Long-term oncological outcomes of apical positive surgical margins at radical prostatectomy in the Shared Equal Access Regional Cancer Hospital cohort

Prognostic differences among the positive surgical margin locations following robot-assisted radical prostatectomy in a large Japanese cohort (the MSUG94 group)

BACKGROUND

To investigate whether subgroups of prostate cancer patients, stratified by positive surgical margin locations, have different oncological outcomes following robot-assisted radical prostatectomy.

METHODS

A retrospective multicenter cohort study in prostate cancer patients undergoing robot-assisted radical prostatectomy was conducted at 10 institutions in Japan. Pre- and post-operative outcomes were collected from enrolled patients. Biochemical recurrence and clinical and pathological variables were evaluated among subgroups with different positive surgical margin locations.

RESULTS

A total of 3195 patients enrolled in this study. Data from 2667 patients (70.1% [N = 1869] with negative surgical margins and 29.9% [N = 798] with positive surgical margins based on robot-assisted radical prostatectomy specimens) were analyzed. The median follow-up period was 25.0 months. The numbers of patients with apex-only, middle-only, bladder-neck-only, seminal-vesicle-only and multifocal positive surgical margins were 401, 175, 159, 31 and 32, respectively. In the multivariate analysis, PSA level at surgery, pathological Gleason score based on robot-assisted radical prostatectomy specimens, pathological T stage, pathological N stage and surgical margin status were independent risk factors significantly associated with biochemical recurrence-free survival. Patients undergoing robot-assisted radical prostatectomy with multifocal positive surgical margins and seminal-vesicle-only positive surgical margins were associated with worse biochemical recurrence-free survival than those with apex-only, middle-only and bladder-neck-only positive surgical margins. Patients undergoing robot-assisted radical prostatectomy with apex-only positive surgical margins, the most frequent positive surgical margin location, were associated with more favorable biochemical recurrence-free survival that those with middle-only and bladder-neck-only positive surgical margins. The study limitations included the lack of central pathological specimen evaluation.

CONCLUSIONS

Although positive surgical margin at any locations is a biochemical recurrence risk factor after robot-assisted radical prostatectomy, positive surgical margin location status should be considered to accurately stratify the biochemical recurrence risk after robot-assisted radical prostatectomy.

Preoperative Multiparametric Prostate Magnetic Resonance Imaging Structured Report Informs Risk for Positive Apical Surgical Margins During Radical Prostatectomy

BACKGROUND

The prostatic apex is the most frequent location of positive surgical margin (PSM) after surgery. Data regarding the ability of multiparametric magnetic resonance imaging (mpMRI) to prospectively identify men at risk for apical PSMs (aPSMs) using a structured report are lacking.

OBJECTIVES

The aims of the study are to determine and to compare the rate of aPSM in men with versus without prospectively flagged at-risk prostate lesions during clinical mpMRI interpretation using whole-mount histopathology as the reference standard.

METHODS

This single-center, retrospective study of prospectively collected data included treatment-naive men with abnormal 3T mpMRI (PI-RADS v2 score ≥3) between January 2016 and December 2018 followed by surgery. During routine clinical interpretation, radiologists flagged prostate lesions abutting the apical most gland and/or encircling the distal most prostatic urethra using standardized language available as a "pick list" option in the structured report. Logistic regression was used to compare the rate of PSM in 2 groups (flagged vs nonflagged men). Propensity score covariate adjustment corrected for potential selection bias according to age, prostate-specific antigen (PSA), PSA density, grade group, and pT stage. The estimate was further adjusted by including surgeon as a covariate.

RESULTS

A total of 428 men were included. A statistically significant higher proportion of aPSMs was noted in flagged (56% [51/91]) compared with nonflagged apical lesions (31% [105/337]; adjusted odds ratio, 2.5; 95% confidence interval, 1.6-4.1; P < 0.01). The difference in aPSM between both groups also varied according to the surgeon performing the RP. Prostate-specific antigen, PSA density, lesion size, apical location, Prostate Imaging Reporting & Data System score, grade group, pT stage, and surgeon's experience were associated with higher PSM rate. Biochemical recurrence, defined as PSA greater than 0.2 ng/mL on 2 measurements after RP, was significantly associated with PSM status (propensity score adjusted odds ratio, 3.1; 95% confidence interval, 1.8-5.3; P < 0.0001); however, patients flagged by radiologists did not have a significant difference in biochemical recurrence rates as compared with nonflagged patients ( P = 0.11).

