Positive margins after radical prostatectomy: Implications for failure and role of adjuvant treatment

Factors affecting biochemical recurrence of prostate cancer after radical prostatectomy in patients with positive and negative surgical margin

Purpose

To investigate the clinical and pathological predictive factors affecting biochemical recurrence (BCR) after radical prostatectomy (RP) in patients with positive and negative surgical margin (SM).

Methods

Patients who underwent RP were retrospectively reviewed for the study. Demographic, clinical, pathological and oncological data were evaluated. All data were compared between patients with positive SM and negative SM to detect factors associated with SM status. Later, patients were divided into two groups as BCR-negative and BCR-positive groups. Data were separately compared between BCR groups for all patients, SM-negative and SM-positive patients, respectively.

Results

A total of 254 patients with a mean age of 63.5 years and the mean prostate-specific antigen of 10.9 ng/ml were evaluated in the study. SM positivity was found to be an independent prognostic factor for BCR (p = 0.013, Odds Ratio (OR): 0.267, 95% Confidence Interval (CI): 0.094-0.755). In SM-positive patients, biopsy Gleason Score and International Society of Urological Pathology grade were found to be independent predictive factors for BCR (p < 0.05). However, only tumor to SM distance (TSMD) was found to be an independent risk factor for BCR (p = 0.024) in SM-negative patients. The predictive cutoff value of the TSMD was found to be 75 μm for BCR (100% sensitivity and 63.9% specificity) (AUC = 0.803, p = 0.024). Although all of 46 patients with >75 μm TSMD were recurrence free, 5 of 31 patients with <75 μm TSMD had BCR (p = 0.009; OR: 0.839 CI: 0.719-0.979).

Conclusion

High Gleason Score and International Society of Urological Pathology grade of biopsy were found to be associated with BCR in SM-positive patients. For SM-negative patients, only TSMD was found to be associated with BCR after RP.

Prostate cancer: more effective use of underutilized postoperative radiation therapy

Introduction: Adverse pathological features at radical prostatectomy such as extracapsular extension, seminal-vesicle involvement, positive surgical margins and/or lymph node invasion define a particular subgroup of patients that might benefit from additional treatment after surgery, in particular radiation therapy.Areas covered: Post-prostatectomy radiation is intended as adjuvant, early-salvage or salvage depending on the timing and PSA levels at the treatment. After providing the most used definitions, the high-level evidence supporting adjuvant radiation is reviewed together with the limitations affecting its utilization. In recent years early-salvage radiation was hypothesized to be a non-inferior alternative based on good-quality retrospective data. Recently, preliminary results of ongoing trials provide additional evidence. In light of the need to identify patients that will truly benefit from adjuvant radiation, clinically based and molecular tools available for this purpose are reviewed.Expert opinion: In order to tailor treatment for the patient after radical prostatectomy, there is a need for a tool that could both improve the oncological outcomes and be cost-effective. To date, genomic testing provides the most promising results that will be reasonably improved in the coming years.

The impact of single positive surgical margin features on biochemical recurrence after robotic radical prostatectomy

OBJECTIVE

Parameters predictive of biochemical or clinical recurrence after Radical Prostatectomy (RP) were determined as pre-treatment PSA value, pathologic tumor stage, tumor grade and presence of Positive Surgical Margin (PSM), extracapsular extension and seminal vesicle invasion and the status of pelvic lymph nodes. The aim of our study is to evaluate the effect of additional features in patients undergoing RP in our clinic.

MATERIALS AND METHODS

We studied 556 RP operations performed between 2009 and 2016 for prostate cancer at this clinic. Preoperative and postoperative data of the patients were retrospectively reviewed. RP specimens were examined by two pathologists specialized in this subject. Of these patients, 78 (14.02%) patients with PSM were included in the study. The pathology slides of these patients were reassessed. The length of PSM (mm), localization (apex, basis and posterolateral) and Gleason pattern at this margin was determined and statistical correlations with BCR were calculated.

RESULTS

The mean follow-up after the RP of 41 patients included in the study was 37.4 ± 13.2 months. During the follow-up period of the patients, BCR was observed in 16 patients (39.02%). No statistically significant difference was observed in age and prostate volume between the groups with and without BCR development (p > 0.05). Preoperative PSA level was found to be statistically significantly higher in the group with BCR development compared to the group without recurrence (p = 0.004). In-group comparisons in each aforementioned Gleason score groups were performed in terms of BCR development and the preoperative Gleason score in the group with development of recurrence was found to be statistically significantly higher compared to the group without recurrence (p = 0.007). The length of the surgical margin was measured as 7.4 ± 4.4 mm in the BCR-developing group and 4.7 ± 3.8 mm in the no-BCR- developing group; it was statistically significantly higher in the group with development of recurrence (p = 0.03).

