinical applications. Urinary molecular markers will soon be available to aid in the decision of repeat prostate biopsies. Recent findings suggest the importance of androgen signaling in disease development and progression. The further understanding of interaction of inflammation, diet, and genetic predisposition will improve risk stratification in the near future.

Prognostic factors and reporting of prostate carcinoma in radical prostatectomy and pelvic lymphadenectomy specimens

This paper, based on the activity of the Morphology-Based Prognostic Factors Committee of the 2004 World Health Organization-sponsored International Consultation, describes various methods of handling radical prostatectomy specimens for both routine clinical use and research purposes. The correlation between radical prostatectomy findings and postoperative failure is discussed in detail. This includes issues relating to pelvic lymph node involvement, detected both at the time of frozen section and in permanent sections. Issues of seminal vesicle invasion, including its definition, routes of invasion and relationship to prognosis, are covered in detail. The definition, terminology and incidence of extra-prostatic extension are elucidated, along with its prognostic significance relating to location and extent. Margins of resection are covered in terms of their definition, the etiology, incidence and sites of positive margins, the use of frozen sections to assess the margins and the relationship between margin positivity and prognosis. Issues relating to grade within the radical prostatectomy specimen are covered in depth, including novel ways of reporting Gleason grade and the concept of tertiary Gleason patterns. Tumor volume, tumor location, vascular invasion and perineural invasion are the final variables discussed relating to the prognosis of radical prostatectomy specimens. The use of multivariate analysis to predict progression is discussed, together with proposed modifications to the TNM system. Finally, biomarkers to predict progression following radical prostatectomy are described, including DNA ploidy, microvessel density, Ki-67, neuroendocrine differentiation, p53, p21, p27, Bcl-2, Her-2/neu, E-cadherin, CD44, retinoblastoma proteins, apoptotic index, androgen receptor status, expression of prostate-specific antigen and prostatic-specific acid phosphatase and nuclear morphometry.

DNA replication regulation protein Mcm7 as a marker of proliferation in prostate cancer

BACKGROUND

Recent studies have shown that minichromosome maintenance (MCM) proteins (Mcm2-7) may be useful proliferation markers in dysplasia and cancer in various tissues.

AIMS

To investigate the use of Mcm7 as a proliferation marker in 79 lymph node negative prostate cancers and compare it with Ki-67, a commonly used cell proliferation marker.

METHODS

The percentage of proliferating cells (proliferation index; PI) was calculated for basal and luminal epithelial cells in benign prostate tissue, prostatic intraepithelial neoplasia (PIN), and epithelial cells in adenocarcinoma. The PI for each biomarker was correlated with the preoperative prostate specific antigen concentration, the Gleason score, surgical resection margin status, and the AJCC pT stage for each patient.

RESULTS

The mean PIs for Ki-67 and Mcm7 were: benign luminal epithelium 0.7 and 1.2 and benign basal epithelium 0.8 and 8.2; PIN non-basal epithelium 4.9 and 10.6 and PIN basal epithelium 0.7 and 3.1; adenocarcinoma 9.8 and 22.7, respectively. Mcm7 had a significantly higher mean PI (p<0.0001) than Ki-67 for all cell categories except benign luminal epithelial cells. Mcm7 was a better discriminatory marker of proliferation between benign epithelium, PIN, and invasive adenocarcinoma (p<0.0001) than Ki-67. The drop in Mcm7 mean basal cell PI from benign epithelium to PIN epithelium was significantly larger than for Ki-67 (p<0.0001). Mcm7 had a significantly higher PI than Ki-67 at each risk level.

CONCLUSION

Mcm7 may be a useful proliferation marker in prostatic neoplasia and warrants further evaluation as a complementary tool in the diagnosis of PIN and prostate carcinoma.

