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A V D'Amico

Publications and source records attributed to A V D'Amico.

At least 19 recordsLinked to original sources
PubMed2004

Perineural invasion is associated with increased relapse after external beam radiotherapy for men with low-risk prostate cancer and may be a marker for occult, high-grade cancer.

PURPOSE: To investigate the risk of postradiotherapy prostate-specific antigen (PSA) failure on the basis of pretreatment risk factors in prostate cancer patients with and without perineural invasion (PNI) in prostate biopsy specimens and to explain the observation that otherwise low-risk patients with PNI experience decreased freedom from PSA failure after external beam radiotherapy (RT). METHODS AND MATERIALS: The study cohort consisted of 381 patients who underwent RT between 1989 and 2000 for clinically localized prostate cancer. A single genitourinary pathologist scored the absence or presence of PNI on all prostate biopsy specimens. Patients were divided into low-, intermediate- and high-risk subgroups on the basis of their 1992 American Joint Committee on Cancer T-stage, pretreatment PSA level, and Gleason score. Cox regression uni- and multivariate analyses were performed to evaluate whether the presence or absence of PNI in the biopsy specimen was a predictor of the time to post-RT PSA failure for patients in each pretreatment risk group. PSA failure was defined using the American Society for Therapeutic Radiology and Oncology consensus definition. Actuarial PSA failure-free survival was estimated using the Kaplan-Meier method, and comparisons were performed using the log-rank test. RESULTS: Cox regression univariate analysis revealed that PNI was a significant predictor of the time to PSA failure in the low-risk (p = 0.04) and high-risk (p = 0.03) cohorts. The 5-year PSA failure-free survival rate was 50% vs. 80% (p = 0.04) in low-risk patients, 70% vs. 75% (p = 0.72) in intermediate-risk patients, and 29% vs. 53% (p = 0.03) in high-risk patients with and without PNI, respectively. Cox regression multivariate analysis within the high-risk group revealed that a PSA level > or =20 ng/mL (p = 0.01) and Gleason score > or =8 (p = 0.02), but not PNI, were the only significant predictors of the time to PSA failure after RT. However, an association was found between the presence of PNI in the needle biopsy specimen and a biopsy Gleason score of 8-10 (p = 0.06). The association was stronger between the presence of PNI in the needle biopsy specimen and a biopsy Gleason score of 7-10 (p = 0. 033). CONCLUSION: A decrement in PSA outcome after RT for low-risk patients with PNI-positive biopsy specimens was found. The association between PNI and high Gleason score provides a possible explanation for the loss of statistical significance of PNI in the Cox regression multivariate analysis of the high-risk cohort. The data suggest that PNI found in the biopsy specimen of an otherwise low-risk patient predicts for occult high-grade disease that is missed owing to the sampling error associated with prostate biopsy. The association between PNI and a high Gleason score argues for the use of more aggressive therapy, such as hormonal therapy with RT and/or dose escalation, in these select patients.

Analysis of Variance↗
PubMed2001

A practical method to achieve prostate gland immobilization and target verification for daily treatment.

PURPOSE: A practical method to achieve prostate immobilization and daily target localization for external beam radiation treatment is described. METHODS AND MATERIALS: Ten patients who underwent prostate brachytherapy using permanent radioactive source placement were selected for study. To quantify prostate motion both with and without the presence of a specially designed inflatable intrarectal balloon, the computerized tomography-based coordinates of all intraprostatic radioactive sources were compared over 3 consecutive measurements at 1-min intervals. RESULTS: The placement and inflation of the intrarectal balloon were well tolerated by all patients. The mean (range) displacement of the prostate gland when the intrarectal balloon was present vs. absent was 1.3 (0-2.2) mm vs. 1.8 (0-9.1) mm (p = 0.03) at 2 min respectively. The maximum displacement in any direction (anterior-posterior, superior-inferior, or right-left) when the intrarectal balloon was inflated vs. absent was reduced to < or =1 mm from 4 mm. CONCLUSIONS: Both prostate gland immobilization and target verification are possible using a specially designed inflatable intrarectal balloon. Using this device, the posterior margin necessary on the lateral fields to ensure dosimetric coverage of the entire prostate gland could be safely reduced to 5 mm and treatment could be set up and verified using a lateral portal image.