CONCLUSIONS

Standard language built into structured reports for mpMRI of the prostate helps identify preoperatively patients at risk for aPSM.

CLINICAL IMPACT

Multiparametric MRI is able to identify patients at increased risk for aPSM, and this information can be conveyed in a structured report to urologists, facilitating patient counseling and treatment decisions.

The Effect of Adverse Surgical Margins on the Risk of Biochemical Recurrence after Robotic-Assisted Radical Prostatectomy

Positive surgical margins (PSM) after radical prostatectomy are associated with a greater risk of biochemical recurrence (BCR). However, not all PSM harbour the same prognosis for recurrence. We aim to determine the impact of different PSM characteristics and their coexistence on the risk of BCR. This retrospective study included 333 patients that underwent robotic-assisted radical prostatectomy for prostate cancer between 2015−2020 at a single institution. The effect of PSM and their adverse characteristics on the risk of BCR was assessed using Cox proportional hazard models. Kaplan−Meier was used to represent BCR-free survival stratified by margin status. With a median follow-up of 34.5 months, patients with PSM had a higher incidence of BCR, higher risk of relapse and lower BCR-free survival than negative margins (p < 0.001). We established as adverse characteristics: PSM length ≥ 3 mm, multifocality and Gleason at margin > 3. PSM ≥ 3 mm or multifocal PSM were associated with an increased risk for BCR compared to favourable margins (HR 3.50; 95% CI 2.05−5.95, p < 0.001 and HR 2.18; 95% CI 1.09−4.37, p = 0.028, respectively). The coexistence of these two adverse features in the PSM also conferred a higher risk for biochemical relapse and lower BCR-free survival. Adverse Gleason in the margin did not confer a higher risk for BCR than non-adverse margins in our models. We concluded that PSM are an independent predictor for BCR and that the presence of adverse characteristics, such as length and focality, and their coexistence in the PSM are associated with a greater risk of recurrence. Nevertheless, subclassifying PSM with adverse features did not enhance the model’s predictive performance in our cohort.

Diagnostic potential of radiological apical tumor involvement

We commend Veerman et al. for investigating the diagnostic performance of radiological apical tumor involvement (radATI) in preoperative prostate magnetic resonance imaging (MRI) and its impact on clinical outcomes in patients with localized prostate cancer. This retrospective study evaluated the diagnostic accuracy of MRI to detect pathological ATI (pathATI) in robot-assisted radical prostatectomy specimens. They found patients with radATI more likely to develop biochemical recurrence (BCR), p = 0.003, and have apical positive surgical margins (APSM), p = 0.004. We believe that the author's acknowledgement of the relationship between tumor location and cancer risk is an important step in the classification of prostate cancer. An important question that is under addressed is, what is it about apical tumors that carry additional risk? Higher rates of PSM due to incomplete surgical excision may contribute to increased recurrence risk in the apex. If this is the case, surgical management must be tailored by a tumor location-based risk assessment. The literature suggests that a single APSM may be clinically insignificant for long-term outcomes. Conversely, the authors also recommend radATI be treated with reduced apical nerve sparing to avoid APSM. We believe that this approach may lead to overtreatment in the presence of an otherwise good prognosis. We believe the extent of APSMs upon diagnosis would be an interesting topic for further investigation. The authors may also wish to perform multivariable analysis for the effect of radATI on BCR. We believe that MRI may play a critical role in enhancing diagnosis and prognostication of prostate cancer.

