Patterns of care and outcomes of radiotherapy for lymph node positivity after radical prostatectomy

Treating Primary Node-Positive Prostate Cancer: A Scoping Review of Available Treatment Options

There is currently no consensus on the optimal treatment for patients with a primary diagnosis of clinically and pathologically node-positive (cN1M0 and pN1M0) hormone-sensitive prostate cancer (PCa). The treatment paradigm has shifted as research has shown that these patients could benefit from intensified treatment and are potentially curable. This scoping review provides an overview of available treatments for men with primary-diagnosed cN1M0 and pN1M0 PCa. A search was conducted on Medline for studies published between 2002 and 2022 that reported on treatment and outcomes among patients with cN1M0 and pN1M0 PCa. In total, twenty-seven eligible articles were included in this analysis: six randomised controlled trials, one systematic review, and twenty retrospective/observational studies. For cN1M0 PCa patients, the best-established treatment option is a combination of androgen deprivation therapy (ADT) and external beam radiotherapy (EBRT) applied to both the prostate and lymph nodes. Based on most recent studies, treatment intensification can be beneficial, but more randomised studies are needed. For pN1M0 PCa patients, adjuvant or early salvage treatments based on risk stratification determined by factors such as Gleason score, tumour stage, number of positive lymph nodes, and surgical margins appear to be the best-established treatment options. These treatments include close monitoring and adjuvant treatment with ADT and/or EBRT.

Narrative review of management strategies and outcomes in node-positive prostate cancer

Pelvic nodal involvement is present in 13% of new prostate cancer diagnoses each year and is associated with a poor prognosis compared to localized disease. Grouped as stage IV along with distant metastatic disease, node-positive nonmetastatic patients historically received systemic therapy alone as primary treatment. This treatment paradigm has shifted as data have demonstrated that these patients may benefit from aggressive locoregional therapy and are potentially curable. There is currently a lack of randomized evidence to define the optimal management for node-positive patients. While a few trials have included node-positive patients, the majority of data are derived from large multi-institutional series or population-based series. This narrative review summarizes the current literature supporting curative-intent management strategies for patients diagnosed with nonmetastatic clinically node-positive prostate cancer (cN1M0), as well as patients found to have pathologic nodal disease at the time of surgery (pN1M0). Treatment of both scenarios requires multimodality considerations including surgery, radiation therapy (RT) and systemic therapy to minimize the risks of both locoregional and distant recurrence. Future considerations include developments in enhanced imaging and systemic therapy. Inclusion of node-positive patients on prospective, randomized trials such as NRG GU 008 is needed to enhance our understanding of optimal management strategies.

Pathologically Node-Positive Prostate Cancer: Casting for Cure When the Die Is Cast?

The postoperative management of men with lymph node involved prostate cancer (pN+) remains a challenge as there is a general lack of randomized trial data and a range of management strategies. Retrospective studies suggest a variable clinic course for patients with pN+ prostate cancer. Some men progress rapidly to metastatic disease despite further therapies, whereas other men can have a period of prolonged quiescence without adjuvant androgen deprivation therapy (ADT) or radiation therapy (RT). For men who have undergone radical prostatectomy, randomized trial data indicate that the addition of ADT in pN+ disease extends metastasis-free, prostate cancer-specific, and overall survival. Additional retrospective studies suggest that adding RT is potentially beneficial in this setting, improving overall and cancer-specific survival especially in men with certain pathologic parameters. Conversely, men with lower disease burden in their lymph nodes have longer times to progression and may be candidates for observation and salvage therapy as opposed to adjuvant ADT/RT.

Distribution of prostate cancer recurrences on gallium-68 prostate-specific membrane antigen (68 Ga-PSMA) positron-emission/computed tomography after radical prostatectomy with pathological node-positive extended lymph node dissection

Objectives

To examine the anatomical distribution of prostate cancer (PCa) recurrence on gallium‐68 prostate‐specific membrane antigen (⁶⁸Ga‐PSMA) positron‐emission tomography (PET)/computed tomography (CT) in patients with biochemical recurrence (BCR) after undergoing radical prostatectomy (RP) with pathological lymph node metastasis (pN1) in their extended pelvic lymph node dissection (ePLND), and to compare the location of PCa recurrence with the location of the initial lymph node metastasis at ePLND.

