Knowledge, attitudes and decision-making preferences of men considering participation in the TROG RAVES Prostate Cancer Trial (TROG 08.03)

Discord Among Radiation Oncologists and Urologists in the Postoperative Management of High-Risk Prostate Cancer

OBJECTIVE

To query specialty-specific differences regarding postoperative radiotherapy (RT) for high-risk prostate cancer.

MATERIALS AND METHODS

Electronic mail survey of radiation oncologists (ROs) and urologists. We sought to maximize absolute response number to capture contemporary practice ethos. The outcome of interest was association between response and specialty. Training level/expertise, practice setting, percentage of consultation caseload consisting of high-risk prostate cancer, and nationality were set as effect modifiers for multivariate logistic regression.

RESULTS

In total, 846 ROs and 407 urologists responded. ROs were more likely to prefer adjuvant radiotherapy (ART). ART or early salvage radiotherapy (SRT, with early SRT defined as that delivered at prostate-specific antigen<0.2), whereas urologists were more likely to prefer early or delayed SRT (P<0.0001). ROs were more likely to prefer lower PSA thresholds for initiating SRT (P<0.0001), and more likely to recommend ART in the setting of adverse pathologic features or node-positive disease (P<0.0001). Significantly more ROs would recommend concurrent androgen deprivation therapy or pelvic nodal RT in the setting of node-positive or Gleason score 8 to 10 disease (P<0.0001).

CONCLUSIONS

Specialty-specific differences were readily elucidated with respect to timing and indications for ART and SRT, as well as for indications for androgen deprivation therapy and nodal RT. These differences are likely to create a sense of dissonance for patients, which may in turn explain the underutilization of postoperative RT in general practice.

Comparison Between Adjuvant and Early-Salvage Postprostatectomy Radiotherapy for Prostate Cancer With Adverse Pathological Features

Importance

Prostate cancer with adverse pathological features (ie, pT3 and/or positive margins) after prostatectomy may be managed with adjuvant radiotherapy (ART) or surveillance followed by early-salvage radiotherapy (ESRT) for biochemical recurrence. The optimal timing of postoperative radiotherapy is unclear.

Objective

To compare the clinical outcomes of postoperative ART and ESRT administered to patients with prostate cancer with adverse pathological features.

Design, Setting, and Participants

This multi-institutional, propensity score-matched cohort study involved 1566 consecutive patients who underwent postprostatectomy ART or ESRT at 10 US academic medical centers between January 1, 1987, and December 31, 2013. Propensity score 1-to-1 matching was used to account for covariates potentially associated with treatment selection. Data were collected from January 1 to September 30, 2016. Data analysis was conducted from October 1, 2016, to October 21, 2017.

Main Outcomes and Measures

Freedom from postirradiation biochemical failure, freedom from distant metastases, and overall survival. All outcomes were measured from date of surgery to address lead-time bias.

Results

Of 1566 patients, 1195 with prostate-specific antigen levels of 0.1 to 0.5 ng/mL received ESRT and 371 patients with prostate-specific antigen levels lower than 0.1 ng/mL received ART. The median age (interquartile range) was 60 (55-65) years. After propensity score matching, the median (interquartile range) follow-up after surgery was similar between the ESRT and ART groups (73.3 [44.9-106.6] months vs 65.8 [40-107] months; P = .22). Adjuvant RT, compared with ESRT, was associated with higher freedom from biochemical failure (12-year actuarial rates: 69% [95% CI, 60%-76%] vs 43% [95% CI, 35%-51%]; effect size, 26%), freedom from distant metastases (95% [95% CI, 90%-97%] vs 85% [95% CI, 76%-90%]; effect size, 10%), and overall survival (91% [95% CI, 84%-95%] vs 79% [95% CI, 69%-86%]; effect size, 12%). Adjuvant RT, lower Gleason score and T stage, nodal irradiation, and postoperative androgen deprivation therapy were favorable prognostic features on multivariate analysis for biochemical failure. Sensitivity analysis demonstrated that the decreased risk of biochemical failure associated with ART remained significant unless more than 56% of patients in the ART group were cured by surgery alone. This threshold is greater than the estimated 12-year freedom from biochemical failure rate of 33% to 52% after radical prostatectomy alone, as determined by a contemporary dynamic nomogram.

Conclusions and Relevance

Adjuvant RT, compared with ESRT, was associated with reduced biochemical recurrence, distant metastases, and death for high-risk patients, pending prospective validation. These findings suggest that a greater proportion of patients with prostate cancer who have adverse pathological features may benefit from postprostatectomy ART rather than surveillance followed by ESRT.

Use of the Electronic Medical Record to Facilitate Intervention for Patients With Rising Prostate-Specific Antigen Values After Radical Prostatectomy: A Feasibility Study

PURPOSE

Salvage radiotherapy (SRT) is the standard of care offered when postprostatectomy prostate-specific antigen (PSA) levels are ≥ 0.2 ng/mL. However, emerging evidence suggests that early SRT (ie, SRT delivered at PSA values < 0.2 ng/mL, but generally ≥ 0.05 ng/mL) improves oncologic outcomes. We evaluated the feasibility of improving referral rates for discussion of early SRT by using a dynamic registry that identifies through the electronic medical record patients with rising postprostatectomy PSA levels.

METHODS

We developed an iteratively updated registry that identifies patients who fall within two postoperative PSA strata: ≥ 0.05 to < 0.1 ng/mL and ≥ 0.1 to < 0.2 ng/mL. We compared referral rates to radiation oncology during a 3-year period before use of this registry with those during a 1-year period after promotion of the registry in multidisciplinary tumor board settings.

RESULTS

Before promotion of the registry, referral rates for patients with PSA values ≥ 0.05 to < 0.1 ng/mL and ≥ 0.1 to < 0.2 ng/mL were 35% and 65%, respectively. After promotion of the registry, referral rates within each stratum increased significantly to 82% and 94%, respectively ( P < .05 for both by Fisher's exact test). The overall rate of referral for patients with PSA values ≥ 0.05 to < 0.2 ng/mL rose from 48% to 90% ( P < .001).

CONCLUSION

The creation of a registry of patients with rising postprostatectomy PSA values can facilitate increased referral rates for early SRT without burdening providers with a clinical support tool embedded within the EMR itself. This is true even in the case of already high baseline rates of referral for early SRT. The changes reported herein most likely reflect a Hawthorne effect wherein the ability to track referrals rather than a direct function of the registry influenced practice patterns. Nonetheless, the registry provided an integral framework to allow for tracking.