Recent trends in Gleason grading of prostate cancer: I. Pattern interpretation

Histologic grading remains the most useful tissue-based predictor of prognosis of prostate cancer. The Gleason system is now the only grading system recommended by the World Health Organization (WHO) for prostatic carcinoma. In recent years, there has been a gradual shift of how the Gleason grading is applied in practice. There has been a general trend toward upgrading of prostate cancer. A consensus conference was organized in 2005 by the International Society of Urological Pathology with the purpose to standardize both the perception of histologic patterns and how grade information is compiled and reported. The recommendations regarding pattern interpretation are summarized and discussed in this review.     

Gleason grading of prostate carcinoma in needle biopsies vs. radical prostatectomy specimens

The Gleason grading system for prostatic carcinoma is the dominant method used around the world in research and in daily practice. It is based on glandular architecture. The grading system should be applied to all prostatic tissue samples, including needle core biopsies and radical prostatectomy specimens. Its prognostic value was tested in a large population with long-term follow-up that included use of survival as an end point. The Gleason grading system shows a reasonable degree of correlation between biopsy and radical prostatectomy specimens. Several sources of discrepancy between these 2 types of specimen have been identified. Further educational endeavors are needed to arrive at a greater consensus and accuracy in the use of the Gleason system.     

Correlation of modified Gleason grading of prostate carcinoma with age, serum prostate specific antigen and tumor extent in needle biopsy specimens

OBJECTIVE: To investigate the correlation of biopsy grade with age, serum prostate specific antigen (PSA) and biopsy tumor extent using the conventional and modified Gleason grading systems. STUDY DESIGN: A total of 828 consecutive needle biopsy specimens of prostate carcinoma were collected from the years 1995 and 2000 (graded with conventional Gleason grading) and 2006 and 2007 (graded with modified Gleason grading). RESULTS: Both conventional and modified Gleason grading correlated with age, serum PSA, percent positive biopsies and percent cancer length. In 2006-2007, the patients were on average younger and more biopsy cores were taken per patient. Serum PSA and percent positive cores were lower than in the 1995 and 2000 group, indicating a stage shift downward, but the Gleason scores were nevertheless higher. CONCLUSION: Conventional and modified Gleason grading both correlated with age, serum PSA and cancer involvement in needle biopsies. With modified Gleason grading there is a grade shift upward despite the downstaging that has been observed in recent years.     

Operator Dependent Choice of Prostate Cancer Biopsy Has Limited Impact on a Gene Signature Analysis for the Highly Expressed Genes IGFBP3 and F3 in Prostate Cancer Epithelial Cells

Background

Predicting the prognosis of prostate cancer disease through gene expression analysis is receiving increasing interest. In many cases, such analyses are based on formalin-fixed, paraffin embedded (FFPE) core needle biopsy material on which Gleason grading for diagnosis has been conducted. Since each patient typically has multiple biopsy samples, and since Gleason grading is an operator dependent procedure known to be difficult, the impact of the operator''s choice of biopsy was evaluated.

Methods

Multiple biopsy samples from 43 patients were evaluated using a previously reported gene signature of IGFBP3, F3 and VGLL3 with potential prognostic value in estimating overall survival at diagnosis of prostate cancer. A four multiplex one-step qRT-PCR test kit, designed and optimized for measuring the signature in FFPE core needle biopsy samples was used. Concordance of gene expression levels between primary and secondary Gleason tumor patterns, as well as benign tissue specimens, was analyzed.

Results

The gene expression levels of IGFBP3 and F3 in prostate cancer epithelial cell-containing tissue representing the primary and secondary Gleason patterns were high and consistent, while the low expressed VGLL3 showed more variation in its expression levels.

Conclusion

The assessment of IGFBP3 and F3 gene expression levels in prostate cancer tissue is independent of Gleason patterns, meaning that the impact of operator''s choice of biopsy is low.     

Value of the cribriformity factor in grading prostatic carcinoma.

