The Hunt for Lymph Nodes: Is Total Submission of Standard-Template and Extended-Template Pelvic Lymph Node Dissections Necessary for Detecting Metastatic Prostate Cancer?

CONTEXT.—

There are no consensus guidelines on submission of pelvic lymph node dissection (PLND) specimens for radical prostatectomies. Complete submission is only performed by a minority of laboratories. Our institution has been following this practice for standard-template and extended-template PLND.

OBJECTIVE.—

To investigate the utility of total submission of PLND specimens for prostate cancer and understand its impact on patients and the laboratory.

DESIGN.—

Retrospective study examining 733 cases of radical prostatectomies with PLND performed at our institution. Reports and slides with positive lymph nodes (LNs) were reviewed. Data on LN yield, cassette usage, and impact of submission of remaining fat after dissection of grossly identifiable LNs were assessed.

RESULTS.—

Most cases involved submission of extra cassettes for remaining fat (97.5%, n = 697 of 715). Extended PLND yielded a higher mean number of total and positive LNs versus standard PLND (P < .001). However, extended PLND required significantly more cassettes for remaining fat (mean, 8; range, 0-44). There was poor correlation between number of cassettes submitted for PLND with total and positive LN yield and between remaining fat with LN yield. Most positive LNs were grossly identified (88.5%, n = 139 of 157) and were typically larger than those not. Only 4 cases (0.6%, n = 4 of 697) would have been understaged without complete submission of PLND.

CONCLUSIONS.—

Total submission of PLND increases detection of metastasis and LN yield yet increases workload significantly with only minimal patient management impact. Hence, we recommend that meticulous gross identification and submission of all LNs be pursued without the need to submit the remaining fat of PLND.

Anterior or Posterior Prostate Cancer Tumor Nodule Location Predicts Likelihood of Certain Adverse Outcomes at Radical Prostatectomy

CONTEXT.—

Effect of tumor nodule (TN) location in the prostate on adverse radical prostatectomy (RP) outcomes is not well studied in contemporary cohort.

OBJECTIVE.—

To investigate the significance of TN location with respect to extraprostatic extension (EPE), seminal vesicle invasion (SV+), and positive margin status (SM+) in 1388 RPs.

DESIGN.—

Each TN at RP was independently graded, staged, and volumetrically assessed. TNs with at least 80% of their volume occupying either the anterior or posterior part of the prostate were categorized accordingly and included in our study, while all other TNs were excluded.

RESULTS.—

A total of 3570 separate TNs (median = 3 per RP; range = 1-7 per RP) were scored. There were 1320 of 3570 (37%) anterior TNs and 2250 of 3570 (63%) posterior TNs. Posterior TNs were more likely to be higher grade, and exhibit EPE (18% versus 9.4%) and SV+ (4% versus 0.15%), all P < .001. Anterior TNs with EPE were more likely to exhibit SM+ than posterior TNs with EPE (62% versus 30.8%, P < .001). TN location, grade, and volume were significant factors associated with adverse RP outcomes in our univariable analysis. When we controlled for grade and tumor volume in a multivariable analysis using anterior TN location as a reference, posterior TN location was an independent predictor of EPE and SV+ and was less likely to be associated with SM+ (odds ratio = 3.1, 81.5, and 0.7, respectively).

CONCLUSIONS.—

These associations may be useful in preoperative surgical planning, particularly with respect to improving radiographic analysis of prostate cancer.

Percentage of Gleason pattern 4 and tumor volume predict adverse pathological stage and margin status at radical prostatectomy in grade Group 2 and grade Group 3 prostate cancers

BACKGROUND

Increasing percentages of Gleason pattern 4 (GP4%) in radical prostatectomy (RP) correlate with an increased likelihood of nonorgan-confined disease and earlier biochemical recurrence (BCR). However, there are no detailed RP studies assessing the impact of GP4% and corresponding tumor volume (TV) on extraprostatic extension (EPE), seminal vesicle (SV) invasion (SV+), and positive surgical margin (SM) status (SM+).

