Importance and outcome relevance of central pathology review in prostatectomy specimens: data from the SAKK 09/10 randomized trial on prostate cancer

Local extension findings on MRI compensate for the ability of pathological staging to predict oncological outcome

BACKGROUND

We investigated whether local extension findings on preoperative MRI and excisional pathology are associated with positive surgical margin and biochemical recurrence after robot-assisted radical prostatectomy.

METHODS

We identified 704 of our patients that underwent robot-assisted radical prostatectomy between 2012 and 2020, and extracted the 326 patients who had preoperative MRI scans and a radiologist reading. These patients were classified into groups according to the presence of local extension on MRI and pathological findings: ≤ cT2pT2 (195 cases), ≤ cT2pT3 (55 cases), cT3pT2 (31 cases), and cT3pT3 (45 cases). We compared positive surgical margin and biochemical recurrence between them.

RESULTS

Median age was 69 years, positive surgical margin rate was 20.2%, and five-year biochemical recurrence rate was 20.3%. Of the 226 patients without local invasion on excisional pathology, those with local extension on MRI (cT3pT2) had relatively higher positive surgical margin rate (29.0% vs. 14.4%, p = 0.05) and significantly higher five-year biochemical recurrence rate (25.8% vs. 9.3%, p = 0.01) than those without local extension on MRI (≤ cT2pT2). Similarly, among the 100 patients with local extension on excisional pathology, those with cT3pT3 had relatively higher positive surgical margin (37.8% vs. 21.8%, p = 0.08) and significantly higher five-year biochemical recurrence (53.3% vs. 29.3%, p = 0.01) than those with ≤ cT2pT3. In multivariate analysis, local extension on MRI was an independent predictor of biochemical recurrence (OR 2.1, 95%CI 1.1-3.9, p = 0.01).

CONCLUSIONS

Local extension on MRI is a prognostic factor independent of pathological stage. The use of MRI may complement the prognostic value of excisional pathology of prostate cancer.

Prognostic Importance of Lymphovascular Invasion for Specific Subgroup of Patients with Prostate Cancer After Robot-Assisted Radical Prostatectomy (The MSUG94 Group)

OBJECTIVE

This study aimed to investigate whether lymphovascular invasion (LVI) was associated with oncological outcomes in patients with prostate cancer (PCa) undergoing robotic-assisted radical prostatectomy (RARP).

METHODS

This retrospective multicenter cohort study was conducted on 3195 patients with PCa who underwent RARP in nine institutions in Japan. The primary endpoints were the associations between biochemical recurrence (BCR) and LVI and between BCR and clinicopathological covariates, while the secondary endpoints were the association between LVI and the site of clinical recurrence and metastasis-free survival (MFS).

RESULTS

In total, 2608 patients met the inclusion criteria. At the end of the follow-up period, 311 patients (11.9%) were diagnosed with BCR and none died of PCa. In patients with pathological stage T2 (pT2) + negative resection margins (RM-), and pT3+ positive RM (RM+), LVI significantly worsened BCR-free survival (BRFS). For patients with PCa who had pT3 and RM+, the 2-year BRFS rate in those with LVI was significantly worse than in those without LVI. Patients with LVI had significantly worse MFS than those without LVI with respect to pT3, RM+, and pathological Gleason grade (pGG). In multivariate analysis, LVI was significantly associated with BRFS in patients with pT3 PCa, and with worse MFS in PCa patients with pT3, RM+, and pGG ≥ 4.

CONCLUSIONS

LVI was an independent prognostic factor for recurrence and metastasis after RARP, particularly in patients with pT3 and RM+ PCa. Locally advanced PCa with positive LVI and RM+ requires careful follow-up because of the high likelihood of recurrence.

Nomogram Predicting Locally Advanced Prostate Cancer in Patients with Clinically Organ-Confined Disease Who Underwent Robot-Assisted Radical Prostatectomy: A Retrospective Multicenter Cohort Study in Japan (The MSUG94 Group)

PURPOSE

We created a clinically applicable nomogram to predict locally advanced prostate cancer using preoperative parameters and performed external validation using an external independent validation cohort.