Architectural and histometric features for the objective grading of prostate adenocarcinoma in histologic specimens were analyzed in five cases each of Gleason primary grades 2, 3A, 3B, 3C, 4A and 4B, selected as "typical" for the histopathologic images. Tissue sections from the selected cases were stained by the Feulgen method. Fifteen fields for each grade, for a total of 4,430 glands, were digitized by a video-based microphotometer at low resolution (pixel spacing of 2 microns). Outer and inner outlines of the glandular epithelium were traced manually using a mouse. For each field the number of glands, the gland area, the lumen area, the area of the glandular epithelium and the cribriformity factor were computed. The gland area and its variance proved to be useful indicators for lower-grade lesions, whereas the variance of cribriformity resulted in an excellent grading indicator in the Gleason 3-4 range when cribriform glands were present.     

Clinical Validation of the 2005 ISUP Gleason Grading System in a Cohort of Intermediate and High Risk Men Undergoing Radical Prostatectomy

In 2005, the International Society of Urological Pathology (ISUP) introduced several modifications to the original Gleason system that were intended to enhance the prognostic power of Gleason score (GS). The objective of this study was to clinically validate the 2005 ISUP Gleason grading system for its ability to detect metastasis. We queried our institutional RP database for men with NCCN clinically localized intermediate to high-risk disease undergoing radical prostatectomy (RP) between 1992 and 2010 with no additional treatment until the time of metastatic progression. A case-cohort design was utilized. A total of 333 available RP samples were re-reviewed and GS was reassigned per the 2005 ISUP Gleason system. Cumulative incidence of metastasis was 0%, 8.4%, 24.5% and 44.4% among specimens that were downgraded, unchanged, had one point GS increase and two point GS increase, respectively. The hazard ratio for metastasis raised in GS 8 and 9 compared to GS 7 from 2.77 and 5.91 to 3.49 and 9.31, respectively. The survival c-index of GS increased from 0.70 to 0.80 when samples were re-graded at 5 years post RP. The c-index of the reassigned GS was higher than the original GS (0.77 vs 0.64) for predicting PCSM at 10 years post RP. The regraded GS improved the prediction of metastasis and PCSM. This validates the updated Gleason grading system using an unambiguous clinical endpoint and highlights the need for reassignment of Gleason grading according to 2005 ISUP system when considering comparisons of novel biomarkers to clinicopathological variables in archival cohorts.     

Epithelium segmentation and automated Gleason grading of prostate cancer via deep learning in label‐free multiphoton microscopic images

In the current clinical care practice, Gleason grading system is one of the most powerful prognostic predictors for prostate cancer (PCa). The grading system is based on the architectural pattern of cancerous epithelium in histological images. However, the standard procedure of histological examination often involves complicated tissue fixation and staining, which are time‐consuming and may delay the diagnosis and surgery. In this study, label‐free multiphoton microscopy (MPM) was used to acquire subcellular‐resolution images of unstained prostate tissues. Then, a deep learning architecture (U‐net) was introduced for epithelium segmentation of prostate tissues in MPM images. The obtained segmentation results were then merged with the original MPM images to train a classification network (AlexNet) for automated Gleason grading. The developed method achieved an overall pixel accuracy of 92.3% with a mean F1 score of 0.839 for epithelium segmentation. By merging the segmentation results with the MPM images, the accuracy of Gleason grading was improved from 72.42% to 81.13% in hold‐out test set. Our results suggest that MPM in combination with deep learning holds the potential to be used as a fast and powerful clinical tool for PCa diagnosis.     

