Clinical utility of the percentage of positive prostate biopsies in defining biochemical outcome after radical prostatectomy for patients with clinically localized prostate cancer

Permanent interstitial brachytherapy for the management of carcinoma of the prostate gland

PURPOSE

We summarize the permanent prostate brachytherapy literature, including biochemical outcomes, quality of life parameters and areas of controversy.

MATERIALS AND METHODS

The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness.

RESULTS

Using various planning and intraoperative techniques the majority of the brachytherapy literature demonstrates durable biochemical outcomes for patients with low, intermediate and high risk features. For low risk patients there is no advantage to combining supplemental external beam radiation therapy with brachytherapy. In addition, supplemental external beam radiation therapy may not improve biochemical outcomes for patients at intermediate and high risk if the target volume consists of the prostate with a generous periprostatic margin. There is no defined role for adjuvant hormonal manipulation. Although a reliable set of pretreatment criteria to predict implant related morbidity is not available, severe urinary and rectal morbidity is rare. The incidence of brachytherapy induced erectile dysfunction is significantly greater than initially reported but the majority of patients respond favorably to sildenafil.

CONCLUSIONS

Continued refinements in brachytherapy planning and implementation techniques, postimplantation evaluation and continued elucidation of the etiology of urinary, bowel and sexual dysfunction should result in further improvements in biochemical and quality of life outcomes.

Neoadjuvant therapy for high-risk localized prostate cancer

Prostate cancer patients with clinical stage T3 disease, biopsy Gleason scores of 8 to 10, or serum prostate-specific antigen levels greater than 20 ng/mL are at high risk of recurrence despite local therapy. Although hormonal therapy has palliative benefit for the majority of patients with metastatic disease, randomized trials have not demonstrated a survival benefit for its administration prior to surgery for locally advanced disease. Historically, chemotherapy has been felt to have little activity in hormone-refractory prostate cancer, but new evidence may refute this belief. Ongoing clinical trials are now investigating the use of chemotherapy in the neoadjuvant setting. We review the recent literature regarding the use of neoadjuvant hormonal manipulation, chemotherapy, and promising new molecular targeted agents in patients with high-risk localized prostate cancer.

Pretreatment predictors of time to cancer specific death after prostate specific antigen failure

PURPOSE

Whether pretreatment factors that predict for time to prostate specific antigen (PSA) failure also predict for time to prostate cancer specific death after PSA failure for patients with competing causes of mortality treated during the PSA era was the subject of this study.

MATERIALS AND METHODS

Of 415 men with a median age of 73 years who underwent external beam radiation therapy between 1988 and 2001 for clinically localized prostate cancer 160 (39%) experienced PSA failure and 96 (23%) died. In 46 men (48%) the cause of death was prostate cancer. Cox regression multivariable analyses (multivariable analysis) were performed to evaluate the ability of the pretreatment PSA and centrally reviewed biopsy Gleason score to predict time to prostate cancer specific death after PSA failure.

RESULTS

When analyzed as categorical variables using multivariable analysis, biopsy Gleason score 4 + 3 (p = 0.02), 8 to 10 (p = 0.02) disease and a pretreatment PSA greater than 20 ng./ml. (p = 0.03) were significant predictors of time to prostate cancer specific death after PSA failure. Estimates of prostate cancer specific death 5 years after PSA failure were 24%, 40% and 59% (p = 0.01) for patients with a biopsy Gleason score < or = 6, 3 + 4, 4 + 3 or higher and 22%, 40% and 60% (p = 0.04) for patients with a pretreatment PSA of 10 or less, greater than 10 and 20 or less, or greater than 20 ng./ml., respectively.

CONCLUSIONS

Patients at high risk for PSA failure after radiation therapy based on pretreatment PSA greater than 20 ng./ml. or biopsy Gleason score 4 + 3 or greater are also at high risk for death from prostate cancer after PSA failure despite competing causes of mortality.

Comparison of percentage of total prostate needle biopsy tissue with cancer to percentage of cores with cancer for predicting PSA recurrence after radical prostatectomy: results from the SEARCH database

OBJECTIVES

Tumor volume in the prostate needle biopsy is an important prognosticator for patients with prostate cancer. However, the best method to measure tumor volume in the prostate needle biopsy is unknown. We compared the total percentage of biopsy tissue with cancer to the percentage of cores positive for their ability to predict adverse pathologic findings and biochemical failure after radical prostatectomy (RP).

METHODS

A retrospective survey of 355 patients from the Shared Equal Access Regional Cancer Hospital database treated with RP between 1990 and 2002 was undertaken. Multivariate analysis was used to compare the percentage of cores and percentage of tissue with cancer to the standard clinical variables of age, prostate-specific antigen (PSA) level, biopsy Gleason score, and clinical stage for their ability to predict positive surgical margins, non-organ-confined disease, seminal vesicle invasion, and time to PSA recurrence after RP.

RESULTS

On multivariate analysis, the percentage of tissue with cancer significantly predicted non-organ-confined disease and seminal vesicle invasion, but the percentage of cores did not significantly predict any of the pathologic features examined. In separate multivariate analysis, only the percentage of tissue with cancer, but not the percentage of cores with cancer, significantly predicted PSA failure. Moreover, when compared in the same multivariate analysis, only the percentage of tissue with cancer (hazard ratio 8.25, 95% confidence interval 3.06 to 22.22, P <0.001) was a significant predictor. The area under the receiver operating curves for predicting PSA failure was significantly greater for the percentage of tissue with cancer (0.697) than for the percentage of cores (0.644, P = 0.022). Cutpoints for the percentage of tissue with cancer (less than 20%, 20% to 40%, and greater than 40%) and the percentage of cores (less than 34%, 34% to 50%, greater than 50%) both provided significant preoperative risk stratification for biochemical failure, although the percentage of tissue with cancer cutpoints provided better risk stratification (higher hazard ratios and lower P value). Cutpoints for the percentage of tissue with cancer but not the percentage of cores positive further stratified patients who were at low (P = 0.041), intermediate (P = 0.002), and high (P = 0.023) risk on the basis of the PSA level and biopsy Gleason score.

CONCLUSIONS

The percentage of tissue with cancer was better than the percentage of cores at predicting advanced pathologic features and PSA recurrence after RP. Unlike the percentage of cores, the percentage of tissue with cancer cutpoints further stratified low, intermediate, and high-risk patients on the basis of PSA level and biopsy Gleason score. Although the percentage of tissue with cancer is a slightly more cumbersome measurement than the percentage of positive cores, it provided statistically and clinically superior preoperative risk stratification for biochemical failure after RP.

Using the percentage of biopsy cores positive for cancer, pretreatment PSA, and highest biopsy Gleason sum to predict pathologic stage after radical prostatectomy: the Center for Prostate Disease Research nomograms

OBJECTIVES

To develop probability nomograms to predict pathologic outcome at the time of radical prostatectomy (RP) on the basis of established prognostic factors and prostate biopsy quantitative histology.

METHODS

Using information from the database of the Center for Prostate Disease Research (CPDR), univariate and multivariate analyses were performed on 1510 men who had undergone transrectal ultrasound and biopsy for diagnosis and had radical prostatectomy as primary therapy, with variables of age, race, clinical stage, pretreatment prostate-specific antigen (PSA), biopsy Gleason sum, and percentage of biopsy cores positive for cancer (total number of cores positive for cancer divided by the total number of cores obtained). The percentages of biopsy cores positive were grouped as less than 30%, 30% to 59%, and greater than or equal to 60%. The three most significant variables were used to develop probability nomograms for pathologic stage.

RESULTS

PSA, biopsy Gleason sum, and percentage of cores positive were the three most significant independent predictors of pathologic stage. The assigned percentage of biopsy core-positive subgroups along with pretreatment PSA and highest Gleason sum were used to develop probability nomograms for pathologic stage.

CONCLUSIONS

Pretreatment PSA, highest biopsy Gleason sum, and the percentage of cores positive for cancer are the most significant predictors for pathologic stage after radical prostatectomy. On the basis of these findings, CPDR probability nomograms were developed to predict pathologic outcome at the time of RP.

