Mitotic activity and prognosis in prostatic adenocarcinoma

Significance and outcome of nuclear anaplasia and mitotic index in prostatic adenocarcinomas

OBJECTIVES

The Gleason grading system measures architectural differentiation and disregards nuclear atypia and the cell proliferation index. Several studies have reported that nuclear grade and mitotic index (MI) are prognostically useful.

PATIENTS AND METHODS

This study included 232 radical prostatectomy specimens. Nuclear anaplasia (NA) was determined on the basis of nucleomegali (at least 20µm); vesicular chromatin; eosinophilic macronucleoli, nuclear lobulation, and irregular thickened nuclear membranei. The proportion of area of NA was recorded in each tumor in 10% increments. The MI was defined as the number of mitotic figures in 10 consecutive high-power fields (HPF).

RESULTS

In univariate analysis, significant differences included associations between biochemical prostate-specific antigen recurrence (BCR) and Gleason score, extraprostatic extension, positive surgical margin, the presence of high-pathologic stage, NA≥10% of tumor area, MI≥3/10 HPF, and preoperative prostate-specific antigen. In a stepwise Cox regression model, a positive surgical margin, the presence of a NA≥10% of tumor area, and a MI of≥3/10 HPF were independent predictors of BCR after radical prostatectomy. NA≥10% of tumor area appeared to have a stronger association with outcome than MI≥3/10 HPF, as still associated with BCR when Gleason score was in the model.

CONCLUSIONS

The results of our study showed that, in addition to the conventional Gleason grading system, NA, and MI are useful prognostic parameters while evaluating long-term prognosis in prostatic adenocarcinoma.

Lactate dehydrogenase 5 isoenzyme overexpression defines resistance of prostate cancer to radiotherapy

Background:

Radiotherapy provides high-cure rates in prostate cancer. Despite its overall slow clinical growth, high proliferation rates documented in a subset of tumours relate to poor radiotherapy outcome. This study examines the role of anaerobic metabolism in prostate cancer growth and resistance to radiotherapy.

Methods:

Biopsy samples from 83 patients with prostate cancer undergoing radical hypofractionated and accelerated radiotherapy were analysed for MIB1 proliferation index and for lactate dehydrogenase isoenzyme LDH5, a marker of tumour anaerobic metabolism. Ninety-five surgical samples were in parallel analysed. Correlation with histopathological variables, PSA and radiotherapy outcome was assessed. Dose–response experiments were performed in PC3 and DU145 cancer cell lines.

Results:

High MIB1 index (noted in 25% of cases) was directly related to Gleason score (P<0.0001), T3-stage (P=0.0008) and PSA levels (P=0.03). High LDH5 (noted in 65% of cases) was directly related to MIB1 index (P<0.0001), Gleason score (P=0.02) and T3-stage (P=0.001). High Gleason score, MIB1, LDH5 and PSA levels were significantly related to poor BRFS (P=0.007, 0.01, 0.03 and 0.01, respectively). High Gleason score (P=0.04), LDH5 (P=0.01) and PSA levels (P=0.003) were significantly related to local recurrence. MIB1 and T-stage did not affect local control. Silencing of LDHA gene in both prostate cancer cell lines resulted in significant radiosensitisation.

Conclusions:

LDH5 overexpression is significantly linked to highly proliferating prostate carcinomas and with biochemical failure and local relapse following radiotherapy. Hypoxia and LDHA targeting agents may prove useful to overcome radioresistance in a subgroup of prostate carcinomas with anaerobic metabolic predilection.

Biological dose volume histograms during conformal hypofractionated accelerated radiotherapy for prostate cancer

Radiobiological data suggest that prostate cancer has a low alpha/beta ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated radiotherapy scheme for the treatment of high risk prostate cancer. Anteroposterior fields to the pelvis deliver a daily dose of 2.7 Gy, while lateral fields confined to the prostate and seminal vesicles deliver an additional daily dose of 0.7 Gy. Radiotherapy is accomplished within 19 days (15 fractions). Dose volume histograms, calculated for tissue specific alpha/beta ratios and time factors, predict a high biological dose to the prostate and seminal vesicles (77-93 Gy). The biological dose to normal pelvic tissues is maintained at standard levels. Radiobiological dosimetry suggests that, using hypofractionated and accelerated radiotherapy, high biological radiation dose can be given to the prostate without overdosing normal tissues.

