Postoperative radiation for prostate cancer

Stratification based on adverse laboratory/pathological features for predicting overall survival in patients undergoing radical prostatectomy: A K-CaP registry-based analysis

When making clinical decisions concerning additional treatment for patients who have undergone radical prostatectomy (RP), adverse laboratory/pathological features are considered major factors. We investigated and compared the prognostic efficacy of adverse laboratory/pathological features in predicting overall survival (OS) and biochemical failure (BCF) in these patients.The Korean Prostate Cancer Database was used to identify patients undergoing RP between May 2001 and April 2013. Patients with incomplete clinicopathological data or positive lymphadenectomy results were excluded. Finally, 4486 patients included in the final analysis were categorized based on their adverse laboratory/pathological features.Adverse pathological features and detectable prostate-specific antigen (PSA) levels 6 weeks after surgery were observed in 1977 (44.1%) and 634 (14.1%) patients, respectively. PSA levels, pathological Gleason score ≥8, adverse pathological features [positive surgical margin (PSM), seminal vesicle invasion (SVI), and extracapsular extension (ECE)], and adverse laboratory features (detectable PSA levels after 6 weeks) together were significant predictors of BCF-free survival (BCFFS). SVI was identified as a predictor of OS. Additionally, patients with ECE, PSM, and detectable PSA levels after 6 weeks, but without SVI, showed similar OS to those without ECE, PSM, and detectable PSA levels after 6 weeks and with SVI (log-rank test, P = .976).We successfully stratified patients based on adverse laboratory/pathological features after RP and demonstrated that these are important prognostic factors for OS and BCFFS. Additionally, we identified the criteria for selecting appropriate patients for undergoing additional treatment based on OS and BCFFS.

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.

Long-term results of adjuvant versus early salvage postprostatectomy radiation: A large single-institutional experience

PURPOSE

The purpose of this study was to evaluate freedom from biochemical failure (FFBF), freedom from androgen deprivation therapy (FFADT), freedom from distant metastases (FFDM), and overall survival (OS) after adjuvant radiation therapy (ART) versus early salvage radiation therapy (ESRT) in men with prostate cancer and adverse pathologic features (pT3 and/or positive surgical margins).

METHODS AND MATERIALS

Of 718 patients consecutively treated with postoperative radiation therapy (RT) for prostate cancer between 1992 and 2013, we retrospectively identified 171 men receiving ART and 230 receiving ESRT (RT delivered at a prostate-specific antigen level ≤0.5 ng/mL) who had adverse pathologic features. Postirradiation FFBF (BF was defined as prostate-specific antigen level rise to ≥0.2 ng/mL), FFADT, FFDM, and OS were compared using Kaplan-Meier and Cox regression methods. Propensity score (PS)-matching was performed to estimate treatment effects while accounting for covariates predicting treatment allocation.

RESULTS

Median follow-up was 7.4 and 8.0 years for patients treated with ART and ESRT, respectively. Ten-year FFBF (69% vs 56%, P = .003) and 10-year FFADT (88% vs 81%, P = .046) rates were higher after ART; however, FFDM and OS did not significantly differ. After PS-matching, ART was associated with improved FFBF (P < .0001), FFADT (P = .0001), and FFDM (P = .02). Findings were confirmed in multivariable analyses in unmatched and PS-matched cohorts. Sensitivity analyses showed that FFBF benefit associated with ART lost statistical significance only after 38% of ART patients were assumed to have been cured by surgery and excluded from the model. This corresponds to the upper bound of patients with adverse pathologic features who did not recur after observation in prior randomized trials.

CONCLUSIONS

Postoperative RT confers excellent long-term cancer control. These results suggest ART may be associated with improved FFBF, FFADT, and FFDM, but comparable OS. Given the retrospective study design, these findings should be interpreted with caution. Optimal timing of postoperative RT further awaits results of ongoing trials.

Declining Use of Radiotherapy for Adverse Features After Radical Prostatectomy: Results From the National Cancer Data Base

BACKGROUND

Patterns of postoperative radiotherapy (RT) use in prostate cancer (PCa) after the publication of major randomized trials have not been well characterized.

OBJECTIVE

To describe patterns of postoperative RT use after radical prostatectomy (RP) in patients with adverse pathologic features in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective analysis of 97 270 patients with PCa diagnosed between 2005 and 2011 whose presentation and outcomes were recorded in the National Cancer Data Base.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Temporal changes in receipt of postoperative RT and factors associated with receipt of this treatment using the Cochran-Armitage trend test and multiple logistic regression, respectively.

RESULTS AND LIMITATIONS

Between 2005 and 2011, receipt of postoperative RT decreased steadily from 9.1% to 7.3% (ptrend<0.001). Use of RT with or without androgen deprivation therapy monotonically decreased with advancing age from 8.5% in patients aged 18-59 yr to 6.8% in patients aged 70-79 yr (ptrend<0.001). Receipt of RT was higher at community cancer programs compared with teaching/research centers (14% vs 7.3%; odds ratio [OR]: 2.16; p<0.001), in those with pT3-4 disease and positive margins compared with those with pT3-4 and negative margins (17% vs 5.9%; OR: 2.89; p<0.001), and in patients with a Gleason score of 8-10 compared with those with a Gleason score of 2-6 (17% vs 4.2%; OR: 3.50; p<0.001). Limitations include lack of postprostatectomy prostate-specific antigen level.

CONCLUSIONS

Postoperative RT use for localized PCa in patients with adverse pathologic features is declining in the United States.

PATIENT SUMMARY

In this report, we show that use of postoperative radiotherapy in patients with prostate cancer with adverse pathologic features is declining. Patients treated at community cancer programs, those with locally advanced disease and positive margins, and those with a high Gleason score were more likely to receive postoperative radiotherapy.

Evaluating the clinical impact of a genomic classifier in prostate cancer using individualized decision analysis

BACKGROUND

Currently there is controversy surrounding the optimal way to treat patients with prostate cancer in the post-prostatectomy setting. Adjuvant therapies carry possible benefits of improved curative results, but there is uncertainty in which patients should receive adjuvant therapy. There are concerns about giving toxicity to a whole population for the benefit of only a subset. We hypothesized that making post-prostatectomy treatment decisions using genomics-based risk prediction estimates would improve cancer and quality of life outcomes.

METHODS

We developed a state-transition model to simulate outcomes over a 10 year horizon for a cohort of post-prostatectomy patients. Outcomes included cancer progression rates at 5 and 10 years, overall survival, and quality-adjusted survival with reductions for treatment, side effects, and cancer stage. We compared outcomes using population-level versus individual-level risk of cancer progression, and for genomics-based care versus usual care treatment recommendations.

RESULTS

Cancer progression outcomes, expected life-years (LYs), and expected quality-adjusted life-years (QALYs) were significantly different when individual genomics-based cancer progression risk estimates were used in place of population-level risk estimates. Use of the genomic classifier to guide treatment decisions provided small, but statistically significant, improvements in model outcomes. We observed an additional 0.03 LYs and 0.07 QALYs, a 12% relative increase in the 5-year recurrence-free survival probability, and a 4% relative reduction in the 5-year probability of metastatic disease or death.

CONCLUSIONS

The use of genomics-based risk prediction to guide treatment decisions may improve outcomes for prostate cancer patients. This study offers a framework for individualized decision analysis, and can be extended to incorporate a wide range of personal attributes to enable delivery of patient-centered tools for informed decision-making.