Pathologic features the urologist should expect on a prostate biopsy

In recent years, the pathological evaluation of prostate biopsy specimens has made great improvements in diagnostic accuracy and comprehensiveness. In this article, we review major pathological findings on prostate biopsy, their interpretation and reporting, as well as their clinical significance and utility. We discuss especially the clinically relevant histological features in either a positive or negative biopsy. We emphasize that both Gleason score and extent of cancer involvement in a needle core biopsy are important predictors of clinical outcome after either radical prostatectomy or radiation. Special issues regarding diagnosis and grading of minimal cancer on needle core biopsies are discussed. We also highlight the current standards on high-grade prostatic intraepithelial neoplasia and atypical small acinar proliferation on needle core biopsies. In summary, the pathology reports on needle biopsies are far beyond the simple presence or absence of cancer; they contain invaluable information to clinicians on patient management and counseling.

Comparison of preoperative prostate specific antigen density and prostate specific antigen for predicting recurrence after radical prostatectomy: results from the search data base

PURPOSE

Prostate specific antigen (PSA) density based on the surgical weight of the radical prostatectomy specimen has previously been shown to be an independent predictor of biochemical recurrence after radical prostatectomy. We determined whether preoperative PSA density calculated using transrectal ultrasound prostate volume was a better predictor of advanced pathological findings or biochemical recurrence after radical prostatectomy relative to PSA.

MATERIALS AND METHODS

We examined 552 men from the newly established Shared Equal Access Regional Cancer Hospital data base of men treated with radical prostatectomy at equal access medical centers to determine whether preoperative PSA density was a significant predictor of an adverse pathological condition or PSA recurrence after radical prostatectomy. Models using PSA density were compared with models using PSA to determine whether PSA density improved risk stratification relative to PSA. PSA density was examined as a continuous and a categorical variable using cutoffs to separate patients into groups at different risks for PSA failure.

RESULTS

PSA density and PSA were significant predictors of adverse pathological findings on univariate analysis. Using PSA density in the multivariate model resulted in slightly better but statistically insignificant improvement in prediction of positive surgical margins (p = 0.134) and extracapsular extension (p = 0.771) relative to using PSA in the model. Neither PSA nor PSA density were significant independent predictors of seminal vesicle invasion. Area under the ROC curves for predicting biochemical recurrence for PSA and PSA density were not significantly different (0.589 and 0.58, respectively, p = 0.691). On separate multivariate analyses PSA density and PSA were significant independent predictors of biochemical failure. The multivariate model using PSA density provided only slight improvement in risk assessment relative to the model using PSA (index C = 0.589 and 0.581, respectively). To determine whether using PSA density as a categorical variable would result in improved prognostication we evaluated PSA density to determine the cutoff points that would provide the greatest risk stratification. PSA density cutoffs of less than 0.4, 0.4 to 1 and greater than 1 ng./ml./cc separated patients into 3 distinct groups at increasing risk for biochemical failure (p <0.001). While these cutoffs provided better risk stratification than when PSA density was examined as a continuous variable (index C = 0.684 versus 0.58), they provided only marginal improvement relative to the standard PSA cutoffs of less than 10, 10 to 20 and greater than 20 ng./ml. (index C = 0.676).

CONCLUSIONS

The use of preoperative PSA density relative to PSA provided only slight improvement for predicting adverse pathological findings and biochemical recurrence after radical prostatectomy. The minimal and statistically insignificant improvement in preoperative risk assessment provided by PSA density does not justify the time and effort necessary to calculate this value.

Can the core length involved with prostate cancer identify clinically insignificant disease in low risk patients diagnosed on the basis of a single positive core?

Clinically insignificant prostate cancer, defined as at most microscopic foci of Gleason grade < or = 3 disease in the radical prostatectomy specimen, has been recognized in some low risk (PSA < 10, biopsy Gleason score < or = 6, clinical Tlc, 2a) patients with minimal biopsy cancer volume. The purpose of this study is to determine if the fraction of cancer in a single positive core biopsy could identify a subset of low risk prostate cancer patients with clinically insignificant disease. Of 1100 patients with Tlc,2 prostate cancer that consecutively underwent radical prostatectomy at Brigham and Women's Hospital between 1989 to 2000, 130 low risk patients whose diagnoses were made on the basis of a single positive core comprised the study cohort. The pathologic findings at radical prostatectomy were enumerated for men with < or = 5% of a single core involved with prostate cancer in order to determine the rate of clinically insignificant prostate cancer in this population. Estimates of PSA survival were calculated using the actuarial method of Kaplan and Meier. Pairwise comparisons were made using the log rank test. For patients with < or = 5% (n = 14) and > 5% (n = 116) involvement of a single positive core, the 4 year PSA failure free survivals were 100% vs. 89% (P = 0.048), respectively. Within the subset of patients with < or = 5% of a single core involved, 7% (1/14) met the criteria for clinically insignificant disease. However, of the remaining 93%, 3, 8, and 2 patients had pathologic stage T2a, T2b, and T3a, respectively. Eleven patients had prostatectomy Gleason scores < or = 3 + 3, two patients had pathologic Gleason scores of 3 + 4, and one patient had a positive surgical margin. Given that only 7% of low risk patients in this cohort with < or = 5% involvement of a single positive core had clinically insignificant disease, the involved core length alone cannot be used to identify patients with clinically insignificant disease. Further studies are needed in order to delineate which patients may not benefit from treatment.

Predicting recurrence after radical prostatectomy for patients with high risk prostate cancer

PURPOSE

Previous studies have shown that patients with clinical stage T2c-T3 prostate cancer, serum prostate specific antigen (PSA) at diagnosis greater than 20 ng./ml. or a biopsy Gleason score of 8 to 10 are at high risk for disease recurrence after radical prostatectomy. We determined the most important pretreatment predictors of disease recurrence in this high risk population.

MATERIALS AND METHODS

We identified 547 patients with high risk prostate cancer who underwent radical prostatectomy at University of California, San Francisco or as part of the Cancer of the Prostate Strategic Urological Research Endeavor data base, a longitudinal disease registry of patients with prostate cancer. High risk disease was defined as 1992 American Joint Committee on Cancer clinical stage T2c-T3 disease in 411 patients, serum PSA at diagnosis greater than 20 ng./ml. in 124 and/or biopsy Gleason score 8 to 10 in 114. Disease recurrence was defined as PSA 0.2 ng./ml. or greater on 2 consecutive occasions after radical prostatectomy or second cancer treatment more than 6 months after surgery. The Cox proportional hazards analysis was performed to determine significant independent predictors of disease recurrence. The likelihood of disease recurrence for clinically relevant patient groups was determined using the Kaplan-Meier method and compared using the log rank test.

RESULTS

Median followup after surgery was 3.1 years. Disease recurred in 177 patients (32%). Multivariate analysis demonstrated that serum PSA at diagnosis, biopsy Gleason score, ethnicity and the percent of positive prostate biopsies were significant independent predictors of disease recurrence, while patient age and clinical tumor stage were not. Patients with a Gleason score 8 to 10 tumor and a serum PSA of 10 ng./ml. or less had a significantly higher likelihood of remaining disease-free 5 years after surgery than those with PSA greater than 10 ng./ml. (47% versus 19%, p <0.05). Patients with a serum PSA at diagnosis of greater than 20 ng./ml. and a Gleason score of less than 8 had a significantly higher likelihood of remaining disease-free 5 years after surgery than similar patients with a Gleason score of 8 or greater (45% versus 0%, p <0.05).

CONCLUSIONS

PSA, Gleason score, ethnicity and the percent of positive prostate biopsies appear to be the most important pretreatment predictors of disease recurrence in men with high risk prostate cancer. Patients with high grade disease may continue to be appropriate candidates for local therapy if PSA is less than 10 ng./ml. at diagnosis or there are fewer than 66% positive prostate biopsies.

Advanced age at diagnosis is an independent predictor of time to death from prostate carcinoma for patients undergoing external beam radiation therapy for clinically localized prostate carcinoma

BACKGROUND

Whether age at diagnosis is predictive of time to prostate carcinoma specific death after external beam radiation therapy (RT) for patients who are diagnosed with clinically localized prostate carcinoma during the prostate specific antigen (PSA) era has not been investigated previously.

METHODS

A multivariate Cox regression analysis was used to evaluate the ability of pretreatment risk group and age at diagnosis to predict time to all causes of death and time to death from prostate carcinoma for 381 patients who underwent RT for clinically localized prostate carcinoma.