Impact of nerve sparing in robot-assisted radical prostatectomy on the risk of positive surgical margin and biochemical recurrence

OBJECTIVES

Nerve sparing may increase positive surgical margin rate during radical prostatectomy. Our objective was to analyze the positive surgical margin rate and location as well as its impact on biochemical recurrence according to nerve sparing procedure in robot-assisted radical prostatectomy.

METHODS

We included 814 patients treated with robot-assisted radical prostatectomy between 2009 and 2021, and evaluated the impact of nerve sparing on positive surgical margin and biochemical recurrence using logistic regression and Cox models.

RESULTS

Unilateral nerve sparing and bilateral nerve sparing were performed in 152 (18.6%) cases and 118 (14.5%) cases, respectively. On multivariable analysis, in addition to nerve sparing, bilateral nerve sparing, but not unilateral nerve sparing was associated with an increased risk of positive surgical margin compared with non-nerve sparing. Positive surgical margin at any location increased the risk of biochemical recurrence. During unilateral nerve sparing, positive surgical margin in nerve sparing side, but not in non-nerve sparing side was associated with increased risk of biochemical recurrence on multivariate analysis.

CONCLUSIONS

Taken together, surgeons need to notice an increased risk of biochemical recurrence associated with positive surgical margin when performing nerve sparing in robot-assisted radical prostatectomy, and then need to choose the patients suitable for nerve sparing.

Impact of Nerve-Sparing Status on Positive Surgical Margin Location and Biochemical Recurrence in Patients with Prostate Cancer Post Radical Prostatectomy

PURPOSE

This study was designed to assess the relationship between nerve-sparing (NS) status, positive surgical margin (PSM) location, and biochemical recurrence (BCR) based on a multicenter, radical prostatectomy (RP) database.

METHODS

We retrospectively reviewed data from 726 patients who underwent RP without any neoadjuvant or adjuvant treatment between 2010 and 2014. We statistically assessed the impact of NS sides on PSM location and BCR.

RESULTS

PSM rates were 21.9% in the 726 patients studied, 13.2% in patients with ≤pT2, and 46.8% in patients with ≥pT3. Regarding PSM locations, the anterior-apex (AA) was the most common site for PSM (43.3%). After adjusting for confounding factors, bilateral nerve sparing (BNS) had a significantly higher odds ratio of PSM than the absence of NS did (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.85-4.99). In the UNS RP in patients with ≤pT2, non-AA PSM on the non-NS side was significantly higher than that on the NS side (92.9% vs. 45.5%, p = 0.009). In all patients, 5.8% experienced BCR during a median follow-up of 43.5 months. PSM was significantly associated with BCR-free survival in patients with ≤pT2 (p = 0.013), but not in patients with ≥pT3 (p = 0.185). Non-AA PSM at the non-NS side was an independent risk factor for BCR (hazard ratio [HR] 2.56, 95% confidence interval [CI] 1.12-5.85), whereas AA PSMs, including NS/non-NS sides and non-AA PSM at the NS side, were not associated with BCR-free survival.

CONCLUSIONS

Avoidance of non-AA PSM on the non-NS side may be rather important for maintaining BCR-free survival after RP.

Focused Submission of Tissue for Radical Prostatectomy Following Multiparametric Magnetic Resonance Imaging/Ultrasound Fusion-Targeted Biopsy

Prostate cancer can be difficult to appreciate grossly and therefore partial sampling of the gland can lead to incorrect grading, staging, or margin status. However, submitting the entire prostate is more time consuming and costly. We investigated the use of magnetic resonance imaging/ultrasound-targeted biopsy for the selective submission of prostatectomy specimens. We performed a retrospective review for patients with cancer on targeted prostate biopsy who underwent subsequent radical prostatectomy. Prostatectomy specimens were submitted in their entirety and assessed for Grade Group, extraprostatic extension (EPE), margins, and number of blocks. For Targeted-Grossing (TG) assessment, apex margin, bladder neck margin, seminal vesicles, and vas deferens sections were included. For the remainder of the prostate, only sections from areas shown to be positive for cancer on targeted biopsy were included in the analysis. With total tissue submission, EPE was found in 39/81 (48.1%) cases and positive margins in 19/81 (23.5%) cases. The TG method required significantly fewer blocks: 15.8 ± 5.9 versus 44.9 ± 11.9 (P < .0001). The TG method would have diagnosed the correct stage in 73/81 (90.1%) cases, Grade Group in 74/81 (91.4%) cases, and margin status in 79/81 (97.5%) cases. EPE was missed completely by the TG method in 7 cases (P = .008), of which 5/7 (71.4%) had focal EPE. There was no significant difference in stage (P = .24), Grade Group (P = .95), or margin status (P = .16) between the 2 methods. Grossing utilizing selective tissue submission from areas found to be positive for prostate cancer on magnetic resonance imaging/ultrasound-targeted prostate biopsy remains inferior to complete submission of tissue for radical prostatectomy specimens.