Number and location of nucleoli and presence of apoptotic bodies in diagnostically challenging cases of prostate adenocarcinoma on needle biopsy

There is limited published data regarding the significance of the number or position of nucleoli and the presence of apoptotic bodies in diagnostically challenging cases of adenocarcinoma of the prostate on needle biopsy material. One hundred consecutive prostate cancers on needle biopsy were sent because of diagnostic difficulty to an expert in urological pathology, and the remaining normal benign prostatic glands on the same core were evaluated for the number and location of nucleoli and for the presence of mitotic figures and apoptotic bodies. The Gleason scores of the cases were 6 (86%), 7 (9%), and 8 to 10 (5%). For comparison, the same parameters were evaluated in mimickers of cancer on needle biopsy from other cases, including partial atrophy (n = 135), fully developed atrophy (n = 89), adenosis (n = 50), prostate glands with acute inflammation (n = 50), and high-grade prostatic intraepithelial neoplasia (n = 100). Findings were recorded under high dry magnification (x40) using hematoxylin and eosin-stained sections. Although the number and position of nucleoli did not discriminate between cancer and benign mimickers, mitotic figures and apoptotic bodies were more commonly seen in cancer. Apoptotic bodies in particular were seen fairly frequently (34%) in prostatic adenocarcinoma (also seen in 13% of high-grade prostatic intraepithelial neoplasia), yet rarely in benign mimickers on needle biopsy. Our findings indicate that the presence of apoptotic bodies should be added to the list of histological features that are helpful in the diagnosis of challenging cases of prostate cancer on needle biopsy.

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.

Mitotic counting in surgical pathology: sampling bias, heterogeneity and statistical uncertainty

Mitotic counting in surgical pathology: sampling bias, heterogeneity and statistical uncertainty Although several articles on the methodological aspects of mitotic counting have been published, the effects of macroscopic sampling and tumour heterogeneity have not been discussed in any detail. In this review the essential elements for a standardized mitotic counting protocol are described, including microscopic calibration, specific morphological criteria, macroscopic selection, counting procedure, effect of biological variation, threshold, and the setting of an area of uncertainty ('grey area'). We propose that the use of a standard area for mitotic quantification and of a grey area in mitotic counting protocols will facilitate the application of mitotic counting in diagnostic and prognostic pathology.

High stromal hyaluronan level is associated with poor differentiation and metastasis in prostate cancer

Several epithelial tumours accumulate hyaluronan (HA) which promotes cancer cell invasion and metastasis. We analysed the expression of HA and its receptor CD44 and their prognostic value in 166 prostate cancer patients followed up for a mean of 13 years; standard deviation (S.D.) 2.7; range 8.7-21.4 years. HA was detected with a specific biotinylated probe prepared from cartilage aggrecan and link protein, and CD44 with an antibody recognising all forms of CD44. The peri- and intratumoral stroma from half of the patients strongly expressed immunohistochemically detectable HA in < or = 15% of the stromal area; the tumours in the remaining half expressed HA in > 15% of the area. The staining of cancer cells for HA was scored positive or negative, and for CD44 the median value of 80% of positive tumour cells was used as a cut-off point. The expression of HA in cancer cells was weakly associated with perineural infiltration of the tumour (P = 0.03) and high Gleason score (P = 0.002). There was also a significant inverse relationship between the expression of HA and CD44 in cancer cells (P < 0.001). The high level of HA in the peri-and intratumoral stroma was related to metastasis, high T-category, high Gleason score, perineural infiltration and high mitotic activity of the tumour (for all P < 0.001). There was a significant inverse relationship between the expression of CD44 in cancer cells and high level of strong expression of HA in the tumour stroma (P < 0.001). A low fraction of CD44-positive cells was related to a high TM-category, high Gleason score and rapid cell proliferation (for all P < 0.0001; M/V P value = 0.0013). In the univariate survival analysis, the high level of strong expression of HA in tumour stroma predicted an unfavourable outcome in the entire series (P = 0.003) and also in the M0 tumours (P = 0.07), while in T1-2 M0 tumours the prognostic value did not reach the level of statistical significance (P = 0.1). A low fraction of CD44-positive cells predicted a poor outcome in the entire series (P < 0.001) and also in M0 tumours (P = 0.003). Cancer cell-associated HA expression had no prognostic value in any tumour categories. In the multivariate analysis of prognostic factors, HA expression in the cancer cells or in the tumour stroma had no additional value to the standard prognostic factors TM-classification, Gleason score and CD44 expression. Our results show that stromal HA accumulation is related to several malignant features and adverse clinical outcome in prostate cancer. However, further studies based on uniformly treated patient cohorts are needed to establish the clinical significance of these findings in current clinical practice.

