Prognostic Impact of Pelvic Lymph Node Dissection During Radical Prostatectomy on Patients With High-risk Prostate Cancer Treated With Neoadjuvant Chemohormonal Therapy

BackgroundWe aimed to determine the prognostic and staging benefit of limited pelvic lymph node dissection (PLND) during radical prostatectomy (RP) in high-risk prostate cancer (PC) patients treated with neoadjuvant chemohormonal therapy.MethodsWe retrospectively analyzed 516 patients with high-risk localized PC (<cT4N0M0) who received neoadjuvant androgen-deprivation therapy plus estramustine phosphate followed by RP between January 2010 and March 2020. Since we stopped limited-PLND for such patients in October 2015, we compared the biochemical recurrence-free survival (BCR-FS) between the limited-PLND group (before October 2015, n = 283) and the non-PLND group (after November 2015, n = 233).ResultsThe rate of node metastases in the limited-PLND group were 0.8% (2/283). Operation time was significantly longer (176 vs. 162 min) and the rate of surgical complications were much higher (all grades; 19 vs. 6%, grade ≥ 3; 3 vs. 0%) in the limited-PLND group. The inverse probability of treatment weighting-Cox analysis revealed limited PLND had no significant impact on BCR-FS (hazard ratio, 1.31; P = 0.421).ConclusionsLimited PLND during RP after neoadjuvant chemohormonal therapy showed a relatively low rate of positive nodes, higher rate of complications, and no significant impact on BCR-FS.

Neoadjuvant Chemohormonal Therapy before Radical Prostatectomy for Japanese Patients with High-Risk Localized Prostate Cancer

Background: Radical prostatectomy (RP) is the standard treatment in patients with high-risk prostate cancer (PCa). However, there is a high rate of recurrence, and new approaches are required to improve surgical efficacy. Here, we evaluated the feasibility and safety of neoadjuvant chemohormonal therapy (NCHT) before RP for Japanese patients with high-risk localized prostate cancer (PCa). Methods: From February 2009 to April 2016, 21 high-risk patients were enrolled in this prospective study. Patients were treated with docetaxel (70 mg/m2) every four weeks for three cycles and luteinizing hormone-releasing hormone agonist. Patients with grade 3–4 toxicities had 25% dose reductions for the following course. Results: Median follow-up was 88.6 months. The dose of docetaxel was reduced in 13 patients. The estimated five-year biochemical progression-free survival (bPFS) rate was 57.1%. National Comprehensive Cancer Network criteria (high-risk, but not very high-risk (nVHR) versus VHR) was associated with bPFS (p = 0.03). Five-year bPFS rates in the nVHR and VHR groups were 76.9% and 25.0%, respectively. There was a significant difference in bPFS between the nVHR and VHR groups (p = 0.023) by Kaplan–Meier analysis. Conclusions: Although our study included a small number of cases, at least in our exploration, NCHT was safe and feasible. However, more extensive treatment modalities are needed to improve outcomes, especially in VHR patients.

UnCHAARTED territory: The role of docetaxel rechallenge following chemohormonal therapy for metastatic castrate-sensitive prostate cancer.