RESULTS

Age at diagnosis, as a continuous variable (P(continuous) = 0.04), and risk group (P(categorical) = 0.02) were independent predictors of time to death from prostate carcinoma, whereas only age at diagnosis (P(continuous) = 0.01) was a predictor of time to all causes of death. When analyzed as a categorical variable, beginning at age 73 years, age at diagnosis was an independent predictor (P(categorical) < 0.04) of time to death from prostate carcinoma. Upon further analysis, this finding was limited to high-risk patients. For example, age > or = 75 years at diagnosis predicted for a shorter median time to death from prostate carcinoma (6.3 years vs. 9.7 years; P = 0.002) in high-risk patients.

CONCLUSIONS

Patients with clinically localized, high-risk prostate carcinoma who were diagnosed at age > or = 73 years and were treated with RT had a worse prognosis compared with patients who were diagnosed age < 73 years, raising the possibility that a more aggressive prostate carcinoma biology may develop during andropause.

Is ethnicity an independent predictor of prostate cancer recurrence after radical prostatectomy?

PURPOSE

Prostate cancer incidence and mortality are higher in black than in white American men. We determined whether ethnicity is an independent predictor of disease recurrence in men undergoing radical prostatectomy.

MATERIALS AND METHODS

We studied 1,468 patients who underwent radical prostatectomy at the University of California, San Francisco or as part of the Cancer of the Prostate Strategic Urological Research Endeavor database, a longitudinal disease registry of patients with prostate cancer. Preoperative characteristics, including age, race, prostate specific antigen (PSA) at diagnosis, clinical T stage, biopsy Gleason score and percent positive prostate biopsies at diagnosis were determined in each patient. Disease recurrence was defined as PSA 0.2 ng./ml. or greater on 2 consecutive occasions after radical prostatectomy or second cancer treatment at least 6 months after surgery. Cox proportional hazards analysis was performed to determine independent predictors of time to disease recurrence. To control for pretreatment disease characteristics simultaneously patients were assigned to previously described risk groups based on clinical tumor stage, PSA at diagnosis and biopsy Gleason score. The likelihood of disease recurrence per risk group stratified according to ethnicity was determined using the Kaplan-Meier method and compared using the log rank test. Additional multivariate analysis was performed in the subset of patients enrolled in Cancer of the Prostate Strategic Urological Research Endeavor on whom education and income information was available.

RESULTS

Disease recurred in 304 of the 1,468 patients (21%). Black ethnicity, serum PSA at diagnosis, biopsy Gleason score and percent positive prostate biopsies were independent predictors of recurrence on multivariate analysis. Black ethnicity remained an independent predictor of disease recurrence in the multivariate model after stratifying patients into risk groups (p = 0.0007). Ethnicity was most important in patients at high risk, in whom estimated 5-year disease-free survival was 65% and 28% in white and black men, respectively. Education, income and ethnicity correlated highly. When education and income were entered into the multivariate model, ethnicity was no longer an independent predictor of outcome after prostatectomy.

CONCLUSIONS

Ethnicity appears to be an independent predictor of disease recurrence after adjusting for pretreatment measures of disease extent in patients undergoing radical prostatectomy. It appears to be particularly important in those with high risk disease characteristics. However, black ethnicity, education and income are highly correlated variables, suggesting that sociodemographic factors may contribute to the poorer outcomes in black patients even after adjusting for differences in pretreatment disease characteristics.

Substratification of stage T1C prostate cancer based on the probability of biochemical recurrence

OBJECTIVES

To evaluate the influence of preoperative prostate-specific antigen (PSA), biopsy Gleason sum, and prostate biopsy quantitative histologic findings on the probability of biochemical failure in an attempt to identify criteria to substratify Stage T1c prostate cancer more accurately.

METHODS

We reviewed the records of 1149 patients who underwent prostatectomy for T1c disease between 1988 and 2000. Biochemical recurrence (PSA 0.2 ng/mL or greater) defined the endpoint in this study. Recursive partitioning analysis was used to establish cutpoints for preoperative PSA level, biopsy Gleason sum, number of positive biopsy cores, and maximal percentage of any single biopsy core involved with cancer. These cutoff values were then evaluated using Kaplan-Meier estimations to determine the probability of remaining biochemically recurrence free.

RESULTS

Using a PSA cutpoint of 10 ng/mL or a biopsy Gleason sum of 7, two groups of patients were identified (T1cI and T1cII). The rate of freedom from PSA recurrence at 3, 5, and 10 years after surgery for T1cI was 98%, 96%, and 96%, respectively, and for T1cII was 86%, 83%, and 73%, respectively (P <0.001). For T1cII patients, the greatest percentage of cancer in a single biopsy core was found to be a predictor of biochemical failure on multivariate analysis and, using a cutoff value of 50%, further stratified the PSA recurrence-free rates for the men in group T1cII (90% and 85% versus 75% and 56% at 5 and 10 years after surgery, respectively, P = 0.03).

CONCLUSIONS

The results of this study demonstrate that within Stage T1c there are two populations of patients with significantly different recurrence probabilities: T1cI (Gleason sum less than 7 and PSA 10 ng/mL or less) and T1cII (Gleason sum 7 or greater or PSA greater than 10 ng/mL). Furthermore, using a cutpoint of 50% of cancer in a single core of biopsy tissue, additional risk stratification is afforded to men with higher risk "T1cII" cancer.

Percentage of positive biopsy cores as predictor of clinical outcome in prostate cancer treated with radiotherapy

PURPOSE

The clinical significance of pretreatment biopsy characteristics is not well understood relative to known prognostic factors. We performed a complete pathology analysis of pretreatment biopsy specimens in an attempt to clarify their impact on clinical outcome following radiotherapy.

MATERIALS AND METHODS

From 1991 to 1999, 160 patients with locally advanced prostate cancer were prospectively treated with external beam radiotherapy in combination with high dose rate brachytherapy at our hospital and had pretreatment biopsy material available for complete pathological review. Patients with pretreatment prostate specific antigen (PSA) 10.0 ng./ml. or greater, Gleason 7 or greater or clinical stage T2b-T3c N0 M0 disease were eligible for study entry. Pelvic external beam radiotherapy (46.0 Gy.) was supplemented with 3 (1991 to 1995) or 2 (1995 to 1999) ultrasound guided transperineal interstitial iridium high dose rate implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy. per implant. All pretreatment biopsy specimen slides from each case were reviewed by a single pathologist (N. S. G.). Median followup was 4.2 years. Biochemical failure was defined as 3 consecutive PSA increases.

RESULTS

On univariate analysis pretreatment PSA, Gleason score, clinical T classification, percentage of positive biopsy cores, dose per implant and total radiotherapy dose (equivalent in 2 Gy. fractions) were significantly associated with biochemical failure. Perineural invasion was of borderline significance (p = 0.07). On univariate analysis for clinical failure only Gleason score and percent positive cores were significant. Percent positive cores was associated with biochemical and clinical failure whether analyzed in subgroups or as a continuous variable. Patients with less than 33% positive cores had a 5-year biochemical control rate of 83% and 5-year clinical failure rate of only 7%. Conversely, patients with more than 67% positive cores had a 5-year biochemical control rate of only 57% and 25% had clinical failure at 5 years. Since percent positive cores correlated with biochemical and clinical failure, an analysis was performed to determine which other prognostic factors were associated with percent positive cores. Pretreatment PSA level, Gleason score, clinical T classification and perineural invasion were significantly associated with a higher percent positive cores. Nevertheless, on Cox multiple regression analysis higher percent positive cores, pretreatment PSA and Gleason score remained independently associated with biochemical failure but not T classification. On Cox multiple regression analysis for clinical failure only Gleason score remained independently significant with percent positive cores maintaining borderline significance (p = 0.07).

CONCLUSIONS

Percent positive pretreatment biopsy cores is a powerful predictor of biochemical and clinical outcome for prostate cancer treated with radiotherapy, independent of other known prognostic factors. Percent positive cores should be seriously considered as a primary factor in risk group stratification for prostate cancer.

Changing prostate-specific antigen outcome after surgery or radiotherapy for localized prostate cancer during the prostate-specific antigen era

PURPOSE

To evaluate the change in prostate-specific antigen (PSA) outcome after radical prostatectomy (RP) or external beam radiotherapy (EBRT), controlling for follow-up during the PSA era.