PATIENTS AND METHODS

From a retrospective multicenter cohort study of 3622 Japanese patients with prostate cancer who underwent robot-assisted radical prostatectomy at ten institutions, the patients were divided into two groups (MSUG cohort and validation cohort). Locally advanced prostate cancer was defined as pathological T stage ≥ 3a. A multivariable logistic regression model was used to identify factors strongly associated with locally advanced prostate cancer. Bootstrap area under the curve was calculated to assess the internal validity of the prediction model. A nomogram was created as a practical application of the prediction model, and a web application was released to predict the probability of locally advanced prostate cancer.

RESULTS

A total of 2530 and 427 patients in the MSUG and validation cohorts, respectively, met the criteria for this study. On multivariable analysis, initial prostate-specific antigen, prostate volume, number of cancer-positive and cancer-negative biopsy cores, biopsy grade group, and clinical T stage were independent predictors of locally advanced prostate cancer. The nomogram predicting locally advanced prostate cancer was demonstrated (area under the curve 0.72). Using a nomogram cutoff of 0.26, 464 of 1162 patients (39.9%) could be correctly diagnosed with pT3, and 2311 of 2524 patients (91.6%) could avoid underdiagnosis.

CONCLUSIONS

We developed a clinically applicable nomogram with external validation to predict the probability of locally advanced prostate cancer in patients undergoing robot-assisted radical prostatectomy.

Clinical factors associated with biochemical recurrence of prostate cancer with seminal vesicle invasion followed by robot-assisted radical prostatectomy: a retrospective multicenter cohort study in Japan (the MSUG94 group)

Locally advanced prostate cancer (PCa) with pathological seminal vesicle invasion (pT3b) is a very-high-risk disease associated with biochemical recurrence (BCR), local recurrence, distant metastases, or mortality following definitive therapies. This study aimed to evaluate the risk factors associated with BCR following robot-assisted radical prostatectomy (RARP) in PCa patients with pT3b. A retrospective multicenter cohort study was conducted on 3,195 patients with PCa who underwent RARP at nine domestic centers between September 2011 and August 2021. Biochemical recurrence-free survival (BRFS) after RARP in PCa patients with pT3b was the primary end-point of the study. The secondary end-point was to determine the association between BCR and covariates. We enrolled 188 PCa patients with pT3b. The median follow-up period was 32.8 months. At the end of the follow-up period, 76 patients (40.4%) developed BCR, of whom 15 (8.0%) were BCR at the date of surgery. The 1-, 2-, and 3-year BRFS rates were 76.4, 65.9, and 50.8%, respectively. Multivariate analysis identified initial prostate-specific antigen level and positive surgical margins (PSM) as significant predictors of BCR in PCa patients with pT3b undergoing RARP. In this study, we investigated the BRFS in PCa patients with pT3b. As PSM was an independent predictor of BCR in PCa patients with pT3b, these patients may require a combination of therapies to improve the BCR.

A Nomogram for Predicting Prostate Cancer with Lymph Node Involvement in Robot-Assisted Radical Prostatectomy Era: A Retrospective Multicenter Cohort Study in Japan (The MSUG94 Group)

Background: To create a nomogram for predicting prostate cancer (PCa) with lymph node involvement (LNI) in the robot-assisted radical prostatectomy (RARP) era. Methods: A retrospective multicenter cohort study was conducted on 3195 patients with PCa who underwent RARP at nine institutions in Japan between September 2012 and August 2021. A multivariable logistic regression model was used to identify factors strongly associated with LNI. The Bootstrap-area under the curve (AUC) was calculated to assess the internal validity of the prediction model. Results: A total of 1855 patients were enrolled in this study. Overall, 93 patients (5.0%) had LNI. On multivariable analyses, initial prostate-specific antigen, number of cancer-positive and-negative biopsy cores, biopsy Gleason grade, and clinical T stage were independent predictors of PCa with LNI. The nomogram predicting PCa with LNI has been demonstrated (AUC 84%). Using a nomogram cut-off of 6%, 492 of 1855 patients (26.5%) would avoid unnecessary pelvic lymph node dissection, and PCa with LNI would be missed in two patients (0.1%). The sensitivity, specificity, and negative predictive values associated with a cutoff of 6% were 74%, 80%, and 99.6%, respectively. Conclusions: We developed a clinically applicable nomogram for predicting the probability of patients with PCa with LNI.

