Significance of small foci of Gleason score 7 or greater prostate cancer on needle biopsy

The 2019 International Society of Urological Pathology (ISUP) Consensus Conference on Grading of Prostatic Carcinoma

Five years after the last prostatic carcinoma grading consensus conference of the International Society of Urological Pathology (ISUP), accrual of new data and modification of clinical practice require an update of current pathologic grading guidelines. This manuscript summarizes the proceedings of the ISUP consensus meeting for grading of prostatic carcinoma held in September 2019, in Nice, France. Topics brought to consensus included the following: (1) approaches to reporting of Gleason patterns 4 and 5 quantities, and minor/tertiary patterns, (2) an agreement to report the presence of invasive cribriform carcinoma, (3) an agreement to incorporate intraductal carcinoma into grading, and (4) individual versus aggregate grading of systematic and multiparametric magnetic resonance imaging-targeted biopsies. Finally, developments in the field of artificial intelligence in the grading of prostatic carcinoma and future research perspectives were discussed.

Identifying Clinically Significant Prostate Cancers using 3-D In Vivo Acoustic Radiation Force Impulse Imaging with Whole-Mount Histology Validation

Overly aggressive prostate cancer (PCa) treatment adversely affects patients and places an unnecessary burden on our health care system. The inability to identify and grade clinically significant PCa lesions is a factor contributing to excessively aggressive PCa treatment, such as radical prostatectomy, instead of more focal, prostate-sparing procedures such as cryotherapy and high-dose radiation therapy. We have performed 3-D in vivo B-mode and acoustic radiation force impulse (ARFI) imaging using a mechanically rotated, side-fire endorectal imaging array to identify regions suspicious for PCa in 29 patients being treated with radical prostatectomies for biopsy-confirmed PCa. Whole-mount histopathology analyses were performed to identify regions of clinically significant/insignificant PCa lesions, atrophy and benign prostatic hyperplasia. Regions of suspicion for PCa were reader-identified in ARFI images based on boundary delineation, contrast, texture and location. These regions of suspicion were compared with histopathology identified lesions using a nearest-neighbor regional localization approach. Of all clinically significant lesions identified on histopathology, 71.4% were also identified using ARFI imaging, including 79.3% of posterior and 33.3% of anterior lesions. Among the ARFI-identified lesions, 79.3% corresponded to clinically significant PCa lesions, with these lesions having higher indices of suspicion than clinically insignificant PCa. ARFI imaging had greater sensitivity for posterior versus anterior lesions because of greater displacement signal-to-noise ratio and finer spatial sampling. Atrophy and benign prostatic hyperplasia can cause appreciable prostate anatomy distortion and heterogeneity that confounds ARFI PCa lesion identification; however, in general, ARFI regions of suspicion did not coincide with these benign pathologies.

High-grade prostatic adenocarcinoma present in a single biopsy core is associated with increased extraprostatic extension, seminal vesicle invasion, and positive surgical margins at prostatectomy

OBJECTIVE

To evaluate the pathologic outcome of prostate-specific antigen-screened patients with high-grade (Gleason score ≥ 8) prostate cancer limited to 1 biopsy core, without clinical evidence of disease.

METHODS

Ninety-two patients with only 1 biopsy core with cancer and treated by radical prostatectomy were divided into 4 groups according to the biopsy Gleason score: 3 + 3 = 6 (23 cases), 3 + 4 = 7 (25 cases), 4 + 3 = 7 (20 cases), and ≥ 8 (24 cases).

RESULTS

Cases with Gleason score ≥ 8 showed a significantly higher proportion of extraprostatic extension (50%), positive surgical margins (21%), and seminal vesicle invasion (12%) when compared with the other groups. Patients with Gleason score ≥ 8 in the biopsy had a 25-fold increased in the odds ratio for extraprostatic extension in the prostatectomy. The incidence of extraprostatic extension was higher in those with prostatic cancer involving ≥ 50% of one core (88%) compared with cases involving <50% (32%).

