Definitive therapy for prostate carcinoma: Mayo Clinic results at 15 years after treatment

Radiation therapy in prostate cancer

Adenocarcinoma of the prostate is one of the most frequently diagnosed cancers of men in the Western hemisphere and is second only to lung cancer for male cancer mortality. Most patients are diagnosed in the early/clinically localized stage, which can be treated curatively with radiation therapy alone. Innovative methods such as brachytherapy, three-dimensional conformal radiotherapy (3D-CRT), and IMRT (intensity modulated radiotherapy) are able to deliver very high tumoricidal doses to the diseased prostate, with minimal side effects to the surrounding tissue. Radiation therapy combined with hormonal treatment can be curative in locally advanced disease. Radiation therapy is also very effective in alleviating symptoms of metastatic prostate cancer (bone metastases, spinal cord compression, and bladder outlet obstruction).

FAILURE AFTER PRIMARY RADIATION OR SURGERY FOR PROSTATE CANCER: DIFFERENCES IN RESPONSE TO ANDROGEN ABLATION

PURPOSE

Androgen ablation is the standard treatment for recurrent and metastatic prostate cancer. Surprisingly few studies have documented the specific results for local and distant failure in patients treated primarily with radiation or radical prostatectomy. We report the long-term outcome of a series of those patients.

MATERIALS AND METHODS

We followed until death 94 patients in whom primary radiation therapy failed and 67 in whom radical prostatectomy failed. All patients received androgen ablation.

RESULTS

Statistically (p = 0.04) more patients in the radiation group (78%) died of prostate cancer than in the radical prostatectomy group (63%). Of the radiation group with local failure alone 63%, died of prostate cancer at a median of 5.03 years. Of the surgery group with isolated local failure 50% died of cancer at a median of 9.83 years. Of the patients treated with radiation with distant metastasis 93% died of cancer with a median time to death of 2.34 years. Of the patients treated with surgery 69% died of prostate cancer at a median of 3.27 years. The differences in survival between the 2 groups was significant.

CONCLUSIONS

This study is unique in providing followup until death of patients treated with radical prostatectomy and radiation who had clinical failure and were treated with androgen ablation. Compelling is the finding that survival after androgen ablation after surgical failure is superior to that for radiation. If confirmed, this would be a significant consideration for future studies of patients in whom primary therapy fails.

Long-term follow-up of radiotherapy for prostate cancer

PURPOSE

To determine the long-term outcome of radiotherapy for prostate cancer.

METHODS AND MATERIALS

A total of 136 consecutive patients with prostate cancer underwent primary radiotherapy. All but 4 patients received 6000 cGy to the prostate. The minimal follow-up was 22.9 years.

RESULTS

Of the 136 patients, 93 had Stage B (T2), 9 Stage A (T1), and 34 Stage C (T3). Sixty-nine percent of the patients developed recurrence, and 51% of all patients died of prostate cancer. The recurrences developed at a steady state throughout the length of follow-up. One half the recurrences occurred after 10 years, and recurrence was still observed >20 years after treatment. The survival rate at 5, 10, 15, 20, and 25 years was 81%, 59%, 37%, 16%, and 10%, respectively. The recurrence-free survival rate at 25 years was 17%. The median survival for Grade 3-4 patients was 6.3 years and for Grade 1-2 patients was 13.0 years. The median survival for those with T1 tumors was 12.9 years; T2 tumors, 12.4 years; and T3 tumors, 9.5 years.

CONCLUSION

Despite favorable early results, with long-term follow-up, patients continued to experience prostate cancer recurrence. Unless they died an intercurrent death, they were highly likely to develop recurrence and die of prostate cancer. The conclusions from treatment studies with <15 years of follow-up should be viewed as preliminary.

Long-term results of a randomized trial for the treatment of Stages B2 and C prostate cancer: radical prostatectomy versus external beam radiation therapy with a common endocrine therapy in both modalities

OBJECTIVES

To improve the treatment of locally advanced prostate cancer (Stages B2 and C), a prospective randomized trial was conducted to compare radical prostatectomy versus external beam radiotherapy with the combination of endocrine therapy in both modalities.

