Natural history of 'second' biochemical failure after salvage radiation therapy for prostate cancer: a multi-institution study.

OBJECTIVES: To describe the natural history of prostate cancer in men who experience a second biochemical recurrence (BCR) after salvage radiotherapy (SRT) after prostatectomy. PATIENTS AND METHODS: After undergoing SRT at one of two institutions between 1986 and 2013, 286 patients experienced a second BCR, defined as two rises in prostate-specific antigen (PSA) of ≥0.2 ng/mL above nadir. Event rates for distant metastasis (DM) or freedom from DM (FFDM), castration-resistant prostate cancer (CRPC), prostate cancer-specific survival (PCSS), and overall survival (OS) were estimated using the Kaplan-Meier method. Cox regression was used for comparative analyses. RESULTS: At a median of 6.1 years after second BCR, DM, CRPC, PCSS and OS rates were 41%, 27%, 83% and 73%, respectively. On multivariable analysis, interval to second BCR <1 year (hazard ratio [HR] 2.66, 95% confidence interval [CI] 1.71-4.14; P < 0.001], Gleason score 8-10 (HR 1.65, 95% CI 1.07-2.54; P = 0.022), and concurrent ADT during SRT (HR 1.76, 95% CI 1.08-2.88; P = 0.024) were associated with FFDM, while PCSS was associated with interval to second BCR <1 year (HR 3.00, 95% CI 1.69-5.32; P < 0.001) and concurrent ADT during SRT (HR 2.15, CI 1.13-4.08; P = 0.019). These risk factors were used to stratify patients into three groups, with 6-year FFDM rates of 71%, 59% and 33%, and PCSS rates of 89%, 79%, and 65%, respectively. CONCLUSION: Following second BCR after SRT, clinical progression is enriched in a subgroup of patients with prostate cancer, while others remain without DM for long intervals. Stratifying patients into risk groups using prognostic factors may aid counselling and future trial design.

Erectile function after stereotactic body radiotherapy for localized prostate cancer.

OBJECTIVE: To elucidate the functional erection rate after prostate stereotactic body radiotherapy (SBRT) and to develop a comprehensive prognostic model of outcomes after treatment. PATIENTS AND METHODS: Between 2008 and 2013, 373 consecutive men with localized prostate cancer were treated with SBRT at a single academic institution as part of a prospective clinical trial or prospective registry. Prospective longitudinal patient-reported health-related quality of life (HRQoL) data was collected using the Expanded Prostate Cancer Index Composite (EPIC)-26 instrument. Functional erections were strictly defined as 'firm enough for intercourse' according to EPIC-26. Detailed comorbidity data were also collected. Logistic regression models were used to predict 24- and 60-month functional erection rates. Observed erection rates after SBRT were compared with those after other radiation therapies (external beam radiation therapy [EBRT] and brachytherapy) using prospectively validated models. RESULTS: The median (interquartile range) follow-up was 56 (37-73) months and the response rate at 2 years was 84%. For those with functional erections at baseline, 57% and 45% retained function at 24 and 60 months, respectively. On multivariable analysis for 24-month erectile function, significant variables included higher baseline sexual HRQoL (adjusted odds ratio [aOR] 1.55 per 10 points, 95% confidence interval [CI] 1.37-1.74; P < 0.001) and older age (aOR 0.66 per 10 years, 95% CI 0.43-1.00; P = 0.05). At 60 months, baseline HRQoL and age remained associated with erectile function, along with body mass index (aOR 0.45, 95% CI 0.26-0.78; P < 0.001). The 24- and 60-month models had excellent discrimination (c-index 0.81 and 0.84, respectively). Erection rates after SBRT were not statistically different from model-predicted rates after EBRT or brachytherapy for the whole cohort and the cohort with baseline erectile function. CONCLUSIONS: Intermediate- to long-term post-SBRT erectile function results are promising and not significantly different from other radiotherapy techniques. Clinicians can use our prognostic model to counsel patients regarding expected erectile function after SBRT.

