Postprostatectomy radiotherapy for high-risk prostate cancer

Benefit on Biochemical Control of Adjuvant Radiation Therapy in Patients with Pathologically Involved Seminal Vesicles after Radical Prostatectomy

Aims and Background

To determine whether there is a benefit for biochemical control with adjuvant radiation therapy to the surgical bed following radical prostatectomy in patients with seminal vesicle invasion and pathologically negative pelvic lymph nodes (pT3b-pT4 pN0).

Methods

We retrospectively reviewed the clinical records of radical prostatectomy patients treated between 1995 and 2002. A total of 66 patients with seminal vesicle invasion were identified: 45 of these patients received adjuvant radiation therapy and 21 were observed. Radiation therapy was initiated within 4 months of prostatectomy. Median dose was 66 Gy (range, 60–70 Gy). Median follow-up from the day of surgery was 40.6 months (mean, 41.5; range, 12–99). Biochemical recurrence was defined as the first value ≥0.2 ng/ml.

Results

At two years, the proportion of patients free from biochemical recurrence was 80% in patients who received adjuvant radiation therapy versus 54% for those not given radiation therapy (P = 0.036). Actuarial biochemical recurrence at 5 years was 59% vs 41% for the radiation therapy and no radiation therapy groups, respectively. On univariate Cox regression model, the hazard of biochemical failure was also associated with a detectable (≥0.2 ng/ml) postsurgical prostate-specific antigen (P = 0.02) prior to radiation therapy. Pathological T stage (pT3b vs pT4), Gleason score, primary Gleason pattern and positive surgical margins were not significantly associated with biochemical recurrence. The hazard of biochemical failure was around 85% lower in the radiation therapy group than in the observation group (P = 0.002).

Conclusions

Data from the present series suggest that adjuvant radiation therapy for patients with seminal vesicle invasion and undetectable (≤0.2 ng/ml) postoperative prostate-specific antigen significantly reduces the likelihood of biochemical failure.

Adjuvant and salvage radiotherapy after prostatectomy: a systematic review and meta-analysis

PURPOSE

In men with adverse prognostic factors (APFs) after radical prostatectomy (RP), the most appropriate timing to administer radiotherapy remains a subject for debate. We conducted a systemic review and meta-analysis to evaluate the therapeutic strategies: adjuvant radiotherapy (ART) and salvage radiotherapy (SRT).

MATERIALS AND METHODS

We comprehensively searched PubMed, EMBASE, Web of Science and the Cochrane Library and performed the meta-analysis of all randomized controlled trials (RCTs) and retrospective comparative studies assessing the prognostic factors of ART and SRT.

RESULTS

Between May 1998 and July 2012, 2 matched control studies and 16 retrospective studies including a total of 2629 cases were identified (1404 cases for ART and 1185 cases for SRT). 5-year biochemical failure free survival (BFFS) for ART was longer than that for SRT (Hazard Ratio [HR]: 0.37; 95% CI, 0.30-0.46; p<0.00001, I(2) = 0%). 3-year BFFS was significantly longer in the ART (HR: 0.38; 95% CI, 0.28-0.52; p<0.00001, I(2) = 0%). Overall survival (OS) was also better in the ART (RR: 0.53; 95% CI, 0.41-0.68; p<0.00001, I(2) = 0%), as did disease free survival (DFS) (RR: 0.53; 95% CI, 0.43-0.66; p<0.00001, I(2)  = 0%). Exploratory subgroup analysis and sensitivity analysis revealed the similar results with original analysis.

CONCLUSION

ART therapy offers a safe and efficient alternative to SRT with longer 3-year and 5-year BFFS, better OS and DFS. Our recommendation is to suggest ART for patients with APFs and may reduce the need for SRT. Given the inherent limitations of the included studies, future well-designed RCTs are awaited to confirm and update this analysis.