The prognostic value of inducible nitric oxide synthase in local prostate cancer

OBJECTIVE

To compare the clinical and histological data from patients with prostate cancer with the results of the immunohistochemical analysis of inducible nitric oxide synthase (iNOS), and thus determine the prognostic value of iNOS.

PATIENTS AND METHODS

The study included 82 patients (mean age 64.6 years, SD 6.1) with local prostate cancer treated by radical prostatectomy in two Finnish hospitals. Their mean (SD) follow-up was 3.3 (2.2) years. An immunohistochemical method was used to detect the expression of iNOS in these specimens, and the expression graded according to staining intensity as none, weak or strong.

RESULTS

There was weak or strong expression of iNOS in 25 (31%) and 56 (68%) of the patients, respectively, and one specimen was negative for iNOS. Strong expression of iNOS was related to high a preoperative prostate specific antigen (PSA) level (P = 0.006) and high pT classification (P < 0.001), but not to nodal status, grade, seminal vesicle or capsular invasion, surgical margin status, perineural infiltration, tumour infiltrating lymphocytes or proliferation rate of cancer cells. A PSA failure was detected in 29 patients but was not predicted by iNOS expression. A Cox multivariate analysis showed that surgical margin positivity, seminal vesicle involvement and number of tumour infiltrating lymphocytes predicted the PSA failure.

CONCLUSION

A high expression of iNOS was related to a high pT classification and the preoperative PSA level but not to other established prognostic factors; iNOS expression was not a predictor of PSA failure in patients with local prostate cancer.

Alpha-catenin expression has prognostic value in local and locally advanced prostate cancer

Normally functioning cell-cell adhesion plays an important role in the maintenance of tissue architecture and cell cohesion. E-cadherin is an important adhesion molecule of epithelial cells. In many types of cancer the expression of E-cadherin is reduced leading to increased risk of disease progression. alpha-Catenin is one of the intracellular elements of the E-cadherin-catenin complex. The abnormalities in the expression of alpha-catenin seem to associate with malignant cellular features and disease progression in prostate cancer. To further analyse the significance of alpha-catenin expression, we studied 215 cases of prostate cancer by immunohistochemistry and the results were related to other known prognostic factors and patient survival during a mean follow-up period of 13 years. alpha-Catenin expression was down-regulated in 19% of the cases and 3% of the tumours were totally alpha-catenin-negative. The abnormal alpha-catenin expression and cytoplasmic signal were significantly linked with high T-category, metastatic disease, high Gleason score, perineural growth, high mitotic rate, high S phase fraction and DNA aneuploidy (P < 0.05 for all). In the survival analysis, reduced alpha-catenin expression (P = 0.06) and cytoplasmic signal (P = 0.04) were related to unfavourable patient outcome. In the multivariate analysis, including TM-classification and Gleason score, alpha-catenin expression had independent prognostic value in T1-2 M0 tumors. In the M0 tumours, abnormal alpha-catenin signal was independently associated with recurrence-free survival as well. The results indicate that down-regulation of alpha-catenin is related to several malignant cellular features, and it seems to have prognostic significance in the early phases of cancer progression. We suggest that alpha-catenin expression can provide prognostic information in early prostate cancer.

Prognostic value and expression of p21(waf1/cip1) protein in prostate cancer

BACKGROUND

p21(waf1/cip1) protein is a cyclin-dependent kinase inhibitor able to arrest the cell cycle at the G1 phase by inhibiting DNA replication. The expression of p21(waf1/cip1) and its prognostic value in prostate cancer are largely unexplored.

METHODS

We used immunohistochemistry to analyze the expression of p21(waf1/cip1) in 213 prostate cancer cases, and the results were related to other known prognostic factors and patient survival during a long-term follow-up.

RESULTS

The expression of p21 (waf1/cip1) protein was significantly associated with high Gleason score (P = 0.001), DNA aneuploidy (P = 0.013), high S-phase fraction (P = 0.019), and expression of Ki-67 (P = 0.021) and bcl-2 (P = 0.001) as well as cyclin A (P = 0.035) and D proteins (P<0.001). In univariate survival analysis the signal of p21(waf1/cip1) was significantly related to unfavorable prognosis (P = 0.010) both in the entire cohort and in local tumors (P = 0.034). In multivariate analysis, M-category, clinical T-category, Gleason score, and patient age were independent prognostic factors. In local tumors the expression of p21(waf1/cip1) together with clinical T-category and S-phase fraction were significant independent predictors of cancer related survival.

