Discontinuous unilateral involvement of 12 part core biopsies by adenocarcinoma predicts bilateral involvement of subsequent radical prostatectomy

Standardization of reporting discontinuous tumor involvement in prostatic needle biopsy: a systematic review

Discontinuous tumor involvement (DTI) is a not uncommon finding in the tumor in prostate needle core biopsies undertaken for diagnosis of prostate cancer (PCa). The objective of this review is to establish a clear definition of DTI in order to provide a standardized method of measurement which reliably reflects pathologic features and disease progression following radical prostatectomy (RP). A systematic literature search was performed using PubMed up to March 2020 to identify studies of PCa patients which included needle biopsies containing DTI and matched subsequent RP treatment with or without follow-up information. The methodology and quality of reporting of DTI are reviewed, compared, and summarized. DTI is a frequent finding in diagnostic biopsy for PCa (up to 30%). Six studies were compared by methods of measurement used for predicting pathologic features and outcomes which are observed in subsequent RP. In most cases with DTI (> 90%), intervening benign tissue in the tumor core was less than 5 mm. DTI found in the biopsy was likely to be associated with a single, irregular tumor nodule going in and out of the plane of the section, but DTI was not associated with multiple small foci of the tumor. Immunohistochemistry (IHC) also demonstrated that about 75% of cases of DTI shared an IHC profile which supports the concept that DTI most likely comes from a homogeneous tumor nodule. Furthermore, DTI was associated with positive surgical margin (PSM) and bilateral tumor in RP specimens. Compared to additive measurement (with the subtraction of intervening benign tissue), linear measurement (including intervening benign tissue) of DTI was more accurately predictive of aggressive disease in the RP including higher pT stage, PSM, and greater actual extent of the tumor. However, the advantage of linear measurement was lost in cases where there was an upgrade from the biopsy to the RP which may result from undersampling. For cases with either very small tumor foci or very extensive cancer volume, no difference was observed in these two methods of measurement. DTI in core biopsies may represent undersampling of a larger irregular nodule but likely does not result from multifocality and is similarly unlikely to represent multiclonality. Linear measurement of DTI was more accurately predictive of post-RP pathologic findings and oncologic prognosis. This method should be applied for patient selection for AS.

Essential Updates in Grading, Morphotyping, Reporting, and Staging of Prostate Carcinoma for General Surgical Pathologists

CONTEXT.—

Within this decade, several important updates in prostate cancer have been presented through expert international consensus conferences and influential publications of tumor classification and staging.

OBJECTIVE.—

To present key updates in prostate carcinoma.

DATA SOURCES.—

The study comprised a review of literature and our experience from routine and consultation practices.

CONCLUSIONS.—

Grade groups, a compression of the Gleason system into clinically meaningful groups relevant in this era of active surveillance and multidisciplinary care management for prostate cancer, have been introduced. Refinements in the Gleason patterns notably result in the contemporarily defined Gleason score 6 cancers having a virtually indolent behavior. Grading of tertiary and minor higher-grade patterns in radical prostatectomy has been clarified. A new classification for prostatic neuroendocrine tumors has been promulgated, and intraductal, microcystic, and pleomorphic giant cell carcinomas have been officially recognized. Reporting the percentage of Gleason pattern 4 in Gleason score 7 cancers has been recommended, and data on the enhanced risk for worse prognosis of cribriform pattern are emerging. In reporting biopsies for active surveillance criteria-based protocols, we outline approaches in special situations, including variances in sampling or submission. The 8th American Joint Commission on Cancer TNM staging for prostate cancer has eliminated pT2 subcategorization and stresses the importance of nonanatomic factors in stage groupings and outcome prediction. As the clinical and pathology practices for prostate cancer continue to evolve, it is of utmost importance that surgical pathologists become fully aware of the new changes and challenges that impact their evaluation of prostatic specimens.

Continuous versus discontinuous tumor involvement: A dilemma in prostate biopsy quantitation

BACKGROUND

No consensus has been reached for an optimal method of quantifying discontinuous tumor foci separated by intervening benign tissue on prostate biopsy (PBx). We examined sets of PBx, where cancer involved only one core, and corresponding radical prostatectomy (RP) specimens.

METHODS AND RESULTS

Cases were divided into 3 groups-Group 1 (n = 80): <3 mm in end-to-end tumor measurement (continuous/discontinuous); Group 2 (n = 22): ≥3 mm in tumor length (continuous); and Group 3 (n = 15): ≥3 mm in end-to-end tumor measurement (discontinuous). The rate of Gleason score ≥7 was considerably lower in Group 1 (9%/30% on PBx/RP) than in Group 2 (50% [P < 0.001]/59% [P = 0.015] on PBx/RP) or Group 3 (40% [P = 0.005]/46% [P = 0.237] on PBx/RP). pT2 disease was significantly more often found in Group 1 (88%) than in Group 2 (68%, P = 0.049) or Group 3 (60%, P = 0.018). Surgical margin was significantly more often positive in Group 3 (27%) than in Group 1 (5%, P = 0.020), but not Group 2 (9%, P = 0.198). Moreover, estimated cancer volume (cc, mean ± SD) was significantly smaller in Group 1 (1.89 ± 1.98) than in Group 2 (3.56 ± 2.92, P = 0.026) or Group 3 (3.44 ± 2.02, P = 0.013). Kaplan-Meier analysis revealed higher risks of biochemical recurrence after RP in Group 2, compared with Group 1 (P = 0.001) or Group 3 (P = 0.096). In 93 patients with biopsy Gleason score 6 cancer, higher rates of pT2+/3 disease (P = 0.023) and positive margin (P = 0.026), as well as larger cancer volume (P = 0.063), on RP were still seen in Group 3, compared with Group 1, but their differences were not statistically significant between Group 2 and Group 3.

CONCLUSIONS

Linear quantitation including intervening benign tissue on PBx may more precisely predict the actual tumor extent.