Adjuvant radiotherapy following radical prostatectomy for pathologic T3 or margin-positive prostate cancer: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Results following radical prostatectomy (RP) are suboptimal in patients found to have cancer extending beyond the prostatic capsule (pT3) or present at the resection margins (R1). The optimal postoperative management of such patients is undefined. Therapeutic alternatives include adjuvant radiotherapy (RT) or active surveillance.

METHODS

Randomized controlled trials (RCTs) were eligible for inclusion in this systematic review if they compared adjuvant RT in the immediate period after RP to active surveillance - with therapies held in reserve for salvage - in prostate cancer patients with pT3 or R1 disease or both. The primary outcome of interest was overall survival.

RESULTS

Three RCTs representing 1,743 patients satisfied the eligibility criteria. Two trials reported data on overall survival; a meta-analysis of the data showed no significant improvement associated with adjuvant RT (hazard ratio=0.91, 95% CI 0.67-1.22, p=0.52). All trials reported data on biochemical progression-free survival (bPFS). On meta-analysis, adjuvant RT significantly improved bPFS (hazard ratio=0.47, 95% CI 0.40-0.56, p<0.00001). One trial provided comparative graded toxicity data; there were no significant differences between arms in severe (grade 3) gastrointestinal or genitourinary toxicity at five years.

CONCLUSIONS

To date, adjuvant RT has not been shown to improve overall survival compared with active surveillance. Longer follow-up from completed RCTs is required to accurately assess this outcome. Adjuvant RT does, however, significantly improve bPFS and is not associated with excess severe late toxicity.

Therapy of recurrent disease after radical prostatectomy in 2007

Recurrence rates of 20-40% after prostatectomy are described. This review will discuss curative treatment options for salvage after primary therapy. Relevant information was identified through searches of published studies, abstracts from scientific meetings, and review articles. Clinical experience in salvage therapy is limited. Conformal radiotherapy to the prostatic bed for PSA relapse and biopsy proven local recurrences after prostatectomy remains the only potentially curative therapy. It can provide durable biochemical control in a range from 17 to 78%. Salvage radiotherapy is well tolerated. Some prognostic factors exist which can help to select the right patient for this treatment. Patients have to be treated early for PSA relapse. Conformal radiotherapy to the prostatic bed for PSA relapse and biopsy proven local recurrences after prostatectomy is a good documented curative therapy. In a patient with a high probability of local recurrence early radiotherapy for PSA relapse is suggested.

Adjuvant and salvage treatment options for patients with high-risk prostate cancer treated with radical prostatectomy

The management of high-risk prostate cancer following radical prostatectomy remains a treatment dilemma. Multimodality approaches incorporating surgery, radiation therapy and systemic agents offer the hope of improved cure rates; however, most randomized studies to date are either immature or negative. The systemic treatment options best studied is androgen deprivation, which has been shown to demonstrate a survival advantage in patients with lymph node-positive disease. Systemic chemotherapy has demonstrated a modest survival advantage in androgen-independent disease. Current studies are exploring its role in the adjuvant and neo-adjuvant setting. Lastly, recent randomized trials have demonstrated a biochemical advantage to adjuvant radiation therapy, but it remains to be seen if this will translate to an improvement is survival end points or if salvage radiation therapy would be just as effective. In this update article, we review the use of external beam radiation therapy and systemic agents in combination with surgery for high-risk prostate cancer patients.

Approaching clinical problems in prostate cancer radiotherapy using the number needed to treat (NNT) technique

The goals of this article are to review the application of the number needed to treat (NNT) concept to selected clinical problems in prostate cancer radiotherapy. Particular emphasis will be placed on (1) comparison of radiotherapy with other treatment options for early-stage disease, (2) the role of hormone therapy in addition to radiotherapy over a spectrum of disease presentation, and (3) systematic comparison of adjuvant versus salvage radiotherapy in the post-prostatectomy setting. Limitations of NNT calculations based on non-randomized comparisons also are discussed.

