Efficacy and limitations of delayed/salvage radiation therapy after radical prostatectomy

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.

Usefulness of ultrasensitive prostate-specific antigen assay for early detection of biochemical failure after radical prostatectomy

BACKGROUND

In order to assess whether the prostate-specific antigen (PSA) nadir obtained with an ultrasensitive PSA assay can be used as a prognostic indicator for patients undergoing radical prostatectomy, we investigated it retrospectively.

METHODS

Between October 1997 and July 2003, 46 patients underwent radical prostatectomy for prostate cancer at our institution. None of them received preoperative treatment. Levels of PSA were measured with an ultrasensitive PSA assay every 1-3 months after prostatectomy. Biochemical recurrence was defined as a PSA level of 0.2 ng/mL or higher.

RESULTS

There was a significant difference in PSA nadir between the biochemical recurrence group and the no recurrence group (P < 0.001). The receiver operating characteristics (ROC) curve gave an optimal cut-off value for PSA nadir of 0.01 ng/mL, demonstrating a significant difference in biochemical recurrence after radical prostatectomy. No patient with a PSA nadir level <0.01 ng/mL showed biochemical failure, while 15 out of 22 patients with PSA nadir levels >or=0.01 ng/mL showed biochemical failure.

CONCLUSION

The PSA nadir level obtained using an ultrasensitive PSA assay is an excellent predictor of biochemical recurrence after radical prostatectomy. Early detection of recurrence offers the possibility of early salvage therapy.

Radiotherapy after radical prostatectomy: does transient androgen suppression improve outcomes?

PURPOSE

The long-term biochemical relapse-free survival and overall survival were compared for patients receiving either radiotherapy (RT) alone or radiotherapy combined with a short-course of total androgen suppression for failure after radical prostatectomy.

METHODS AND MATERIALS

Between 1985 and 2001, a total of 122 patients received RT after radical prostatectomy at our institution. Fifty-three of these patients received a short-course of total androgen suppression (TAS) 2 months before and 2 months concurrent with RT with a nonsteroidal antiandrogen and an luteinizing hormone-releasing hormone (LHRH) agonist (combined therapy group); the remaining 69 patients received RT alone. Treatment failure was defined after postoperative RT as a detectable PSA >0.05 ng/mL. Clinical and treatment variables examined included: presurgical PSA, clinical T stage, pathologic Gleason sum (pGS), seminal vesicle (SV) involvement, lymph node involvement, surgical margins, pre-RT PSA, prostate dose, pelvic irradiation, indication for postoperative RT (salvage or adjuvant), and time interval between surgery and RT. Minimum follow-up after postoperative RT was 1 year and median follow-up was 5.9 years (maximum, 14 years) for patients receiving RT alone, and 3.9 years (maximum, 11 years) for patients receiving RT with TAS (combined therapy group). Kaplan-Meier analysis was performed for PSA failure-free survival (bNED) and for overall survival (OS). Cox proportional hazards multivariable analysis examined the influence all clinical and treatment variables predicting for bNED and OS.

RESULTS

The median time to PSA failure after postoperative RT was 1.34 years for the combined therapy group and 0.97 years for the RT alone group (p = 0.19), with no failures beyond 5 years. At 5 years, the actuarial bNED rates were 57% for the combined therapy group compared with 31% for the RT alone group (p = 0.0012). Overall survival rates at 5 years were 100% for the combined therapy group compared with 87% for the RT alone group (p = 0.0008). For pGS <or=7, the 5-year bNED rates were 58% for combined therapy and 38% for RT alone (p = 0.0155), and for pGS >or=8 the 5-year bNED rates were 65% for combined therapy and 17% for RT alone (p = 0.075). The 5-year OS rates for pGS <or=7 were 100% for combined therapy and 98% for RT alone group (p = 0.106), and the 5-year OS for pGS >or=8 was 100% for combined therapy and 54% for RT alone (p = 0.04). On multivariable analysis, only SV involvement (p = 0.0145) and the addition of short-course TAS to postoperative RT (p = 0.0019) were significant covariates predicting for bNED and, similarly, approached significance for overall survival (p = 0.0594 and p = 0.0856, respectively).

CONCLUSIONS

Radiotherapy combined with a short-course TAS after radical prostatectomy appears to confer a PSA relapse-free survival advantage and possibly an overall survival advantage when compared with RT alone. The hypothesis that a transient course of androgen suppression with salvage or adjuvant RT after prostatectomy improves outcomes will need to be tested in a randomized trial.

External beam radiation therapy after radical prostatectomy: efficacy and impact on urinary continence

INTRODUCTION AND OBJECTIVES

The efficacy of adjuvant and salvage external beam radiation (AXRT+SXRT) for prostate cancer after radical prostatectomy (RP) has been debated because of the inability to rule out systemic occult metastasis, uncertainty that radiation eradicates residual local disease and the potential of exacerbating impotency and incontinence. To characterize the effectiveness and treatment morbidity a retrospective review was performed.

METHODS

In all, 38 patients received AXRT and 91 received SXRT. The SXRT group was stratified by PSA level, age, race, pathologic stage, margin status, worst Gleason sum, radiation dose and pelvic field. Complications evaluated were impotence and incontinence. Median follow-up was 60.2 months.

