Prediction of Radioresistant Prostate Cancer Based on Differentially Expressed Proteins

Recurrent Gleason Score 6 Prostate Cancer After Radiotherapy or Ablation: Should We Observe Them All? Results from a Large Multicenter Salvage Radical Prostatectomy Consortium

BACKGROUND

Salvage radical prostatectomy (sRP) yields poor functional outcomes and relatively high complication rates. Gleason score (GS) 6 prostate cancer (PCa) has genetic and clinical features showing little, if not absent, metastatic potential. However, the behavior of GS 6 PCa recurring after previous PCa treatment including radiotherapy and/or ablation has not been investigated.

OBJECTIVE

To evaluate the oncological outcomes of sRP for radio- and/or ablation-recurrent GS 6 PCa.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective data of sRP for recurrent PCa after local nonsurgical treatment were collected from 14 tertiary referral centers from 2000 to 2021.

INTERVENTION

Prostate biopsy before sRP and sRP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A survival analysis was performed for pre-sRP biopsy and sRP-proven GS 6. Concordance between PCa at pre-sRP biopsy and sRP histology was assessed.

RESULTS AND LIMITATIONS

We included GS 6 recurrent PCa at pre-sRP biopsy (n = 142) and at sRP (n = 50), as two cohorts. The majority had primary radiotherapy and/or brachytherapy (83.8% of GS 6 patients at pre-sRP biopsy; 78% of GS 6 patients at sRP) and whole-gland treatments (91% biopsy; 85.1% sRP). Biopsy GS 6 10-yr metastasis, cancer-specific survival (CSS), and overall survival (OS) were 79% (95% confidence interval [CI] 61-89%), 98% (95-99%), and 89% (78-95%), respectively. Upgrading at sRP was 69%, 35.5% had a pT3 stage, and 13.4% had positive nodes. The sRP GS 6 10-yr metastasis-free survival, CSS, and OS were 100%, 100%, and 90% (95% CI 58-98%) respectively; pT3 and pN1 disease were found in 12% and 0%, respectively. Overall complications, high-grade complications, and severe incontinence were experienced by >50%, >10%, and >15% of men, respectively (in both the biopsy and the sRP cohorts). Limitations include the retrospective nature of the study and absence of a centralized pathological review.

CONCLUSIONS

GS 6 sRP-proven PCa recurring after nonsurgical primary treatment has almost no metastatic potential, while patients experience relevant morbidity of the procedure. However, a significant proportion of GS 6 cases at pre-sRP biopsy are upgraded at sRP. In the idea not to overtreat, efforts should be made to improve the diagnostic accuracy of pre-sRP biopsy.

PATIENT SUMMARY

We investigated the oncological results of salvage radical prostatectomy for recurrent prostate cancer of Gleason score (GS) 6 category. We found a very low malignant potential of GS 6 confirmed at salvage radical prostatectomy despite surgical complications being relatively high. Nonetheless, biopsy GS 6 was frequently upgraded and had less optimal oncological control. Overtreatment for recurrent GS 6 after nonsurgical first-line treatment should be avoided, and efforts should be made to increase the diagnostic accuracy of biopsies for recurrent disease.

Importance of magnetic resonance imaging and prostate-specific membrane antigen PET-CT in patients treated with salvage radical prostatectomy for radiorecurrent prostate cancer

BACKGROUND

Accurate staging and identification of optimal candidates for local salvage therapy, such as salvage radical prostatectomy (SRP), is necessary to ensure optimal care in patients with radiorecurrent prostate cancer (PCa). We aimed to analyze performance of magnetic resonance imaging (MRI) and prostate-specific membrane antigen (PSMA)-positron emission tomography (PET)/computed tomography (CT) for predicting pathologic nonorgan confined disease (pT3) and lymph node involvement (pN+) in patients treated with SRP for radiorecurrent PCa.

METHODS

We retrospectively reviewed the institutional database to identify patients who underwent MRI or ⁶⁸ Ga-PSMA-PET/CT before SRP for radiorecurrent PCa. The diagnostic estimates of MRI and PSMA-PET/CT for pT3 and pN+, were calculated.

RESULTS

We identified 113 patients with radiorecurrent PCa who underwent preoperative MRI followed by SRP; 53 had preoperative ⁶⁸ Ga-PSMA-PET/CT. For the detection of pT3 disease, the overall accuracy of MRI was 70% (95% confidence interval [CI] 61-78), sensitivity 40% (95% CI 26-55) and specificity 94% (95% CI 85-98); PSMA-PET/CT had slightly higher accuracy of 77% (95% CI 64-88), and higher sensitivity of 90% (95% CI 68-99), but lower specificity of 70% (95% CI 51-84). For pN+ disease, MRI had poor sensitivity of 14% (95% CI 3-36), specificity of 50 (95% CI 39-61) and total accuracy of 43% (95% CI 34-53); PSMA-PET/CT had an accuracy of 85% (95% CI 72-93), sensitivity of 27% (95% CI 6-61), and specificity of 100% (95% CI 92-100).

CONCLUSION

In patients with radiorecurrent PCa, both, MRI, and ⁶⁸ Ga-PSMA PET/CT are valuable tools for the pre-SRP staging and should be integrated into the standard workup. For lymph node metastases, ⁶⁸ Ga-PSMA PET/CT is a strong rule-in test with nearly perfect specificity; in contrast MRI had a low accuracy for lymph node metastases.

Outcomes with brachytherapy based dose escalation for gleason 8 versus 9-10 prostate cancer: An NCDB analysis

INTRODUCTION

The addition of brachytherapy (BT) in high risk prostate cancer is supported by Level 1 evidence. Whether all high risk patients benefit from BT to the same extent is unknown. The National Cancer Database (NCDB) was used to investigate overall survival (OS) differences between GS 8 and 9-10 treated with external beam radiation (EBRT) only or BT +/- EBRT.

MATERIALS AND METHODS

We included localized prostate adenocarcinoma definitively treated with radiation between 2004-2014. Patients were stratified into various radiation treatment groups: EBRT 7560 - 8640 cGy, EBRT 5940 - 7540 cGy, and BT +/- EBRT. All EBRT only and BT +/- EBRT patients received ADT. A multivariable Cox proportional hazard model was used to assess OS. Propensity score matching was used to account for differences between groups. Median survival was determined based on Kaplan-Meier survival curves.

RESULTS

30,698 patients were included. On multivariable analysis among GS 8 patients, BT was associated with improved OS compared to 7560 - 8640 cGy (HR-0.80 (95% CI 0.70-0.92, P = 0.002). In Gleason 9-10 BT did not result in improved OS compared to 7560 - 8640 cGy (HR- 0.91 (95% CI 0.79 - 1.05, P = 0.212). Results remained significant with propensity score matching and removing patients with medical comorbidities.

CONCLUSION

BT was associated with improved OS when compared to 7560 - 8640 cGy in GS 8, but not in Gleason 9-10 disease. This hypothesis generating study suggests there may be variable benefit with BT in high risk prostate cancer patients on OS. Future prospective studies are needed to investigate whether the benefit of BT is similar across all high risk prostate cancer patients.