227 ADJUVANT RADIOTHERAPY AFTER RADICAL PROSTATECTOMY IN PATIENTS WITH PATHOLOGICALLY HIGH RISK PROSTATE CANCER: 10-YEAR FOLLOW-UP RESULTS

Positive surgical margins in radical prostatectomy patients do not predict long-term oncological outcomes: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort

OBJECTIVE

To assess the impact of positive surgical margins (PSMs) on long-term outcomes after radical prostatectomy (RP), including metastasis, castrate-resistant prostate cancer (CRPC), and prostate cancer-specific mortality (PCSM).

PATIENTS AND METHODS

Retrospective study of 4,051 men in the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort treated by RP from 1988 to 2013. Proportional hazard models were used to estimate hazard ratios (HRs) of PSMs in predicting biochemical recurrence (BCR), CRPC, metastases, and PCSM. To determine if PSMs were more predictive in certain patients, analyses were stratified by pathological Gleason score, stage, and preoperative prostate-specific antigen (PSA) level.

RESULTS

The median (interquartile range) follow-up was 6.6 (3.2-10.6) years and 1 127 patients had >10 years of follow-up. During this time, 302 (32%) men had BCR, 112 (3%) developed CRPC, 144 (4%) developed metastases, and 83 (2%) died from prostate cancer. There were 1,600 (40%) men with PSMs. In unadjusted models, PSMs were significantly associated with all adverse outcomes: BCR, CRPC, metastases and PCSM (all P ≤ 0.001). After adjusting for demographic and pathological characteristics, PSMs were associated with increased risk of only BCR (HR 1.98, P < 0.001), and not CRPC, metastases, or PCSM (HR ≤1.29, P > 0.18). Similar results were seen when stratified by pathological Gleason score, stage, or PSA level, and when patients who underwent adjuvant radiotherapy were excluded.

CONCLUSIONS

PSMs after RP are not an independent risk factor for CRPC, metastasis, or PCSM overall or within any subset. In the absence of other high-risk features, PSMs alone may not be an indication for adjuvant radiotherapy.

Radiotherapy after radical prostatectomy: treatment recommendations differ between urologists and radiation oncologists

Purpose

There is no consensus on optimal use of radiotherapy following radical prostatectomy. The purpose of this study was to describe opinions of urologists and radiation oncologists regarding adjuvant and salvage radiotherapy following radical prostatectomy.

Methods

Urologists and genitourinary radiation oncologists were solicited to participate in an online survey. Respondent characteristics included demographics, training, practice setting, patient volume/experience, and access to radiotherapy. Participant practice patterns and attitudes towards use of adjuvant and salvage radiotherapy in standardized clinical scenarios were assessed.

Results

One hundred and forty-six staff physicians participated in the survey (104 urologists and 42 genitourinary radiation oncologists). Overall, high Gleason score (Gleason 7 vs. 6, RR 1.37 95% CI 1.19-1.56, p<0.0001 and Gleason 8-10 vs. 6, RR 1.56 95% CI 1.37-1.78, p<0.0001), positive surgical margin (RR 1.43 95% CI 1.26-1.62, p<0.0001), and extraprostatic tumour extension (RR 1.16 95% CI 1.05-1.28, p<0.002) conferred an increased probability of recommending adjuvant radiotherapy. Radiation oncologists were more likely to recommend adjuvant radiotherapy across all clinical scenarios (RR 1.48, 95% CI 1.39, 1.60, p <0.001). Major differences were found for patients with Gleason 6 and isolated positive surgical margin (radiotherapy selected by 21% of urologists vs. 70% of radiation oncologists), and patients with extraprostatic extension and negative surgical margins (radiotherapy selected by 18% of urologist vs. 57% of radiation oncologists).

Conclusions

Urologists and radiation oncologists frequently disagree about recommendation for post-prostatectomy adjuvant radiotherapy. Since clinical equipoise exists between adjuvant versus early salvage post-operative radiotherapy, support of clinical trials comparing these approaches is strongly encouraged.

Long-term cancer control after radical prostatectomy and bilateral pelvic lymph node dissection for pT3bN0M0 prostate cancer in the prostate-specific antigen era

OBJECTIVES

We evaluated long-term cancer control outcomes of radical prostatectomy and bilateral pelvic lymph node dissection (RP) for pT3bN0M0 prostate cancer in the era of prostate-specific antigen (PSA) screening.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data from the University of Southern California Prostate Cancer Database was performed. Between 1987 and 2008, 229 men underwent open RP for pT3bN0M0 prostate cancer. The cohort was divided into early (1987-1997) and contemporary (1998-2008) PSA eras. The Kaplan-Meier method and Cox proportional regression models were used to analyze clinical recurrence (CR) and biochemical recurrence (BCR).