METHODS AND MATERIALS

The study cohort consisted of 1440 patients with clinically localized prostate cancer managed with RP (n = 1059) or EBRT (n = 381) between 1989 and 2000. A single genitourinary pathologist reviewed all pathology specimens. For patients with a 2-year minimal follow-up, the 2-year actual PSA outcome stratified by risk group (low vs. high) was calculated for three periods (January 1, 1989 to December 31, 1992; January 1, 1993 to December 31, 1996; and January 1, 1997 to December 31, 2000) and compared for each treatment modality. PSA failure was defined using the American Society for Therapeutic Radiology and Oncology consensus definition for all patients, and comparisons were made using a chi-square metric.

RESULTS

During the study period, the proportion of patients treated with RP and EBRT with low-risk disease increased significantly (p <0.0001) from 60% to 89% and from 26% to 76%, respectively. In addition, the 2-year actual PSA outcome also improved from 60% to 82% (RP: p < 0.0001) and from 67% to 91% (RT: p = 0.0008). The 2-year actual PSA outcome was not significantly different in the low-risk patients but improved during the three periods in the high-risk patients treated with RP (from 20% to 39% to 75%, p = 0.0004) or EBRT (from 50% to 59% to 83%, p = 0.01). This improvement in PSA outcome could be explained by a shift toward a more favorable PSA level (RP: p = 0.0002; RT: p = 0.006) and clinical T stage (RP: p = 0.0008, RT: p < 0.0001) distribution for patients with biopsy Gleason score >or=7 disease.

CONCLUSION

Improved PSA outcome during the PSA era after RP or EBRT has resulted from a shift in presentation toward low-risk disease and earlier detection of high-grade disease.

Pathologic evidence of dose-response and dose-volume relationships for prostate cancer treated with combined external beam radiotherapy and high-dose-rate brachytherapy

PURPOSE

The clinical significance of postradiotherapy (RT) prostate biopsy characteristics is not well understood relative to the known prognostic factors. We performed a detailed pathologic review of posttreatment biopsy specimens in an attempt to clarify their relationship with clinical outcome and radiation dose.

METHODS AND MATERIALS

Between 1991 and 1998, 78 patients with locally advanced prostate cancer were prospectively treated with external beam RT in combination with high-dose-rate brachytherapy at William Beaumont Hospital and had post-RT biopsy material available for a complete pathologic review. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen level > or =10.0 ng/mL, Gleason score > or =7, or clinical Stage T2b-T3cN0M0. Pelvic external beam RT (46.0 Gy) was supplemented with three (1991-1995) or two (1995-1998) ultrasound-guided transperineal interstitial (192)Ir high-dose-rate implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Post-RT prostate biopsies were performed per protocol at a median interval of 1.5 years after RT. All pre- and post-RT biopsy specimen slides from each case were reviewed by a single pathologist (N.S.G.). The presence and amount of residual cancer, most common RT-effect score, and least amount RT-effect score were analyzed. The median follow-up was 5.7 years. Biochemical failure was defined as three consecutive prostate-specific antigen rises.

RESULTS

Forty patients (51%) had residual cancer in the post-RT biopsies. The 7-year biochemical control rate was 79% for patients with negative biopsies vs. 62% for those with positive biopsies with marked RT damage vs. 33% for those with positive biopsies with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores (p = 0.01), lower total RT dose (p = 0.001), lower dose per implant (p = 0.001), and greater percentage of positive post-RT biopsy cores (p = 0.01) were each associated with biochemical failure (Cox regression, univariate analysis). For patients with <25% positive post-RT biopsy cores, the 7-year biochemical control rate was 81% vs. a 62% biochemical control rate for those with 25-49% positive cores and only 32% for those with > or =50% positive cores (p = 0.01). On Cox multiple regression analysis, only the percentage of positive pre-RT biopsy cores and RT dose remained significantly associated with biochemical failure. Of all the factors analyzed, only the pretreatment cancer volume and lower RT dose were significantly associated with residual cancer and/or residual cancer with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores was associated with both a positive post-RT biopsy (p = 0.08) and a greater percentage of positive post-RT biopsy cores (p = 0.04). A lower total RT dose was associated with both a positive post-RT biopsy (p = 0.08) and a greater percentage of positive post-RT biopsy cores (p = 0.02). For patients who received <80 Gy (equivalent in 2-Gy fractions), 73% had positive post-RT biopsies vs. a 56% biopsy positivity rate for those who received 84-90 Gy and only 39% for those who received > or =92 Gy (p = 0.07).

CONCLUSION

Patients with positive post-RT biopsies are more likely to experience biochemical failure, especially when the RT damage is minimal. Patients who have a larger pretreatment tumor volume or receive a lower RT dose are more likely to demonstrate post-RT biopsy positivity and biochemical failure.

Endpoints in prostate cancer clinical trials

Prostate cancer is an extraordinarily heterogeneous disease with a variety of prognostic factors influential in determining ultimate patient outcomes. However, the vast majority of men harboring pathologic evidence of prostate cancer are not clinically diagnosed with this disease. Selected patients, particularly those with low clinical stage and low Gleason scores, may have extremely prolonged time until disease progression and cancer-specific death. Because of the potential for a prolonged natural history, factors, such as age and comorbidities, are often critical in evaluating clinical trial outcomes. Patients with more aggressive disease (higher clinical stage or Gleason score) have less prolonged natural histories. Careful examination of inclusion and exclusion criteria and the presence of clinical or pathologic staging are necessary for proper interpretation of clinical trials. Although surrogate endpoints, such as prostate-specific antigen and pathologic state, are commonly used to assess the effectiveness of therapeutic interventions, the relations between these surrogates and more relevant clinical endpoints have not always been well defined. Although certain endpoints are generalizable (overall survival and cancer-specific survival), clinical stage and treatments dictate the appropriateness of many other clinical trial endpoints. Both disease-related and treatment-related endpoints are important, given the propensity for various interventions to alter quality of life. Prospective randomized trials with adequate follow-up time and the assessment of clinically meaningful endpoints will offer the best opportunity to evaluate the effectiveness of various interventions used in this disease.

Predictive factor analysis as the basis for the clinical utility of percent positive prostate biopsies in patients with intermediate-risk prostate cancer

OBJECTIVES

To define the clinical reason for the further refinement of stratification of prostate-specific antigen (PSA) outcome using percent positive prostate biopsies in intermediate-risk patients.

METHODS

A chi-square metric was used to compare the distribution of pretreatment clinical and post-treatment pathologic factors for patients with intermediate-risk prostate cancer with 50% or less versus greater than 50% positive prostate biopsies. The PSA outcome stratified by the percent positive biopsies was calculated according to the Kaplan-Meier actuarial method. Comparisons of actuarial PSA failure-free survival were performed using the log-rank test.

RESULTS

The group with greater than 50% positive biopsies for prostate cancer had a significantly higher proportion of patients with pretreatment PSA values greater than 10 to 20 ng/mL (P = 0.01), biopsy Gleason score 4+3 (P = 0.05), and 1992 American Joint Committee on Cancer clinical category T2b (P = 0.01) than did the group with less than 50% positive biopsies. The group with greater than 50% positive biopsies also had a significantly higher proportion of patients with prostatectomy Gleason score 4+3 or higher (P = 0.001), pathologic Stage T3b (P <0.0001), and rate of positive surgical margins (P = 0.002) than did the group of patients with less than 50% positive biopsies.

CONCLUSIONS

The results of this study provide an explanation on the basis of the pretreatment and post-treatment predictive factors for the difference in PSA outcome for intermediate-risk patients when stratified by the percent positive biopsies.

Prediction of Progression: Nomograms of Clinical Utility

It is difficult to determine the pathologic stage of a clinically localized prostate cancer by physical examination or imaging studies. Consequently, clinicians rely on predictive models that estimate the probability of lymph node metastases and other pathologic features from clinical factors such as the clinical T stage, the grade in the biopsy specimen, and the serum prostate-specific antigen level. These models do not, however, directly predict prognosis. In developing a tool for predicting the probability that prostate cancer might recur after treatment, we took a novel approach that focused on the risk for the individual patient. In particular, we chose to develop a tool that calculates a continuous probability of recurrence rather than placing the patient in a risk group. This represents a fundamental departure from the classical goal of staging; a departure we argue is long overdue. Clinically localized prostate cancer patients deserve the most accurate and tailored predictions available, which current staging systems do not provide. Such an individualized approach should add value in medical decision making whenever an accurate prediction of the outcome may guide treatment selection.