Salvage Radiotherapy for Recurrent Prostate Cancer: Can the Prognostic Grade Group System Inform Treatment Timing?

PURPOSE

In order to better time salvage radiotherapy (SRT) for post-radical prostatectomy biochemical failure, we examined the association between pre-SRT prostate-specific antigen (PSA) and PSA control as a function of the new prognostic grade group (PGG) system.

PATIENTS AND METHODS

Using the Shared Equal Access Regional Cancer Hospital database, we identified men after radical prostatectomy with PSA > 0.2 ng/mL and without cancer involvement of lymph nodes who underwent SRT alone. SRT failure was defined as post-SRT PSA nadir + 0.2 ng/mL or receipt of post-SRT hormone therapy. Men were stratified by pre-SRT PSA (0.2-0.49, 0.5-0.99, and ≥ 1.0 ng/mL). Multivariable Cox models were used to test the association between pre-SRT PSA and SRT failure, stratified by PGG.

RESULTS

A total of 358 men met the inclusion criteria and comprised our study cohort. Median post-SRT follow-up was 78 months. A total of 174 men (49%) had pre-SRT PSA 0.2-0.49 ng/mL, 97 (27%) PSA 0.5-0.99 ng/mL, and 87 (24%) PSA ≥ 1.0 ng/mL. On multivariable analysis among men with PGG 1-2, pre-SRT PSA 0.2-0.49 ng/mL had similar outcomes as PSA 0.5-0.99 ng/mL; those with PSA ≥ 1.0 ng/mL had higher recurrence risks (hazard ratio = 2.78, P < .001). Among PGG 3-5, PSA 0.5-0.99 ng/mL or ≥ 1.0 ng/mL had a higher recurrence risk (hazard ratio = 2.15, P = .021; and hazard ratio = 2.49, P = .010, respectively) versus PSA 0.2-0.49 ng/mL.

CONCLUSION

In men with higher-grade prostate cancer (PGG 3-5), SRT should be provided earlier (PSA < 0.5 ng/mL), while among men with lower-grade disease (PGG 1-2), SRT results in equal PSA control up to PSA 1.0 ng/mL.

Obesity, risk of biochemical recurrence, and prostate-specific antigen doubling time after radical prostatectomy: results from the SEARCH database

OBJECTIVES

To examine the association between body mass index (BMI) and aggressive biochemical recurrence (BCR) using the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

MATERIAL AND METHODS

We identified 4123 men with complete data treated by radical prostatectomy between 1988 and 2015. We tested the association between BMI and BCR using Cox models, and among men with BCR, prostate-specific antigen doubling time (PSADT) was compared across BMI categories using linear regression. Models were adjusted for age, race, prostate-specific antigen, biopsy Gleason score, clinical stage, year and surgical centre.

RESULTS

Overall, 922 men (22%) were of normal weight (BMI <25 kg/m² ), 1863 (45%) were overweight (BMI 25-29.9 kg/m² ), 968 (24%) were obese (BMI 30-34.9 kg/m² ), and 370 (9%) were moderately or severely obese (BMI ≥35 kg/m² ). After adjustment for multiple clinical characteristics, higher BMI was significantly associated with higher risk of BCR (P = 0.008). Among men with BCR, men in the four BMI categories had similar multivariable-adjusted PSADT values (increasing BMI categories: 20.9 vs 21.3 vs 21.0 vs 14.9 months; P = 0.48).

