Differing risk of cancer death among patients with lymph node metastasis after radical prostatectomy and pelvic lymph node dissection: identification of risk categories according to number of positive nodes and Gleason score

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.

Unambiguous radiologic extranodal extension determined by MRI could be a biomarker in predicting metastatic prostate cancer

OBJECTIVE

To explore the relationship between unambiguous radiologic extranodal extension (rENE) and M1 staging in patients with metastatic PCa.

METHODS

A respective analysis of 1073 patients of PCa N1 staging from January 2004 to May 2022 was retrospectively enrolled. They were divided into rENE + and rENE -  groups and retrospectively analyzed the M staging with nuclear medicine data. The correlation index between unambiguous rENE and M1b staging was calculated. Logistic regression was used to evaluate the predictive performance of unambiguous rENE in M1b staging. ROC curves were used to investigate the relationship between unambiguous rENE and M staging in patients who underwent ⁶⁸ Ga-PSMA PET/CT.

RESULTS

A total of 1073 patients were included. Seven hundred and eighty patients were classified into the rENE + group (mean age, 69.6 years ± 8.7 [standard deviation]), and 293 were classified into rENE -  group (mean age, 66.7 years ± 9.4 [standard deviation]). Relationship between unambiguous rENE and M1b existed (r = 0.58, 95%CI: 0.52-0.64, P < 0.05). Unambiguous rENE could be an independent predictor for M1b (OR = 13.64, 95%CI: 9.23-20.14, P < 0.05). The AUC of unambiguous rENE in predicting M1b and M staging was 0.835 and 0.915, respectively, in patients who underwent ⁶⁸ Ga-PSMA PET/CT.

CONCLUSIONS

Unambiguous rENE could be a strong biomarker to predict M1b and M staging in patients with PCa. When rENE came up, patients should perform nuclear medicine immediately, and a systematic treatment should be considered.

Risk Factors for Pathologically Confirmed Lymph Nodes Metastasis in Patients With Clinical T2N0M0 Stage Prostate Cancer

Objective

To explore the risk factors for postoperatively pathological lymph node metastasis in patients with clinical T2N0M0 stage prostate cancer (PCa).

Methods

We retrospectively analyzed clinicopathological data of 316 patients with clinical T2 stage PCa and preoperative negative lymph nodes [LN(−)] indicated by imaging (cT2N0M0) between January 2014 and May 2019. Multivariate logistic regression analysis was performed to determine risk factors for postoperatively pathological pLN(+) in patients with cT2N0M0 stage PCa. Spearman correlation analysis was used to explore the relationship between tumor burden and Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) score.

Results

A total of 45 patients (14.2%) were confirmed by postoperative pathology to have LN metastasis. Univariate analysis indicated that total prostate-specific antigen (tPSA), PI-RADS v2 score, postoperative Gleason grade group (GGG), intraductal carcinoma of the prostate (IDC-P), clinical T2 substaging, and postoperative pathological tumor burden were risk factors for pLN(+) in all patients. Multivariate analysis showed that tPSA and postoperative GGG were risk factors for pLN(+) in all patients. Univariate analysis revealed that tPSA, PIRADS v2 score, clinical T2 substaging, IDC-P, postoperative pathological tumor burden, and postoperative GGG were risk factors for pLN(+) in patients with GGG ≥ 3. Multivariate analysis suggested that tPSA, PI-RADS v2 score, clinical T2 substaging, postoperative pathological tumor burden, and GGG were risk factors for pLN (+) in patients with GGG ≥ 3. Spearman correlation analysis showed that PI-RADS v2 score was positively correlated with clinical T2 substaging and postoperative pathological tumor burden.

Conclusion

There was a high risk of LN metastasis in patients with cT2 PCa if they had high preoperative tPSA or high postoperative GGG. Patients with cT2 PCa and GGG ≥ 3 had a high risk of LN metastasis if they had high PI-RADS v2 score, high preoperative clinical stage or high postoperative pathological tumor burden. PI-RADS v2 score predicted tumor burden well in patients with GGG ≥ 3.