Biomarker discovery in microarray gene expression data with Gaussian processes

MOTIVATION: In clinical practice, pathological phenotypes are often labelled with ordinal scales rather than binary, e.g. the Gleason grading system for tumour cell differentiation. However, in the literature of microarray analysis, these ordinal labels have been rarely treated in a principled way. This paper describes a gene selection algorithm based on Gaussian processes to discover consistent gene expression patterns associated with ordinal clinical phenotypes. The technique of automatic relevance determination is applied to represent the significance level of the genes in a Bayesian inference framework. RESULTS: The usefulness of the proposed algorithm for ordinal labels is demonstrated by the gene expression signature associated with the Gleason score for prostate cancer data. Our results demonstrate how multi-gene markers that may be initially developed with a diagnostic or prognostic application in mind are also useful as an investigative tool to reveal associations between specific molecular and cellular events and features of tumour physiology. Our algorithm can also be applied to microarray data with binary labels with results comparable to other methods in the literature.     

Correlation of modified Gleason grading with pT stage of prostatic carcinoma after radical prostatectomy

OBJECTIVE: To study the correlation between modified Gleason score (GS) and pT stage of radical prostatectomy (RP) specimens. STUDY DESIGN: Six hundred forty-nine consecutive RP specimens were graded according to the conventional and the modified Gleason grading systems. RESULTS: A total of 29% of the tumors were upgraded. Both variants of GS correlated with pathologic stage. Stage pT2 tumors were assigned a GS of 3-6 less often with modified grading than with conventional grading (29% and 84%, respectively). The only significant difference of stage distribution between conventional and modified GS was for GS 7, where pT2 was the most common stage with modified grading (54%) and pT3 was most common with conventional grading (67%). Of GS 3 + 4 = 7a tumors, 95% were stage pT2, while 79% of GS 4 + 3 = 7b tumors were stage pT3-4. CONCLUSION: The stage distribution of modified GSs of RP specimens differs from that of conventional GSs, but a good correlation exists between grade and pT stage. Notably, GS 4 + 3 = 7b was more often associated with high stage than was GS 3 + 4 = 7a.     

Monitoring response, prediction methodology, staging, and imaging in prostate cancer

The predictive values of various tests and examinations are assessed as they relate to prostate cancer progression and treatment. The usefulness of post-treatment biopsy specimens is greatest 2 years after radiation therapy completion. Gleason grading is not reliable in the setting of hormonal ablation therapy. For patients with extracapsular extension, the survival curves separate depending on whether positive or negative surgical margins are obtained. Prostate-specific antigen doubling time is increasingly used as an indicator of disease recurrence after local therapy and prostate cancer-specific survival.     

A letter from Dr. Gleason

Henry A. Gleason, one of America’s first ecologists, writes about the beginnings of the science in the United States and how his concepts developed in the setting of Clements’ and Cowles’ ideas of vegetation and succession and how he came up with his individualistic concept of the plant association.     

Adenocarcinoma of the prostate in perspective.

Adenocarcinoma of the prostate is responsible for one of every nine deaths from cancer in Canada. In this review epidemiologic factors are considered and current staging systems are outlined. The American Urological System is recommended for staging because of its ability to reflect changes in the understanding of the biologic behaviour of this neoplasm. The adoption of a quantitative grading scheme is suggested to complement the information obtained from the staging assessment. The routes of spread of this disease, along with the procedures used to assess metastatic involvement, are described. Immunologic methods for the analysis of prostatic acid phosphatase have been shown to be superior to the enzymatic methods previously used, and the role of the new techniques is discussed. Emphasis is placed on radiotherapy and endocrine therapy for the treatment of this neoplasm, and the concept of withholding endocrine therapy until symptoms appear is discussed. Potential future developments in this field are considered.     

青龙河底栖无脊椎动物群落结构及其水质评价

本文论述了青龙河底栖生物种类、数量、分布和结构等特点及其与环境因子间的关系。应用Beck、Gleason、Shannon、Simpson等生物指数对水质状况进行评价。结果表明青龙河除个别断面受污染外,大部分河段属尚清洁水。     

通往风景园林行业的BIM之路——数字化竖向设计教育

随着全球建造业向数字化全面转型,建筑信息模型（BIM)的教学将是未来几年风景园林设计与实施的重要主题。介绍了风景园林专业BIM的教学方法和数字化竖向设计及其应用在BIM场地设计项目中的重要性。数字化竖向设计是实现BIM的途径。风景园林教育必须在其教学中讲解BIM建模方法和过程。     

Third trimester placental grading by ultrasonography as a test of fetal wellbeing.