Human prostate cancer risk factors

Prostate cancer has the highest prevalence of any nonskin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. This review is a contemporary and comprehensive, literature-based analysis of the putative risk factors for human prostate cancer, and the results were presented at a multidisciplinary consensus conference held in Crystal City, Virginia, in the fall of 2002. The objectives were to evaluate known environmental factors and mechanisms of prostatic carcinogenesis and to identify existing data gaps and future research needs. The review is divided into four sections, including 1) epidemiology (endogenous factors [family history, hormones, race, aging and oxidative stress] and exogenous factors [diet, environmental agents, occupation and other factors, including lifestyle factors]); 2) animal and cell culture models for prediction of human risk (rodent models, transgenic models, mouse reconstitution models, severe combined immunodeficiency syndrome mouse models, canine models, xenograft models, and cell culture models); 3) biomarkers in prostate cancer, most of which have been tested only as predictive factors for patient outcome after treatment rather than as risk factors; and 4) genotoxic and nongenotoxic mechanisms of carcinogenesis. The authors conclude that most of the data regarding risk relies, of necessity, on epidemiologic studies, but animal and cell culture models offer promise in confirming some important findings. The current understanding of biomarkers of disease and risk factors is limited. An understanding of the risk factors for prostate cancer has practical importance for public health research and policy, genetic and nutritional education and chemoprevention, and prevention strategies.

Radical perineal prostatectomy: a model for evaluating local response of prostate therapy

To establish a model for preoperative counseling and postoperative outcome in patients who choose radical perineal prostatectomy for the clinically localized prostatic malignancy, the following postulates have been identified: (1) the use of preoperative prostate specific antigen (PSA) and Gleason Sum at the time of biopsy can be used to segregate the outcome among patients with Gleason Sum 2 through 6, 7, and 8 through 10. (2) Postoperative PSA levels are excellent surrogate endpoints for defining disease control. (3) The biology of the primary malignancy defines the interval of death after recurrence. A total of 1242 men with the median age of 65.2 years who had Stage cT 1-2 NOMO disease underwent radical perineal prostatectomy. The final pathologic specimen was characterized with regard to disease extent and Gleason Sum. Patients were followed at 2 weeks, 2 months, and then at 6-month intervals for biochemical, physical, and radiographic evidence of disease recurrence. Outcome was evaluated by determining time to biochemical failure (PSA 0.5 ng/ml or greater) or cancer associated death (death with a detectable PSA independent of treatment). Median time to non-cancer death was 19.3 years. Median cancer-associated death endpoints were not reached by patients with organ confined disease. Results were 17.7 years for specimen confined disease and 12.7 years for margin positive disease. At 5 years, 8, 35, and 65% of patients with organ confined, specimen confined, or margin positive disease, respectively, had PSA failure. This served as an excellent surrogate endpoint, preceding cancer associated death by 5-12 years, depending on the biological aggressiveness predicted by Gleason Sum. When segregated by Gleason Sum 2 through 6, 7 or 8 through 10 at the time of biopsy, there was a distinct differentiation in survival among these Gleason Sum classifications according to the PSA at the time of biopsy. This study confirms our postulates and provides guidelines for preparing different therapies among institutions. It also emphasizes that enthusiasm for new treatments may be based on insufficient follow-up. PSA is an excellent surrogate endpoint and it is valuable in segregating patients prior to therapeutic selection and predicting outcome.

Complex functions of mutant p53 alleles from human prostate cancer

BACKGROUND

Few studies have used multiple assays to examine the functionality of mutant p53 in prostate cancer (CaP). We employed seven functional assays to study 16 representative mutant p53 alleles, six from localized and ten from metastatic CaP.

METHODS

Yeast assays were employed to determine loss of function (LOF), partial function (PF), and dominant-negative status. Assays using p53-null Saos2 cells were used to determine whether mammalian cells transfected with mutant p53 could up-regulate the MDR-1 or PCNA promoters, alter IL-6 expression or confer the ability to grow in soft agar. As a further test of gain of function (GOF), p53-null PC3 cells stably transfected with these mutant p53 alleles were examined for cell cycle distributions.

RESULTS

All 16 mutant p53 alleles demonstrated either total or partial LOF. All but one allele also had at least one gain of function; however, the pattern of GOF was different for each mutant allele. Alleles derived from both localized and metastatic CaP had similar GOF characteristics; however, only alleles from metastatic disease had significantly increased S-phase fractions.

CONCLUSIONS

Different mutant p53 alleles from CaP had different, complex functional profiles. The lack of predictable patterns for these alleles suggest that each mutation may uniquely affect p53 function.

Ki67 protein: the immaculate deception?

This article updates our previous review of Ki67 published in Histopathology 10 years ago. In this period the numbers of papers published featuring this antibody has increased 10-fold from 338 to 3489 indicating the considerable enthusiasm with which this antibody has been studied. This review attempts to provide an update on the characterization of the Ki67 protein, its function and its use as a prognostic or diagnostic tool.