Quantitative metastatic lymph node burden and survival in Merkel cell carcinoma

BACKGROUND

Current lymph node (LN) staging for Merkel cell carcinoma (MCC) does not account for the number of metastatic LNs, which is a primary driver of survival in multiple cancers.

OBJECTIVE

To determine the impact of the number of metastatic LNs on survival in MCC.

METHODS

Patients with MCC undergoing surgery were identified from the National Cancer Database (NCDB). The association between metastatic LN number and survival was modeled with restricted cubic splines. A novel nodal classification system was derived by using recursive partitioning analysis. MCC patients undergoing surgery in the Surveillance, Epidemiology, and End Results (SEER) Program were used as validation cohort.

RESULTS

Among 3670 patients in the NCDB, increasing metastatic LN number was associated with decreased survival (P < .001). Mortality risk increased continuously with each additional positive LN when using multivariable, nonlinear modeling. According to a novel staging system derived via recursive partitioning analysis, the hazard ratio for death in multivariable regression compared with patients without LN involvement was 1.24 (P = .049), 2.08 (P < .001), 3.24 (P < .001), and 6.13 (P < .001) for the proposed N1a (1-3 metastatic LNs with microscopic detection), N1b (1-3 metastatic LNs with macroscopic detection), N2 (4-8 metastatic LNs), and N3 (≥9 metastatic LNs), respectively. This system was validated in the SEER cohort and showed improved concordance compared with the American Joint Committee on Cancer, Eighth Edition.

LIMITATIONS

Retrospective design.

CONCLUSIONS

Number of metastatic LNs is the dominant nodal factor driving survival in patients with MCC.

The Role of Radical Prostatectomy and Lymph Node Dissection in Clinically Node Positive Patients

Patients diagnosed with clinically node-positive prostate cancer represent a population that has historically been thought to harbor systemic disease. Increasing evidence supports the role of local therapies in advanced disease, but few studies have focused on this particular population. In this review we discuss the limited role for conventional cross sectional imaging for accurate nodal staging and how molecular imaging, although early results are promising, is still far from widespread clinical utilization. To date, evidence regarding the role of radical prostatectomy and pelvic lymph node dissection in clinically node-positive disease comes from retrospective studies; overall surgery appears to be a reasonable option in selected patients, with improved oncological outcomes that could be attributed to both to its potential curative role in disease localized to the pelvis and to the improved staging to help guide subsequent multimodal treatment. The role of surgery in clinically node-positive disease needs higher-level evidence but meanwhile, radical prostatectomy with extended pelvic lymph-node dissection can be offered as a part of a multimodality approach with the patient.

Evaluation of Lymph Node Ratio Association With Long-term Patient Survival After Surgery for Node-Positive Merkel Cell Carcinoma

Importance

Merkel cell carcinoma (MCC) carries the highest mortality rate among cutaneous cancers and is rapidly rising in incidence. Identification of prognostic indicators may help guide patient counseling and treatment planning. Lymph node ratio (LNR), the ratio of positive lymph nodes to the total number of examined lymph nodes, is an established prognostic indicator in other cancers.

Objectives

The primary objective was to evaluate the association between LNR and patient survival after surgery for node-positive MCC. The secondary objective was to evaluate whether the survival rates associated with adjuvant therapies vary by patient LNR status.

Design, Setting, and Participants

Retrospective cohort study of patients with node-positive MCC treated with surgery and lymphadenectomy. We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) registry for patient records. Data originated from 2004 through 2017 for the NCDB and from 1973 through 2016 for the SEER registry. The SEER registry comprises a population-based US cohort while cases from the NCDB include all reportable cases from Commission on Cancer-accredited facilities and represents approximately 70% of all newly diagnosed cancers in the United States. All data analysis took place between August 1, 2018, and February 11, 2019.