Programmed Death-ligand 1 Expression in Upper Tract Urothelial Carcinoma.

BACKGROUND: Urothelial carcinoma (UC) is the most common malignancy of the urinary tract. Upper tract (renal pelvis and ureter) urothelial carcinomas (UTUC) account for approximately 5% of UCs but a significant subset are invasive and associated with poor clinical outcomes. OBJECTIVE: To evaluate programmed death-ligand 1 (PD-L1) expression in UTUC. DESIGN, SETTING, AND PARTICIPANTS: UTUC cases from 1997-2016 were retrospectively identified from the surgical pathology database at a single large academic institution. The cohort included 149 cases: 27 low-grade and 24 high-grade pathologic T (pT)a, 29 pT1, 23 pT2, 38 pT3, and eight pT4. PD-L1 immunohistochemistry (IHC) was performed on representative whole tumor sections using anti-PD-L1 primary antibody clone 5H1. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PD-L1 expression was evaluated using a previously established cut-off for positivity (≥ 5% membranous staining). Association between PD-L1 IHC expression and clinicopathologic parameters was examined with Fisher's exact test; the effect of PD-L1 expression on cancer-specific mortality was assessed using the Cox proportional hazard model. RESULTS AND LIMITATIONS: Approximately one-third (32.7%) of invasive primary UTUC and 23.5% of all primary UTUC (invasive and noninvasive tumors) demonstrated positive PD-L1 expression. Positive PD-L1 expression was associated with high histologic grade, high pathologic stage, and angiolymphatic invasion. Cancer-specific survival was not significantly associated with positive PD-L1 expression using a 5% cut-off. Study limitations include the retrospective nature and the fact that PD-L1 expression by IHC is an imperfect surrogate for response to therapy. CONCLUSIONS: Positive PD-L1 expression in approximately one-third of primary invasive UTUC and association with high-risk clinicopathologic features provide a rational basis for further investigation of PD-L1-based immunotherapeutics in these patients. PATIENT SUMMARY: Upper tract urothelial carcinoma is often associated with poor clinical outcome. While current treatment options for advanced upper tract urothelial carcinoma are limited, programmed death-ligand 1 positivity in approximately one-third of invasive tumors provides a rational basis for further investigation of programmed death-ligand 1-based immunotherapeutics in these patients.

External beam radiation therapy with or without low-dose-rate brachytherapy: Analysis of favorable and unfavorable intermediate-risk prostate cancer patients.

PURPOSE: To compare the tumor control and toxicity in men with intermediate-risk prostate cancer treated with either external beam radiation therapy (EBRT) or EBRT plus low-dose-rate brachytherapy (combo-RT). METHODS AND MATERIALS: Between 1995 and 2012, 579 men with intermediate-risk prostate cancer were treated with either EBRT (n = 388) or combo-RT (n = 191). Outcomes assessed included biochemical recurrence-free survival (bRFS), distant metastasis-free survival (DMFS), and cumulative incidence of genitourinary (GU) and gastrointestinal toxicity. Favorable and unfavorable intermediate-risk subgroups were analyzed. RESULTS: Median followup was 7.5 years. Combo-RT group had improved 10-year bRFS compared with EBRT (91.7% vs. 75.4%, p = 0.014). On multivariable analysis, combo-RT (hazard ratio, 0.48; 95% confidence interval: 0.25, 0.92; p = 0.03) was associated with improved bRFS. Combo-RT had significantly improved bRFS compared with EBRT in the unfavorable subgroup (p = 0.02) but not in the favorable subgroup (p = 0.37). DMFS was similar within the entire cohort and by risk group. Combo-RT was associated with an increased rate in the 6-year cumulative incidence of Grade 3 GU toxicity (hazard ratio, 3.48; 95% confidence interval: 1.1, 11.1; p = 0.026); however, 57% of Grade 3 GU toxicity was resolved, 29% had partial improvement, and only 1 patient had persistent Grade 3 GU toxicity. CONCLUSIONS: In intermediate-risk prostate cancer, combo-RT improved bRFS but not DMFS and increased Grade 3 GU toxicity. The bRFS benefit was limited to unfavorable intermediate-risk patients.