Factors that influence the measurement of prostate cancer DNA ploidy and proliferation in paraffin embedded tissue evaluated by flow cytometry

DNA ploidy and proliferation have been shown in several studies to be prognostic markers for prostate cancer. Flow cytometry (FCM) is often used in the determination of ploidy and proliferation. However, FCM cannot readily distinguish among benign epithelium, stromal and inflammatory cells, high grade prostatic intraepithelial neoplasia (HGPIN), and cancer cells. In this study, we evaluated H&E histologic features of 322 radical prostatectomy formalin-fixed, paraffin-embedded tissue blocks used for determining DNA ploidy, percent S-phase (%S), and %S + %G2M by FCM. The microscopic findings included Gleason score, extent of cancer and HGPIN in the tissue block, and presence of a needle track. The amount of cancer in the block was expressed as a percentage of the total tissue surface area in quartiles: < or =25%, 26-50%, 51-75%, and > or =76%. The extent of HGPIN was recorded in rough 5% intervals. Needle track effect was defined as a combination of fibrohistiocytic reaction, fibrin clot, granuloma formation, and chronic inflammation. The associations between these histologic features and DNA ploidy and proliferation (%S and %S + %G2M) were assessed. In multivariate analyses, Gleason score, the amount of tumor in the tissue block, and the extent of HGPIN were significantly associated with ploidy. Gleason score was the only parameter significantly associated with the proliferation measure of %S. If we included %G2M as part of the proliferative fraction of the histogram, however, both Gleason score and the amount of tumor in the block were significantly associated with this measure of proliferation. The presence of a needle track was not significantly associated with DNA ploidy, %S, or %S + %G2M. In summary, prostate cancer DNA ploidy and proliferation results assessed by FCM in paraffin-embedded tissue blocks were associated with the Gleason score, amount of cancer in the tissue block, and extent of HGPIN. However, the presence of a needle track was not associated with the FCM results.

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.

The increased accumulation of [18F]fluorodeoxyglucose in untreated prostate cancer

BACKGROUND

To evaluate the clinical usefulness of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) compared with histopathological grading, clinical stage and serum prostatic specific antigen (PSA) level in the detection and characterization of prostate cancer.

METHODS

Forty-four patients with histologically proven prostate cancer and five control subjects with benign prostatic hyperplasia (BPH) were prospectively investigated with FDG-PET prior to treatment.

RESULTS

By visual inspection, FDG accumulation was positive in 28 patients with prostate cancer (sensitivity 64%), whereas all were negative in the control group. FDG-PET in three patients with lymph node metastases did not show any high intrapelvic accumulations corresponding to metastatic sites. Among 12 patients with multiple bone metastases which were detected with 99m-HMDP bone scintigraphy, nine (75%) showed moderate to high FDG accumulation at the sites of bone metastases. Quantitatively, FDG accumulation in prostate cancer was significantly higher than in BPH and there was a tendency for FDG uptake of tumors to be higher with higher histological Gleason grades. Furthermore, FDG uptake in tumors with lymph node and/or bone metastasis was significantly higher than that of localized stages. However, the correlation between PSA and FDG uptake in the prostate cancer was very weak for clinical relevance.

CONCLUSIONS

Although FDG-PET was not sensitive enough to detect prostate cancer in clinical use, it is suggested that glucose metabolism in prostate cancer tended to be higher in patients with tumors of advanced stages.

Relationship of Ki-67 labeling index to DNA-ploidy, S-phase fraction, and outcome in prostate cancer treated with radiotherapy

BACKGROUND

Our purpose was to evaluate the relationship of Ki-67 labeling index (Ki67-LI) to deoxyribonucleic acid (DNA) ploidy, S phase fraction (SPF), other clinical prognostic factors, and clinical outcome for patients with prostate cancer treated by external beam radiotherapy.

METHODS

Tissue was retrieved from 42 patients who underwent transurethral resection of the prostate before treatment with external beam radiotherapy between 1987-1993. DNA histogram profiles were classified as diploid (diploid + near-diploid) and nondiploid (tetraploid + aneuploid). Immunohistochemical staining of Ki-67 by the MIB-1 monoclonal antibody was used to calculate Ki67-LI. Median patient follow-up was 62 months. Treatment failure was defined as two consecutive rises in serum prostate-specific antigen (PSA) or clinical evidence of disease recurrence.