METHODS

In 1301 consecutive RPs, we analyzed each tumor nodule (TN) for TV, Grade Group (GG), presence of focal versus nonfocal EPE, SV+ , and SM+. Using GG1 (GP4% = 0) TNs as a reference, we recorded GP4% for all GG2 or GG3 TNs. We performed a multivariable analysis (MVA) using a mixed effects logistic regression that tested significant variables for risk of EPE, SV+, and SM+, as well as a multinomial logistic regression model that tested significant variables for risks of nonorgan-confined disease (pT2+, pT3a, and pT3b) versus organ-confined disease (pT2).

RESULTS

We identified 3231 discrete TNs ranging from 1 to 7 (median: 2.5) per RP. These included GG1 (n = 2115), GG2 (n = 818), GG3 (n = 274), and GG4 (n = 24) TNs. Increasing GP4% weakly paralleled increasing TV (tau = 0.07, p < .001). In MVA, increasing GP4% and TV predicted a greater likelihood of EPE (odds ratio [OR]: 1.03 and 4.41), SV+ (OR: 1.03 and 3.83), and SM+ (1.01, p = .01 and 2.83), all p < .001. Our multinomial logistic regression model demonstrated an association between GP4% and the risk of EPE (i.e., pT3a and pT3b disease), as well as an association between TV and risk of upstaging (all p < .001).

CONCLUSIONS

Both GP4% and TV are independent predictors of adverse pathological stage and margin status at RP. However, the risks for adverse outcomes associated with GP4% are marginal, while those for TV are strong. The prognostic significance of GP4% on BCR-free survival has not been studied controlling for TV and other adverse RP findings. Whether adverse pathological stage and margin status associated with larger TV could decrease BCR-free survival to a greater extent than increasing RP GP4% remains to be studied.

Prognostic significance of histomorphologic features of lymph node metastases in prostate cancer patients treated with radical prostatectomy: A single center study

OBJECTIVE

We assessed the prognostic value of histomorphologic features of lymph node (LN) metastases in patients with prostate cancer treated with radical prostatectomy MATERIALS AND METHODS: We evaluated the effect of the features of LN metastasis on the risk of biochemical recurrence (BCR) in 280 LN-positive patients who underwent radical prostatectomy between 2006 to 2018. LN specific parameters recorded included number of metastatic LNs, size of the largest metastatic focus, Gleason Grade (GG) of the metastatic focus, and extranodal extension (ENE).

RESULTS

A solitary positive LN was found in 166/280 (59%), 95/280 (34%) patients had 2-4 positive LNs, and 19/280 (7%) had 5 or more positive LNs. The size of the largest metastatic focus > 2 mm (macrometastasis) in 154/261 (59%). GG of the metastatic focus was as follows: GG 1-2: 29/224 (13%); GG 3: 27/224 (12%); and GG 4-5: 168/224 (75%). ENE was identified in 99/244 (41%). We found the number of LNs positive (2-4 vs. 1 Hazard ratio (HR) = 1.60; 95% CI: 1.02 to 2.5; P = 0.04) and GG of the metastatic focus (GG 4&5 vs. 1-3 HR = 1.90; 95% CI: 1.14-3.2; P= 0.014) to be independent predictors of the risk of BCR after surgery on multivariate analysis.

CONCLUSIONS

Our study showed the number of LNs positive and GG of the LN metastatic focus to be significant independent predictors of BCR after radical prostatectomy. We recommend reporting histomorphologic parameters of LN metastasis as they may help in defining BCR risk categorization.

Prostatic Ductal Adenocarcinoma Controlled for Cancer Grade and Tumor Volume Does Not Have an Independent Effect on Adverse Radical Prostatectomy Outcomes Compared to Usual Acinar Prostatic Adenocarcinoma

OBJECTIVE

To study if prostatic ductal adenocarcinoma (PDA) controlled by Grade Group (GG), PSA, and tumor volume (TV) is an independent predictor of adverse radical prostatectomy (RP) outcomes.