METHODS

One hundred patients were enrolled and 95 were evaluated. Forty-six patients underwent radical prostatectomy with pelvic lymph node dissection, and 49 were treated with radiation by linear accelerator with 40 to 50 Gy to the whole pelvis and a 20-Gy boost to the prostatic area. For all patients, endocrine therapy was initiated 8 weeks before surgery or radiation, and continued thereafter. The living patients were asked to respond to a quality-of-life questionnaire.

RESULTS

The follow-up period ranged from 6.0 to 94.4 months (median 58.5). The progression-free and cause-specific survival rates at 5 years were 90.5% and 96.6% in the surgery group and 81.2% and 84.6% in the radiation group, respectively. The surgery group had better progression-free and cause-specific survival rates (P = 0.044 and 0.024, respectively). More patients in the surgery group complained of urinary incontinence. The questionnaire revealed that quality of life was less disturbed in the radiation group.

CONCLUSIONS

Radical prostatectomy combined with endocrine therapy may contribute to the survival benefit of patients with locally advanced prostate cancer. External beam radiotherapy in combination with endocrine therapy can be used in selected patients because of its low morbidity.

Actuarial disease-free survival after prostate cancer brachytherapy using interactive techniques with biplane ultrasound and fluoroscopic guidance

PURPOSE

To evaluate the effectiveness and safety of interactive transperineal brachytherapy under biplane ultrasound and fluoroscopic guidance in patients with localized prostate cancer.

METHODS AND MATERIALS

Brachytherapy using 125I or 103Pd radioactive seeds either alone or in combination with adjunctive external beam radiotherapy (XRT) was administered to 490 patients at a single institution. Post-treatment follow-up included clinical assessment of disease status, assays of serum prostate-specific antigen (PSA) levels and documentation of treatment-related symptoms and complications.

RESULTS

Actuarial disease-free survival at 5 yr was 79% (95% CI, 71-85%), and the 5-yr actuarial rate of local control was 98% (95% CI, 94-99%). Post-treatment PSA nadir and pretreatment PSA level were found to be significant predictors of disease-free survival. In patients with a PSA nadir < 0.5 ng/ml, 5-yr disease-free survival was 93% (95% CI, 84-97%), compared with 25% (95% CI, 5-53%) in patients whose PSA nadir was 0.5-1.0 ng/ml and 15% (95% CI, 3-38) in patients with a PSA nadir > 1.0 ng/ml. Brachytherapy was well tolerated with few post-treatment complications.

CONCLUSION

A broad range of patients with localized prostate cancer can benefit from transperineal brachytherapy with minimal morbidity. A post-treatment PSA nadir below 0.5 ng/ml provides a useful prognostic indicator of favorable long-term outcome.

Early prostate-specific antigen failure following radical perineal versus retropubic prostatectomy: the importance of seminal vesicle excision

OBJECTIVES

Because of renewed interest in the radical perineal prostatectomy, we chose to evaluate factors influencing differences in biochemical failure as measured by prostate-specific antigen (PSA) between radical perineal and the radical retropubic prostatectomies.

METHODS

We undertook a retrospective review of 87 men with clinically localized prostate cancer who underwent radical retropubic (64%) or radical perineal (36%) prostatectomy, noting age, race, preoperative PSA, Gleason score, clinical stage, capsular penetration, surgical approach, and completeness of seminal vesicle (SV) excision. The two groups were comparable with respect to tumor factors such as preoperative PSA, Gleason score, clinical stage, and capsular penetration. Time to postoperative PSA failure (0.2 ng/mL or greater) was evaluated with univariate and multivariate analysis of multiple contributing factors.

RESULTS

Twenty-eight percent of patients had a PSA level rising to 0.2 ng/mL or greater in the follow-up period. Patients who underwent perineal prostatectomy had a higher PSA failure rate (45%) than those treated by the retropubic approach (18%) and patients with incomplete SV excision had a higher failure rate (69%) than patients with bilateral SV excision (20%). When time to PSA failure was examined by multivariate analysis, completeness of SV excision, clinical stage, and Gleason score had a statistically significant impact on this outcome. In perineal prostatectomy patients, bilateral SV excision had a significantly longer time to PSA failure than in patients with incomplete excision. There was no significant difference in time to PSA failure between patients who underwent radical retropubic prostatectomy and the patients who underwent perineal prostatectomy with bilateral SV excision.