Materials and Methods

We retrospectively reviewed 100 patients with BCR (PSA 0.05–5.00 ng/mL) after RP with pN1 ePLND who underwent ⁶⁸Ga‐PSMA PET/CT to guide salvage therapy. Clinical and pathological features and anatomical locations of PCa recurrence on ⁶⁸Ga‐PSMA PET/CT were obtained, and management impact was recorded.

Results

In all, 68 patients (68%) had a positive and 32 patients (32%) had a negative ⁶⁸Ga‐PSMA PET/CT result. Of the 68 patients with a positive ⁶⁸Ga‐PSMA PET/CT, 44 (65%) showed abnormal uptake only in the pelvic area, seven (10%) only outside the pelvic area, and 17 (25%) both within and outside the pelvic area. ⁶⁸Ga‐PSMA PET/CT‐positive pelvic lymph nodes were often (84%) detected on the same side as the lymph node metastasis diagnosed at ePLND. Based on the outcomes of the ⁶⁸Ga‐PSMA PET/CT, change of management was noted in 68% of the patients.

Conclusion

Recurrence of PCa on ⁶⁸Ga‐PSMA PET/CT was limited to the pelvis in the majority of patients with BCR after RP with pN1 ePLND. Moreover, recurrence was often detected on the same side as the lymph node metastasis at ePLND. The results confirm the diagnostic value of ⁶⁸Ga‐PSMA PET/CT in patients with BCR after RP with pN1 ePLND. Prospective studies are needed to support the long‐term benefit of ⁶⁸Ga‐PSMA PET/CT‐dictated management changes.

Pathologically Node-Positive Prostate Carcinoma - Prevalence, Pattern of Care and Outcome From a Population-Based Study

AIMS

To evaluate the prevalence, patterns of care and outcome of pathologically node-positive (pN+) prostate cancer (P-Ca) after radical prostatectomy from a provincial population database.

PATIENTS AND METHODS

Patients were identified from a provincial cancer registry and a genitourinary cancer outcomes unit (2005-2014). Of a total of 4723 patients who underwent radical prostatectomy, 167 patients with pN+ P-Ca were identified (28/2181 from 2005-2007 and 139/2542 from 2010-2014). Persistently elevated postoperative prostate-specific antigen (PSA) ≥ 0.2 ng/ml was noted in 52 (31%) patients, 23 (44.2%) of whom had salvage androgen deprivation therapy plus radiotherapy (ADT + RT), 25 (48%) were managed with ADT alone and four (7.8%) had no treatment. Of 115 patients with postoperative PSA <0.2 ng/ml, 47 (41%) had ADT alone and 50 (43.5%) had ADT + RT. Survival estimation was carried out using the Kaplan-Meier method. The association of prognostic factors with survival was evaluated using univariate and multivariate analysis and was limited to the newer cohort (2010-2014).

RESULTS

The median age was 64 years; the median baseline PSA was 12.5 ng/mL (range 2.5-108.4). After a median follow-up of 48 months, overall survival at 5 and 10 years for the entire cohort were 89% and 81%, respectively, and distant metastasis-free survival (DMFS) at the same time points were 77% and 58%, respectively. For the newer cohort, 5-year overall survival and DMFS were 91.5% and 76%, respectively. On univariate analysis, persistently elevated postoperative PSA ≥0.2 ng/ml (P = 0.0003), seminal vesicle involvement (P = 0.027), ≥2 nodes (P = 0.035) and ADT alone (P = 0.054) had a poor prognostic impact on DMFS, whereas margin involvement had a marginally negative influence on overall survival (P = 0.06). On multivariate analysis, postoperative PSA ≥0.2 ng/ml (hazard ratio 4.4, 95% confidence interval 1.7-11.4; P = 0.002) continued to have a significant association with DMFS. On a sensitivity analysis, postoperative PSA ≥0.1 also had a significant association with DMFS on univariate and multivariate analysis (hazard ratio 3.69, 95% confidence interval 1.32-10.29; P = 0.01). Similarly, postoperative PSA ≥0.4 ng/ml had a significant association with DMFS (hazard ratio 3.87, 95% confidence interval 1.58-9.46, P = 0.003).