Exposures

The ratio of positive lymph nodes to the total number of examined lymph nodes, LNR, was stratified into quartiles.

Main Outcomes and Measures

Overall survival (NCDB) and disease-specific survival (SEER).

Results

We identified 736 eligible cases in the NCDB and 538 eligible cases in the SEER registry. Among these 1274 patients, the mean (SD) age was 71.1 (11.5) years, and 401 (31.5%) were women. After controlling for clinical and tumor factors including AJCC N staging, patient LNR of 0.07 to 0.31 (hazard ratio [HR], 1.37; 95% CI, 1.03-1.81) and greater than 0.31 (HR, 2.84; 95% CI, 2.10-3.86) was associated with significantly worse survival than an LNR less than 0.07. Univariate supplementary analysis performed in the SEER data set revealed a similar association of LNR with disease-specific survival. For patients with an LNR greater than 0.31, treatment with surgery and adjuvant chemoradiation therapy was associated with improved survival compared with surgery and adjuvant radiation therapy alone (HR, 0.61; 95% CI, 0.38-0.97), while this was not found for patients with an LNR of 0.31 or lower (HR, 0.93; 95% CI, 0.65-1.33).

Conclusions and Relevance

For lymph node-positive MCC, LNR offers a potentially prognostic metric alongside traditional TNM staging that may be useful for both patient counseling and treatment planning after surgery.

The oncologic results of cryoablation in prostate cancer patients with bone metastases

OBJECTIVE

To explore the role of whole gland cryoablation plus ADT in prostate cancer (PCa) with bone metastases compared with ADT treatment alone in metastatic PCa.

METHODS

A total of 30 patients with biopsy-proven PCa with bone metastases underwent cryoablation and ADT treatment. The control group consisted of 30 men who were initially treated with ADT only and who were followed until progression, development of castration resistant PCa or death. Patients were pair matched for age, PSA level, clinical stage, preoperative biopsy Gleason score and bone metastases. Time to clinical progression, time to CRPC, cancer-specific survival and overall survival were analysed using descriptive statistical analysis.

RESULTS

Age at diagnosis, baseline PSA, biopsy Gleason score and ECOG status were comparable between the two groups. Prostate cryoablation was well tolerated and no serious complications occurred. At the last follow-up, patients in the cryoablation and ADT treatment group had a lower median PSA nadir (0.4 ng/ml vs. 0.8 ng/ml, p < 0.01) and longer time to CRPC (33 ± 0.9 mo vs. 22 ± 0.8 mo, p < 0.01). Further analyses detected the statistically significant benefits of cryoablation treatment not only in PFS (41 ± 1.4 mo vs. 22 ± 0.8 mo, p < 0.01), but also in CSS (52 ± 1.9 mo vs. 32 ± 2.4 mo, p ± 0.01) and OS (41 ± 1.5 mo vs. 28 ± 1.7 mo, p < 0.01). Moreover, there were fewer palliative procedures for local progression in the cryoablation group than the controls.

CONCLUSIONS

Cryoablation plus ADT might be a treatment option in the multimodality management of metastatic prostate cancer. Further investigations are warranted.

Predicting survival in node‐positive prostate cancer after open, laparoscopic or robotic radical prostatectomy: A competing risk analysis of a multi‐institutional database

Objectives

To investigate cancer‐specific mortality and other‐cause mortality in prostate cancer patients with nodal metastases.

Methods

The study included 411 patients treated with radical prostatectomy and pelvic lymph node dissection for prostate cancer with lymph node metastases at 10 tertiary care centers between 1995 and 2014. Kaplan–Meier analyses were used to assess cancer‐specific mortality‐free survival rates at 8 years' follow up in the overall population, and after stratifying patients according to clinical and pathological parameters. Uni‐ and multivariable competing risk Cox regression analyses were used to assess cancer‐specific mortality and other‐cause mortality. Finally, cumulative‐incidence plots were generated for cancer‐specific mortality and other‐cause mortality after stratifying patients according to the number of positive lymph nodes and the median age at surgery, according to the competing risks method.