CONCLUSIONS

Incomplete excision of SVs during a radical perineal prostatectomy contributes to an earlier postoperative biochemical recurrence as measured by a rising PSA, and may explain the higher disease recurrence rate for radical perineal prostatectomies as opposed to radical retropubic prostatectomies in this study.

Prostate cancer mortality in northern Sweden, with special reference to tumor grade and patient age

OBJECTIVES

This study is designed to estimate the prostate cancer-specific mortality according to patient age and tumor grade in an unselected population of patients with prostate cancer who mostly received deferred or direct hormonal treatment as initial treatment.

METHODS

The study population was composed of 6514 patients diagnosed with prostate cancer during 1971 to 1987 in northern Sweden. For those who died during follow-up, the cause of death was determined from the comprehensive Swedish registry data (population registries and causes of death registry).

RESULTS

About 85% of these patients died during the 7 to 23 years of follow-up, and the prostate cancer-specific mortality was estimated to be 55%. Age at diagnosis was found to be a strong predictor of prostate cancer death. Patients diagnosed before the age of 60 had an 80% risk of dying of prostate cancer, whereas those over 80 years of age at diagnosis had less than a 50% risk of prostate cancer-related death.

CONCLUSIONS

The prostate cancer mortality is high but decreases with older age at diagnosis. We found, using data from the causes of death registry, that the relative survival and the cause-specific survival of these patients were compatible with each other.

A multiple prognostic index predictive of disease outcome after irradiation for clinically localized prostate carcinoma

BACKGROUND

This investigation was conducted to identify independent pretherapy disease-related factors associated with disease outcome in patients with clinically localized carcinoma of the prostate (CaP) and to develop models that incorporated relevant covariates for estimating the risk of disease relapse after irradiation (RT).

METHODS

The outcome of 500 patients treated only with RT between March 1987 and June 1993 for clinical Stages T1-4N0,XM0 CaP was evaluated. The risk of disease relapse as a function of individual prognostic variables, and combinations thereof, was determined using logistic regression.

RESULTS

With a median follow-up of 43 months (range, 4-103 months), 69 patients (14%) had clinical evidence of local recurrence (27 patients), regional lymph node relapse (4 patients), or metastatic relapse (38 patients) within 5 years of RT. Forty additional patients (8%) had biochemical relapse based solely on the post-RT serum prostate specific antigen (PSA) profile. Clinical tumor stage (P = 0.0006), Gleason score (P = 0.001) of the diagnostic biopsy specimen, and pretherapy PSA (P < 0.0001) were associated with disease relapse. The risk of any relapse within 5 years of RT was determined and graphically displayed as risk estimate plots for combinations of these pretherapy prognostic variables.

CONCLUSIONS

The combination of pretherapy clinical tumor (T) stage, Gleason score, and PSA level can be used to obtain improved estimates of the risk for disease relapse in patients treated solely with RT for clinically localized CaP. Risk estimate plots of this type may facilitate exchange of therapeutic outcome information, be instrumental in pretherapy decision-making for the new patient with this condition, and aid in the selection of patients for future studies.

Long-term control of prostate cancer with radiation. Past, present, and future

This article details the methods of determining cancer-free status and addresses the long-term results of external beam radiation. It demonstrates that when similar patients are compared, the results of prostatectomy and radiation in early disease do not differ. The new technology in conformal radiation produces outcomes superior to conventional radiation technique in cure of cancer and reduction of serious complications.

Prostate cancer and radiation therapy--the message conveyed by serum prostate-specific antigen

PURPOSE

Prostate-specific antigen (PSA) is a powerful pretreatment prognosticator and a sensitive post-treatment outcome measure for clinically localized prostate cancer treated with radiation therapy. Today, the pretreatment serum PSA level appears to supersede both grade and T-stage as a determinant of outcome. This study was undertaken to attempt a reconciliation between the old (pre-PSA) and the new (PSA) data-in particular to address the question of why stage and grade apparently play so little role in this PSA era.