CONCLUSION

In patients with prostate cancer limited to 1 biopsy core, the presence of Gleason score ≥ 8 significantly increased the incidence of extraprostatic extension, positive surgical margins, and seminal vesicle invasion. The odds ratio was substantially higher in patients with ≥ 50% of Gleason ≥ 8 in the biopsy core. These data might be taken into account for proper clinical management of this set of patients.

[Prostate cancer: Gleason scores correlation between biopsies and surgical gross specimen]

The Gleason score is a histopronostic criterion which gives an appraisal of prostate cancer aggressiveness and outcomes.

OBJECTIVE

The goal of this retrospective study was to assess the relationship between Gleason scores appreciated on biopsies and later on surgical gross specimen.

RESULTS

During the period of the study, 123 patients benefit of a histological diagnosis of prostate cancer recording Gleason score on biopsies and postsurgical intervention on gross specimen. After analysis of biopsies and for gross specimen the reported Gleason scores vary from 3 to 9 and the mean was 5.9 and 6.1 respectively. There was a good concordance between the Gleason scores for biopsies and gross specimen in about 32.5% of cases. We noted a difference of score of one point in 37.3% of patients and a difference of two points and more in 30% of cases. In 28.4% the Gleason scores were overestimated while in 39% they were underestimated. More than half of the patients' cohort was classified in the group of histologically moderately differentiated cancer. When grouping the patients according to the histological types well, moderately or less differentiated cancers, the Gleason scores concordance for biopsies and for gross specimen change from 32.5% up to 74.8%. The correlation can be considered good for the less differentiated cancers.

CONCLUSION

Gleason score showed some limits in the appreciation of the prediction. The grouping of patients according to the three distinct histological differentiation groups increases the concordance between the score of Gleason on biopsy specimen and gross specimen but it seems less powerful for cancers well and moderately differentiated cancers.

Factors associated with downgrading in patients with high grade prostate cancer

OBJECTIVE

To determine the factors associated with downgrading between biopsy and prostatectomy in the contemporary era using extended-template biopsy techniques.

MATERIALS AND METHODS

The UCSF Urologic Oncology Database was used to identify subjects diagnosed with high grade prostate cancer (primary pattern 4 or 5) in at least one core on extended-pattern biopsy. Multivariable logistic regression analysis was performed to identify independent factors associated with downgrading at radical prostatectomy, defined as a change from primary pattern 4 or 5 to primary pattern 3.

RESULTS

Downgrading occurred in 68 (34%) of 202 subjects who met the study criteria. Fourteen (47%) of 30 subjects with ≤25% of cores that were high grade and 9 (43%) of 21 subjects with <10% of total tissue containing cancer were downgraded. In a multivariable model, patients with mixed grade cores had much higher odds of downgrading than those with all high grade cores (OR 3.0 95% 1.3-7.1), P < 0.01). The proportion (per 10% increment) of positive cores containing high grade cancer (OR 0.8 95% CI 0.7-0.9 P < 0.01) and the percent (per 10% increment) of total tissue containing cancer (OR 0.7 95% CI 0.6-0.9 P = 0.01) were significantly associated with lower odds of downgrading.

CONCLUSIONS

Downgrading following radical prostatectomy is a common event. Biopsy over-grading may preclude men from active surveillance or lead to unnecessary lymphadenectomy, excess radiation, or prolonged hormone therapy. The proportion of positive biopsy cores that are high grade and the percent of total tissue containing cancer should be incorporated into decision making.