In a study of 2000 unselected pregnant women the development of a mature placental appearance (grade 3) on ultrasonography by 34-36 weeks'' gestation, observed in 15% of cases, was associated with maternal smoking, low parity, low maternal age, and being white. These women had an increased risk of problems during labour and their babies had an increased risk of low birth weight, poor condition at birth, and perinatal death. The women were randomly allocated to two groups: in one group the result of the placental grading was reported to the clinician responsible for care; in the second the result was noted but not reported. There was a significant decrease in the risk of perinatal death in the group where the grading was known. This reduction was responsible for a difference in the principal outcome index, a heterogeneous group of measures of mortality and morbidity, but this difference was not significant. This study alone does not justify routine late scanning, and further, larger trials are required. Nevertheless, the results do provide a basis for the reporting of placental grading when ultrasound examination is performed during the third trimester.     

922. LINDERA OBTUSILOBA

Lindera obtusiloba Blume is illustrated. Its distribution in China, Japan and Korea is reported. The synonyms are listed and discussed. Instructions for its cultivation are given.     

Urinary tract morphometry. An overview

An overview is presented of the application of morphometry to conditions in the urinary tract, with the work of a number of researchers briefly summarized. The data discussed show that morphometric techniques are already being successfully applied in the differential diagnosis and grading of some diseases of the prostate, urinary bladder and kidney. In the prostate, nonneoplastic changes can be differentiated from neoplasms and prostatic carcinomas can be more precisely graded. Both cytologic and histologic preparations of bladder carcinomas can be graded by morphometric techniques. Morphometry has found another application in assisting in the distinction between normal kidneys and those with "minimal-change" disease. The specific criteria pertaining to the use of morphometric methods in each of these situations are also discussed.     

Method and metaphysics in Clements's and Gleason's ecological explanations

To generate explanatory theory, ecologists must wrestle with how to represent the extremely many, diverse causes behind phenomena in their domain. Early twentieth-century plant ecologists Frederic E. Clements and Henry A. Gleason provide a textbook example of different approaches to explaining vegetation, with Clements allegedly committed, despite abundant exceptions, to a law of vegetation, and Gleason denying the law in favor of less organized phenomena. However, examining Clements's approach to explanation reveals him not to be expressing a law, and instead to be developing an explanatory structure without laws, capable of progressively integrating causal complexity. Moreover, Clements and Gleason largely agree on the causes of vegetation; but, since causal understanding here underdetermines representation, they differ on how to integrate recognized causes into general theory--that is, in their methodologies. Observers of the case may have mistakenly assumed that scientific representation across the disciplines typically aims at laws like Newton's, and that representations always reveal scientists' metaphysical commitments. Ironically, in the present case, this assumption seems to have been made even by observers who regard Clements as nai ve for his alleged commitment to an ecological law.     

Radiation therapy failure in prostate cancer patients: risk factors and methods of detection

Radiation therapy for clinically localized prostatic carcinoma remains one of the mainstays among therapeutic approaches; however, patients continue to fail radiation therapy at too high a rate. This article reviews the risk factors and methods of detection for prostate cancer recurrence. The relative merits of the three major pre-therapy prognostic indicators-TNM staging, Gleason score, and serum prostate-specific antigen (PSA) levels-are discussed. The use of staging and Gleason score, as well as digital rectal examination, transrectal ultrasound, and post-radiation prostate biopsies in detecting failure of radiation therapy is reviewed. Challenges relating to the use of serum PSA levels as an indicator of recurrence are examined. Finally, this article makes recommendations as to procedure for evaluating patients suspected of failing radiation therapy.