MATERIALS

One-hundred and twenty-eight PDA and 1141 acinar continuous RPs were studied. Each tumor nodule (TN) was individually graded, staged, and its TV measured. Univariate analysis (UVA) identified features associated with lymph node metastasis (LN+), extraprostatic extension (EPE), positive surgical margins (SM+), and seminal vesicle invasion (SV+). We then assessed PDA effect on RP outcomes in a multivariate analysis (MVA).

RESULTS

In 127 cases PDA was present in 1 TN and no TN was pure PDA. One-hundred and twenty-three cases had PDA in TNs with highest grade, stage, and TV. Patients with PDA were older (65 vs 63 years, P < 0.001), had higher GG (P < 0.001), and LN+ (6.3% vs 2.7%, P = 0.049). Controlling these variables by GG eliminated statistical significance. Overall, there were 3249 separate TNs (129 PDA and 3120 acinar). In UVA, PDA predicted EPE (92/124 vs 517/3045), SV+ (28/1129 vs 116/3,120), and SM+ (51/129 vs 296/3120), all P < 0.001. In MVA, PDA lost its effect on EPE (OR = 0.88, P = 0.64), SM+ (OR = 0.86, P = 0.5), and SV+ (OR = 0.99, P = 0.98).

CONCLUSION

Controlled for grade and TV, PDA was not an independent predictor of adverse RP outcomes, but former 2 were. Hence, higher GG and TV associated with PDA TNs may be predictive of adverse RP outcomes rather than PDA by itself. These conclusions may be used in preoperative risk stratification and definitive therapy planning when PDA is identified on needle biopsy.

Optimal sampling of pelvic lymphadenectomy specimens following radical prostatectomy: is complete tissue submission justified?

There is currently no consensus among pathologists on the optimal method of sampling pelvic lympadenectomy specimens (PLND) in prostate cancer. We evaluated the impact of complete PLND submission on lymph node (LN) yield, detection of metastasis and laboratory workload in a series of 141 cases. Following isolation of grossly identifiable LNs/potential LNs, the remaining fatty tissue was embedded in toto. Complete PLND submission increased median LN yield from 10 (1–42) to 17 (3–57). Metastatic deposits were identified in nine non-palpable LNs, which altered the pN category in four cases (3%). The primary tumour (pT) was grade group ≥3 and/or pT3 at radical prostatectomy in 96% of pN+ cases. A median of seven additional blocks (1–28) was required for complete tissue embedding. Our findings indicate that submission of the entire fat can optimise PLND assessment but has a significant impact on laboratory workload. Complete submission of selected high-risk cases may be a reasonable alternative.

Handling and reporting of pelvic lymphadenectomy specimens in prostate and bladder cancer: a web-based survey by the European Network of Uropathology

AIMS

Pathological evaluation of lymphadenectomy specimens plays a pivotal role in accurate lymph node (LN) staging. Guidelines standardising the gross handling and reporting of pelvic LN dissection (PLND) in prostate (PCa) and bladder (BCa) cancer are currently lacking. This study aimed to establish current practice patterns of PLND evaluation among pathologists.

METHODS AND RESULTS

A web-based survey was circulated to all members of the European Network of Uropathology (ENUP), comprising 29 questions focusing on the macroscopic handling, LN enumeration and reporting of PLND in PCa and BCa. Two hundred and eighty responses were received from pathologists throughout 23 countries. Only LNs palpable at grossing were submitted by 58%, while 39% routinely embedded the entire specimen. Average LN yield from PLND was ≥10 LNs in 56% and <10 LNs in 44%. Serial section(s) and immunohistochemistry were routinely performed on LN blocks by 42% and <1% of respondents, respectively. To designate a LN microscopically, 91% required a capsule/subcapsular sinus. In pN+ cases, 72% reported the size of the largest metastatic deposit and 94% reported extranodal extension. Isolated tumour cells were interpreted as pN1 by 77%. Deposits identified in fat without associated lymphoid tissue were reported as tumour deposits (pN0) by 36% and replaced LNs (pN+) by 27%. LNs identified in periprostatic fat were included in the PLND LN count by 69%.

CONCLUSION

This study highlights variations in practice with respect to the gross sampling and microscopic evaluation of PLND in urological malignancies. A consensus protocol may provide a framework for more consistent and standardised reporting of PLND specimens.