CONCLUSION

Length and location of the PSM and the Gleason score detected in the PSM region could not predict biochemical recurrence according to the results of this present study. However high preoperative PSA value is an independent prognostic factor for biochemical recurrence.

Improving postoperative radiotherapy following radical prostatectomy

INTRODUCTION

Prostate cancer has one of the highest incidences in the world, with good curative treatment options like radiotherapy and radical prostatectomy. Unfortunately, about 30% of the patients initially treated with curative intent will develop a recurrence and need adjuvant treatment. Five randomized trials covered the role of postoperative radiotherapy after radical prostatectomy, but there is still a lot of debate about which patients should receive postoperative radiotherapy. Areas covered: This review will give an overview on the available literature concerning post-operative radiotherapy following radical prostatectomy with an emphasis on the five randomized trials. Also, new imaging techniques like prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mp-MRI) and the development of biomarkers like genomic classifiers will be discussed in the search for an improved selection of patients who will benefit from postoperative radiotherapy following radical prostatectomy. With new treatment techniques like Intensity Modulated Radiotherapy, toxicity profiles will be kept low. Expert commentary: Patients with biochemical recurrence following radical prostatectomy with an early rise in prostate-specific antigen (PSA) will benefit most from postoperative radiotherapy. In this way, patients with only high risk pathological features can avoid unnecessary treatment and toxicity, and early intervention in progressing patients would not compromise the outcome.

Theranostic Agents for Photodynamic Therapy of Prostate Cancer by Targeting Prostate-Specific Membrane Antigen

Prostatectomy has been the mainstay treatment for men with localized prostate cancer. Surgery, however, often can result in major side effects, which are caused from damage and removal of nerves and muscles surrounding the prostate. A technology that can help surgeons more precisely identify and remove prostate cancer resulting in a more complete prostatectomy is needed. Prostate-specific membrane antigen (PSMA), a type II membrane antigen highly expressed in prostate cancer, has been an attractive target for imaging and therapy. The objective of this study is to develop low molecular weight PSMA-targeted photodynamic therapy (PDT) agents, which would provide image guidance for prostate tumor resection and allow for subsequent PDT to eliminate unresectable or remaining cancer cells. On the basis of our highly negatively charged, urea-based PSMA ligand PSMA-1, we synthesized two PSMA-targeting PDT conjugates named PSMA-1-Pc413 and PSMA-1-IR700. In in vitro cellular uptake experiments and in vivo animal imaging experiments, the two conjugates demonstrated selective and specific uptake in PSMA-positive PC3pip cells/tumors, but not in PSMA-negative PC3flu cells/tumors. Further in vivo photodynamic treatment proved that the two PSMA-1-PDT conjugates can effectively inhibit PC3pip tumor progression. The two PSMA-1-PDT conjugates reported here may have the potential to aid in the detection and resection of prostate cancers. It may also allow for the identification of unresectable cancer tissue and PDT ablation of such tissue after surgical resection with potentially less damage to surrounding tissues. Mol Cancer Ther; 15(8); 1834-44. ©2016 AACR.

Does the distance between tumor and margin in radical prostatectomy specimens correlate with prognosis: relation to tumor location

The posterior half of the prostate has a smooth well-defined edge unlike anteriorly. Often, tumor extends close to the posterior margin, where it is controversial whether pathologists should measure the distance between the tumor and the margin. There are no published data regarding the significance of a close margin factoring in the anatomical location within the radical prostatectomy (RP). We identified 158 RPs with 39 anterior-predominant carcinomas and 119 cases with posterior-predominant cancer. Distances between the tumor and inked margin were measured with an ocular micrometer. Eighty-seven cases had no progression with a minimum 6-year follow-up (median, 8; range, 6-9). Eighteen cases had progression with a median time to progression of 2 years with all men progressing within 6 years after RP. There was no statistically significant difference in the risk of progression relative to distance of tumor to the posterior margin (P=.09). The mean distance of tumor to the anterior margin for the cases that progressed was 0.6 mm (median, 0.5 mm; range, 0.05-1.18) compared to 1.9 mm (median, 1.1; range, 0.02-4) for the cases that did not progress (P=.02). Of 7 cases with anterior-predominant tumors that progressed, 5 had tumor located less than 1 mm from the anterior margin. In conclusion, if cancer is present less than 1 mm from the anterior margin, there is an increased tendency to recur, and this finding should be included in pathology reports. However, close margins posteriorly are not clinically significant and should not be reported.

Margin details matter: The prognostic significance of pseudocapsule invasion at the site of involved margin in prostatectomy specimens

BACKGROUND

An involved surgical margin at prostatectomy has long been associated with elevated risk of prostate cancer recurrence; however, not all patients with an involved margin will relapse, and thus details of the involved margin may provide an opportunity for risk subset stratification. The present investigation seeks to determine whether a difference exists in recurrence rates when the margin involvement is at a site of prostate pseudocapsule invasion vs. within the prostate parenchyma proper.