CONCLUSION

While we confirmed that higher BMI was associated with BCR, we found no link between BMI and PSADT at the time of recurrence. Our data suggest obese men do not have more aggressive recurrences. Future studies are needed to test whether obesity predicts response to salvage therapies.

Radical prostatectomy and the effect of close surgical margins: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database

OBJECTIVE

To evaluate biochemical recurrence (BCR) patterns amongst men undergoing radical prostatectomy (RP) with specimens having negative (NSM), positive (PSM), and close surgical margins (CSM) from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort, as PSM after RP are a significant predictor of biochemical failure and possible disease progression, with CSM representing a diagnostic challenge for surgeons.

PATIENTS AND METHODS

Men undergoing RP between 1988 and 2015 with known final pathological margin status were evaluated. The cohort was divided into three groups based on margin status; NSM, PSM, and CSM. CSM were defined by distance of tumour ≤1 mm from the surgical margin. BCR was defined as a prostate-specific antigen (PSA) level of >0.2 ng/mL, two values at 0.2 ng/mL, or secondary treatment for an elevated PSA level. Predictors of BCR, metastases, and mortality were analysed using Cox proportional hazard models.

RESULTS

Of 5515 men in the SEARCH database, 4337 (79%) men met criteria for inclusion in the analysis. Of these, 2063 (48%) had NSM, 1902 (44%) had PSM, and 372 (8%) had CSM. On multivariable analysis, relative to NSM, men with CSM had a higher risk of BCR (hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.25-1.82; P < 0.001) but a decreased risk of BCR when compared to those men with PSM (HR 2.09, 95% CI 1.86-2.36; P < 0.001). Metastases, prostate cancer-specific mortality and all-cause mortality did not differ based on margin status alone.

CONCLUSIONS

Management of men with CSM is a diagnostic challenge, with a disease course that is not entirely benign. The evaluation of other known risk factors probably provides greater prognostic value for these men and may ultimately better select those who may benefit from adjuvant therapy.

Does Early Prostate Specific Antigen Doubling Time after Radical Prostatectomy, Calculated Prior to Prostate Specific Antigen Recurrence, Correlate with Prostate Cancer Outcomes? A Report from the SEARCH Database Group

PURPOSE

Short prostate specific antigen doubling time following recurrence after radical prostatectomy portends a poor prognosis. Prostate specific antigen doubling time is traditionally calculated using prostate specific antigen values 0.2 ng/ml or greater. We determined whether early prostate specific antigen doubling time, calculated from the first detectable postoperative prostate specific antigen up to and including the first recurrence value, correlates with prostate cancer outcomes.

MATERIALS AND METHODS

Cox models were used to examine the association between early prostate specific antigen doubling time and castration resistant prostate cancer, metastases, and all cause and prostate cancer specific mortality in 674 men who underwent radical prostatectomy between 1988 and 2014 and had a biochemical recurrence. Early prostate specific antigen doubling time was examined as a log transformed continuous and a categorical variable.

RESULTS

After adjusting for multiple clinicopathological characteristics, log transformed early prostate specific antigen doubling time was not associated with any outcome. However, when early doubling time was categorized as 15 or greater, 9 to 14.9, 3 to 8.9 and less than 3 months, on multivariable analysis men with early doubling time less than 3 months were at increased risk for castration resistant prostate cancer (HR 6.20, p = 0.004), metastases (HR 5.26, p = 0.001), prostate cancer specific mortality (HR 5.06, p = 0.026) and all cause mortality (HR 1.63, p = 0.065) compared to those with an early doubling time of 15 months or greater. However, the association with all cause mortality was not significant. Those with an early prostate specific antigen doubling time of 3 to 8.9 months were at increased risk for castration resistant prostate cancer (HR 3.56, p = 0.015), all cause mortality (HR 1.67, p = 0.006) and prostate cancer specific mortality (HR 3.17, p = 0.044) but not metastases (p = 0.13).