RESULTS

The mean and median Ki67-LIs were 3.1 and 2.4, respectively (range, 0-12.4). Mean Ki67-LI values were significantly associated with higher stage, Gleason score, and pretreatment PSA. Nondiploid tumors had significantly higher Ki67-LIs, as did patients who failed radiotherapy over the follow-up period. SPF was not significantly correlated with Ki67-LI. As a categorical variable, the most significant relationships were seen when Ki67-LI was subdivided into thirds around the median (Ki67-LI </=1.5%, Ki67-LI >1.5-3.5%, and Ki67-LI >3.5%). This trichotomous variable correlated significantly with pretreatment PSA (P = 0.0008), tumor stage (P = 0.016), Gleason score (P = 0.024), and treatment failure (P = 0.0015), but not with DNA-ploidy (P = 0.15). In actuarial univariate analyses, Ki67-LI appeared to be a more significant predictor of patient outcome (P = 0.003) than DNA-ploidy (P = 0.035).

CONCLUSIONS

The Ki67-LI correlated with known prognostic factors such as pretreatment PSA, tumor stage, and Gleason score, and was also weakly related to DNA-ploidy. In comparison to DNA-ploidy, Ki67 LI seems to be a better correlate of treatment outcome.

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.

Radical perineal prostatectomy: oncological outcome during a 20-year period

PURPOSE

We examined 4 postulates: 1) radical perineal prostatectomy provides a substantial disease control benefit in men with clinically confined prostate cancer, 2) postoperative prostate specific antigen (PSA) levels are an excellent surrogate end point for defining disease control, 3) the biology of primary malignancy defines the interval to death after recurrence and 4) the interval from intervention to death from recurrence is so long that current series of alternative curative therapies have insufficient duration of observation to permit a comparison with the results of surgery.

MATERIALS AND METHODS

A total of 1,242 men with a median age of 65.2 years who had stage cT1 to 2 N0M0 disease underwent radical perineal prostatectomy. The final pathology specimen was characterized in regard to disease extent, and Gleason grade and score. Patients were followed at 2 weeks, at 2 months and then at 6-month intervals for biochemical, physical and radiographic evidence of disease recurrence. Outcome was evaluated by determining time to biochemical failure (PSA 0.5 ng./ml. or greater) and cancer associated death.

RESULTS

Median time to noncancer death was 19.3 years. Median cancer associated death end point was not reached by patients with organ and specimen confined disease, while it was 12.7 years for margin positive disease. At 5 years 8, 35 and 65% of the patients with organ confined, specimen confined and margin positive disease, respectively, had PSA failure. This served as an excellent surrogate end point, preceding cancer associated death by 5 to 12 years depending on the biological aggressiveness predicted by Gleason grade or score. Biologically aggressive organ confined disease that had been surgically removed was associated with a high percentage of disease-free survival.

CONCLUSIONS

Our study confirms our postulates. It also provides guidelines for comparing therapies among institutions and emphasizes that enthusiasm for new treatments may be based on insufficient followup. Patient selection may severely bias outcome independent of treatment when death is used as the end point. Our study establishes the value of PSA as a surrogate end point.

Surgical control of clinically localized prostate carcinoma is equivalent in African-American and white males

BACKGROUND

Few studies have compared the outcome of radical prostatectomy between African-American males (AAM) and white males, and the results of the few studies that have are conflicting. Therefore, the authors examined the impact of radical surgery on localized prostate carcinoma in both patient populations, and assessed whether stratification by pathologic extent of local disease would yield an equivalent outcome.

METHODS

Prostate specific antigen (PSA) failure and carcinoma-associated death rates were assessed in 1319 patients (115 AAM and 1204 white males), 872 of whom had a pretreatment serum PSA level taken. The percent of prostate involved by tumor, tumor wet weight, and DNA ploidy status were available in 755, 522, and 638 patients, respectively.

RESULTS

AAM were diagnosed at an earlier age than white males (62.8 years vs. 65.4 years; P = 0.0001). The distribution of pathologic extent of local disease was similar in both races, and AAM had a statistically higher rate of tumors with a Gleason sum of 7-10 at surgery than white males (64% vs. 46%). Race did not play a role in the outcome of patients with organ-confined or specimen-confined tumors. However, in patients with positive surgical margins, the median time to PSA failure and the median carcinoma-associated survival were less in AAM compared with white males. Tumor volume was significantly larger in AAM compared with white males. After multivariate adjustment for the pathologic extent of local disease, tumor grade at surgery, preoperative PSA, tumor volume, and age, African-American race was not a significant prognostic indicator for carcinoma-associated death and PSA failure (P = 0.17 and 0.14, respectively).