CONCLUSIONS

The results suggest that the expression of p21(waf1/cip1) protein is associated both with cell proliferation and patient survival in prostate cancer.

Expression of cyclin A and D proteins in prostate cancer and their relation to clinopathological variables and patient survival

BACKGROUND

Cell proliferation and its regulation are important determinants of the prognosis of prostate cancer patients. Cyclins are important regulators of cell proliferation in human cancer, but their prognostic value has not been previously analyzed in prostate cancer.

METHODS

The immunohistochemical expression and prognostic value of cyclins A and D were studied in prostate cancer in a cohort of 213 patients followed-up for a mean of 12 years.

RESULTS

The expression of cyclin A was both cytoplasmic and nuclear, whereas the expression of cyclin D was nuclear. The mean (SD) fraction of cyclin A- and cyclin D-positive cells was 2.1 (7.9)% and 16.3 (23.4)%, respectively. The expression of cyclin A was related to TM-category, histological differentiation, perineural invasion, S-phase fraction, and expression of Ki67 and bcl-2 (for all, P<0.05). The expression of cyclin D was related to TM-classification, histological differentiation, perineural invasion, DNA ploidy, S-phase fraction, expression of Ki67, and mitotic index (for all, P< or =0.01). In survival analysis, expression of cyclin A predicted cancer-related survival in the entire cohort (P<0.001). Expression of cyclin D predicted cancer-related survival in the entire cohort (P<0.0001), in MO (P = 0.0007), and in T1-2NxM0 tumors (P = 0.0003). In Cox multivariate analysis, T-category, M-category, patient age, and the fraction of cyclin A-positive cells were independent predictors of survival in the entire series. In local tumors, T-category, Gleason score, DNA ploidy, or S-phase fraction were independent prognostic factors, and cyclins had no independent prognostic value.

CONCLUSIONS

The results show that the expression of cyclins A and D is related to several malignant cellular features in prostate cancer, but they have no independent prognostic value.

Prognostic factors in gastric cancer: the value of vascular invasion, mitotic rate and lymphoplasmacytic infiltration

A retrospective analysis of 321 gastric cancer patients was made to assess the prognostic value of TNM classification, tumour differentiation, Laurén classification, proliferative rate, inflammatory reaction and tumour invasion in vascular or neural structures of the gastric wall. The TNM classification showed the strongest correlation with survival in univariate and multivariate analyses (P < 0.0001). The invasion in lymphatic or vascular system and Laurén classification were also independent prognosticators in multivariate analysis (P < 0.05). In univariate analysis, the WHO-grade, the size and the location of the tumour and perinueral invasion were significant prognostic factors (P < 0.01), as were the infiltration of lymphocytes and plasma cells in the tumour (P < 0.05). On the other hand, the mitotic indices reflecting the proliferative activity of the tumour cells showed no significant correlation with the prognosis. The results indicate that the prognostic power of the TNM classification can be further increased by assessment of the above special histological features in gastric cancer.

Ki67 labelling index: an independent predictor of progression in prostate cancer treated by radical prostatectomy

The clinical course of prostate cancer is highly variable and cannot satisfactorily be predicted by histological criteria alone. Both tumour cell proliferation and neuroendocrine differentiation have been suggested as additional prognostic parameters, neuroendocrine differentiation being considered to enhance tumour cell proliferation. This study investigated the prognostic value of tumour cell proliferation [Ki67 labelling index (LI), MIB 1] and neuroendocrine differentiation and their relationship to each other. One hundred and thirty-seven paraffin-embedded radical prostatectomy specimens were examined. Neuroendocrine differentiation was found in 58 per cent of cases, but was not associated with pTN stage, Gleason score, Ki67 LI, or tumour progression. Ki67 LI was not significantly associated with pTN stage or with Gleason score. High grade (P = 0.0005), advanced local stage (P = 0.0004), positive lymph nodes (P = 0.02), and high Ki67 LI (P = 0.0203) were predictors of tumour progression if univariate analysis was performed, but Cox stepwise regression showed that only advanced local stage (P = 0.0025) and Ki67 LI (P = 0.0105) were independent predictors of tumour progression, the relative risk being 3.6 and 2.5, respectively. It is concluded that Ki67 is an important prognostic marker in prostate cancer with a potential for routine application.