Timing and patterns of recurrences and deaths from prostate cancer following adjuvant pelvic radiotherapy for pathologic stage T3/4 adenocarcinoma of the prostate

To determine the timing and patterns of late recurrence after radical prostatectomy (RP) alone or RP plus adjuvant radiotherapy (RT). Between 1970 and 1983, 159 patients underwent RP for newly diagnosed adenocarcinoma of the prostate and were found to have positive surgical margins, extracapsular extension and/or seminal vesicle invasion. Of these, 46 received adjuvant RT and 113 did not. The RT group generally received 45-50 Gy to the whole pelvis, then a boost to the prostate bed (total dose of 55-65 Gy). In the RP group, 62% received neoadjuvant/adjuvant androgen deprivation vs 17% in the RT group. Patients were analyzed with respect to timing and patterns of failure. Only one patient was lost to follow-up. The median follow-up for surviving patients was nearly 20 years. The median time to failure in the surgery group was 7.5 vs 14.7 years in the RT group (P=0.1). Late recurrences were less common in the surgery group than the RT group (9 and 1% at 10 and 15 years, respectively vs 17 and 9%). In contrast to recurrences, nearly half of deaths from prostate cancer occurred more than 10 years after treatment. Deaths from prostate cancer represented 55% of all deaths in these patients. Recurrences beyond 10 years after RP in this group of patients were relatively uncommon. Despite its long natural history, death from prostate cancer was the most common cause of mortality in this population with locally advanced tumors, reflecting the need for more effective therapy.

Radical versus postoperative radiotherapy for localized prostate cancer: a 10-year experience of an academic hospital

This study is a presentation of our department's experience in the treatment of localized prostate cancer with either radical or postoperative radiotherapy (RT). Fifty-five patients with clinical localized prostate cancer were reviewed. Thirty-three patients (T1-T2AN0M0 stage) were treated with radical RT and 22 (T2B-T3N0M0 stage) with postoperative RT. All patients received hormonal therapy. Primary end points of the study were the incidence of clinical and biochemical recurrences and death in the whole group and according to treatment modality. Within a median follow-up of 18 months the overall incidence of clinical relapse was 16.9%, of biochemical relapse 12.7% and of death 10.9%. Both treatment options achieved similar outcomes despite the fact that the patients in the postoperative RT group were of higher stage. Radical RT group tended to have better overall and disease-free survival compared to postoperative RT group, but there was no statistically significant evidence. Long-term toxicity was negligible.

Cancer of the prostate

Prostate carcinoma, with about 190,000 new cases occurring each year (15% of all cancers in men), is the most frequent cancer among men in northern and western Europe. Causes of the disease are essentially unknown, although hormonal factors are involved, and diet may exert an indirect influence; some genes, potentially involved in hereditary prostate cancer (HPC) have been identified. A suspect of prostate cancer may derive from elevated serum prostate-specific antigen (PSA) values and/or a suspicious digital rectal examination (DRE) finding. For a definitive diagnosis, however, a positive prostate biopsy is requested. Treatment strategy is defined according to initial PSA stage, and grade of the disease and age and general conditions of the patient. In localized disease, watchful waiting is indicated as primary option in patients with well or moderately differentiated tumours and a life expectancy <10 years, while radical prostatectomy and radiotherapy (with or without hormone-therapy) could be appropriate choices in the remaining cases. Hormone-therapy is the treatment of choice, combined with radiotherapy, for locally advanced or bulky disease and is effective, but not curative, in 80-85% of the cases of advanced disease. Patients who develop a hormone-refractory prostate cancer disease (HRPC) have to be evaluated for chemotherapy because of the recent demonstration of improved overall survival (2-2.5 months) and quality of life with docetaxel in more than 1,600 cases.

What is the best postoperative treatment for patients with pT3bN0M0 adenocarcinoma of the prostate?