CONCLUSIONS

The outcome of radical prostatectomy was similar in both racial groups, although AAM with positive surgical margins tended to fail earlier than white males, suggesting greater biologic aggressiveness of residual disease. Because local extent of disease impacts on PSA failure and survival, and because the disease appears to present earlier in AAM, the AAM population may benefit from early detection programs.

DNA ploidy and survival of patients with clinically localized prostate cancer treated without intent to cure

BACKGROUND

The optimal approach to diagnosis and treatment of localized prostate cancer remains controversial. Deoxyribonucleic acid (DNA) ploidy has been suggested as an important predictor for outcome in prostate cancer. The purpose of this study was to correlate DNA ploidy with disease-specific survival in patients with clinically localized prostate cancer treated with no intent to cure.

METHODS

DNA ploidy was determined by flow cytometry in archival formalin fixed, paraffin embedded tumor tissue obtained at diagnosis in 120 patients with clinically localized prostate cancer with a nearly complete follow-up.

RESULTS

Ninety (75%) of the tumors were diploid, while only 11 (9%) tumors were categorized as tetraploid. Tumor DNA ploidy (diploid versus nondiploid) significantly associated with histopathological grade (P=0.002) and disease-specific survival (P=0.011), while there was no association with tumor stage (P=0.054). In a multivariate Cox analysis, histopathological grade (P=0.005) was the only significant predictor of disease-specific death, while analyzing the 96 low-grade tumors separately, DNA ploidy became significant (P= 0.024).

CONCLUSIONS

Flow cytometric determined nondiploidy was associated with disease-specific death in patients with clinically localized prostate cancer, but DNA ploidy provided additional prognostic information in patients with low-grade tumors only.

Tumor cell proliferation and survival in patients with prostate cancer followed expectantly

PURPOSE

Prostate cancers have different biological potentials, and aggressive tumors are difficult to identify when still localized. Tumor cell proliferation determined by MIB-1 expression has been suggested as an important predictor for outcome in several human cancers including the prostate. We test the possible prognostic value of tumor cellular proliferation in prostate cancer patients treated with no intent to cure.

MATERIALS AND METHODS

Formalin fixed, paraffin embedded tumor tissue obtained at the time of diagnosis from 221 patients originating from a well known complete Danish prostate cancer population was immunohistochemically investigated. The tumor cell proliferation rate was determined using the MIB-1 antibody. Tumors were clinically localized in 57% of the patients.

RESULTS

Tumor cell proliferation rate expressed by the MIB-1 score significantly correlated with tumor stage (p <0.001) and malignancy grade (p <0.001). The MIB-1 score, divided into low and high by the median value, showed significant association with disease specific survival in the entire study population (p <0.0001), as well as in the 125 patients suffering from clinically localized disease (p=0.018). Multivariate analyses showed that MIB-1 was a significant (p=0.0003) prognostic factor in the entire population, including advanced disease stages. However, in the theoretically curable clinically localized subpopulation MIB-1 was not significant (p=0.08) contrary to histopathological grade (p=0.02), erythrocyte sedimentation rate (p=0.02) and T classification (p=0.035).

CONCLUSIONS

Prostate tumor cell proliferation, expressed by MIB-1 immunoreactivity, demonstrated significant association with disease specific survival. However, MIB-1 is a close alternative to histopathological grade in describing the natural history of clinically localized prostate cancer. The additional prognostic value and the practical consequence of tumor cell proliferation remain to be clarified.

Accuracy of biopsy Gleason scores from a large uropathology laboratory: use of a diagnostic protocol to minimize observer variability

OBJECTIVES

To examine the correlation of biopsy Gleason scores with radical prostatectomy specimens from a laboratory that uses protocols designed to minimize observer variability. This protocol mandates consensus case review of all nonbenign cases.

METHODS

Between August 24, 1993 and June 26, 1997, 106 patients who underwent radical prostatectomy at Johns Hopkins Hospital, Baltimore, Maryland had their prostate cancer diagnosed and graded at one laboratory (DIANON Systems). We analyzed the Gleason scores from the biopsy and radical prostatectomy specimens.