Metastasis-free survival and patterns of distant metastatic disease after PSMA-PET-guided salvage radiotherapy in recurrent or persistent prostate cancer after prostatectomy

INTRODUCTION

Prostate specific membrane antigen positron-emission tomography (PSMA-PET) is increasingly used to guide salvage radiotherapy (sRT) in prostate cancer (PCa) patients with biochemical recurrence/persistence after prostatectomy. This work examines (i) metastasis-free survival (MFS) following PSMA-PET guided sRT and (ii) the metastatic patterns on PSMA-PET images after sRT.

METHODS

This retrospective, multicenter (9 centers, 5 countries) study included patients referred for PSMA-PET due to recurrent/persistent disease after prostatectomy. Patients with distant metastases (DM) on PSMA-PET prior to sRT were excluded. Cox-regression was performed to assess the impact of clinical parameters on MFS. The distribution of PSMA-PET detected DM following sRT and their respective risk factors were analysed.

RESULTS

All (n=815) patients received intensity-modulated RT to the prostatic fossa. In case of PET-positive pelvic lymph nodes (PLN-PET, n=275, 34%), pelvic lymphatics had been irradiated. Androgen deprivation therapy had been given in 251 (31%) patients. The median follow-up after sRT was 36 months. The 2-/4-year MFS following sRT were 93%/81%. In multivariate analysis the presence of PLN-PET was a strong predictor for MFS (HR=2.39, p<0.001). Following sRT, DM were detected by PSMA-PET in 128/198 (65%) patients and two metastatic patterns were observed: 43% had DM in sub diaphragmatic paraaortic LNs (abdominal-lymphatic) whereas 45% in bones, 9% in supra diaphragmatic LNs and 6% in visceral organs (distant). Two distinct signatures with risk factors for each pattern were identified.

CONCLUSION

MFS in our study is lower compared to previous studies, obviously due to the higher detection rate of DM in PSMA-PET after sRT. Thus, it remains unclear whether MFS is a surrogate endpoint for overall survival in PSMA PET-staged patients in the post sRT setting. PLN-PET may be proposed as a new surrogate parameter predictive of MFS. Analysis of recurrence patterns in PET after sRT revealed risk factor signatures for two metastatic patterns (abdominal-lymphatic and distant), which may allow individualized sRT concepts in the future.

Local Extent of Prostate Cancer at MRI versus Prostatectomy Histopathology: Associations with Long-term Oncologic Outcomes