CONCLUSIONS

Early prostate specific antigen doubling time less than 9 months, calculated using prostate specific antigen values before and up to biochemical recurrence, is associated with an increased risk of castration resistant prostate cancer, metastases, and prostate cancer specific and all cause mortality among men with biochemical recurrence after radical prostatectomy. Early prostate specific antigen doubling time allows for risk stratification at biochemical recurrence and before prostate specific antigen doubling time is calculable, enabling these men to be referred for early aggressive secondary treatment and/or clinical trials.

Timing of Prostate-specific Antigen Nadir After Radical Prostatectomy and Risk of Biochemical Recurrence

OBJECTIVE

To evaluate the association between the prostate-specific antigen (PSA) nadir level and the time to nadir (TTN) with biochemical recurrence (BCR) risk after radical prostatectomy (RP) in the Shared Equal-Access Research Cancer Hospital (SEARCH) database.

MATERIALS AND METHODS

This is a retrospective analysis of 1939 men from the SEARCH database treated with RP between 1998 and 2015 with available ultrasensitive PSA nadir within 1-6 months after RP. Uni- and multivariable analyses of PSA nadir and TTN with time from nadir to BCR were performed with Cox models (adjusted for demographics, tumor features, and preoperative PSA).

RESULTS

Among men with an undetectable PSA nadir, the TTN was unrelated to BCR (1.0-2.9 vs 3-6 months: hazard ratio [HR] 0.86, P = .46). Regardless of TTN, men with detectable nadir had an increased risk of BCR (TTN of 3-6 months: HR 1.81, P = .024; TTN of 1.0-2.99 months: HR 3.75, P <.001 vs undetectable nadir and TTN of 3-6 months). Among men with a detectable PSA at 1-3 months, 53% had a lower PSA level during follow-up 3-6 months after RP, which was undetectable in 32% and lower but still detectable in 21%.

CONCLUSION

In the post-RP setting, men with both a detectable nadir and a shorter TTN had an increased risk of BCR. Intriguingly, about half of the men with a detectable PSA in the first 3 months after RP had a lower PSA level during follow-up between 3 and 6 months after RP. If confirmed in future studies, this has important implications for patients considering adjuvant therapy based on postoperative PSA values in the first 3 months after RP.

Validation of the 2015 prostate cancer grade groups for predicting long-term oncologic outcomes in a shared equal-access health system

BACKGROUND

A 5-tier prognostic grade group (GG) system was enacted to simplify the risk stratification of patients with prostate cancer in which Gleason scores of ≤6, 3 + 4, 4 + 3, 8, and 9 or 10 are considered GG 1 through 5, respectively. The authors investigated the utility of biopsy GG for predicting long-term oncologic outcomes after radical prostatectomy in an equal-access health system.

METHODS

Men who underwent prostatectomy at 1 of 6 Veterans Affairs hospitals in the Shared Equal Access Regional Cancer Hospital database between 2005 and 2015 were reviewed. The prognostic ability of biopsy GG was examined using Cox models. Interactions between GG and race also were tested.

RESULTS

In total, 2509 men were identified who had data available on biopsy Gleason scores, covariates, and follow-up. The cohort included men with GG 1 (909 patients; 36.2%), GG 2 (813 patients; 32.4%), GG 3 (398 patients; 15.9%), GG 4 (279 patients; 11.1%), and GG 5 (110 patients; 4.4%) prostate cancer. The cohort included 1002 African American men (41%). The median follow-up was 60 months (interquartile range, 33-90 months). Higher GG was associated with higher clinical stage, older age, more recent surgery, and surgical center (P < .001) as well as increased biochemical recurrence, secondary therapy, castration-resistant prostate cancer, metastases, and prostate cancer-specific mortality (all P < .001). There were no significant interactions with race in predicting measured outcomes.

CONCLUSIONS

The 5-tier GG system predicted multiple long-term endpoints after radical prostatectomy in an equal-access health system. The predictive value was consistent across races. Cancer 2017;123:4122-4129. © 2017 American Cancer Society.