Tumour growth fraction measured by immunohistochemical staining of Ki67 is an independent prognostic factor in preoperative prostate biopsies with small-volume or low-grade prostate cancer

Accurate prognostic parameters in prostate biopsies are needed to better counsel individual patients with prostate cancer. We evaluated the prognostic impact of morphologic and immunohistochemical parameters in preoperative prostate cancer biopsies. A consecutive series of prostate biopsies of 279 men (72% with clinical stage T1c and 23% with T2) who subsequently underwent radical prostatectomy was prospectively analysed for Gleason score, number and percentage of positive cores (NPC, PPC), total percentage of biopsy tissue with tumour (TPT), maximum tumour percentage per core (MTP), and expression of Ki67, Bcl-2 and p53. All biopsy features were significantly associated with at least one feature of the radical prostatectomy specimen. pT stage was independently predicted by PSA, seminal vesicle invasion by Ki67 LI, positive margins by PSA and MTP, large tumour diameter by PSA and PPC, and Gleason score by biopsy Gleason score, MTP, and Ki67 LI, respectively. Biopsy Gleason score, NPC (1 vs. >1), TPT (<7 vs. >or=7%), and Ki67 LI (<10 vs. >or=10%) were significant predictors of biochemical recurrence after radical prostatectomy (p < 0.01, each). KI67 LI was the only independent prognostic factor in case of a low TPT (<7%) or low Gleason score (<7), the hazard ratio being 6.76 and 6.44, respectively. In summary, preoperative Gleason score, NPC, TPT and Ki67 LI significantly predict the risk of recurrence after radical prostatectomy, and Ki67 is an independent prognosticator in biopsies with low-volume or low-grade prostate cancer. Analysis of Ki67 LI in these biopsies may help to better identify patients with clinically insignificant prostate cancer.

Prognostic and predictive factors and reporting of prostate carcinoma in prostate needle biopsy specimens

The information provided in the surgical pathology report of a prostate needle biopsy of carcinoma has become critical in the subsequent management and prognostication of the cancer. The surgical pathology report should thus be comprehensive and yet succinct in providing relevant information consistently to urologists, radiation oncologists and oncologists and, thereby, to the patient. This paper reflects the current recommendations of the 2004 World Health Organization-sponsored International Consultation, which was co-sponsored by the College of American Pathologists. It builds on the existing work of several organizations, including the College of American Pathologists, the Association of Directors of Anatomic and Surgical Pathologists, the Royal Society of Pathologists, the European Society of Urologic Pathology and the European Randomized Study of Screening for Prostate Cancer.

Preoperative prediction of Gleason grade in radical prostatectomy specimens: the influence of different Gleason grades from multiple positive biopsy sites

The Gleason score of prostate adenocarcinomas is an important preoperative predictor of cancer behavior, and is used to help guide treatment. In the setting of more than two positive biopsy sites, pathologists usually grade the tumor at each site separately, and the Gleason score may differ from each positive site. This study seeks to determine if the highest Gleason score in all biopsy sites, or the Gleason score in the site with the highest tumor volume on the needle biopsy is the best predictor of final Gleason score in the radical prostatectomy specimens. Various preoperative biopsy findings were analyzed. All 151 patients had at least two positive biopsy sites and underwent radical prostatectomy. Primary and secondary Gleason pattern grades were assigned for each positive biopsy site. The tumor volume in the needle biopsy site was defined by the percentage of areas of biopsy cores involved by cancer. The radical prostatectomy specimens were completely embedded and processed in the whole-mount method. The Gleason score from both the biopsy site with the highest Gleason score and the biopsy site with the highest tumor volume on the needle biopsy correlated equally well with final Gleason score at radical prostatectomy (Spearman correlation coefficient =0.54 for both, P<0.001). The Gleason score from both the biopsy site with the highest Gleason score and the biopsy site with the highest tumor volume on the needle biopsy also correlated with primary Gleason pattern grade at radical prostatectomy (Spearman correlation coefficient =0.53 for both, P<0.001). Secondary Gleason pattern grade from the biopsy site with the highest tumor volume on the needle biopsy correlated with secondary Gleason pattern grade at radical prostatectomy slightly better than those from the biopsy site with the highest Gleason score (Spearman correlation coefficient, 0.32 vs 0.24; both P<0.001). Our data indicate that the highest Gleason score from all sites and the Gleason score from the site with the highest tumor volume on the needle biopsy are equally and significantly predictive of final Gleason score on radical prostatectomy. Both methods of prediction are significantly predictive of primary and secondary Gleason pattern grade on radical prostatectomy. We recommend that the highest Gleason score from all positive biopsy sites should be used when assigning an initial score using needle biopsies.