RESULTS

The 5-y disease-free survival (DFS) rate was 61.3% for AXRT and 36.3% for SXRT. Multivariate analysis of the SXRT cohort showed Gleason score, pathologic stage and pre-XRT PSA to be predictors of disease recurrence. After XRT 26% had worsened continence.

CONCLUSIONS

Patients who recur after RP whose pathologic stage is pT2 or pT3c, Gleason score of 8 or higher or pre-XRT PSA is >2.0 ng/dl may have microscopic metastatic disease and a decreased chance of cure with SXRT alone. Continence was further impaired after XRT.

Radiotherapy for a rising PSA following radical prostatectomy

Controversy exists regarding the management of recurrent disease, heralded by a rising prostate specific antigen (PSA), in men who have undergone primary treatment of prostate cancer by radical prostatectomy. Although retrospective in nature, the use of salvage radiation therapy (RT) after prostatectomy has been extensively investigated and reported. Salvage RT alone is likely not optimal for every man presenting with recurrent disease after RP. Those with palpable recurrent disease or unfavorable disease characteristics are less likely to benefit from salvage RT alone and may respond better to a combined modality approach. However, early referral and proper patient selection maximizes the potential for durable biochemical control after salvage RT in men with rising PSA alone.

Radiotherapy for Men With Isolated Increase in Serum Prostate Specific Antigen After Radical Prostatectomy

PURPOSE

In this retrospective study we determined the results of salvage external beam radiation therapy (RT) to the prostate bed for isolated increase of serum prostate specific antigen (PSA) after radical prostatectomy.

MATERIALS AND METHODS

A total of 60 patients underwent RT for PSA failure after radical prostatectomy from 1993 to 1999. Median followup was 51 months. Biochemical disease-free survival (bDFS) with a serum PSA of 0.3 ng/ml or less was estimated using the Kaplan-Meier method. Potential prognostic factors were evaluated for significant associations with bDFS.

RESULTS

Median PSA before RT was 0.69 ng/ml. Median radiation dose was 64.8 Gy. The 5-year actuarial bDFS was 45%. There were 32 patients with a minimum followup of 4 years (median 73 months) who experienced a 5-year bDFS rate of 43%. PSA before RT (p = 0.016), RT dose (p = 0.026), surgical margin involvement (p = 0.017) and Gleason score (p = 0.018) were identified as prognostic factors for bDFS. A significant association with bDFS was present at 5 years of 65%, 34% and 0% for PSA before RT less than 0.6, 0.6 to 1.2, and greater than 1.2 ng/ml, respectively (p = 0.036). Patients with PSA before RT less than 0.6 ng/ml and total RT dose greater than 64.8 Gy had improved bDFS at 5 years compared to all others (77% vs 32%, p = 0.04). Of 60 patients 3 (5%) experienced chronic grade 3 toxicity.

CONCLUSIONS

Optimal benefit from salvage RT was achieved in patients with a PSA less than 0.6 ng/ml and doses of RT greater than 64.8 Gy. Early treatment with a sufficiently high dose of RT maximizes the potential for salvage.

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 failure of radical prostatectomy: a single-institution experience

OBJECTIVES

To review the efficacy of salvage radiotherapy (RT), to treat elevated prostate-specific antigen (PSA) levels for presumed local recurrence of prostatic adenocarcinoma after retropubic prostatectomy, and identify the factors that may predict for successful treatment.

METHODS

Fifty-one patients with hormonally naive pT2-3N0-1M0 prostate cancer were treated with RT for locally persistent or recurrent disease. The patients received a median dose of 65.7 Gy (range 61.2 to 72.3) to the prostate bed. Successfully treated patients had undetectable PSA levels; the endpoint of the study was biochemical failure.

RESULTS

The median follow-up was 3.8 years; 42 of 51 patients had at least 2 years of follow-up. Twenty-three patients (45%) were biochemically free of disease. The estimated biochemically free of disease rate at 3 and 5 years was 56% and 16%, respectively. Whether the patients were treated for persistently elevated PSA levels or for rising PSA levels from undetectable levels after retropubic prostatectomy, their PSA values were equally likely to drop to undetectable levels (65%). Univariate analysis demonstrated two factors that significantly predicted for successful salvage treatment: the absence of seminal vesicle invasion and the absence of lymphovascular invasion. A pretreatment PSA level less than 0.425 ng/mL trended toward statistical significance (P = 0.059). Only seminal vesicle invasion maintained significance on multivariate analysis. The RT was well tolerated, and the gastrointestinal and genitourinary toxicity was largely Radiation Therapy Oncology Group grade 1.

CONCLUSIONS

Salvage RT is moderately effective in treating patients with locally persistent or recurrent prostate adenocarcinoma. Seminal vesicle invasion and lymphovascular invasion predicted for unsuccessful treatment.