Radical Prostatectomy Findings in White Hispanic/Latino Men With NCCN Very Low-risk Prostate Cancer Detected by Template Biopsy

Radical prostatectomy (RP) outcomes have been studied in White and Black non-Hispanic men qualifying for Epstein active surveillance criteria (EASC). Herein, we first analyzed such outcomes in White Hispanic men. We studied 70 men with nonpalpable Gleason score 3+3=6 (Grade Group [GG] 1) prostate cancer (PCa) with ≤2 positive cores on biopsy who underwent RP. In 18 men, prostate-specific antigen (PSA) density (PSAD) was >0.15 ng/mL/g. Three of these had insignificant and 15 had significant PCa. The remaining 52 men qualified for EASC. One patient had no PCa identified at RP. Nineteen (37%) had significant PCa defined by volume (n=7), grade (n=7), and volume and grade (n=5). Nine cases were 3+4=7 (GG 2) (5/9 [56%] with pattern 4 <5%), 2 were 3+5=8 (GG 4), and 1 was 4+5=9 (GG 5). Patients with significant PCa more commonly had anterior dominant disease (11/19, 58%) versus patients with insignificant cancer (7/33, 21%) (P=0.01). In 12 cases with higher grade at RP, the dominant tumor nodule was anterior in 6 (50%) and posterior in 6 (median volumes: 1.1 vs. 0.17 cm, respectively; P=0.01). PSA correlated poorly with tumor volume (r=0.28, P=0.049). Gland weight significantly correlated with PSA (r=0.54, P<0.001). While PSAD and PSA mass density correlated with tumor volume, only PSA mass density distinguished cases with significant disease (median, 0.008 vs. 0.012 μg/g; P=0.03). In summary, a PSAD threshold of 0.15 works well in predicting significant tumor volume in Hispanic men. EASC appear to perform better in White Hispanic men than previously reported outcomes for Black non-Hispanic and worse than in White non-Hispanic men. Significant disease is often Gleason score 3+3=6 (GG 1) PCa >0.5 cm. Significant PCa is either a larger-volume anterior disease that may be detected by multiparametric magnetic resonance imaging-targeted biopsy or anterior sampling of the prostate or higher-grade smaller-volume posterior disease that in most cases should not pose immediate harm and may be detected by repeat template biopsies.

Complete Tissue Submission to Increase Lymph Node Detection in Pelvic Lymph Node Packets Submitted for Patients Undergoing Radical Prostatectomy and Radical Cystectomy

BACKGROUND

Pelvic lymphadenectomy has prognostic and therapeutic implications in both bladder and prostate cancer. Pelvic lymphadenectomy specimens are fatty and identification of lymph nodes (LNs) can be difficult during the grossing process. We investigated the benefit of a new grossing method requiring entire LN packet submission.

MATERIALS/METHODS

We introduced a new grossing protocol requiring total submission of LN packets for patients undergoing radical prostatectomy (RP) or radical cystectomy (RC). A retrospective review was performed to evaluate clinical and pathologic data for RP (n = 59) and RC (n = 56) cases performed 18 months prior to and 18 months following implementation of the new lymphadenectomy grossing protocol.

RESULTS

For RP and RC cases, significantly more LNs were found when total LN packets were submitted with the new technique: mean 14.1 versus 8.7, and mean 25.2 versus 15.9, respectively ( P = .007, P = .011). For RP cases, there was no significant change in the number of LN packets submitted for evaluation from the operating room ( P = .76). For RC cases, more LNs were found with the new technique despite a significantly fewer number of LN packets sent from the operating room in the cohort that were processed with the new technique: mean 2.2 versus 4.0 LN packets ( P < .001). Significantly more paraffin blocks were required using the new grossing method for both RP and RC: mean 13.53 versus 6.9 and mean 19.0 versus 12.4, respectively ( P < .001, P = .018).

CONCLUSIONS

Submitting all additional fatty tissue after palpable identification of LNs can significantly increase the detection of LNs in RP and RC cases.