Background It is unknown how the imperfect accuracy of MRI for local staging of prostate cancer relates to oncologic outcomes. Purpose To analyze how staging discordances between MRI and histopathologic evaluation relate to recurrence and survival after radical prostatectomy. Materials and Methods Health Insurance Portability and Accountability Act-compliant retrospective analysis of preprostatectomy T2-weighted prostate MRI (January 2001 to December 2006). Extraprostatic extension and seminal vesicle invasion were assessed by using five-point Likert scales; scores of 4 or higher were classified as positive. Biochemical recurrence (BCR), metastases, and prostate cancer-specific mortality rates were estimated with Kaplan-Meier and Cox models. Results A total of 2160 patients (median age, 60 years; interquartile range, 55-64 years) were evaluated. Among patients with histopathologic extraprostatic (pT3) disease (683 of 2160; 32%), those with organ-confined disease at MRI (384 of 683; 56%) experienced better outcomes than those with concordant extraprostatic disease at MRI and pathologic analysis: 15-year risk for BCR, 30% (95% CI: 22, 40) versus 68% (95% CI: 60, 75); risk for metastases, 14% (95% CI: 8.4, 24) versus 32% (95% CI: 26, 39); risk for prostate cancer-specific mortality, 3% (95% CI: 1, 6) versus 15% (95% CI: 9.5, 23) (P < .001 for all comparisons). Among patients with histopathologic organ-confined disease (pT2) (1477 of 2160; 68%), those with extraprostatic disease at MRI (102 of 1477; 7%) were at higher risk for BCR (27% [95% CI: 19, 37] vs 10% [95% CI: 8, 14]; P < .001), metastases (19% [95% CI: 6, 48] vs 3% [95% CI: 1, 6]; P < .001), and prostate cancer-specific mortality (2% [95% CI: 1, 9] vs 1% [95% CI: 0, 5]; P = .009) than those with concordant organ-confined disease at MRI and pathologic analysis. At multivariable analyses, tumor extent at MRI (hazard ratio range, 4.1-5.2) and histopathologic evaluation (hazard ratio range, 3.6-6.7) was associated with the risk for BCR, metastases, and prostate cancer-specific mortality (P < .001 for all analyses). Conclusion The local extent of prostate cancer at MRI is associated with oncologic outcomes after prostatectomy, independent of pathologic tumor stage. This might inform a strategy on how to integrate MRI into a clinical staging algorithm. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gottlieb in this issue.

Predicting Biochemical Failure in Irradiated Patients With Prostate Cancer by Tumour Volume Measured by Multiparametric MRI

BACKGROUND/AIM

We examined the prognostic value of intraprostatic gross tumour volume (GTV) as measured by multiparametric MRI (mpMRI) in patients with prostate cancer following (primary) external beam radiation therapy (EBRT).

PATIENTS AND METHODS

In a retrospective monocentric study, we analysed patients with prostate cancer (PCa) after EBRT. GTV was delineated in pre-treatment mpMRI (GTV-MRI) using T2-weighted images. Cox-regression analyses were performed considering biochemical failure recurrence-free survival (BRFS) as outcome variable.

RESULTS

Among 131 patients, after a median follow-up of 57 months, biochemical failure occurred in 27 (21%). GTV-MRI was not correlated with % of positive biopsy cores, Gleason score and initial PSA (all r<0.2) and only moderately correlated with cT stage (r=0.32). In univariate analysis, cT stage, Gleason score and GTV-MRI were higher in subjects with shorter BRFS (p<0.05). GTV-MRI remained a significant predictor for BRFS in multivariate analyses, independent of Gleason score and cT stage.

CONCLUSION

GTV, defined using mpMRI, provides incremental prognostic value for BRFS, independent of established risk factors. This supports the implementation of imaging-based GTV for risk-stratification, although further validation is needed.

International Multi-Site Initiative to Develop an MRI-Inclusive Nomogram for Side-Specific Prediction of Extraprostatic Extension of Prostate Cancer

BACKGROUND

To develop an international, multi-site nomogram for side-specific prediction of extraprostatic extension (EPE) of prostate cancer based on clinical, biopsy, and magnetic resonance imaging- (MRI) derived data.

METHODS

Ten institutions from the USA and Europe contributed clinical and side-specific biopsy and MRI variables of consecutive patients who underwent prostatectomy. A logistic regression model was used to develop a nomogram for predicting side-specific EPE on prostatectomy specimens. The performance of the statistical model was evaluated by bootstrap resampling and cross validation and compared with the performance of benchmark models that do not incorporate MRI findings.

RESULTS

Data from 840 patients were analyzed; pathologic EPE was found in 320/840 (31.8%). The nomogram model included patient age, prostate-specific antigen density, side-specific biopsy data (i.e., Gleason grade group, percent positive cores, tumor extent), and side-specific MRI features (i.e., presence of a PI-RADSv2 4 or 5 lesion, level of suspicion for EPE, length of capsular contact). The area under the receiver operating characteristic curve of the new, MRI-inclusive model (0.828, 95% confidence limits: 0.805, 0.852) was significantly higher than that of any of the benchmark models (p < 0.001 for all).