Selecting a secondary treatment

There is compelling evidence that early hormonal therapy prolongs life in many stages of prostate cancer. Large-scale trials to answer this question have not yet been conducted in surgically treated patients or in patients with PSA-only relapse. Thus, many physicians and patients use early hormone therapy in PSA-only relapse. Many unique new agents are being tested in this population and may offer benefits. Patients and physicians are encouraged to participate in such trials, with hormone therapy reserved for subsequent use. Following failure of primary hormone therapy, a standard algorithm of care exists: antiandrogen withdrawal, use of alternative or first-line anti-androgens. ketoconazole. and chemotherapy. At each interval, clinical trials should be offered since none of these maneuvers are proven to prolong life.

Predictors of biochemical outcome with salvage conformal radiotherapy after radical prostatectomy for prostate cancer

PURPOSE

To identify predictors of biochemical outcome following radiotherapy in patients with a rising prostate-specific antigen (PSA) after radical prostatectomy for prostate cancer.

PATIENTS AND METHODS

One hundred fifteen patients with a rising PSA after radical prostatectomy received salvage three-dimensional conformal radiotherapy (3D-CRT) alone or with neoadjuvant androgen deprivation. Tumor-related and treatment-related factors were evaluated to identify predictors of subsequent PSA failure.

RESULTS

The median follow-up time after 3D-CRT was 42 months. The 4-year actuarial PSA relapse-free survival, distant metastasis-free survival, and overall survival rates were 46%, 83%, and 95%, respectively. Multivariate analysis, which was limited to 70 patients receiving radiation without androgen deprivation therapy, showed that negative/close margins (P =.03), absence of extracapsular extension (P <.01), and presence of seminal vesicle invasion (P <.01) were independent predictors of PSA relapse after radiotherapy. Neoadjuvant androgen deprivation did not improve the 4-year PSA relapse-free survival in patients with positive margins, extracapsular extension, and no seminal vesicle invasion (P =.24). However, neoadjuvant androgen deprivation did improve PSA relapse-free survival when one or more of these variables were absent (P =.03).

CONCLUSIONS

Salvage 3D-CRT can provide biochemical control in selected patients with a rising PSA after radical prostatectomy. Among patients with positive margins and no poor prognostic features, 77% achieved PSA control after salvage 3D-CRT. Salvage neoadjuvant androgen deprivation therapy may improve short-term biochemical control, but it requires further study.

Salvage radiotherapy for rising or persistent PSA after radical prostatectomy

OBJECTIVES

To assess the effectiveness of salvage radiotherapy (RT) for a persistent or rising prostate-specific antigen (PSA) level after radical prostatectomy, and to identify the pretreatment factors that may predict for patients likely to benefit from this treatment.

METHODS

Seventy-three consecutive patients were treated during a 10-year period (1989 to 1999) with RT after radical prostatectomy. Twelve patients were excluded from analysis because of either an undetectable PSA level before RT or lack of follow-up data. No patients had clinical or radiographic evidence of distant disease. An undetectable PSA level (less than 0.1 ng/mL) was required to be considered disease free.

RESULTS

The median PSA level before RT was 0.8 ng/mL (range 0.1 to 63). The median radiation dose prescribed was 66.6 Gy. The actuarial PSA-free survival rate at 4 years was 39%. Failure was uncommon in patients followed up beyond 4 years. Univariate analysis revealed that a pre-RT PSA level of less than 1.0 ng/mL (P = 0.001), Gleason score less than 8 (P = 0.003), and achievement of an undetectable PSA level after prostatectomy (P = 0.018) were significant predictors of improved disease-free survival. On multivariate analysis, both a pre-RT PSA level of less than 1.0 ng/mL and a Gleason score less than 8 maintained statistical significance.

CONCLUSIONS

Salvage RT provides a reasonable chance of intermediate-term disease-free survival in patients with PSA persistence or relapse after radical prostatectomy. Patients with a higher PSA level (greater than 1 ng/mL) and Gleason score of 8 or more are less likely to benefit from this treatment, and improved therapies are needed for this subset of patients. Patients should be referred promptly for salvage RT after detection of relapse.

Salvage radiotherapy for PSA failure after radical prostatectomy

BACKGROUND AND PURPOSE

Prostate-specific antigen (PSA) failure after radical prostatectomy is a common clinical scenario, and there is no consensus on how it should be managed. Salvage radiation to the prostatic bed is a potentially curative treatment option, and is the subject of this review. Patient selection, and the efficacy and toxicity of treatment will be discussed, and recommendations made for current practice and future studies.

METHODS

An English language MEDLINE search was performed, limited to the years 1989-2000, using the MeSH headings 'prostatic neoplasms' and 'radiotherapy'. The 660 abstracts identified were reviewed, and articles concerning patient selection for, or outcome of, post-operative radiation to the prostatic bed selected. After exclusion of articles concerning adjuvant, rather than salvage, radiation, this left a total of 22 case series, including 1062 patients for the review of treatment efficacy.

RESULTS AND CONCLUSIONS

The quality of the evidence makes it difficult to form a judgment regarding the efficacy of salvage radiation following radical prostatectomy, particularly in men with a PSA level in the range 0.01-0.2 ng/ml. Salvage radiation may be more effective given earlier rather than later. These considerations have important consequences for the interpretation of current trials of adjuvant radiation following radical prostatectomy.