WITHDRAWN:Epidemiology of prostate cancer and its precursors

Ahead of Print article withdrawn by publisher.

Do older men benefit from curative therapy of localized prostate cancer?

PURPOSE

Prior decision-analytic models are based on outdated or suboptimal efficacy, patient preference, and comorbidity data. We estimated life expectancy (LE) and quality-adjusted life expectancy (QALE) associated with available treatments for localized prostate cancer in men aged >/= 65 years, adjusting for Gleason score, patient preferences, and comorbidity.

METHODS

We evaluated three treatments, using a decision-analytic Markov model: radical prostatectomy (RP), external beam radiotherapy (EBRT), and watchful waiting (WW). Rates of treatment complications and pretreatment incontinence and impotence were derived from published studies. We estimated treatment efficacy using three data sources: cancer registry cohort data, pooled case series, and modern radiotherapy studies. Utilities were obtained from 141 prostate cancer patients and from published studies.

RESULTS

For men with well-differentiated tumors and few comorbidities, potentially curative therapy (RP or EBRT) prolonged LE up to age 75 years but did not improve QALE at any age. For moderately differentiated cancers, potentially curative therapy resulted in LE and QALE gains up to age 75 years. For poorly differentiated disease, potentially curative therapy resulted in LE and QALE gains up to age 80 years. Benefits of potentially curative therapy were restricted to men with no worse than mild comorbidity. When cohort and pooled case series data were used, RP was preferred over EBRT in all groups but was comparable to modern radiotherapy.

CONCLUSION

Potentially curative therapy results in significantly improved LE and QALE for older men with few comorbidities and moderately or poorly differentiated localized prostate cancer. Age should not be a barrier to treatment in this group.

Pathologic features the urologist should expect on a prostate biopsy

In recent years, the pathological evaluation of prostate biopsy specimens has made great improvements in diagnostic accuracy and comprehensiveness. In this article, we review major pathological findings on prostate biopsy, their interpretation and reporting, as well as their clinical significance and utility. We discuss especially the clinically relevant histological features in either a positive or negative biopsy. We emphasize that both Gleason score and extent of cancer involvement in a needle core biopsy are important predictors of clinical outcome after either radical prostatectomy or radiation. Special issues regarding diagnosis and grading of minimal cancer on needle core biopsies are discussed. We also highlight the current standards on high-grade prostatic intraepithelial neoplasia and atypical small acinar proliferation on needle core biopsies. In summary, the pathology reports on needle biopsies are far beyond the simple presence or absence of cancer; they contain invaluable information to clinicians on patient management and counseling.

Morphological assessment of radical prostatectomy specimens. A protocol with clinical relevance

The increase in prostate cancer detection has induced a sharp increase in the number of radical prostatectomies Proper examination of radical prostatectomy (RP) specimens by pathologists is critical in determining the need for adjuvant treatment and prediction of patient outcome. The pathology report should include relevant clinical information as well as provide prognostically useful information derived from the macroscopic examination and microscopic evaluation of the RP specimen

Diagnostic accuracy of prostate needle biopsy

The introduction of prostate-specific antigen screening has resulted in stage migration and an increased incidence of localized prostate cancer. In this era of increasing nonpalpable disease, it has become necessary to systematically sample the entire prostate gland. Transrectal ultrasound-guided prostate biopsy procedures have evolved greatly over the past decade from the original sextant biopsy. Technological advances, better understanding of zonal anatomy of the prostate, whole mount sectioning of radical prostatectomy specimens, and computer modeling of localized prostate cancers have all led to extended biopsy core protocols directed at the lateral zones of the gland. These have increased the diagnostic accuracy of needle biopsy and have become a standard regimen. However, it remains controversial how to proceed with repeat biopsy in the face of an initial benign diagnosis, and optimal biopsy strategy remains undefined. It is hoped that quantitative analysis of prostate biopsy histology may eventually provide some prognostic information to guide the patient and urologist in preoperative planning.