The purpose of this paper to identify the optimal therapy after radical prostatectomy (RP) for patients with adenocarcinoma of the prostate invading the seminal vesicles (pT3bN0M0 or SVI). A PubMed search using the keywords 'prostate', 'seminal vesicle', 'prostatectomy', 'radiotherapy', 'androgen blockade' was performed to identify literature regarding rates of disease failure in patients with SVI who are observed or treated with androgen blockade (AB), radiotherapy (RT) or RT + AB after RP. The outcome of 68 patients treated at Duke University with post-operative AB, RT or RT + AB for pT3bN0M0 is also presented. More than 70% of patients with SVI develop disease recurrence after surgery. For many, recurrence occurs within 2 y after RP. These patients have poor control rates with postoperative RT alone. While experience with AB and RT+AB is limited, control rates are generally superior to RT alone. At Duke University, after a median follow-up of nearly 4 y, patients treated with RT + AB or AB alone for pT3bN0M0 achieved better 5-y progression-free survival (PFS) compared with those who received RT alone (78 and 68 vs 30%, P = 0.03 and 0.046, respectively). There was no PFS difference between those who received AB alone or RT + AB (68 vs 78%, P=0.5). Seminal vesicle invasion confers a poor prognosis after RP. SVI is a consistent predictor of poor outcome after RT. The limited data available examining AB and RT + AB in pT3bN0M0 disease, including data from Duke University, are encouraging. Nonetheless, postoperative AB, RT and RT + AB for pT3bN0M0 disease require prospective evaluation, as RP alone is rarely curative.

Postprostatectomy adjuvant versus salvage radiotherapy

BACKGROUND

Radiotherapy (RT) has been used with success after radical retropubic prostatectomy (RRP), both in the adjuvant and salvage settings. The purpose of the current investigation was to systematically compare adjuvant versus salvage RT in a manner that incorporates both treatment efficacy and complications.

METHODS

A literature review was performed of reports of post-RRP salvage and adjuvant RT, and 12 trials comprising 1060 patients met the appropriate inclusion criteria. The biochemical failure-free survival in each study/arm was tabulated, and these values were entered into a model to compute an unadjusted number-needed-to treat (NNT). RT complications were then considered, accounting for differences in toxicity incidences in the salvage versus adjuvant setting, to compute complication-adjusted NNTs. In all the trials, the signs and magnitudes of the NNTs obtained were used to compare adjuvant with salvage RT.

RESULTS

The absolute NNT analysis showed an advantage of adjuvant compared with salvage RT. After adjustment for RT complications, however, the advantage shifted to salvage RT. This transition point from superiority of adjuvant RT to superiority of salvage RT was sensitive to the estimated incidence and severity of RT side effects.

CONCLUSIONS

Adjuvant post-RRP RT was advantageous in comparison to salvage RT if the side effects of RT were estimated to be negligible. However, with moderate incidence/severity of RT side effects, salvage RT was advantageous. The findings herein must be tested in a prospective study in which both health-related quality of life and cancer control are documented in patients receiving adjuvant versus salvage post-RRP RT. Further work is needed to better estimate parameters entered into the model to determine the precise transition point between adjuvant and salvage RT with modern RT techniques.

Long-term results of adjuvant hormonal therapy plus radiotherapy following radical prostatectomy for patients with pT3N0 or pT3N1 prostate cancer

BACKGROUND

The objective of the present study was to evaluate the efficacy of adjuvant androgen suppression in conjunction with external beam irradiation after radical prostatectomy in patients with pathologically confirmed extraprostatic disease.

METHODS

Between July 1988 and October 1999, 38 patients with pT3N0 or pT3N1 prostate cancer received adjuvant hormonal therapy and external beam irradiation following radical retropubic prostatectomy and pelvic lymphadenectomy. Administration of luteinizing hormone-releasing hormone analog or castration were initiated as an adjuvant androgen suppression within 4 weeks after surgery, whereas pelvic irradiation was performed at a median dose of 50 G within 3 months after surgery. The prognostic advantage of this combined adjuvant therapy was analyzed.