Anatomical patterns of recurrence following biochemical relapse after post-prostatectomy salvage radiation therapy: a multi-institutional study.

OBJECTIVES: To characterise the frequency and detailed anatomical sites of failure for patients receiving post-radical prostatectomy (RP) salvage radiation therapy (SRT). PATIENTS AND METHODS: A multi-institutional retrospective study was performed on 574 men who underwent SRT between 1986 and 2013. Anatomical recurrence patterns were classified as lymphotrophic (lymph nodes only), osteotrophic (bone only), or multifocal if both were present. Isolated first failure sites were defined as sites of initial clinically detected recurrence that remained isolated for at least 3 months. RESULTS: The median follow-up after SRT was 6.8 years. The 8-year rates of local, regional, and distant failure for patients undergoing SRT were 2%, 6%, and 21%, respectively. Of the 22% men (128 of 574) who developed a clinically detectable recurrence, 17%, 50%, and 31% were lymphotrophic, osteotrophic, and multifocal, respectively. The trophic nature of metastases was prognostic for distant metastases-free survival (DMFS) and prostate cancer-specific survival (PCSS); the 10-year rates of DMFS were 18%, 5%, and 7% (P < 0.01), and PCSS were 78%, 68%, and 56% (P < 0.01), for lymphotrophic, osteotrophic, and multifocal failure patterns, respectively. CONCLUSIONS: We demonstrate that trophism for metastatic site has significant prognostic impact on PCSS in men treated with SRT. Radiographic local failure is an uncommon event after SRT when compared to historical data of patients treated with surgery monotherapy. However, distant failure remains a challenge in this patient population and warrants further therapeutic investigation.

Predictors of multidomain decline in health-related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer.

BACKGROUND: Stereotactic body radiation therapy (SBRT) for localized prostate cancer involves high-dose-per-fraction radiation treatments. Its use is increasing, but concerns remain about treatment-related toxicity. The authors assessed the incidence and predictors of a global decline in health-related quality of life (HRQOL) after prostate SBRT. METHODS: From 2008 to 2014, 713 consecutive men with localized prostate cancer received treatment with SBRT according to a prospective institutional protocol. Expanded Prostate Cancer Index Composite (EPIC-26) HRQOL data were collected at baseline and longitudinally for 5 years. EPIC-26 is comprised of 5 domains. The primary endpoint was defined as a decline exceeding the clinically detectable threshold in ≥4 EPIC-26 domains, termed multidomain decline. RESULTS: The median age was 69 years, 46% of patients had unfavorable intermediate-risk or high-risk disease, and 20% received androgen-deprivation therapy. During 1 to 3 months and 6 to 60 months after SBRT, 8% to 15% and 10% to 11% of patients had multidomain declines, respectively. On multivariable analysis, lower baseline bowel HRQOL (odds ratio, 1.8; 95% confidence interval, 1.2-2.7; P < .01) and baseline depression (odds ratio, 5.7; 95% confidence interval, 1.3-24.3; P = .02) independently predicted for multidomain decline. Only 3% to 4% of patients had long-term multidomain declines exceeding twice the clinical threshold, and 30% of such declines appeared to be related to prostate cancer treatment or progression of disease. CONCLUSIONS: Prostate SBRT has minimal long-term impact on multidomain decline, and the majority of more significant multidomain declines appear to be unrelated to treatment. This emphasizes the importance of focusing not only on the side effects of prostate cancer treatment but also on other comorbid illnesses that contribute to overall HRQOL. Cancer 2017;123:1635-1642. © 2017 American Cancer Society.