Brachytherapy↗
PubMed2001

Optimizing patient selection for prostate monotherapy.

PURPOSE: Patients at low risk for prostate-specific antigen (PSA) failure following definitive local therapy are those with PSA of 10 or less, biopsy Gleason Score of 6 or less, and 1992 American Joint Committee on Cancer (AJCC) clinical Stage T1c or T2a. However, low-risk patients managed with radical prostatectomy and found to have prostatectomy Gleason score > or = 3+4 have a less favorable PSA outcome when compared to patients with prostatectomy Gleason score < or = 3+3. This study was performed to determine whether the percentage of positive prostate biopsy cores could predict upgrading from a biopsy Gleason score of 6 or less to a prostatectomy Gleason score > or = 3+4 in low-risk patients to optimize selection for prostate only radiation therapy. METHODS AND MATERIALS: Concordance testing of the biopsy Gleason score and the primary and secondary prostatectomy Gleason grades was performed in 427 prostate cancer patients treated with radical prostatectomy and at low risk for PSA failure. Logistic regression multivariable analysis was performed to test the ability of the established prognostic factors and the percentage of positive prostate biopsies (<34%, 34-50%, >50%) to predict for upgrading from biopsy Gleason score of 6 or less prostatectomy Gleason score > or = 3+4. PSA failure-free survival was reported using the actuarial method of Kaplan and Meier and comparisons were made using a log-rank test. RESULTS: Twenty-nine percent of the 427 study patients were upgraded from a biopsy Gleason score of 6 or less to a prostatectomy Gleason score > or = 3+4. The presence of greater than 50% positive biopsies was the only significant factor for predicting the upgrading from biopsy Gleason score of 6 or less to prostatectomy Gleason score > or = 3+4 on logistic regression multivariable analysis with the variables treated as continuous and categorical. Specifically, upgrading occurred in 26% vs. 59% of patients with 50% or less vs. greater than 50% positive biopsies, respectively. This translated into a 5-year PSA failure-free survival which was significantly higher (92% vs. 62%, p = 0.00001) for men with 50% or less vs. greater than 50% positive prostate biopsies, respectively. CONCLUSION: The presence of greater than 50% positive biopsies was associated with higher rates of pathologic upgrading which translated into lower 5-year PSA failure-free survival following radical prostatectomy (RP). Therefore, the percentage of positive biopsies may be useful in optimizing the selection of low-risk patients for prostate only radiation therapy such as external beam radiation or implant monotherapy.

Biopsy↗
PubMed2001

The clinical utility of the percent of positive prostate biopsies in predicting biochemical outcome following external-beam radiation therapy for patients with clinically localized prostate cancer.

PURPOSE: An investigation was performed of the clinical utility of the percent of positive prostate biopsies in predicting prostate-specific antigen (PSA) outcome following external-beam radiation therapy (RT) for men with PSA-detected or clinically palpable prostate cancer. METHODS AND MATERIALS: A Cox regression multivariable analysis was used to determine whether the percent of positive prostate biopsies provided clinically relevant information about PSA outcome following external beam RT in 473 men while accounting for the previously established risk groups based on the pretreatment PSA level, biopsy Gleason score, and the 1992 American Joint Commission on Cancer (AJCC) clinical T stage. RESULTS: Controlling for the known prognostic factors, the percent of positive prostate biopsies added clinically significant information (p = 0.02) regarding time to PSA failure following RT. Specifically, 76% of the patients in the intermediate risk group (1992 AJCC T(2b) or biopsy Gleason 7 or PSA > 10 ng/mL and < or = 20 ng/mL) could be classified into either an 30% or 85% 5-year PSA control cohort using the preoperative prostate biopsy data. CONCLUSION: The previously validated stratification of PSA outcome following radical prostatectomy (RP) using the percent of positive prostate biopsies in intermediate-risk patients is also clinically significant for men treated with external beam RT. The percent positive prostate biopsies should be considered in conjunction with the PSA level, biopsy Gleason score, and 1992 AJCC clinical T stage when counseling patients with newly diagnosed and clinically localized prostate cancer about PSA outcome following RP or external beam RT.

Biopsy↗
PubMed2001

ROC optimization may improve risk stratification of prostate cancer patients.