RESULTS

Exact correlation existed between biopsy and radical prostatectomy Gleason scores for 72 (68%) cases; 103 (97%) correlated within 1 grade, all cases correlated within 2 grades; 26 (25%) biopsies were undergraded and 8 (8%) were overgraded. Positive predictive values for biopsy Gleason scores 5, 6, and 7 were 66%, 67%, and 71%, respectively. Grouped Gleason scores (well differentiated [2 to 4], moderately differentiated [5, 6], moderately to poorly differentiated [7], and poorly differentiated [8 to 10]) correlated exactly for 74 (70%) cases and within 1 group for all cases. Patient age, digital rectal examination results, total number of positive cores, and maximum percentage of tumor on biopsy did not affect correlation, but prostate-specific antigen (PSA) levels did affect correlation (exact correlation 96% when the PSA level was less than 5 ng/mL; 50% when the PSA level was 11 ng/mL or greater, P <0.01).

CONCLUSIONS

The combination of experience and the protocol described minimizes intra- and interobserver variability, thereby improving the predictive value of biopsy Gleason grading. Biopsy and radical prostatectomy Gleason scores correlate more poorly when the PSA level is high (11 ng/mL or greater) than when the PSA level is low (less than 5 ng/mL).

An evaluation of the markers p53 and Ki-67 for their predictive value in prostate cancer

BACKGROUND AND OBJECTIVES

p53 and Ki-67 are but two markers being evaluated for their predictive value in prostate cancer. The purpose of this study was to compare p53 and Ki-67 with age, stage, Gleason score, and ploidy for their prognostic abilities in prostate cancer.

METHODS

Prostate cancer specimens from 134 patients were immunohistochemically stained for p53 and Ki-67 expression and differences evaluated by SPSS analysis of variance (ANOVA) methods. The dependent variable was patient survival and the independent variables were age, stage, Gleason score, and ploidy.

RESULTS

In decreasing order of prediction of survival were stage (P < 0.001), Gleason score (P < 0.001), age (P = 0.1869), Ki-67 (P = 0.2284), p53 (P = 0.4282) and ploidy (P = 0.8141).

CONCLUSION

It is concluded that stage and Gleason score are significant predictors of survival while p53, Ki-67, age and ploidy are not.

Prognostic value of MIB-1 in advanced ovarian carcinoma as determined using automated immunohistochemistry and quantitative image analysis

BACKGROUND AND OBJECTIVES

The monoclonal antibody MIB-1 is an immunohistochemical marker reacting most strongly with cells in late S phase, G2, and M portions of the cell cycle. This antibody, reactive in formalin-fixed, paraffin-embedded tissue, allows the quantitation of a proliferation index (PI) in both current clinical cases and archival material using a computerized image analyzer (CIA).

METHODS

Since many laboratories make use of automated immunohistochemistry (AIH), this study was performed to explore the technical feasibility of using AIH (Ventana ES 320) in combination with CIA (CAS 200) to evaluate MIB-1 PI as a prognostic marker as assessed by overall survival in 50 archival (formalin-fixed, paraffin-embedded), advanced stage primary ovarian carcinomas.

RESULTS

Exploratory methods confirmed that 15% was a cutpoint that could dichotomize these 50 patients into two prognostic groups based on overall survival. The median survival of patients whose carcinoma had a high MIB-1 expression (> or = 15%) was 16 months compared with 30 months in the patients whose tumors demonstrated low MIB-1 expression (< 15%, P = 0.01). After adjustment for age, MIB-1 retained its prognostic significance (P = 0.02). Patients 60 years and older had shorter survival than younger patients (P = 0.06), but these two groups did not differ with respect to PI (P = 0.76). Those patients with a negative second look laparotomy had a longer median survival of 70 months compared with 18.5 months in patients with a positive second look (P < 0.001); the median PIs were 17% and 27%, respectively (P = 0.36). There were no significant relationships between clinical stage, nuclear grade, DNA ploidy, p53, and either survival or PI.

CONCLUSIONS

In this study, we concluded that the combination of AIH and CIA yielded a reliable quantitation of MIB-1 proliferative index and that this proliferative marker had prognostic significance in late stage ovarian carcinoma. Further studies in a larger group of patients are needed to confirm the relationship between proliferation index and other known clinicopathologic and genetic variables.