RESULTS

During the median observation period of 92 months, biochemical recurrence occurred in four of the 38 patients and five patients died. Of these five patients, only one died of prostate cancer progression. The 10-year biochemical recurrence-free, cancer-specific and overall survival rates of the 38 patients were 86.7%, 90.9% and 78.7%, respectively. Among several factors examined, only tumor grade was significantly associated with biochemical recurrence-free survival in these patients; however, there were no factors that were independent predictors for biochemical recurrence, based on multivariate analysis. Furthermore, biochemical recurrence-free survival in the 38 patients was significantly superior to that in 54 patients with locally advanced disease who did not receive any postoperative therapies until biochemical recurrence; however, there was no significant difference in cancer-specific and overall survival between these two groups.

CONCLUSION

Despite retrospective analysis with a relatively small number of patients, results of the present study suggest favorable effects of the combined adjuvant treatments with androgen ablation and pelvic irradiation on cancer control for patients with pT3N0 or pT3N1 disease. However, considering the absence of a significant difference in cancer-specific and overall survival between patients with and without adjuvant treatments, it might not be necessary to routinely perform combined hormonal and radiation therapies in an adjuvant setting for pT3N0 or pT3N1 prostate cancer.

Prostate cancer: radical prostatectomy

Today, more men than ever before are being followed after radical prostatectomy. Prognosis and follow-up should be based on the pathologic specimen. Measurable prostate-specific antigen (PSA) after surgery defines failure, with time to detectable PSA and rate of PSA rise being useful prognostic factors. The natural history of untreated biochemical failure is protracted, a fact to be considered in discussions of adjuvant treatment. Early in disease recurrence, imaging studies to locate residual disease rarely are useful clinically. Both adjuvant and salvage radiation to the prostate bed have benefits and risks, but neither is superior in overall prostate cancer survival. The timing of hormone therapy remains largely empiric. The promise of effective cytotoxic chemotherapy still is greater than its actual benefits, although novel cytostatic agents are being developed. The future management of this disease will improve with better molecular definition of risk and therapeutic response.

Salvage radiotherapy for biochemical recurrence after radical prostatectomy: a study of 62 patients

OBJECTIVES

To determine the predictive factors of prostate-specific antigen (PSA) recurrence after salvage radiotherapy (RT) for biochemical recurrence following radical prostatectomy (RP) to identify patients who may benefit from this treatment.

METHODS

From June 1992 to January 2002, 62 patients experiencing PSA recurrence after RP were treated with RT at a dose of 65 Gy. No patient received hormonal therapy. PSA recurrence after RT was defined as three consecutive increased PSA measurements. The risk of experiencing PSA recurrence after RT was analyzed according to 10 factors: patient age, pre-RP PSA level, pathologic stage, Gleason score, surgical margin status, PSA nadir after RP, time to PSA recurrence after RP, pre-RT PSA level, PSA nadir after RT, and length of follow-up after RT.

RESULTS

With a mean follow-up of 44 months (range 3 to 110), 23 patients (37.1%) experienced PSA recurrence after RT. Using univariate analysis, six factors were found to be predictive of PSA recurrence after RT: the length of follow-up after RT (P <0.0001), PSA nadir after RP (P = 0.0004), time to PSA recurrence after RP (P = 0.003), pre-RP PSA level (P = 0.008), Gleason score (P = 0.011), and pre-RT PSA level (P = 0.028). Using multivariate analysis, only the Gleason score (P = 0.015) and length of follow-up after RT (P = 0.02) were found to be predictive of PSA recurrence after RT. A Gleason score greater than 7 was a significant predictor of PSA recurrence after salvage RT (P = 0.04).

CONCLUSIONS

In our experience, the Gleason score and length of follow-up were the sole independent predictors of PSA recurrence after salvage RT. Our findings suggest that patients with a Gleason score of 7 or less are more likely to benefit from salvage RT after RP and that the durability of the PSA response may be only transient.