OBJECTIVES: Rational treatment decision requires accurate projection of the clinical course of a patient. Current methods in clinical outcome analysis mostly focus on population data. We investigated the applicability and optimization of the widely used actuarial method to project individual clinical outcomes. METHODS: We designed and implemented a Clinical Outcome Prediction Expert (COPE) that performs, assesses, and optimizes actuarial prediction on individual cases. We analyzed a post-prostatectomy database, consisting of 1043 patients. Sixty percent of the database was used for training and 40% for validation. Stratified actuarial curves are used to project individual outcomes. The prostate-specific antigen (PSA) level, the Gleason score, and the clinical American Joint Commission on Cancer Staging T-stage before treatment were used as predictors. The area under the receiver operator characteristic (ROC) curve was used to measure predictive performance. RESULTS: We obtained simple optimized stratification of pretreatment PSA level of 10 ng/mL or less, or more than 10 ng/mL; Gleason score of 6 or lower, or higher than 6; and clinical AJCC T-stage of T2a or lower, or higher. The optimized univariate risk scores were used to generate a multivariate score. After optimization, we found the higher risk group consisted of patients with PSA more than 10 ng/mL, or with PSA of 10 ng/mL or less and Gleason score higher than 6 and clinical AJCC T-stage higher than T2a. The optimized multivariate risk score has the highest ROC area of 0.77 among all predictors. CONCLUSIONS: The best conditions to perform actuarial prediction on individual cases are not known a priori and require optimization. This study shows that ROC optimization simplifies risk stratification and may improve the accuracy of clinical outcome prediction.

Data Interpretation, Statistical↗
PubMed2001

Estimating the impact on prostate cancer mortality of incorporating prostate-specific antigen testing into screening.

OBJECTIVES: Whether early detection using prostate-specific antigen (PSA) and digital rectal examination (DRE) compared with DRE alone will reduce prostate cancer mortality awaits the results of ongoing prospective randomized trials. However, the impact that early detection could have on prostate cancer-specific survival can be estimated by assuming that PSA failure after radical prostatectomy (RP) will translate into death from prostate cancer. METHODS: The study population consisted of 1274 men with clinically localized prostate cancer who underwent RP in Boston, Massachusetts or Philadelphia, Pennsylvania between 1989 and 2000 and had a preoperative PSA level greater than 4 but not more than 10 ng/mL. The primary endpoint was actuarial freedom from PSA failure (defined as PSA outcome). RESULTS: The relative risk of PSA failure after RP for patients diagnosed with a PSA of greater than 4 to 5, 5 to 6, 6 to 7, or 7 to 8 ng/mL compared with greater than 8 up to 10 ng/mL was 0.3 (95% confidence interval [CI] 0.2 to 0.5), 0.5 (95% CI 0.4 to 0.8), 0.6 (95% CI 0.4 to 0.9), or 0.9 (95% CI 0.6 to 1.3), respectively. On the basis of the estimates of the 5-year PSA outcome, patients with a biopsy Gleason score of 5 or 6 (781 of 1274; 61%) consistently benefited from RP performed when the PSA at diagnosis was greater than 4 to 7 ng/mL compared with greater than 8 to 10 ng/mL (93% versus 78%, P <0.0001). A benefit to early detection was not found for the vast majority (266 of 312; 88%) of patients who had a biopsy Gleason score of 7 or higher. CONCLUSIONS: Early detection using both PSA and DRE-based screening may benefit men who present with biopsy Gleason score 5 or 6 prostate cancer and a PSA level greater than 4 to 7 ng/mL compared with greater than 8 up to 10 ng/mL. This finding awaits validation from ongoing prospective randomized trials.

Actuarial Analysis↗
PubMed2001

Using the receiver operating characteristic curve to select pretreatment and pathologic predictors for early and late postprostatectomy PSA failure.