METHODS AND MATERIALS

We analyzed the outcome of two cohorts of men with T1-T4, NO, or NX, MO prostate cancer, one group (648 patients) treated and followed in the pre-PSA era (1966-1988), another group (707 patients) treated and followed in the PSA era (1987-1993)--who received definitive radiation as their only initial treatment. The patterns of relapse and prognostic factors for these groups were compared and contrasted using univariate and multivariate techniques.

RESULTS

At a median follow-up of 6.5 years, the relapse patterns in the pre-PSA series were: local in 109 (17%), nodal in 17 (3%), and distant metastatic in 186 (29%). Actuarial local and metastatic rates at 5 years were 13 and 26%, respectively. Local recurrence was only weakly predictable, Gleason grade being the only significant, albeit weak, covariate. Metastatic failure, however, was highly significantly and meaningfully correlated with Gleason grade and T-stage. Because metastasis was the most common adverse end point in this series, overall freedom from progression also correlated with grade and stage. At a median follow-up of 31 months, the patterns of failure in the PSA series were: local in 77 (11%), nodal in 3 (< 1%), and distant metastatic in 24 (3%). Actuarial local and metastatic rates at 5 years were 30 and 6%, respectively. Local recurrence was highly and meaningfully correlated with pretreatment PSA level, which was the only significant determinant of this end point. Metastatic failure was highly correlated with Gleason grade and T-stage, with PSA playing a much lesser, though significant role. The inversion of failure patterns (local vs. distant) between the two series was striking. The high incidence of local failure in the PSA series was almost entirely related to positive prostatic biopsies pursuant to the investigation of the postradiation rising PSA profile. Of the 77 local recurrences, 69 (90%) were identified in this way. Among 99 men with rising PSA values who underwent investigation (CT scans, bone scans, and biopsies), disease was found in 86, and the patterns of disease in these 86 were: local only in 62 (72%), local and metastatic in 7, and metastatic in 17 (20%). The most common event in the PSA series was the rising PSA profile, and this, too, strongly correlated with the pretreatment PSA level.

CONCLUSION

Based on our earlier finding that the major source of pretreatment serum PSA in patients with clinically localized disease is the primary tumour itself and on the findings in the present report, we conclude that the new major message conveyed by serum PSA relates to the primary tumor and its likely outcome. Gleason grade and T-stage remain major determinants of metastatic relapse. The total and permanent eradication of prostate cancer from the prostate with conventional doses of external beam radiation therapy is harder to achieve than generally appreciated.

Radiation therapy for T1 and T2 prostate cancer: prostate-specific antigen and disease outcome

OBJECTIVES

To evaluate disease outcome using serum prostate-specific antigen (PSA) as an outcome measure in patients with T1 or T2 prostate cancer treated with radiation therapy in the PSA era.

METHODS

We reviewed the outcome for 461 patients with T1 (n = 205) or T2 (n = 256) prostate cancer followed for a median of 31 months after radiation therapy as the sole initial treatment. Univariate and multivariate analyses were used to delineate significant prognostic factors.

RESULTS

The freedom from relapse or rising PSA rate was 70% at 6 years and the survival rate was 83%. Although T stage, Gleason grade, serum prostatic acid phosphatase level, and serum PSA level were each significant determinants of outcome in univariate analysis, pretreatment PSA level was the only clearly independent covariate (P < 0.0001) in multivariate analysis. The 5-year actuarial freedom from relapse or from rising PSA levels is shown according to the pretreatment PSA level: 4 ng/mL or less (117 patients), 91%; more than 4 but 10 ng/mL or less (169 patients), 69%; more than 10 but 20 ng/mL or less (118 patients), 62%; and more than 20 ng/mL (57 patients), 38%. PSA doubling times in 75 patients with rising post-treatment profiles ranged from 1.3 to 78.2 months (mean, 14.4; median 11.3). Faster doubling times correlated significantly with adverse pretreatment prognostic factors (high-grade, high pretreatment PSA, and aneuploidy). To date, the survival rate of patients with rising PSA profiles was not depressed below the expected.

CONCLUSIONS

Radiation therapy is an acceptable modality for treating T1 or T2 disease and produces results comparable to those following radical prostatectomy when patients are stratified according to their pretreatment PSA value. The rapid PSA doubling times observed in patients with relapsing disease are more consistent with a "selective" rather than an "aggravation" mechanism.