International validation of a preoperative nomogram for prostate cancer recurrence after radical prostatectomy

PURPOSE

We evaluated the predictive accuracy of a recently published preoperative nomogram for prostate cancer that predicts 5-year freedom from recurrence. We applied this nomogram to patients from seven different institutions spanning three continents.

METHODS

Clinical data of 6,754 patients were supplied for validation, and 6,232 complete records were used. Nomogram-predicted probabilities of 60-month freedom from recurrence were compared with actual follow-up in two ways. First, areas under the receiver operating characteristic curves (AUCs) were determined for the entire data set according to several variables, including the institution where treatment was delivered. Second, nomogram classification-based risk quadrants were compared with actual Kaplan-Meier plots.

RESULTS

The AUC for all institutions combined was 0.75, with individual institution AUCs ranging from 0.67 to 0.83. Nomogram predictions for each risk quadrant were similar to actual freedom from recurrence rates: predicted probabilities of 87% (low-risk group), 64% (intermediate-low-risk group), 39% (intermediate-high-risk group), and 14% (high-risk group) corresponded to actual rates of 86%, 64%, 42%, and 17%, respectively. The use of neoadjuvant therapy, variation in the prostate-specific antigen recurrence definitions between institutions, and minor differences in the way the Gleason grade was reported did not substantially affect the predictive accuracy of the nomogram.

CONCLUSION

The nomogram is accurate when applied at international treatment institutions with similar patient selection and management strategies. Despite the potential for heterogeneity in patient selection and management, most predictions demonstrated high concordance with actual observations. Our results demonstrate that accurate predictions may be expected across different patient populations.

Using PSA, biopsy Gleason score, clinical stage, and the percentage of positive biopsies to identify optimal candidates for prostate-only radiation therapy

PURPOSE

An identification of prostate cancer patients most likely to benefit from prostate-only radiation was made based upon the pretreatment prostate-specific antigen (PSA), biopsy Gleason score, clinical stage, percentage of positive biopsies, and the 5-year postoperative PSA outcome.

METHODS

Between 1989 and 2000, 2099 patients underwent radical prostatectomy for clinically localized prostate cancer. The primary end points were pathologic evidence of seminal vesicle invasion 2(SVI), extracapsular extension (ECE) with or without positive surgical margins, and the 5-year postoperative PSA outcome.

RESULTS

Pretreatment PSA, biopsy Gleason score, and clinical stage were used to assign patients to low-, intermediate-, and high-risk groups. These risk groups were stratified by the percentage of positive biopsies and the primary pathologic and biochemical outcomes examined. The rates of SVI, ECE with positive margin, and no biochemical evidence of disease (bNED) for low-risk patients with < or =50% positive biopsies were 2%, 7%, and 93%, respectively. Patients with >50% positive biopsies had higher rates of SVI and ECE (5% and 11%, respectively) and 52% bNED (p < 0.0001). For intermediate-risk patients with < or =17% positive biopsies, the rates of SVI, ECE with positive margin, and bNED were 3%, 9%, and 90%, respectively. As the percentage of positive biopsies increased above 17% in intermediate-risk patients, there was a statistically significant increase in SVI and ECE and a significant decrease in bNED.

CONCLUSIONS

Low-risk patients with < or =50% positive biopsies and intermediate-risk patients with < or =17% positive biopsies had a very low risk of SVI and ECE with positive surgical margins. Given that the presence of SVI and ECE with positive surgical margins was uncommon (<10%) with a > or =90% PSA failure-free survival after radical prostatectomy, these patients may be optimal candidates for radiation therapy directed at the prostate only (prostate gland + 1.5-cm margin).

Biochemical outcome after radical prostatectomy or external beam radiation therapy for patients with clinically localized prostate carcinoma in the prostate specific antigen era

BACKGROUND

To the authors' knowledge, consensus is lacking regarding the relative long-term efficacy of radical prostatectomy (RP) versus conventional-dose external beam radiation therapy (RT) in the treatment of patients with clinically localized prostate carcinoma.

METHODS

A retrospective cohort study of 2635 men treated with RP (n = 2254) or conventional-dose RT (n = 381) between 1988-2000 was performed. The primary endpoint was prostate specific antigen (PSA) survival stratified by treatment received and high-risk, intermediate-risk, or low-risk group based on the serum PSA level, biopsy Gleason score, 1992 American Joint Commission on Cancer clinical tumor category, and percent positive prostate biopsies.

RESULTS

Estimates of 8-year PSA survival (95% confidence interval [95% CI]) for low-risk patients (T1c,T2a, a PSA level < or = 10 ng/mL, and a Gleason score < or = 6) were 88% (95% CI, 85, 90) versus 78% (95% CI, 72, 83) for RP versus patients treated with RT, respectively. Eight-year estimates of PSA survival also favored RP for intermediate-risk patients (T2b or Gleason score 7 or a PSA level > 10 and < or = 20 ng/mL) with < 34% positive prostate biopsies, being 79% (95% CI, 73, 85) versus 65% (95% CI, 58, 72), respectively. Estimates of PSA survival in high-risk (T2c or PSA level > 20 ng/mL or Gleason score > or = 8) and intermediate-risk patients with at least 34% positive prostate biopsies initially favored RT, but were not significantly different after 8 years.

CONCLUSIONS

Intermediate-risk and low-risk patients with a low biopsy tumor volume who were treated with RP appeared to fare significantly better compared with patients who were treated using conventional-dose RT. Intermediate-risk and high-risk patients with a high biopsy tumor volume who were treated with RP or RT had long-term estimates of PSA survival that were not found to be significantly different.

Clinical utility of percent prostate needle biopsy tissue with cancer cutpoints to risk stratify patients before radical prostatectomy

OBJECTIVES

The percentage of total prostate needle biopsy tissue with cancer was previously found to be a stronger predictor of biochemical failure after radical prostatectomy (RP) than either biopsy Gleason score or serum prostate-specific antigen (PSA). To improve our ability to predict preoperatively the risk of biochemical recurrence after RP, we sought to determine the cutpoints of the percentage of biopsy tissue with cancer to separate patients into low, intermediate, or high-risk groups. We then examined whether we could further stratify low, intermediate, and high-risk groups (on the basis of the PSA level and biopsy Gleason score) using the percentage of prostate needle biopsy tissue with cancer.

METHODS

A single pathologist reviewed the prostate needle biopsy specimens of 217 men who underwent RP between 1991 and 2001. Biopsy specimens were examined for Gleason score and the percentage of total biopsy tissue with cancer. Cutpoints were identified to define patients with differing risk of biochemical recurrence after RP. These cutpoints were applied to low, intermediate, and high-risk patients, on the basis of PSA and biopsy Gleason score, to determine whether preoperative risk stratification could be improved.

RESULTS

Using the cutpoints for the percentage of prostate needle biopsy tissue with cancer of less than 20% (low risk), 20% to less than 55% (intermediate risk), and 55% or greater (high risk), patients were separated into three groups with differing risks of biochemical failure after RP (hazard ratio 1.95, 95% confidence interval 1.37 to 2.77, P <0.001). These cutpoints further stratified patients with an intermediate (P = 0.002) or high risk (P = 0.05) of biochemical failure (on the basis of the PSA and biopsy Gleason score). However, these cutpoints provided no improvement in risk stratification for patients who were at low risk (P = 0.501) of biochemical failure (on the basis of PSA and biopsy Gleason score).

CONCLUSIONS

The percentage of total prostate needle biopsy tissue with cancer can be used to stratify patients into low, intermediate, and high-risk groups preoperatively for biochemical recurrence after RP. These cutpoints could further stratify patients preoperatively who were at intermediate or high risk of biochemical failure on the basis of PSA and biopsy Gleason score.