CONCLUSIONS

In an international, multi-site study, we developed an MRI-inclusive nomogram for the side-specific prediction of EPE of prostate cancer that demonstrated significantly greater accuracy than clinical benchmark models.

Prediction of survival outcomes following postoperative radiotherapy after radical prostatectomy for prostate cancer

Background: To evaluate predictive factors for survival outcomes after post-prostatectomy radiotherapy.Material and methods: In the years 2003-2008, 324 patients have received postoperative radiotherapy a median time of 14 months after radical prostatectomy. All patients have been treated up to 66.0-66.6 Gy in 1.8-2.0 Gy fractions. Predictive factors were analyzed at two stages, using a multivariable Cox regression analysis: (1) based on factors known before radiotherapy and (2) based on prostate-specific antigen response after radiotherapy.Results: Median follow-up after radiotherapy was 121 months. Prostate-specific antigen before radiotherapy, pN1 and Gleason score remained predictive factors for disease-free (hazard ratio, HR of 6.0, 2.3 and 2.5) and overall survival (HR of 2.8, 2.0 and 1.6) in multivariable analysis. Prostate-specific antigen levels increased despite radiotherapy in 27% of patients in the first six months. Failed response following salvage radiotherapy and prostate-specific antigen doubling time at the time of biochemical recurrence were predictive factors for disease-free (HR of 2.8 and 7.3; p < .01) and overall survival (HR of 2.2 and 2.6; p < .01).Conclusion: To reach the best survival outcomes following prostatectomy, salvage radiotherapy should be initiated early with low prostate-specific antigen levels, especially in patients with higher Gleason scores. Patients not responding to radiotherapy and/or patients with a short prostate-specific antigen doubling time after radiotherapy are candidates for early additional treatments.

On Being Sick and Tired

It is crucial that urologists keep abreast of the latest advances in medical research. This should include an awareness of the role of imaging techniques, collaboration in multidisciplinary teams, adherence to current guidelines, and ongoing documentation of postoperative complications and outcomes. Taken together, these key elements should facilitate optimisation of patient management in routine clinical practice.

Assessment of Histological Remission in Ulcerative Colitis: Discrepancies Between Daily Practice and Expert Opinion

BACKGROUND AND AIMS

Histological remission [HR] is a potential treatment target in ulcerative colitis [UC]. Limited 'real world' data are available on the reliability of histological scoring when assessing minimal histological inflammation. The aim of this study was to investigate the reliability of UC histological scores in colonic biopsies showing mucosal healing [MH] and limited histological inflammation, and to compare the 'daily practice' histological assessment with expert reviews by gastrointestinal [GI] pathologists.

METHODS

We performed a retrospective single-centre study. Colonic biopsies from UC patients with MH [Mayo score ≤ 1] were included. All biopsies assessed in daily practice were reassessed by three blinded GI pathologists using three histological scores (Geboes score [GS], Riley score [RS], Harpaz [Gupta] Index [HGI]) and a global visual scale [GVS]. We evaluated inter- and intra-observer variation between GI pathologists and correlations between scores including the initial histological assessment using Cronbach's alpha and Spearman rho analysis.

RESULTS

In total, 270 biopsies from 39 UC patients were included. The inter-observer concordance for all histological indexes was substantial to almost perfect [GS 0.84; HGI 0.61; GVS 0.74, RS 0.91]. Correlation between the RS and GS was almost perfect [R = 0.86], but we found no correlation between the primary histological assessment and reassessment by GI pathologists.

CONCLUSIONS

Current UC histological scores reliably assess limited histological inflammation in UC patients. The discrepancy between the initial histological assessment and the reassessment by dedicated GI pathologists suggests a gap between daily practice and academic expertise. This issue may limit the implementation of HR as a treatment target for UC in daily practice.