OBJECTIVES: Pretreatment prostate-specific antigen (PSA), prostatectomy Gleason score, margin status, and pathologic T stage are known explanatory variables for the postprostatectomy PSA outcome. We used the receiver operating characteristic (ROC) curve to select those factors that were optimal for predicting early and late postoperative PSA failure. METHODS: We designed and implemented a clinical outcome prediction expert that performs, assesses, and optimizes the actuarial prediction on individual cases. A postprostatectomy database of 1022 patients was divided into 60% for training and 40% for validation. The ROC areas of the predictors were calculated over a range of cutoff time from 24 to 60 months. RESULTS: Multivariate pathologic T stage/prostatectomy Gleason score/margin status had the highest ROC area of 0.900. Patients with Stage T disease less than T3, negative surgical margins, and Gleason score of 6 or less had a 90% probability to be PSA failure free at 4 years versus 36% otherwise. The pathologic T stage/margin status accurately predicted PSA failure at 24 months or less after prostatectomy with an ROC area of 0.800. Lower risk patients (less than Stage T3, negative surgical margins) had a 94% probability to be PSA failure free at 2 years versus 46% otherwise. CONCLUSIONS: A combination of actuarial analysis and ROC optimization accurately identified the individual patients at high risk of early and late postprostatectomy PSA failure.

Actuarial Analysis↗
PubMed2001

Perineural invasion as a predictor of biochemical outcome following radical prostatectomy for select men with clinically localized prostate cancer.

PURPOSE: The presence of perineural invasion on the prostate needle biopsy specimen has been suggested to be an independent predictor of prostate specific antigen (PSA) outcome following radical prostatectomy. We evaluated the clinical use of perineural invasion at biopsy for predicting time to PSA failure following radical prostatectomy after controlling for established prognostic factors. MATERIALS AND METHODS: A prospective evaluation using a Cox regression multivariate analysis of 750 men with clinically localized or PSA detected prostate cancer was performed to evaluate the ability of PSA, biopsy Gleason score, perineural invasion on the needle biopsy specimen and the percent of positive prostate biopsies to predict PSA outcome following radical prostatectomy. RESULTS: Multivariate analysis demonstrated that the presence of perineural invasion on the needle biopsy specimen provided additional information regarding 5-year PSA outcome (82% versus 95%, p = 0.04) for patients who were in the low risk group. This difference in PSA outcome could be explained by higher rates of positive surgical margins (25% versus 17%, p = 0.07). Patients whose prostate needle biopsy contained perineural invasion and who had the corresponding neurovascular bundle resected had a significantly lower positive margin rate (11% versus 100%, p = 0.001) compared to those who had the neurovascular bundle spared. The presence of perineural invasion on biopsy was not a significant predictor of PSA outcome following radical prostatectomy for patients in the intermediate or high risk group. CONCLUSIONS: Resection of the neurovascular bundle on the side corresponding to location of perineural invasion on the biopsy may decrease the positive surgical margin rate and improve outcome for low risk patients.

Adenocarcinoma↗
PubMed2001

MR imaging-guided prostate biopsy with surgical navigation software: device validation and feasibility.

Magnetic resonance (MR) imaging--guided prostate biopsy in a 0.5-T open imager is described, validated in phantom studies, and performed in two patients. The needles are guided by using fast gradient-recalled echo and T2-weighted fast spin-echo images. Surgical navigation software provided T2-weighted images critical to targeting the peripheral zone and the tumor. MR imaging can be used to guide prostate biopsy.

Biopsy, Needle↗
PubMed2001

Combined-modality staging for localized adenocarcinoma of the prostate.

The goal of identifying a set of pretreatment risk-stratifying factors for patients with localized prostate cancer is to be able to individualize treatment and optimize patient selection for clinical trials. Low-risk patients are most likely to remain disease-free following local therapy, whereas high-risk patients are not. By identifying a high-risk group in which approximately two-thirds of the patients fail biochemically within 10 years following local therapy, the ability to detect a difference in outcome as a result of additional therapy (if any difference exists) is maximized. Specifically, small improvements in outcome associated with the use of novel therapies can be measured more quickly in the high-risk population because of the intrinsically higher failure and progression rates. Therefore, novel therapies should be studied first in high-risk populations using a prospective randomized trial design (ie, local therapy with or without novel therapy). If efficacy is established in the high-risk cohort, then testing could be considered in the low-risk population. This review will demonstrate the ability to risk stratify more than 90% of all patients with clinically localized prostate cancer into low- or high-risk groups for biochemical progression following local therapy using four readily available pretreatment clinical parameters.

Adenocarcinoma↗
PubMed2001

Predicting prostate specific antigen outcome preoperatively in the prostate specific antigen era.