Free/total PSA ratio does not improve prediction of pathologic stage and biochemical recurrence after radical prostatectomy

OBJECTIVES

Despite several publications, the ability of the free/total (F/T) prostate-specific antigen (PSA) ratio to predict the pathologic extension of prostate cancer is still a matter of controversy. In addition, its ability to predict biochemical recurrence after radical prostatectomy has not yet been reported.

METHODS

Since January 6, 1996, the F/T PSA ratio was prospectively measured preoperatively in 343 patients undergoing radical prostatectomy as the first treatment for localized prostate cancer.

RESULTS

The ability to predict organ-confined disease was measured by receiver operating characteristic analysis. The areas under the curve were 0.66 for PSA density, 0.61 for total PSA, 0.60 for Gleason score, and 0.587 for the F/T PSA ratio. In multiple logistic regression analyses, the F/T PSA ratio was not a relevant predictor of organ-confined disease (Wald statistic 0.345 for P = 0.55). Similar results were obtained in the subgroup of patients with a PSA level between 2.5 and 10 ng/mL. The biochemical survival for the 270 patients who did not receive adjuvant therapy was 86% at 61 months. Statistically significant univariate predictors (P <0.05) of PSA recurrence were pT stage (log-rank 18.2) and Gleason grade (log-rank 8.8). The F/T PSA ratio was not a significant predictor of recurrence in the univariate analysis (log-rank 3.6 for P = 0.314) and in multivariate analysis (Wald statistic 0.2 for P = 0.97).

CONCLUSIONS

These results suggest that the F/T PSA ratio is not helpful for the prediction of organ-confined disease and PSA recurrence after radical prostatectomy.

Indicators of pathologic stage of prostate cancer and their use in clinical practice

Pathologic stage is the most reliable means of predicting the likelihood of curable prostate cancer at the time of definitive treatment. Its prediction is of the greatest importance to individuals with clinically localized disease, principally because of the therapeutic and prognostic implications. Multivariate models integrating variables that can be derived from clinical and pathologic assessment have been shown to be reliable and useful in urologic practice. Among these variables, the combination of clinical stage, serum PSA, and biopsy Gleason score provides reliable assessment of the risk for extraprostatic disease that can be used readily for counseling individual patients. Other biopsy-derived parameters may contribute additional information, but their value in multivariate analysis has not been validated in a multi-institutional setting. The development of new prognostic markers is a priority objective in current research to distinguish patients in whom cancer cannot be controlled by surgical treatment. For patients undergoing radical prostatectomy, definitive pathologic stage certainly will remain an important prognostic factor; therefore, clinical practice will continue to be determined by its accurate prediction.

Minimal adenocarcinoma in prostate needle biopsy tissue

One of the major diagnostic challenges in prostate needle biopsy interpretation is definitive establishment of a malignant diagnosis based on a minimal or limited amount of carcinoma in needle biopsy tissue. Major and minor diagnostic criteria should be used for interpretation of small foci of carcinoma. The constellation of findings and a combination of the major and minor diagnostic criteria permit a definitive diagnosis of focal adenocarcinoma. The differential diagnosis of minimal prostatic adenocarcinoma in needle biopsy tissue is broad and includes many benign lesions. The benign entities most likelty to be misdiagnosed as minimal prostatic adenocarcinoma are atypical adenomatous hyperplasia (adenosis) and atrophy. High-grade prostatic intraepithelial neoplasia and a descriptive diagnosis of focal glandular atypia or atypical small acinar proliferation also should be considered before diagnosing minimal adenocarcinoma. The most valuable adjunctive study for the diagnosis of minimal adenocarcinoma is immunohistochemistry using antibody 34 beta E12, reactive against basal cell-specific high-molecular-weight cytokeratins. Most cases can be diagnosed based on H&E-stained sections without this immunostain. Most minimal carcinomas in prostate needle biopsy tissue are of intermediate histologic grade, and most are indicative of pathologically significant carcinoma in the whole prostate gland.