Results

Men with prostate‐specific antigen ≤40 ng/mL and those with one to three positive lymph nodes showed higher cancer‐specific mortality‐free survival estimates as compared with their counterparts with prostate‐specific antigen >40 ng/mL and >3 metastatic lymph nodes, respectively (all P < 0.001). At multivariable Cox regression analyses, preoperative prostate‐specific antigen >40 ng/mL, >3 lymph node metastases and pathological Gleason score 8–10 were all independent predictors of cancer‐specific mortality (all P‐values ≤0.001). On competing risk analysis, when patients were stratified according to the number of positive lymph nodes (namely, ≤3 vs >3), the 8‐year cancer‐specific mortality rates were 27.4% versus 44.8% for patients aged <65 years, and 15.2% versus 52.6% for patients aged ≥65 years, respectively.

Conclusions

Three positive lymph nodes represent the best prognostic cut‐off in node‐positive prostate cancer patients. In those individuals with >3 positive lymph nodes, the overall mortality rate is completely related to prostate cancer in young patients.

Nodal occult metastases in intermediate- and high-risk prostate cancer patients detected using serial section, immunohistochemistry, and real-time reverse transcriptase polymerase chain reaction: prospective evaluation with matched-pair analysis

BACKGROUND

The purpose of the study was to prospectively evaluate the incidence of nodal OCM assessed using SS, IHC, and RT-PCR in prostate cancer patients compared with the standard pathological evaluation (SPE), and to evaluate short-term oncological outcomes of patients with OCM.

PATIENTS AND METHODS

Fifty-four consecutive patients with intermediate- or high-risk prostate cancer treated with radical prostatectomy and extended pelvic LN dissection comprised the study population (StP). The central sections with the largest diameter of each LN of the StP and a matched-pair population (MpP) with identical characteristics as the StP were used to assess the improved detection rate of OCM. Pathological characteristics and biochemical recurrence-free survival were assessed according to the presence of macroscopic or OCM.

RESULTS

A total of 1064 LNs were processed in the 54 patients of the StP, with 11 (20.4%) patients with evident metastases at SPE and 7 with OCM (13.0% additional patients); the percentage of positive patients improved from 16.6% (18 of 108) of the MpP to 33.3% (18 of 54) of the StP (16% additional patients). The mean diameter of the 10 additional LNs with OCM found at SS only and of the 6 additional LNs found at IHC only was significantly lower than the mean diameter of the 28 metastases found at routine pathologic examination (RPE) (P < .0001). Patients with OCM showed risk of biochemical recurrence similar to patients with no LN metastases (P = .008).

CONCLUSION

SS, IHC, and RT-PCR can detect a not negligible percentage of OCM missed at RPE. Patients with OCM showed short-term oncological outcomes more similar to those with macroscopic metastases. Longer follow-up studies considering cancer-specific survival are needed.

Is there a relationship between the number of lymph nodes and disease parameters in patients who underwent retropubic prostatectomy

PURPOSE

We aimed to establish the relationship between lymph nodes (LNs) counts that were removed with standard pelvic lymph node dissection (sPLND) and different disease parameters in patients who underwent radical prostatectomy (RP).

MATERIALS AND METHODS

A total of 70 patients who underwent sPLND during RP were scanned retrospectively. The scanned parameters were levels of serum PSA, the total weight of the removed prostate, the amount as a percentage of the tumor in the prostate tissue, the stage of the tumor, the total Gleason score (GS) and the number of standard pelvic lymph nodes that were removed from both right and left sides.

