Adjuvant radiation following radical prostatectomy: what are the known unknowns?

Retrospective study on the benefit of adjuvant radiotherapy in men with intraductal carcinoma of prostate

Background

Intraductal carcinoma of the prostate (IDC-P) is an independent biomarker of recurrence and survival with particular treatment response, yet no study has tested its response to radiotherapy. The aim of our project was to test the impact of adjuvant radiotherapy (ART) in patients with localized to locally advanced prostate cancer (PC) and IDC-P.

Materials and methods

We performed a retrospective study of men with pT2-T3 PC treated by radical prostatectomy (RP) with or without ART, from two centres (1993–2015). Exclusion criteria were the use of another type of treatment prior to biochemical recurrence (BCR), and detectable prostate- specific antigen (PSA) following RP or ART. Primary outcome was BCR (2 consecutive PSA ≥ 0.2 ng/ml). Patients were grouped by treatment (RP_only/RP + ART), IDC-P status, and presence of high-risk features (HRF: Grade Groups 4–5, positive margins, pT3 stage).

Results

We reviewed 293 RP specimens (median follow-up 99 months, 69 BCR). Forty-eight patients (16.4%) were treated by RP + ART. Multivariate Cox regression for BCR indicated that IDC-P had the strongest impact (hazard ratio [HR] = 2.39, 95% confidence interval [CI]:1.44–3.97), while ART reduced the risk of BCR (HR = 0.38, 95%CI: 0.17–0.85). Other HRF were all significant except for pT3b stage. IDC-P[+] patients who did not receive ART had the worst BCR-free survival (log-rank P = 0.023). Furthermore, IDC-P had the same impact on BCR-free survival as ≥1 HRF (log-rank P = 0.955).

Conclusion

Men with IDC-P who did not receive ART had the highest BCR rates, and IDC-P had the same impact as ≥1 HRF, which are often used as ART indications. Once validated, ART should be considered in patients with IDC-P.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1267-3) contains supplementary material, which is available to authorized users.

How Precisely Can Prostate Cancer Be Managed?

Progress has been made in applying genetic information to disease management in the postgenomic era, and precision medicine is emerging in prostate cancer management. The prostate health index, the 4-kallikrein (4K) score, and the PCA3, TMPRSS2-ERG, and Prostarix tests have potential for refining prostate cancer screening in conjunction with traditional prostate-specific antigen testing. The Confirm MDx and PCA3 tests have shown promise in identifying men who need be rebiopsied after a primary negative biopsy. Oncotype DX, Prolaris, the biopsy-based Decipher prostate cancer test, and ProMark may improve predictive risk stratification in addition to the traditional Gleason score and tumor stage. Decipher and Prolaris may predict biochemical recurrence and metastasis after radical prostatectomy and possibly help identify patients who need adjuvant therapy. Androgen receptor splice variant 7 appears effective in guiding the selection of second hormonal manipulation with abiraterone or enzalutamide versus chemotherapy when treating metastatic castration-resistant prostate cancer.

Evaluation of prognostic factors after radical prostatectomy in pT3b prostate cancer patients in Japanese population

OBJECTIVE

The purpose of the current study was to evaluate prognostic factors after radical prostatectomy for prostate cancer patients with seminal vesicle invasion (pT3b) in the Japanese population.

METHODS

Between January 2005 and December 2011, 814 patients underwent radical prostatectomy without neoadjuvant hormonal therapy at our institutions. Among these patients, 31 were (3.8%) presented with pT3b. Kaplan-Meier method was used to determine biochemical recurrence-free, disease-specific and overall survival of patients in this group. Proportional hazards models were used to determine predictors of biochemical recurrence-free survival.

RESULTS

The median follow-up period was 60 months (range, 9-108 months). During follow-up, 23 patients (74.2%) experienced biochemical recurrence, and the overall 3-year probability of freedom from biochemical recurrence was 29%. However, only one patient died of the disease, and the 5-year overall survival was 92%. In multivariate analysis, age at the time of surgery was the only significant variable for predicting biochemical recurrence after radical prostatectomy (P = 0.0356, hazard ratio = 0.92, 95% confidence interval = 0.851-0.994).

CONCLUSIONS

Patients with seminal vesicle invasion of pathological specimens after radical prostatectomy have high biochemical recurrence, but the survival was favorable especially in light of current multimodal treatment regimens. However, patients with younger age at the time of surgery, in particular, should receive multimodal treatments to improve their outcome.

Utility of Risk Models in Decision Making After Radical Prostatectomy: Lessons from a Natural History Cohort of Intermediate- and High-Risk Men

BACKGROUND

Current guidelines suggest adjuvant radiation therapy for men with adverse pathologic features (APFs) at radical prostatectomy (RP). We examine at-risk men treated only with RP until the time of metastasis.

OBJECTIVE

To evaluate whether clinicopathologic risk models can help guide postoperative therapeutic decision making.

DESIGN, SETTING, AND PARTICIPANTS

Men with National Comprehensive Cancer Network intermediate- or high-risk localized prostate cancer undergoing RP in the prostate-specific antigen (PSA) era were identified (n=3089). Only men with initial undetectable PSA after surgery and who received no therapy prior to metastasis were included. APFs were defined as pT3 disease or positive surgical margins.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Area under the receiver operating characteristic curve (AUC) for time to event data was used to measure the discrimination performance of the risk factors. Cumulative incidence curves were constructed using Fine and Gray competing risks analysis to estimate the risk of biochemical recurrence (BCR) or metastasis, taking censoring and death due to other causes into consideration.

RESULTS AND LIMITATIONS

Overall, 43% of the cohort (n=1327) had APFs at RP. Median follow-up for censored patients was 5 yr. Cumulative incidence of metastasis was 6% at 10 yr after RP for all patients. Cumulative incidence of metastasis among men with APFs was 7.5% at 10 yr after RP. Among men with BCR, the incidence of metastasis was 38% 5 yr after BCR. At 10 yr after RP, time-dependent AUC for predicting metastasis by Cancer of the Prostate Risk Assessment Postsurgical or Eggener risk models was 0.81 (95% confidence interval [CI], 0.72-0.97) and 0.78 (95% CI, 0.67-0.97) in the APF population, respectively. At 5 yr after BCR, these values were lower (0.58 [95% CI, 0.50-0.66] and 0.70 [95% CI, 0.63-0.76]) among those who developed BCR. Use of risk model cut points could substantially reduce overtreatment while minimally increasing undertreatment (ie, use of an Eggener cut point of 2.5% for treatment of men with APFs would spare 46% from treatment while only allowing for metastatic events in 1% at 10 yr after RP).

CONCLUSIONS

Use of risk models reduces overtreatment and should be a routine part of patient counseling when considering adjuvant therapy. Risk model performance is significantly reduced among men with BCR.

PATIENT SUMMARY

Use of current risk models can help guide decision making regarding therapy after surgery and reduce overtreatment.