PURPOSE: We evaluated the ability of previously defined risk groups to predict prostate specific antigen (PSA) outcome 10 years after radical prostatectomy in patients diagnosed with clinically localized prostate cancer during the PSA era. MATERIALS AND METHODS: Between 1989 and 2000, 2,127 men with clinically localized prostate cancer underwent radical prostatectomy, including 1,027 at Hospital of the University of Pennsylvania (study cohort) and 1,100 at Brigham and Women's Hospital (validation cohort). Cox regression analysis was done to calculate the relative risk of PSA failure with the 95% confidence interval (CI) in patients at intermediate and high versus low risk. The Kaplan-Meier actuarial method was used to estimate PSA outcome 10 years after radical prostatectomy. RESULTS: Compared with low risk patients (stages T1c to 2a disease, PSA 10 ng./ml. or less and Gleason score 6 or less) the relative risk of PSA failure in those at intermediate (stage T2b disease or PSA greater than 10 to 20 ng./ml. or less, or Gleason score 7) and high (stage T2c disease, or PSA greater than 20 ng./ml. or Gleason score 8 or greater) risk was 3.8 (95% CI 2.6 to 5.7) and 9.6 (95% CI 6.6 to 13.9) in the study cohort, and 3.3 (95% CI 2.3 to 4.8) and 6.3 (95% CI 4.3 to 9.4) in the validation cohort. The 10-year PSA failure-free survival rate in the 1,020 patients in the low, 693 in the intermediate and 414 in the high risk groups was 83%, 46% and 29%, respectively (p <0.0001). CONCLUSIONS: Based on 10-year actuarial estimates of PSA outcome after radical prostatectomy 3 groups of patients were identified using preoperative PSA, biopsy Gleason score and 1992 clinical T category.

Adult↗
PubMed2000

Optimizing target coverage by dosimetric feedback during prostate brachytherapy.

PURPOSE: Postimplant dosimetry of permanent prostate implants shows a loss of coverage compared to the preplan. One contributing factor is needle misplacement. The significance of needle misplacement and the clinical utility of dosimetric feedback were analyzed in the setting of interventional magnetic resonance (IMR) guided prostate brachytherapy. METHODS AND MATERIALS: Information provided by an intraoperative planning system was analyzed for 10 patients. Needle misplacement was measured and the dosimetric consequences calculated. Additional catheters and sources were placed following the insertion of all planned catheters to compensate for nonideal needle placement. RESULTS: Source misplacement ranged from 0.0 to 1.0 cm (median, 0.3 cm). The resulting loss of coverage ranged from 1% to 13%, and the intraoperative dosimetric feedback allowed a recovery of from 0% to 12% coverage. Between 0 and 3 (median, 2) additional needles and from 0 to 10 (median, 8) additional sources were required to restore coverage of the target. Final planned coverage exceeded 94% for all patients. CONCLUSION: The discrepancy between planned and achieved needle placement leads to a loss of dosimetric coverage of the target volume. Dosimetric feedback allows compensation for needle divergence. The technique of real-time dosimetric feedback does not require an IMR system, and could be generalized to ultrasound-guided implants.

Brachytherapy↗
PubMed2000

Pathologic findings and prostate specific antigen outcome after radical prostatectomy for patients diagnosed on the basis of a single microscopic focus of prostate carcinoma with a gleason score </= 7.

BACKGROUND: Whether patients who are diagnosed on the basis of a single microscopic focus of prostate carcinoma with a Gleason score </= 7 (micro PC) have potentially life-threatening disease if they are not treated is unknown. METHODS: Pathologic findings and prostate specific antigen (PSA) outcome after radical prostatectomy (RP) for men who were diagnosed with micro PC were determined. Of 917 patients who were managed with RP during 1989-1999 at the Brigham and Women's Hospital, 66 patients (7%) were diagnosed on the basis of micro PC. Pathologic stage, tumor grade, tumor volume, margin status, and PSA outcome were investigated and are reported. Estimates of PSA outcome were calculated using the actuarial method of Kaplan and Meier. Pairwise comparisons were made using the log rank test. RESULTS: The finding of micro PC at biopsy was associated with macroscopic disease (involving at least half of a single lobe) in 92% of the patients in this series. Although these men had favorable pathologic findings (94% had organ confined disease, 89% had negative tumor margins, and 79% had a prostatectomy Gleason score </= 6), approximately 10% of the patients failed biochemically within 5 years after RP. CONCLUSIONS: The finding of micro PC at biopsy should not be used as a surrogate for clinically insignificant disease.