METHODS

Patients were retrospectively identified for inclusion by clinically localized disease and prostate-specific antigen (PSA) level of< 30 ng/ml at diagnosis, managed with prostatectomy alone and identified to have involvement of surgical margin(s). Exclusion criteria were: pT3b or pN1 disease, immediate/nonsalvage postoperative radiation or hormone therapy, or insufficient follow-up (<12 mo). Pathology slides were reviewed by a pathologist blinded to outcome, for determination of pseudocapsule invasion at a site of margin involvement. Disease recurrence was defined as PSA level of ≥ 0.2 ng/ml and rising, per contemporary guidelines. Kaplan-Meier method was used for construction of disease control estimate confidence intervals; Cox Proportional Hazards Model was used to compare disease control across groups.

RESULTS

Between 2003 and 2010, 155 patients were identified for inclusion in the present study. The median age was 61 years, and all had clinical stage T1 and T2 disease (75% T1c). At diagnosis, the Gleason score was 6, 7, and 8-9 for 103 (66%), 42 (27%), and 10 (6%) patients, respectively, with median PSA level of 5.6 ng/ml (85%≤ 10). For 149 patients with reviewable margin site data, 51 (34%) demonstrated involvement within or beyond the pseudocapsule. At a median follow-up of 68 months (range: 13-137), 62 patients had experienced PSA relapse. The estimated 5-year PSA relapse rates for patients with an involved margin at the site of pseudocapsule invasion vs. prostate parenchyma were 49% vs. 34%, respectively (P = 0.017; hazard ratio = 1.853).

CONCLUSIONS

Early PSA relapse rates are high for patients with involved surgical margin(s) without seminal vesicle or node involvement at prostatectomy; however, for patients who are followed without immediate adjuvant therapy, presence of tumor cells at the margin in a site of pseudocapsule invasion or penetration confers a higher risk of recurrence.

Development of targeted near-infrared imaging agents for prostate cancer

Prostate cancer is the most common noncutaneous malignancy affecting men in North America. Radical prostatectomy remains a definitive treatment for prostate cancer. However, prostate surgeries are still performed "blindly" with the extent of tumor infiltration past the margins of the surgery only being determined postoperatively. An imaging modality that can be used during surgery is needed to help define the tumor margins. With its abundant expression in prostate cancer, prostate-specific membrane antigen (PSMA) is an ideal target for detection of prostate cancer. The purpose of this study was to develop PSMA-targeted near-infrared (NIR) optical imaging probes for intraoperative visualization of prostate cancer. We synthesized a high-affinity PSMA ligand (PSMA-1) with low molecular weight and further labeled it with commercially available NIR dyes IRDy800 and Cy5.5. PSMA-1 and PSMA-1-NIR conjugates had binding affinities better than the parent ligand Cys-CO-Glu. Selective binding was measured for each of the probes in both in vitro and in vivo studies using competitive binding and uptake studies. Interestingly, the results indicated that the pharmacokinetics of the probes was dependent of the fluorophore conjugated to the PSMA-1 ligand and varied widely. These data suggest that PSMA-targeted probes have the potential to be further developed as contrast agents for clinical intraoperative fluorescence-guided surgery.

Radical prostatectomy in high-risk prostate cancer: incidence of specimen-confined disease (pT2-pT3a N0R0) and outcomes

INTRODUCTION

Radical prostatectomy (RP) in patients with high-risk prostate cancer (PC) [prostate specific antigen (PSA) ≥ 20 ng/mL, and/or Gleason score ≥ 8, and/or cT3a disease] is considered an optional therapy, usually as a part of multimodal approach. Aim of the study is to evaluate the outcome of radical prostatectomy in case of specimen-confined (SC) disease and to compare it with patients with pathological locally-advanced disease.

MATERIALS AND METHODS

Data from 176 consecutive patients with high-risk prostate cancer who underwent RP as initial therapy were analyzed, identifying subjects with specimen-confined disease (i.e. negative margins and negative lymph-nodes) in which RP was considered as monotherapy, and comparing oncological outcomes to patients with pathological non-SC disease, in which RP was considered as the first step of a multimodal approach.

RESULTS

In high-risk prostate cancer, pathological report showed the presence of specimen-confined disease in 28.3% of cases. At univariate analysis, age and PSA correlate with the presence of SC disease at radical prostatectomy, while at multivariate analysis only PSA was a significant predictor of SC disease. At 5 years, Kaplan-Meier estimation of biochemical-free and cancer-specific survival was 56.2% and 97.7% vs 40.8% and 92.8% in specimen-confined disease and non-specimen-confined disease, respectively.

CONCLUSIONS

High-risk prostate cancer presents challenges for uro-oncologists since standard treatment is still under debate. One third of patients will present with specimen-confined disease, for which radical prostatectomy represents the sole, initial curative therapy; RP as multimodal therapy in patients without SC disease permits excellent long-term oncological outcomes.