From the Department of Pathology and Laboratory Medicine (Iakymenko, Briski, Nemov, Lugo, Jorda, Kryvenko), University of Miami Miller School of Medicine, Miami, Florida.
From the Desai Sethi Urology Institute (Punnen, Jorda, Parekh, Gonzalgo, Kryvenko), University of Miami Miller School of Medicine, Miami, Florida.
Arch Pathol Lab Med. 2022 Aug 1;146(8):1032-1036. doi: 10.5858/arpa.2021-0279-OA.
CONTEXT.—: Multifocal prostate cancer at radical prostatectomy (RP) may be graded with assessment of each individual tumor nodule (TN) or global grading of all TNs in aggregate.
OBJECTIVE.—: To assess case-level grade variability between these 2 grading approaches.
DESIGN.—: We reviewed 776 RPs with multifocal prostate cancer with 2 or more separate TNs of different Grade Groups (GGs). Two separate grades were assigned to each RP: one based on the TN with the highest grade and a global grade based on the Gleason pattern volumes for all TNs. We then compared the results of these 2 methods.
RESULTS.—: The case-level grade changed by 1 or more GGs between the 2 grading methods in 35% (132 of 374) of GG3 through GG5 cases. Twelve percent (37 of 309) of GG2 cases with Gleason pattern 4 of more than 5% based on individual TN grading decreased their Gleason pattern 4 to less than 5% based on the global approach. Minor tertiary pattern 5 (Gleason pattern 5 <5%) was observed in 6.8% (11 of 161) of GG4 (Gleason score 3 + 5 = 8 and 5 + 3 = 8) and GG5 cases with global grading. The risk of grade discrepancy between the 2 methods was associated with the highest-grade TN volume (inverse relationship), patient age, and number of TNs (P < .001, P = .003, and P < .001, respectively).
CONCLUSIONS.—: The global grading approach resulted in a lower grade in 35% of GG3 through GG5 cases compared with grading based on the highest-grade TN. Two significant risk factors for this discrepancy with a global grading approach occur when the highest-grade TN has a relatively small tumor volume and with a higher number of TNs per RP. The observed grade variability between the 2 grading schemes most likely limits the interchangeability of post-RP multi-institutional databases if those institutions use different grading approaches.
在根治性前列腺切除术（RP）中，多灶性前列腺癌可以通过评估每个单独的肿瘤结节（TN）或汇总所有 TN 的总体分级来分级。
评估这两种分级方法在病例水平上的分级变异性。
我们回顾了 776 例有 2 个或更多不同分级组（GG）的单独 TN 的多灶性前列腺癌 RP。每个 RP 分配了两个单独的等级：一个基于最高等级的 TN，另一个基于所有 TN 的 Gleason 模式体积的总体等级。然后，我们比较了这两种方法的结果。
在 GG3 到 GG5 的病例中，两种分级方法之间的病例水平等级变化了 1 个或更多 GG 的比例为 35%（132/374）。基于单个 TN 分级，12%（37/309）的 GG2 病例中 Gleason 模式 4 超过 5%的病例，根据总体方法，其 Gleason 模式 4 下降到低于 5%。在 GG4（Gleason 评分 3+5=8 和 5+3=8）和 GG5 的病例中，基于总体分级，有 6.8%（11/161）的次要三级模式 5（Gleason 模式 5<5%）。两种方法之间的分级差异的风险与最高等级 TN 体积（负相关）、患者年龄和 TN 数量相关（P<0.001、P=0.003 和 P<0.001）。
与基于最高等级 TN 的分级相比，总体分级方法导致 35%的 GG3 到 GG5 病例的分级降低。当最高等级 TN 的肿瘤体积相对较小且每例 RP 的 TN 数量较高时，采用总体分级方法会出现两种显著的差异风险因素。如果这些机构使用不同的分级方法，两种分级方案之间观察到的分级变异性很可能限制了 RP 后多机构数据库的可互换性。