A validation of two preoperative nomograms predicting recurrence following radical prostatectomy in a cohort of European men

Kattan et al. at Baylor College of Medicine and D'Amico et al. at Harvard Medical School have each developed preoperative nomograms for prostate cancer recurrence after radical prostatectomy based on readily available clinical variables. Calibration and validation of those tools was achieved using North American patient cohorts, and their validity has not yet been shown in patients from other continents. We investigated the predictive accuracy of these nomograms when applied to European men with localized prostate cancer. Clinical data from patients who underwent radical prostatectomy at the University-Hospital Hamburg and fitted the respective derivation criteria were used for external validation (n = 1003 for the Kattan-Nomogram, n = 932 men for the D'Amico-Nomogram). Nomogram predictions of the probability for 2-years and 5-years freedom from recurrence predicted by the D'Amico-Nomogram and the Kattan-Nomogram respectively were compared with actual follow-up. The predictive accuracy of the nomograms was tested using areas under the receiver-operating-characteristic curves (AUC). The D'Amico-Nomogram AUC predicting 2-years probability of freedom from PSA recurrence was 0.80 vs. Kattan-Nomogram 5-years prediction with an AUC of 0.83. Using the 932 patients who exactly fit the derivation criteria of both nomograms, the predictive accuracy of the Kattan-Nomogram was 0.81. The superiority in predictive accuracy of the Kattan-Nomogram was statistically significant (p = 0.0274) but of unclear clinical significance. The two nomograms predicted recurrence with similar accuracy when applied to men diagnosed with localized prostate cancer in Germany. The high predictive accuracy of both nomograms demonstrates that these predictive tools derived in the U.S. can be applied to non-U.S. patients.

Extraprostatic spread of clinically localized prostate cancer: factors predictive of pT3 tumor and of positive endorectal MR imaging examination results

PURPOSE

To identify the factor(s) most predictive of pT3 tumor and those most predictive of a positive endorectal magnetic resonance (MR) imaging result in patients with clinically localized prostate cancer.

MATERIALS AND METHODS

At multivariate analysis, five preoperative clinical parameters-prostate-specific antigen (PSA) level, digital rectal examination (DRE) result, Gleason score and number of involved sextants at transrectal US-guided biopsy, and endorectal MR imaging result-were used to predict pT3 tumor in 336 patients who underwent radical prostatectomy. On the basis of results of the first four examinations, multivariate analysis was performed also to determine predictors of a positive MR imaging study.

RESULTS

Significant predictors of pT3 tumor were positive MR imaging result (P < 2 x 10(-8)), more than one sextant involved at biopsy (P < 5 x 10(-5)), and PSA level greater than 10 ng/mL (P < 7 x 10(-3)). Significant predictors of a positive MR imaging result were three or more sextants involved at biopsy (P < 10(-5)), positive DRE result (P < 5 x 10(-3)), and PSA level greater than 10 ng/mL (P < 16 x 10(-3)). In the subgroup of 175 patients who had at least three positive biopsy specimens, the sensitivity of MR imaging was 50% for detection of occult pT3 tumor and 69% for detection of extensive pT3 tumor. The overall specificity of MR imaging was 95%.

CONCLUSION

Endorectal MR imaging seems to be indicated in carefully selected patients-specifically, those with three or more positive biopsy specimens, a palpable tumor, and/or a PSA level greater than 10 ng/mL.

Clinical utility of the percentage of positive prostate biopsies in predicting prostate cancer-specific and overall survival after radiotherapy for patients with localized prostate cancer

PURPOSE

To determine whether the percentage of positive prostate biopsies provides clinically relevant information to a previously established risk stratification system with respect to the end points of prostate cancer-specific survival (PCSS) and overall survival after radiotherapy for patients with clinically localized prostate cancer.

METHODS AND MATERIALS

A Cox regression multivariable analysis was used to evaluate the ability of the percentage of positive prostate biopsies to predict PCSS and overall survival for 381 men who underwent radiotherapy for localized prostate cancer during the prostate-specific antigen era.

RESULTS

At a median follow-up of 4.3 years (range 0.8-13.3), the presence of < or =50% positive biopsies vs. >50% positive biopsies provided a clinically relevant stratification of the 7-year estimates of PCSS (100% vs. 57%, p = 0.004) in intermediate-risk patients. Moreover, all patients could be stratified into a minimal or high-risk cohort on the basis of the 10-year estimates of PCSS (100% vs. 55%, p <0.0001) and overall survival (87% vs. 40%, p = 0.02) by incorporating the percentage of positive prostate biopsy information into a previously established risk stratification system.

CONCLUSION

The clinically relevant stratification of PCSS using the percentage of positive prostate biopsies in intermediate-risk patients confirms previous findings based on prostate-specific antigen outcome. These data provide evidence to support the ability to stratify newly diagnosed patients with clinically localized disease into a minimal-risk (low-risk + low biopsy volume [< or =50%] intermediate-risk) or high-risk (high biopsy volume [>50%] intermediate-risk + high-risk) cohort for prostate cancer-specific death after conventional dose radiotherapy. Additional follow-up and independent validation are needed to confirm these findings.

Impact of race on prostate-specific antigen outcome after radical prostatectomy for clinically localized adenocarcinoma of the prostate

PURPOSE

To compare prostate-specific antigen (PSA) outcome after radical prostatectomy (RP) for prostate cancer in African-American and white men using previously established risk groups.

PATIENTS AND METHODS

Between 1989 and 2000, 2,036 men (n = 162 African-American men, n = 1,874 white men) underwent RP for clinically localized prostate cancer. Using pretreatment PSA, Gleason score, clinical T stage, and percentage of positive biopsy specimens, patients were stratified into low- and high-risk groups. For each risk group, PSA outcome was estimated using the actuarial method of Kaplan and Meier. Comparisons of PSA outcome between African-American and white men were made using the log-rank test.

RESULTS

The median age and PSA level for African-American and white men were 60 and 62 years old and 8.8 and 7.0 ng/mL, respectively. African-Americans had a statistically significant increase in PSA (P =.002), Gleason score (P =.003), clinical T stage (P =.004), and percentage of positive biopsy specimens (P =.04) at presentation. However, there was no statistical difference in the distribution of PSA, clinical T stage, or Gleason score between racial groups in the low- and high-risk groups. The 5-year estimate of PSA outcome was 87% in the low-risk group for all patients (P =.70) and 28% versus 32% in African-American and white patients in the high-risk group (P =.28), respectively. Longer follow-up is required to confirm if these results are maintained at 10 years.

CONCLUSION

Even though African-American men presented at a younger age and with more advanced disease compared with white men with prostate cancer, PSA outcome after RP when controlled for known clinical predictive factors was not statistically different. This study supports earlier screening in African-American men.

The influence of percentage of preradiation needle biopsies with adenocarcinoma and total radiation dose on the pathologic response of unfavorable prostate adenocarcinoma

We studied relationships among clinicopathologic factors in 78 patients with unfavorable prostate adenocarcinoma treated in a dose-escalation radiation therapy (RT) study using pre- and 18-month protocol post-RT biopsy specimens. Pre-RT factors analyzed were serum prostate-specific antigen (PSA) level, Gleason score, and percentage of needle cores with adenocarcinoma; post-RT factors were percentage of needle cores with adenocarcinoma and amount of radiation effect on the adenocarcinoma. Of 78 patients, 42 (54%) had residual adenocarcinoma in the post-RT biopsy specimen. Lower total RT dose and dose per implant and greater serum PSA level were associated with an increasing percentage of needle cores with residual post-RT adenocarcinoma. Lower RT dose, an increasing percentage of pre-RT needle cores with adenocarcinoma, and a greater serum PSA level were associated with an increasing percentage of post-RT needle cores with no to moderate RT effect scores in adenocarcinoma. The mean percentage of pre-RT and post-RT needle cores with adenocarcinoma was greater in patients with post-RT biopsy specimens with no to moderate RT effect. The percentage of pre-RT needle cores with adenocarcinoma (a surrogate marker of adenocarcinoma volume), serum PSA level, and RT dose are the key components in the dose-response relationship. Gleason score and gland volume did not contribute significantly to this relationship.

Preoperative parameters for predicting early prostate cancer recurrence after radical prostatectomy

OBJECTIVES

To determine whether easily measurable prostate biopsy features could complement Gleason score, prostate-specific antigen (PSA), or clinical stage in predicting recurrence-free survival after prostatectomy. Information relating preoperative parameters to recurrence-free survival is needed to counsel patients with newly diagnosed prostate cancer regarding expectations for postprostatectomy cancer control.