RESULTS

The average age of the patients was 59 years. A positive correlation was found between the total GS and the number of lymph nodes; while this correlation was significant (p = 0.0038), there was no significant difference between lymph nodes counts and other scanned parameters. The average pelvic lymph node numbers of patients with GS of 6-7 and 8 were 10.4-11.5 and 13.2, respectively. Lymph nodes metastases were found in 3 (4.2 %) patients whose average pelvic lymph node number was 17.3.

CONCLUSION

The chance of cure or decreased recurrence is much more possible in patients who had received extended PLND or at least standard one, because of the removal of much more lymph node tissues that have a high probability of disseminating cancer cells. This position can especially be considered in patients with high GS.

External validation of nomogram predicting the probability of specimen-confined disease (pT2-3a, R0N0) in patients undergoing radical prostatectomy and pelvic lymph node dissection

INTRODUCTION

Before radical prostatectomy (RP), a nomogram [Briganti et al., Eur Urol 2012;61:584-592] permits to measure the probability of specimen-confined (SC) disease (pT2-pT3a, node negative with negative margins) in high-risk prostate cancer (PCa). The aim of our study was to perform an external validation of this nomogram.

MATERIALS AND METHODS

Between 2007 and 2011, 623 patients with high-risk PCa (prostate-specific antigen (PSA) >20 ng/ml and/or biopsy Gleason score ≥8 and/or clinical stage T3) underwent RP and pelvic lymph node dissection at tertiary referral centers. Multivariable logistic regression models predicting the presence of SC disease were built in; we then used the area under curve of the receiver operating characteristic analysis to quantify accuracy of the nomogram to predict SC disease. The extent of over- or underestimation was evaluated within calibration plots.

RESULTS

29% (181/623) of men had SC disease at RP. Preoperative PSA, biopsy Gleason score and stage differed significantly (all p < 0.001) between men with SC disease and those without. External validation of the nomogram showed an acceptable accuracy (area under curve: 66.3, 95% CI 62.4-70%) and a perfect calibration plot.

CONCLUSIONS

The external cohort validates the original nomogram, with perfect calibration characteristics. The adequate although reduced accuracy may reflect the wide spectrum and behavior of the so-called high-risk PCa.

Pathological and oncologic outcomes for men with positive lymph nodes at radical prostatectomy: The Johns Hopkins Hospital 30-year experience

BACKGROUND

We report the 30-year institutional experience of radical prostatectomy (RP) for men with clinically localized prostate cancer (PC) found to have lymph node (LN) metastases at surgery.

METHODS

The Johns Hopkins RP Database (1982-2011) was queried for 505 (2.5%) men with node-positive (N1) PC. Survival analysis was completed using the Kaplan-Meier method and proportional hazard regression models.

RESULTS

The proportion of men with N1PC was 8.3%, 3.5%, and 1.4% in the pre- (1982-1990), early- (1991-2000), and contemporary-PSA eras (2001-2011), respectively. A trend toward decreasing PSA, less palpable disease but more advanced Gleason sum was noted in the most contemporary era. Median total and positive nodes were 13.2 (1-41) and 1.7 (1-12), respectively. Of 135 patients with a unilateral tumor, 80 (59.3%), 28 (20.7%), and 15 (11.1%) had ipsilateral, contralateral, and bilateral positive LN. 15-year biochemical-recurrence free, metastases-free and cancer-specific survival was 7.1%, 41.5%, and 57.5%, respectively. Predictors of biochemical-recurrence, metastases and death from PC in multivariate analysis included Gleason sum at RP, the number and percent of positive LN; notably total number of LN dissected did not predict outcome.

CONCLUSIONS

In this highly-selected RP cohort, men found to have N1PC disease at RP can experience a durable long-term metastases-free and cancer-specific survival. Predictors of survival include Gleason sum, number, and percentage of positive LN. While total number of LN dissected was not predictive, approximately 30% of men with N1PC will have positive LN contralateral to the primary prostatic lesion highlighting the importance of a thorough, bilateral pelvic LN dissection.