117 Background: Since docetaxel has been advanced to the metastatic castrate-sensitive prostate cancer (mCSPC) setting, there is a lack of evidence guiding its re-introduction upon castrate-resistant (CR) progression. We sought to identify clinical characteristics and outcomes of patients subjected to docetaxel rechallenge (DR) following prior docetaxel exposure in the mCSPC realm. Methods: Patients rechallenged with docetaxel following treatment in the mCSPC setting were identified from three academic centres in Ontario, Canada. Retrospective chart reviews were performed to identify clinical, treatment and outcome variables. Results: Of the 45 patients with DR initiated between 06/2015 and 07/2020, the median age was 65, 60% had a Gleason score of ≥8, and 64% had an ECOG of ≤1. 56% had bone only metastasis, 4% lymph node only metastasis, 29% bone and lymph node metastasis, and 11% had visceral metastasis. In the mCSPC setting, 98% of patients received 6 cycles of docetaxel with 13% requiring dose delays. Of 43 informative patients, all had a PSA response to chemohormonal therapy. 91% achieved at least a 50% PSA response (PSA50), of which 40% had a 50-89% PSA reduction and 51% had a ≥90% PSA reduction. 29% of patients obtained a PSA nadir of < 0.2 ng/mL. 16% had CR progression in < 6 months, 56% in 6-12 months, and 28% in > 12 months. DR was initiated after a median of 20.8 months (range 6.0-40.4) following the last dose of docetaxel for mCSPC, and was given as first line treatment for CR disease to 7%, second line to 51%, third line to 40%, and fourth line or beyond to 2% of patients. 69% of patients had received an androgen-receptor axis targeted therapy prior to DR, 18% radium 223, and 7% had received a trial drug. Notably, no patients had received cabazitaxel prior to DR. The median number of cycles of docetaxel received at rechallenge was 5 (range 1-11) with 18% of patients requiring treatment delays. 64% of patients stopped treatment due to progression, 16% due to side effects, 7% at the patient’s request, 7% due to completion of the planned number of cycles, and 6% due to death or other causes. Among 44 informative patients, 23% achieved at least a PSA50, with 18% having a 50-90% PSA reduction, and 5% having a ≥90% PSA reduction. The median time to progression (biochemical, radiographic, or death) was 2.3 months (95%CI 1.7-4.4) and the median overall survival was 11.0 months (95%CI 8.5-14.3). Conclusions: DR following exposure to docetaxel in the mCSPC setting resulted in a PSA50 in only around one quarter of patients. Both the median time to progression and overall survival were found to be short. With future investigations, we hope to identify clinical variables that will help predict which patients might benefit most from DR.

Preoperative predictors of biochemical recurrence in a phase II trial of neoadjuvant therapy in very high-risk prostate cancer.

74 Background: Understanding the lethal nature of high risk prostate cancer, there is a need for the development of multimodal therapies. Prior studies have confirmed a survival benefit with the addition of docetaxel to androgen deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer (HSPC). We conducted a Phase II trial enrolling men with very high risk localized, locally advanced or oligometastatic prostate cancer (PC) to examine resistance and response to neoadjuvant chemohormonal therapy. This analysis aims to identify the preoperative predictors of biochemical recurrence (BCR). Methods: UW17009 is an IRB-approved open-label, single-arm trial that recruited 26 men with newly diagnosed advanced PC. Patients received ADT and docetaxel for 3 months followed by prostatectomy. The primary endpoint was pathologic complete response rate. A secondary clinical objective was the rate of PSA recurrence 12 months after surgery. The pre-trial PSAs, age, cancer grade, stage, percent tumor involvement of the initial biopsy, metastatic disease on conventional and 18F-DCFPyL PSMA (DCFPyL) PET/CT and MRI imaging, completion of chemohormonal therapy and PSA nadirs following chemohormonal therapy were assessed in relationship to biochemical recurrence. One way ANOVA was used to evaluate differences among continuous values: age, PSA at diagnosis, percent tumor involvement, and PSA nadir after chemo ADT. Fisher’s exact tests were used to evaluate the differences among categorical variables: stage at diagnosis, positive bone scan, and positive PSMA PET. Results: 26 patients were enrolled and underwent neoadjuvant treatment, radical prostatectomy (RP) and lymph node dissection. The median age was 62 (IQR 58-66), mean PSA at diagnosis was 32.8 ng/dl and 88.4% had Gleason 9 cancer. At study initiation, 12/26 patients had metastatic disease detected by DCFPyL-based PSMA PET. Final pathology demonstrated 81%(21/26) had ≥ pT3 and 73%(19/26) patients had negative margins. Positive lymph nodes were found in 10/26(38.5%) patients on final pathology. At week 6 after surgery, 91%(24/26) had undetectable PSA. At a mean follow up of 12.1 months(5.2-21.4), the biochemical recurrence rate is 58%(15/26). Features associated with BCR include stage, % tumor involvement, and positive PSMA PET scan. All patients with positive margins and 9/10 patients with positive nodes at final pathology developed BCR at a mean follow up of 12 months. Conclusions: In this neoadjuvant cohort, stage T2c, elevated PSA, positive pre-operative PSMA PET/CT, and PSA nadir > 1 following chemohormonal therapy predict biochemical recurrence. Clinically, and in the short term, neoadjuvant chemohormonal therapy prior to definitive surgery for very high risk localized and/or oligometastatic PC generates local tumor control with a high rate of negative surgical margins.