METHODS

The data of a cohort of 588 consecutive prostatectomy patients (median age 61 years, range 39 to 83) with ascertained preoperative data and up to 4 years of postprostatectomy follow-up were analyzed. Bivariate and multivariate Cox proportional hazards analysis evaluated preoperative factors (clinical stage, PSA, biopsy Gleason score, greatest percentage of a biopsy core involved by cancer [GPC], number of biopsy cores containing cancer, perineural invasion) to identify those relating significantly to recurrence-free survival. Functional forms of these factors were evaluated to optimize accuracy in predicting cancer control.

RESULTS

The baseline parameters significantly affecting PSA-free survival included PSA level (P <0.01), biopsy Gleason score (P = 0.04), and GPC (P <0.01). Although clinical stage and perineural invasion had a marginal association with PSA-free survival as univariate factors, this association was not independently significant in multivariable analysis. The multivariate Cox model using PSA, Gleason score, and GPC was highly predictive of PSA free-survival (chi-square = 48.2, P = 0.0001). A set of plots representing these data can be used to identify the risk of early postoperative PSA recurrence on the basis of specific preoperative PSA, Gleason score, and GPC values.

CONCLUSIONS

These findings provide a highly significant model and a simple tool for assisting preoperative patient counseling regarding predicted cancer control after radical prostatectomy.

Percent of cancer in the biopsy set predicts pathological findings after prostatectomy

PURPOSE

The ability to use pretreatment variables to identify patients with organ confined prostate cancer continues to challenge physicians. We examined information available preoperatively, including prostate needle biopsy, clinical stage and preoperative prostate specific antigen (PSA), and evaluated these data based on pathological variables after radical retropubic prostatectomy.

MATERIALS AND METHODS

We reviewed results in 135 consecutive patients who underwent radical retropubic prostatectomy at a single institution. Needle biopsy information, such as the number of cores, percent of tumor per biopsy set, laterality of positive cores and Gleason sum, were compared with pathological data on the radical retropubic prostatectomy specimen, including pathological stage, Gleason sum and tumor volume. Clinical data, including biopsy information and pathological findings, were compared using univariate and multivariate models.

RESULTS

Overall total PSA, percent of tumor in the biopsy and bilateral positive cores directly correlated with tumor volume (p <0.01). Also, increasing PSA, increasing percent of tumor in the biopsy and bilateral positive cores were associated with increased risks of extracapsular extension (p <0.01).

CONCLUSIONS

From the information readily available from prostate needle biopsy these results suggest that percent of tumor in the biopsy is a useful predictor of pathological stage and tumor volume. Furthermore, including percent of tumor in the biopsy set and bilateral disease with traditional variables such as serum PSA and clinical stage may improve pretreatment tumor staging. This finding adds additional credence to the inclusion of percent of tumor in the biopsy set in models for the preoperative prediction of pathological stage and should be factored into discussions with patients on treatment options.

[Indications for curietherapy of the prostate using permanent implants]

In the last decade, brachytherapy emerged as a particularly appealing new way ot treating localized prostate cancer. Recently published 10-12 years biochemical control results appear to be superimposable to the best percentages achieved by surgery or conformal radiotherapy, with a small percentage of complications. This applied to severely patients. Only patients with T1/T2, PSA < 10 ng/mL, and Gleason score < 7 should be proposed such a treatment. The potential benefit of exploring patients with a endorectal coil MRI is being evaluated. The number of positive biopsies is also a parameter which should probably be considered in the therapeutic choice. Moreover, a prostate volume > 60 g, hip mobility limitations, a urinary obstructive syndrome and previous transurethral resection lead to difficulties in technical implantation and therefore must be taken into account when discussing brachytherapy. In conclusion, for adequately selected patients, brachytherapy offers a particularly applied alternative to surgery and external radiotherapy, with satisfactory long term biochemical control rates and limited complications.

Percentage of core lengths involved with prostate cancer: does it add to the percentage of positive prostate biopsies in predicting postoperative prostate-specific antigen outcome for men with intermediate-risk prostate cancer?

OBJECTIVES

To evaluate whether the percentage of core lengths involved with prostate cancer added clinically significant information concerning the time to postoperative prostate-specific antigen (PSA) failure in the intermediate-risk patient beyond what is provided by the percentage of positive biopsies.

METHODS

Cox regression multivariable analysis was performed to compare the ability of the two measurements of biopsy cancer volume to predict the time to PSA failure from a series of 184 surgically treated intermediate-risk patients. PSA outcome was estimated using the actuarial method of Kaplan and Meier, and comparisons were made using the log-rank test.

RESULTS

Both the percentage of core lengths involved with prostate cancer (P = 0.01) and the percentage of positive biopsies (P = 0.002) were significant predictors of the time to PSA failure on univariable analysis. The 4-year PSA outcome was 83% versus 47% (P = 0.0008) and 83% versus 53% (P = 0.007) for the percentage of positive biopsies stratified by 50% or less versus greater than 50% and the percentage of core lengths involved with prostate cancer stratified by 25% or less versus greater than 25%, respectively. However, only the percentage of positive biopsies remained significant (P = 0.03) on multivariable analysis.

CONCLUSIONS

The percentage of core lengths involved with prostate cancer did not provide additional clinically relevant information to the percentage of positive biopsies for patients with intermediate-risk prostate cancer. Therefore, the routine measurement of core involvement may not be necessary in this patient population.

Predicting disease recurrence in intermediate and high-risk patients undergoing radical prostatectomy using percent positive biopsies: results from CaPSURE

OBJECTIVES

To determine whether percent positive biopsies could be used to predict the probability of disease recurrence in contemporary patients undergoing radical prostatectomy in community-based practice settings. Previous studies have demonstrated the importance of systematic prostate biopsy results in the risk assessment for newly diagnosed patients with prostate cancer.

METHODS

We studied 1265 patients enrolled in CaPSURE (a longitudinal registry of patients with prostate cancer) who underwent radical prostatectomy as definitive local treatment of their prostate cancer. Preoperative characteristics, including age, race, prostate-specific antigen (PSA) level at diagnosis, clinical T stage, biopsy Gleason score, and percent positive prostate biopsies at the time of diagnosis, were determined for each patient. Disease recurrence was defined as PSA level of 0.2 ng/mL or greater on two consecutive occasions after radical prostatectomy or the occurrence of a second cancer treatment more than 6 months after surgery. Cox proportional regression analysis was performed to determine the significant independent predictors of disease recurrence. Patients were assigned to previously described risk groups on the basis of clinical tumor stage, PSA at diagnosis, and biopsy Gleason score. The likelihood of disease recurrence for each risk group, stratified according to the percentage of positive biopsies (0% to 33%, 34% to 66%, and more than 66%), was determined using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

The median follow-up was 3.3 years after surgery. The serum PSA level at diagnosis, biopsy Gleason score, percent positive biopsies, and ethnicity were significant independent predictors of disease recurrence. The percentage of positive prostate biopsies was a significant predictor of disease recurrence for low, intermediate, and high-risk patients. For patients with high-risk disease, the likelihood of disease recurrence 5 years after surgery was 24%, 34%, and 59% for patients with 0% to 33%, 34% to 66%, and more than 66% positive biopsies, respectively.

CONCLUSIONS

Serum PSA, biopsy Gleason score, and percent positive biopsies were significant predictors of disease recurrence in this population. The percent positive biopsies may be useful in identifying high-risk patients suitable for definitive local therapy.

Relationship between percent positive biopsies and biochemical outcome after permanent interstitial brachytherapy for clinically organ-confined carcinoma of the prostate gland

PURPOSE

Recently, the percentage of positive prostate biopsies has been reported to be statistically significant in predicting the biochemical outcome after either radical prostatectomy or 3-dimensional conformal external beam radiotherapy. In this study, we evaluated the impact of the percentage of positive prostate biopsies in predicting the 5-year biochemical outcome for patients with clinically organ-confined prostate cancer undergoing permanent interstitial brachytherapy.