CONCLUSION

This study showed a notable difference in the proportion of pN+ P-Ca patients between two different time cohorts. A significant association of persistently elevated postoperative PSA with DMFS was noted in our study. This must be accounted for while tailoring postoperative treatment in pN+ P-Ca.

[Long-term outcomes of prostate cancer patients with lymph nodes metastasis after radical prostatectomy and pelvic lymph node dissection]

INTRODUCTION

The aim of this study was to evaluate biochemical recurrence-free survival (RFS) and to identify useful predictors of such survival in localized prostate cancer patients (cN0) and pelvic lymph node metastasis (pN+) treated with radical prostatectomy and pelvic lymph node dissection.

PATIENTS AND METHODS

This multicenter and retrospective study, assessed overall survival (OS), cancer specific survival (CSS) and biochemical recurrence-free survival (RFS), between January 2005 until December 2010 with 5 years of distance. We evaluated factors predicting long-term RFS in node positive prostate cancer patients.

RESULTS

Thus, 30 patients were included. Median follow-up was 89.9±27.4 months. After surgery, patients were treated with surveillance (n=4, 13.5%), adjuvant hormone therapy (n=22, 73%) or combination of radio and hormone therapy, (n=4, 13.5%). During the follow-up, 50% of patients had biochemical recurrence, with a mean time period of 38±30 months. Five and 10-year RFS were 57% and 41% respectively. Extra lymph nodes extension (P=0.00021) and pathological margin status (P=0.0065) were independent predictors of 5-year RFS.

CONCLUSION

Biochemical RFS of patients treated with radical prostatectomy and subclinical lymph node metastatic disease is adequate and multifactorial. However, this study identifies pathological margin status and extra lymph node extension as independent factors of b RFS.

LEVEL OF EVIDENCE

4.

Approach to the Patient with High-Risk Prostate Cancer

Men classified as having high-risk prostate cancer warrant treatment because durable outcomes can be achieved. Judicious use of imaging and considerations of risk factors are essential when caring for men with high-risk disease. Radical prostatectomy, radiation therapy, and androgen deprivation therapy all play pivotal roles in the management of men with high-risk disease, and potentially in men with metastatic disease. The optimal combinations of therapeutic regimens are an evolving area of study and future work looking into therapies for men with high-risk disease will remain critical.

Contemporary Patterns of Care and Outcomes of Men Found to Have Lymph Node Metastases at the Time of Radical Prostatectomy

PURPOSE

A thorough understanding of the natural history and consensus regarding the optimal management of pathological lymph node positive (pN1) prostate cancer are lacking. Our objective was to describe patterns of care and outcomes of a contemporary cohort of men with pN1 prostate cancer.

MATERIALS AND METHODS

We used the National Cancer Database to identify 7,791 men who were found to have lymph node metastases at radical prostatectomy. Multinomial logistic regression and Cox proportional hazards regression were used to identify patient, tumor and facility characteristics associated with the choice of management strategy after radical prostatectomy and overall survival, respectively.

RESULTS

Initial post-prostatectomy management was observation in 63% of the men, androgen deprivation therapy alone in 20%, radiation therapy alone in 5%, and androgen deprivation therapy and radiation therapy in 13%. Younger age, lower comorbidity burden, higher grade and stage, and positive surgical margins were associated with a higher likelihood of receiving combination therapy. Grade group 4-5 disease, pT3b-T4 disease, positive surgical margins and a higher number of positive lymph nodes were independent predictors of worse overall survival. The adjusted 10-year overall survival probability decreased from 84% to 32% with the presence of an increasing number of adverse prognostic factors. Treatment with combined androgen deprivation therapy and radiation therapy was associated with better overall survival (multivariable HR 0.69, 95% CI 0.52-0.92, p = 0.010 for combination therapy vs observation).