Chemohormonal Therapy in Metastatic Hormone-Sensitive Prostate Cancer

This chapter summarizes the findings of the landmark Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) trial conducted in men with metastatic, hormone-sensitive prostate cancer comparing docetaxel therapy plus systemic androgen-deprivation therapy to androgen-deprivation therapy alone. It demonstrated improved median overall survival and median time to progression in the chemotherapy arm at the price of some increased severe adverse events.

Pathologic response to neoadjuvant therapy of high risk prostate cancer

Background. The role of pathological response, which develops as a result of systemic therapy for localized and locally advanced high risk prostate cancer, is not still fully understood. There are no clear indications for neoadjuvant therapy and no data on the relationship between neoadjuvant therapy and median of overall or progression free survival. According to increasing interest for neoadjuvant chemohormonal therapy followed by radical prostatectomy, we evaluated the features of pathological response and its effects on overall and progression free survival rates.Objective. Estimating residual disease and pathologic response to neoadjuvant therapy of high risk prostate cancer and its relationship with oncological results.Materials and methods. This was a prospective randomized study: patients with prostate cancer of high and very high-risk groups (prostate specific antigen levels >20 ng/ml and/or Gleason score ≥8 and/or clinical stage ≥T2c) were treated with neoadjuvant chemohormonal therapy followed by radical prostatectomy (n = 36). The neoadjuvant course included the intravenous administration of docetaxel once every 21 days (75 mg/m2 up to 6 cycles) and the antagonist of the gonadotropin releasing hormone degarelix according to the standard scheme (6subcutaneous injections every 28 days). The prostate tissue was evaluated for the residual disease, features of pathological response according to the ABC system. Additionally, the expression of IHC markers (p53, bcl-2, p16, Ki-67, androgen receptors, c-MYC, ERG, PTEN) was evaluated on postoperative material using tissue microarray.Results. A totally of 480 H&Epostoperative and 775 H&E biopsy slides were analyzed. Group A included 10 (32.3 %) cases, group B — 16 (51.6 %), and group C — 5 (16.1 %). The variance analysis revealed a significant difference in the frequency of more localized forms of prostate cancer in group B (43.7 %) (p = 0.028). During assessment we did not found any relationship ABC system assignment and preoperative prostate specific antigen level, the presence of a positive surgical margin, the pathological stage of diseases or regional lymph nodes involvement. However, the values of relapse-free survival vary sharply between groups: the highest median of relapse-free survival was found in group B — 23.02 ± 12.61 months, patients of groups A/C could not achieve the level of median relapse-free survival — 11.7 ± 6.43 and 16.19 ± 16.54 months respectively.Conclusion. The effectiveness of neoadjuvant chemohormonal therapy for high risk prostate cancer can be assessed by the features of pathologic response through ABC system which has demonstrated own versatility and reproducibility in presented material. Neoadjuvant therapy with docetaxel and degarelix can improve the treatment outcomes of prostate cancer patients at high and very high risk of disease progression. The data on changes in the prostate tissue can be helpful in predicting the duration of the effect after chemohormonal therapy with subsequent surgery.