Biopsy↗
PubMed2000

Utilizing predictions of early prostate-specific antigen failure to optimize patient selection for adjuvant systemic therapy trials.

PURPOSE: Prostate-specific antigen (PSA) failure within 2 years after radical prostatectomy (RP) has been shown to be a clinically significant predictor of distant failure. This study was performed to estimate 2-year PSA failure rates on the basis of readily available clinical and pathologic factors to identify patients for whom effective adjuvant systemic therapy is needed. PATIENTS AND METHODS: A Cox regression multivariable analysis was used to determine whether the percentage of positive prostate biopsies, PSA level, and the pathologic findings at RP in 1,728 men provided clinically relevant information about PSA outcome after RP. A bootstrapping technique with 2,000 replications was used to provide 95% confidence intervals for the predicted 2-year PSA failure rates, which were determined on the basis of the independent clinical and pathologic predictors of PSA outcome. RESULTS: The independent predictors of time to PSA failure included a percentage of positive prostate biopsies of greater than 34% (P: < or =.009), PSA level greater than 10 ng/mL (P: < or =.01), seminal vesicle invasion (P: =. 02), prostatectomy Gleason score of 8 to 10 (P: =.04), and positive surgical margins (P: =.0001). Predictions of 2-year PSA failure rates and bootstrap estimates of the 95% confidence intervals were arranged in a tabular format, stratified by independent clinical and pathologic predictors of PSA outcome. CONCLUSION: Patients who are most likely to benefit from effective adjuvant systemic therapy after RP can be identified using readily available clinical and pathologic data.

Biopsy↗
PubMed2000

Biochemical outcome following external beam radiation therapy with or without androgen suppression therapy for clinically localized prostate cancer.

CONTEXT: Combined treatment using radiation therapy (RT) and androgen suppression therapy (AST) is used to treat men with clinically localized adenocarcinoma of the prostate, but outcome using this combined therapy compared with RT alone is not known. OBJECTIVE: To determine the relative efficacy of RT plus AST vs RT alone among men with clinically localized prostate cancer. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study of 1586 men with prostate cancer who were treated between January 1989 and August 1999 using 3-dimensional conformal RT with (n = 276) or without (n = 1310) 6 months of AST. MAIN OUTCOME MEASURE: Relative risk (RR) of prostate-specific antigen (PSA) failure (defined according to the American Society for Therapeutic Radiology and Oncology consensus statement), by treatment and high-, intermediate-, or low-risk group based on serum PSA level, biopsy Gleason score, and 1992 American Joint Commission on Cancer clinical tumor category. RESULTS: Estimates of 5-year PSA outcome after RT with or without AST were not statistically different among low-risk patients (P =.09), whereas intermediate- and high-risk patients treated with RT plus AST had significantly better outcomes than those treated with RT alone (P<.001 and =.009, respectively). The RR of PSA failure in low-risk patients treated with RT plus AST was 0.5 (95% confidence interval [CI], 0.3-1.1) compared with patients treated with RT alone. The RRs of PSA failure in intermediate-risk and high-risk patients treated with RT plus AST compared with RT alone were 0.2 (95% CI, 0. 1-0.3) and 0.4 (95% CI, 0.2-0.8), respectively. CONCLUSIONS: Our data suggest a significant benefit in 5-year PSA outcomes for men with clinically localized prostate cancer in intermediate- and high-risk groups treated with RT plus AST vs those treated with RT alone. Results from prospective randomized trials currently under way are needed to validate these findings. JAMA. 2000;284:1280-1283

Adenocarcinoma↗
PubMed2000

Towards enzyme activated antiprostatic agents.

A prodrug conjugate designed to undergo activation by enzymatic prostate specific antigen has been synthesized. The prodrug system undergoes activation with PSA or alpha-chymotrypsin, and shows selective cytotoxicity in a PSA secreting cell line.

Antineoplastic Agents↗