RESULTS

The median follow-up duration was 14.5 years (range, 0.2-21.1y). The predicted 10-year freedom from CR and BCR rates for men treated in the early and contemporary PSA eras were 73% and 95% (Log-rank P = 0.001) and 65% and 73% (Log-rank P = 0.055), respectively. Multivariable analysis showed that pathologic Gleason grade 8-10 (CR: hazard ratio [HR] = 5.11; 95% confidence interval [CI] = 1.72-15.20; P = 0.003; BCR: HR = 3.47; 95% CI = 1.60-7.48; P = 0.002) and contemporary PSA era (CR: HR = 0.15; 95% CI = 0.06-0.41; P<0.001; BCR: HR = 0.49; 95% CI = 0.28-0.86; P = 0.013) were independently associated with cancer control. Adjuvant radiation therapy and positive surgical margins were not independently associated with outcomes.

CONCLUSIONS

RP conferred long-term cancer control in men with pT3bN0M0 prostate cancer treated in the PSA era. Pathologic Gleason grade 8-10 and treatment in the early PSA era were independently associated with poorer cancer control outcomes.

The impact of solitary and multiple positive surgical margins on hard clinical end points in 1712 adjuvant treatment-naive pT2-4 N0 radical prostatectomy patients

BACKGROUND

Positive surgical margins (PSMs) increase the risk of biochemical recurrence (BCR) after radical prostatectomy (RP), but their impact on hard clinical end points is a topic of ongoing discussion.

OBJECTIVE

To evaluate the influence of solitary PSMs (sPSMs) and multiple PSMs (mPSMs) on important clinical end points.

DESIGN, SETTING, AND PARTICIPANTS

Data from 1712 patients from the Centre Hospitalier Universitaire de Québec with pT2-4 N0 prostate cancer (PCa) and undetectable prostate-specific antigen after RP were analyzed.

INTERVENTION

RP without neoadjuvant or adjuvant treatment.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier analysis estimated survival functions, and Cox proportional hazards models addressed predictors of clinical end points.

RESULTS AND LIMITATIONS

Median follow-up was 74.9 mo. A total of 1121 patients (65.5%) were margin-negative, 281 patients (16.4%) had sPSMs, and 310 patients (18.1%) had mPSMs. A total of 280 patients (16.4%) experienced BCR, and 197 patients (11.5%) were treated with salvage radiotherapy (SRT). Sixty-eight patients (4.0%) received definitive androgen deprivation therapy, 19 patients (1.1%) developed metastatic disease, and 15 patients (0.9%) had castration-resistant PCa (CRPC). Thirteen patients (0.8%) died from PCa, and 194 patients (11.3%) died from other causes. Ten-year Kaplan-Meier estimates for BCR-free survival were 82% for margin-negative patients, 72% for patients with sPSMs, and 59% for patients with mPSMs (p<0.0001). Time to metastatic disease, CRPC, PCa-specific mortality (PCSM), or all-cause mortality did not differ significantly among the three groups (p=0.991, p=0.988, p=0.889, and p=0.218, respectively). On multivariable analysis, sPSMs and mPSMs were associated with BCR (hazard ratio [HR]: 1.711; p=0.001 and HR: 2.075; p<0.0001), but sPSMs and mPSMs could not predict metastatic disease (p=0.705 and p=0.242), CRPC (p=0.705 and p=0.224), PCSM (p=0.972 and p=0.260), or all-cause death (p=0.102 and p=0.067). The major limitation was the retrospective design.

CONCLUSIONS

In a cohort of patients who received early SRT in 70% of cases upon BCR, sPSMs and mPSMs predicted BCR but not long-term clinical end points. Adjuvant radiotherapy for margin-positive patients might not be justified, as only a minority of patients progressed to end points other than BCR. PCSM was exceeded 15-fold by competing risk mortality.

Radiation therapy for prostate cancer after prostatectomy: adjuvant or salvage?

Approximately 15-25% of men who undergo radical prostatectomy for localized prostate cancer will experience a PSA-defined biochemical recurrence (BCR) of their cancer--men with poorly differentiated cancer, non-organ-confined disease, and positive surgical margins are at the highest risk. Accumulating evidence indicates that postoperative radiation therapy to the prostate bed favorably influences the course of disease in men with pathological features of poor prognosis. Three phase III randomized trials of adjuvant radiotherapy versus observation have reported improved freedom from BCR, and one study has reported improved metastasis-free survival and overall survival. Similar evidence from randomized trials for salvage radiotherapy is lacking; however, several observational studies have reported durable responses to salvage radiotherapy and reduced cancer-specific mortality in a substantial proportion of high-risk patients, provided that it is administered at the earliest evidence of BCR. The appeal of salvage radiotherapy is that a substantial proportion of patients with non-organ-confined cancer or positive surgical margins are cured after radical prostatectomy alone, thereby limiting the adverse effects of postoperative radiotherapy--which include urinary and bowel dysfunction, sexual dysfunction and secondary pelvic malignancies--to only those whose cancer was not cured by surgery. In the absence of data from randomized trials demonstrating the superiority of adjuvant radiotherapy over a surveillance strategy (with planned salvage radiotherapy at the earliest evidence of BCR), we advocate shared decision making between physicians and patients, based on the relative advantages and disadvantages of each approach.