Adjuvant and salvage radiotherapy after radical prostatectomy for prostate cancer

PURPOSE

The optimal role of radiotherapy (RT) to the prostate bed after radical prostatectomy (RP) is the subject of much debate. In this study, the results of adjuvant RT (ART) and salvage RT (SRT) were compared.

METHODS AND MATERIALS

A total of 146 lymph node-negative patients were treated postoperatively after RP with RT to the prostate bed between 1987 and 1998. Of these, 75 patients had an undetectable prostate-specific antigen (PSA) level and were treated with ART for adverse pathologic features only to a median dose of 60 Gy (range 51-70). A positive margin was identified in 96%, and two of the three with negative margins had seminal vesicle involvement (SVI). SRT was administered for either a persistently detectable PSA level after RP (n = 27) or for a delayed rise in PSA (n = 44) to a median dose of 70 Gy (range 60-78). Adjuvant androgen ablation was given to 37 patients; 2 who had received ART and 35 had who received SRT. The median duration of androgen ablation was 24 months. The primary end point was freedom from biochemical failure (bNED), which was considered to be an undetectable PSA level. The median follow-up was 53 months for all patients: 68 months for the ART patients and 35 months for the SRT patients.

RESULTS

For the ART group, 8 patients subsequently developed a rising PSA level. The 5-year bNED rate was 88%. SVI was the strongest predictor of outcome, with a 5-year bNED rate of 94% for those without SVI and 65% for those with SVI (p = 0.0002). SVI was the only significant factor in Cox proportional hazards regression analysis in the ART cohort. For the SRT group, 20 patients developed a rising PSA level after RT. The 5-year bNED rate was 66% for all SRT patients, and 43% and 78% in those with a persistently detectable PSA and those with a delayed rise in PSA, respectively. In the Cox proportional hazards regression analysis, this subdivision of SRT was statistically significant. Moreover, when the Cox model included all patients and variables, the timing of RT (ART vs. SRT) was an independent correlate of bNED, as was androgen ablation.

CONCLUSION

For RP patients with high-risk pathologic features, the timing of postoperative RT and the PSA status after RP were strong determinants of outcome. Because of the potential confounding factors, direct comparisons of ART and SRT are problematic; however, ART is extremely effective and offers the surest approach for maintaining biochemical control.

Adjuvant external radiation therapy following radical prostatectomy for node-negative prostate cancer

PURPOSE OF REVIEW

The use of adjuvant radiation therapy following prostatectomy is commonplace. The purpose of this review is to summarize completed and ongoing clinical trials and to review recent relevant studies and debates related to this subject.

RECENT FINDINGS

The routine use of adjuvant radiation therapy remains a controversial topic. Recent retrospective matched-pair analyses support its use in appropriately selected patients with positive margins, extraprostatic extension or seminal vesicle invasion, but interpretation of these and other data vary. Although the 5-year biochemical recurrence rate using adjuvant radiotherapy may be decreased from approximately 40 to 10% in patients with either positive margins or extraprostatic extension, its effect on cause-specific mortality is unclear. Two prospective randomized trials with cumulative enrollment of over 1400 patients have examined the role of adjuvant radiation therapy compared with observation following prostatectomy: one trial was a National Cancer Institute-sponsored Intergroup study coordinated by the Southwest Oncology Group, and the other was from the European Organization for Research and Treatment of Cancer. Currently, the Radiation Therapy Oncology Group is conducting a three-arm trial, with broadened stratification criteria as compared with previous trials. This ongoing trial examines the use of adjuvant radiotherapy with or without adjuvant androgen deprivation following prostatectomy and also androgen deprivation alone in patients at high risk for disease relapse.

SUMMARY

In lieu of data from completed randomized trials, indications for immediate adjuvant radiation therapy following prostatectomy exist and are supported by retrospective data with respect to reducing local and biochemical recurrence rates. However, data demonstrating an overall or cause-specific survival advantage for adjuvant radiotherapy as compared with delayed salvage therapy do not exist.