METHODS AND MATERIALS

Two hundred sixty-two hormone naive patients underwent transperineal ultrasound-guided permanent prostate brachytherapy with generous periprostatic margins, using either 103Pd or 125I for clinical T1b/T2b NXM0 (1997 AJCC) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. The actual percentage of positive biopsies (number of positive biopsies/total number of biopsies) was determinable for 255 of the 262 patients. Of the evaluated cases, 133 patients were implanted with 103Pd and 122 patients with 125I. The median patient age was 68 years (range 48-81). The median follow-up was 38.6 months (range 6-73). Follow-up was calculated from the day of implantation. Patients were stratified by the percentage of positive biopsies into the following groups: <34%, 34-50%, and >50%. Additional clinical parameters evaluated included patient age, clinical T-stage, Gleason score, pretreatment prostate specific antigen (PSA), risk group, and prostate volume. Low-risk patients were staged as clinical T1c/T2a, Gleason score < or =6, and pretreatment PSA < or =10 ng/mL, intermediate-risk patients presented with one unfavorable prognostic parameter, and high-risk patients presented with two or more unfavorable prognostic parameters (clinical stage T2b, PSA >10 ng/mL, Gleason score > or =7). Treatment parameters included the use of supplemental external beam radiation and choice of isotope. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology consensus definition.

RESULTS

For the 255 evaluated patients, the 5-year actuarial biochemical no evidence of disease survival rate was 92.5%. For patients with low, intermediate, and high-risk disease, 95.8%, 98.1%, and 79.4% of patients were free of biochemical failure, respectively. When each risk group was stratified into the percent positive biopsy categories of <34%, 34-50%, and >50%, no statistical difference was found in biochemical outcome for the biopsy subgroups. In multivariate analysis, none of the clinical or treatment parameters predicted for failure in the low-risk group; only Gleason score was predictive for intermediate-risk patients and only PSA for high-risk patients. In the overall population, PSA and Gleason score were both found to be predictors of biochemical failure, but not risk group, clinical stage, or percentage of positive biopsies. There was no significant dependence between the percent positive biopsy group and the Kaplan-Meier biochemical survival rates for any of the various subgroups of clinical and treatment parameters, except for clinical stage T1c-T2a (p = 0.006). The median postimplant PSA was 0.2 ng/mL for patients with either low-risk disease or <34% positive biopsies and 0.1 ng/mL for all other risk groups or percent positive biopsy subgroups.

CONCLUSION

Although a significant trend was found for biochemical failure with increasing percent positive biopsies in the overall population, our results suggest that the percentage of positive biopsies is not statistically significant in predicting the 5-year biochemical disease-free outcome for patients with low, intermediate, and high-risk disease undergoing permanent prostate brachytherapy. Only the Gleason score in intermediate-risk patients and the pretreatment PSA level in high-risk patients was predictive of biochemical failure. We believe this relative lack of significance for the percentage of positive biopsies is a result of dose escalation far exceeding other radiotherapy modalities and the ability to aggressively treat the periprostatic region compared with radical prostatectomy by way of the accurate placement of periprostatic seeds.

Percent prostate needle biopsy tissue with cancer is more predictive of biochemical failure or adverse pathology after radical prostatectomy than prostate specific antigen or Gleason score

PURPOSE

Biopsy Gleason score, serum prostate specific antigen (PSA) levels, and clinical stage are known to be independent predictors of adverse pathological features and biochemical failure after radical prostatectomy. We determine whether various prostate needle biopsy parameters were predictive of either adverse pathological findings or disease recurrence after radical prostatectomy.

MATERIALS AND METHODS

A single pathologist reviewed the prostate needle biopsy specimens of 190 men who underwent radical prostatectomy between 1991 and 2000. Biopsy specimens were examined for Gleason score, perineural invasion, number and percent of cores with cancer, and percent of total biopsy tissue with cancer and Gleason grade 4 or 5 cancer. Multivariate analysis was used to determine the prostate needle biopsy parameters and preoperative clinical variables, including serum PSA, clinical stage, patient age and race, that were most significant for predicting positive surgical margins, nonorgan confined disease, seminal vesicle invasion and biochemical failure after radical prostatectomy.

RESULTS

Of the prostate needle biopsy parameters examined percent of tissue with cancer was the strongest predictor of biochemical recurrence in the multivariate analysis (p <0.001). Percent of tissue with cancer was a stronger predictor of biochemical recurrence than either PSA (p = 0.048) or biopsy Gleason score (p = 0.053). It was also a strong independent predictor of seminal vesicle invasion (p = 0.015) and nonorgan confined disease (p = 0.024). Perineural invasion, percent and number of cores with cancer, and percent of tissue with Gleason grade 4 or 5 were not independent predictors of either adverse pathology or biochemical failure.

CONCLUSIONS

Of all the preoperative variables examined, including the standard clinical variables of serum PSA, Gleason score and clinical stage, percent of biopsy tissue with cancer was the strongest predictor of biochemical recurrence, seminal vesicle invasion and nonorgan confined disease. Consideration should be given to reporting percent of total biopsy tissue with cancer in all prostate biopsy results.

10-year biochemical (prostate-specific antigen) control of prostate cancer with (125)I brachytherapy

PURPOSE

To report 10-year biochemical (prostate-specific antigen [PSA]) outcomes for patients treated with 125I brachytherapy as monotherapy for early-stage prostate cancer.

METHODS AND MATERIALS

One hundred and twenty-five consecutively treated patients, with clinical Stage T1-T2b prostate cancer were treated with 125I brachytherapy as monotherapy, and followed with PSA determinations. Kaplan-Meier estimates of PSA progression-free survival (PFS), on the basis of a two consecutive elevations of PSA, were calculated. Aggregate PSA response by time interval was assessed. Comparisons were made to an earlier-treated cohort.

RESULTS

The overall PSA PFS rate achieved at 10 years was 87% for low-risk patients (PSA < 10, Gleason Sum 2-6, T1-T2b). Of 59 patients (47%) followed beyond 7 years, 51 (86%) had serum PSAs less than 0.5 ng/mL; 48 (81%) had serum PSAs less than 0.2 ng/mL. Failures were local, 3.0%; distant, 3.0%. No patients have died of prostate carcinoma. The proportion of patients with a PSA < or =0.2 ng/mL continued to increase until at least 7-8 years posttherapy. A plot of PSA PFS against the proportion of patients achieving serum PSA of less than 0.2 ng/mL suggests a convergence of these two endpoints at 10 years. Patients treated in the era of this study (1988-1990) experienced a statistically improved PFS compared with an earlier era (1986-1987). This difference appears independent of patient selection, suggesting that the maturation of the technique resulted in improved biochemical control.

CONCLUSION

With modern technique, monotherapy with 125I achieves a high rate (87%) of biochemical and clinical control in patients with low-risk disease at 10 years. The decline of PSA following brachytherapy with low-dose-rate isotopes can be protracted. Absolute PSA and PFS curves merge, and are comparable at 10 years.

Treatment outcome by risk group after radical prostatectomy in Japanese men

BACKGROUND

North American investigators have suggested the usefulness of risk-group stratification based on prostate-specific antigen (PSA), clinical stage and biopsy Gleason score for predicting the biochemical outcome of prostate cancer after radical prostatectomy. There have been no reports of the application of this stratification to early biochemical outcome after radical surgery in Japanese men.

METHODS

The study population consisted of 178 men treated with radical retropubic prostatectomy and bilateral pelvic lymph node dissection at Kitasato University Hospital (n = 110) and Kurashiki Central Hospital (n = 68) between October 1992 and May 1999. Pathologic and biochemical outcomes after radical prostatectomy were analyzed based on risk-group stratification. Risk groups were further analyzed according to detailed pathologic findings at biopsy.

RESULTS

The median follow-up period for the 178 patients after radical surgery was 41.5 months (range, 2.0--82.0 months; mean, 40.9 months). Fifty-eight patients experienced PSA failure at a median of 8.0 months following surgery (range, 0.0--58.0). Risk-group stratification distinctly defined groups of pathologic findings in the radical prostatectomy specimens. The proportion of patients with PSA failure for low, intermediate and high-risk groups were 9.5%, 23.9% and 56.9%, respectively (P < 0.0001). Use of the number of cores with cancer and maximum cancer length in biopsy cores failed to improve risk stratification for PSA outcome in all risk groups.

CONCLUSIONS

Risk-group stratification based on preoperative variables may significantly improve a physician's ability to counsel patients about PSA outcome after radical prostatectomy. Further improvement in risk stratification may call for use of variables other than the pathologic information in biopsy cores.