CONCLUSIONS

Patient and tumor characteristics are associated with the choice of management strategy after radical prostatectomy and survival in men with pN1 prostate cancer. Multimodal therapy may be of benefit in this patient population.

Adjuvant and Salvage Radiotherapy after Radical Prostatectomy in Prostate Cancer Patients

CONTEXT

Prostate cancer (PCa) patients found to have adverse pathologic features following radical prostatectomy (RP) are less likely to be cured with surgery alone.

OBJECTIVE

To analyze the role of postoperative radiotherapy (RT) in patients with aggressive PCa.

EVIDENCE ACQUISITION

We performed a systematic literature review of the Medline and EMBASE databases. The search strategy included the terms radical prostatectomy, adjuvant radiotherapy, and salvage radiotherapy, alone or in combination. We limited our search to studies published between January 2009 and August 2016.

EVIDENCE SYNTHESIS

Three randomized trials demonstrated that immediate RT after RP reduces the risk of recurrence in patients with aggressive PCa. However, immediate postoperative RT is associated with an increased risk of acute and late side effects ranging from 15% to 35% and 2% to 8%, respectively. Retrospective studies support the oncologic efficacy of initial observation followed by salvage RT administered at the first sign of recurrence; however, the impact of this delay on long-term control remains uncertain. Hopefully, ongoing randomized trials will shed light on the role of adjuvant RT versus observation±salvage RT in individuals with adverse features at RP. Accurate patient selection based on clinical characteristics and molecular profile is crucial. Dose escalation, whole-pelvis RT, novel techniques, and the use of hormonal therapy might improve the outcomes of postoperative RT.

CONCLUSIONS

Immediate RT reduces the risk of recurrence after RP in patients with aggressive disease. However, this approach is associated with an increase in the incidence of short- and long-term side effects. Observation followed by salvage RT administered at the first sign of recurrence might be associated with durable cancer control, but prospective randomized comparison with adjuvant RT is still awaited. Dose escalation, refinements in the technique, and the concomitant use of hormonal therapies might improve outcomes of patients undergoing postoperative RT.

PATIENT SUMMARY

Postoperative radiotherapy has an impact on oncologic outcomes in patients with aggressive disease characteristics. Salvage radiotherapy administered at the first sign of recurrence might be associated with durable cancer control in selected patients but might compromise cure in others.

[Role of radiotherapy in the management of node-positive prostate cancer]

Node-positive prostate cancer patients represent a small proportion of all prostate cancers for whom limited prospective information is available. Most retrospective or cohort data strongly suggest however that radiotherapy combined with androgen-depriving therapies is the preferable treatment in this setting. Only randomized clinical trials would be able to better define both radiotherapy (dose? volume? fractionation?) and androgen-depriving therapies (duration? role of novel androgen-depriving therapy?) modalities.

Management of Node-Positive and Oligometastatic Prostate Cancer

Historically, stage IV prostate cancer was considered incurable. Although node-positive and oligometastatic prostate cancers are both classified as stage IV, these likely represent distinct clinical groups, and some patients may be curable with aggressive multimodality treatments. There is a lack of randomized evidence, but retrospective studies suggest that radical prostatectomy or radiotherapy may improve survival in these patients. This is an area of great current research interest and prospective randomized trials are needed to help define the optimal treatments for these patients.

Evolving Paradigm of Radiotherapy for High-Risk Prostate Cancer: Current Consensus and Continuing Controversies

High-risk prostate cancer is an aggressive form of the disease with an increased risk of distant metastasis and subsequent mortality. Multiple randomized trials have established that the combination of radiation therapy and long-term androgen deprivation therapy improves overall survival compared to either treatment alone. Standard of care for men with high-risk prostate cancer in the modern setting is dose-escalated radiotherapy along with 2-3 years of androgen deprivation therapy (ADT). There are research efforts directed towards assessing the efficacy of shorter ADT duration. Current research has been focused on assessing hypofractionated and stereotactic body radiation therapy (SBRT) techniques. Ongoing randomized trials will help assess the utility of pelvic lymph node irradiation. Research is also focused on multimodality therapy with addition of a brachytherapy boost to external beam radiation to help improve outcomes in men with high-risk prostate cancer.

Low rates of adjuvant radiation in patients with nonmetastatic prostate cancer with high-risk pathologic features

BACKGROUND

The 2013 American Urological Association/American Society for Radiation Oncology consensus guidelines recommend offering adjuvant radiotherapy (RT) after radical prostatectomy in patients with high-risk pathologic features for recurrence. In the current study, the authors examined practice patterns of adjuvant RT use in patients with elevated pathologic risk factors over a time period spanning the publication of supporting randomized evidence.

METHODS

Using the National Cancer Data Base, a total of 130,681 patients were identified who underwent surgical resection for prostate cancer between 2004 and 2011 with at least 1 of the following pathologic risk factors for early biochemical failure: pT3a disease or higher, positive surgical margins and/or lymph node-positive disease. Using multivariable logistic regression, the authors examined factors associated with adjuvant RT use including patient, clinical, demographic, and temporal characteristics.

RESULTS

Adjuvant RT was administered to 9.9% of the patients with at least 1 pathologic risk factor. Use of adjuvant RT did not change over the study period (P  = .23). On multivariable analysis, we found that patients treated at high-volume surgical facilities were less likely to receive adjuvant RT (15.9% vs 7.8%; odds ratio, 0.58 [95% confidence interval, 0.50-0.65]; P < .0001). Older age, comorbidities, black race, lower income, and lower population density were also associated with lower rates of adjuvant RT.

CONCLUSIONS

Use of adjuvant RT is uncommon and remained unchanged between 2004 and 2011. Patients treated at high-volume surgical facilities are less likely to receive adjuvant RT, irrespective of margin status.

Early radiotherapy after radical prostatectomy improves cancer-specific survival only in patients with highly aggressive prostate cancer: validation of recently released criteria

OBJECTIVES

To test the effect of radiotherapy administered within 6 months after radical prostatectomy on cancer-specific mortality in prostate cancer patients after stratification according to a risk score.

METHODS

Overall, 7616 patients with pT3/4 N0/1 prostate cancer treated with radical prostatectomy between 1995 and 2009 within the Surveillance Epidemiology and End Results Medicare-linked database were included in the study. Competing-risks regression models were carried out to test the effect of early radiotherapy on cancer-specific mortality in the entire cohort, and after stratifying patients according to the risk score based on the number and nature of adverse pathological characteristics (Gleason score 8-10; pT3b/4, lymph node invasion).

RESULTS

The risk score was associated with increasing 5- and 10-year cancer-specific mortality rates (P < 0.001). When considering only patients with a risk score ≥ 2, 5- and 10-year cancer-specific mortality rates were significantly lower for individuals undergoing early radiotherapy compared with their counterparts not receiving early radiotherapy (2.9 and 6.9 vs 5.7 and 16.2%, respectively; P = 0.002). The corresponding number required to treat to prevent one death from prostate cancer at 10-year follow up was 10. Early radiotherapy was not associated with lower cancer-specific mortality rates overall and in patients with a risk score <2. This was confirmed in multivariable analyses, where early radiotherapy decreased the risk of cancer-specific mortality only in patients with a risk score ≥ 2 (P ≤ 0.02).

CONCLUSIONS

The presence of two or more of the following pathological features might be used to identify patients who benefit from early radiotherapy: Gleason score 8-10, pT3b/4 and lymph node invasion.