Determining prostate cancer-specific death through quantification of stromogenic carcinoma area in prostatectomy specimens

We previously reported that reactive stroma grading in prostate cancer (PCa) is predictive of biochemical recurrence in prostatectomies and biopsies. In this study, we tested whether quantifying the percentage of reactive stromal grade 3 (RSG 3; stromogenic carcinoma pattern) in the entire tumor is predictive of PCa-specific death. Whole-mount prostatectomies operated by a single surgeon obtained between 1983 and 1998 were reviewed. Reactive stroma was evaluated as described previously, and areas of RSG 3 in the entire tumor were registered as percentages of total tumor. Statistical analysis was performed using Spearman, Kaplan-Meier, and Cox analyses. In all, 872 cases were evaluable. Quantification of RSG 3 percentage was an independent predictor of biochemical recurrence, analyzed as a continuous or grouped variable. Patients with higher RSG 3 percentages (larger tumor areas with RSG 3) had a significantly decreased biochemical recurrence-free survival than those with a lower RSG 3 percentage, even within the Gleason score 7 subset of patients. A nomogram introduced this new variable to the model. Furthermore, quantification of RSG 3 percentage was significantly predictive of PCa-specific death. Quantification of the RSG 3 (stromogenic carcinoma) area in PCa provides additional novel information on prognosis. These data substantiate the concept that the tumor microenvironment holds significant predictive information, as well as biological significance.

Long-term outcomes for patients with prostate cancer having intermediate and high-risk disease, treated with combination external beam irradiation and brachytherapy

Background. Perception remains that brachytherapy-based regimens are inappropriate for patients having increased risk of extracapsular extension (ECE). Methods. 321 consecutive intermediate and high-risk disease patients were treated between 1/92 and 2/97 by one author (M. Dattoli) and stratified by NCCN guidelines. 157 had intermediate-risk; 164 had high-risk disease. All were treated using the combination EBRT/brachytherapy ± hormones. Biochemical failure was defined using PSA >0.2 and nadir +2 at last followup. Nonfailing patients followup was median 10.5 years. Both biochemical data and original biopsy slides were independently rereviewed at an outside institution. Results. Overall actuarial freedom from biochemical progression at 16 years was 82% (89% intermediate, 74% high-risk) with failure predictors: Gleason score (P = .01) and PSA (P = .03). Hormonal therapy did not affect failure rates (P = .14). Conclusion. This study helps to strengthen the rationale for brachytherapy-based regimens as being both durable and desirable treatment options for such patients. Prospective studies are justified to confirm these positive results.

Incremental value of magnetic resonance imaging in the advanced management of prostate cancer

Prostate cancer is a major public health burden throughout the world. The high incidence of prostate cancer, combined with earlier detection and downstaging at the time of diagnosis, and the slow natural progression and biological heterogeneity of the disease, has made its management a complex and controversial issue. There is growing demand for patient-specific therapies that can minimize treatment morbidity while maximizing treatment benefits. There are a number of clinical parameters and clinical nomograms to help with the choice of treatment. Magnetic resonance imaging (MRI) is a technique which makes safer, more individualized therapies possible due to high spatial resolution, superior contrast resolution, multiplanar capability, and a large field of view. Other MRI techniques such as MR spectroscopic imaging, dynamic contrast-enhanced MRI or perfusion MRI, and diffusion-weighted imaging complement MRI by reflecting tissue biochemistry, Brownian motion of water molecules, and capillary wall permeability, respectively. This editorial review highlights the incremental value of MRI in the advanced management of prostate cancer to non-invasively improve cancer staging, biologic potential, treatment planning, therapy response, local recurrence, and to guide target biopsy for clinical suspected cancer with previous negative biopsy. Finally, some future prospects for MRI in prostate cancer management are given.

Computerized analysis of prostate lesions in the peripheral zone using dynamic contrast enhanced MRI

A novel automated computerized scheme has been developed for determining a likelihood measure of malignancy for cancer suspicious regions in the prostate based on dynamic contrast-enhanced magnetic resonance imaging (MRI) (DCE-MRI) images. Our database consisted of 34 consecutive patients with histologically proven adenocarcinoma in the peripheral zone of the prostate. Both carcinoma and non-malignant tissue were annotated in consensus on MR images by a radiologist and a researcher using whole mount step-section histopathology as standard of reference. The annotations were used as regions of interest (ROIs). A feature set comprising pharmacokinetic parameters and a T1 estimate was extracted from the ROIs to train a support vector machine as classifier. The output of the classifier was used as a measure of likelihood of malignancy. Diagnostic performance of the scheme was evaluated using the area under the ROC curve. The diagnostic accuracy obtained for differentiating prostate cancer from non-malignant disorders in the peripheral zone was 0.83 (0.75-0.92). This suggests that it is feasible to develop a computer aided diagnosis system capable of characterizing prostate cancer in the peripheral zone based on DCE-MRI.

Diet and lifestyle interventions in active surveillance patients with favorable-risk prostate cancer

Active Surveillance (AS) is a viable, alternative option for patients who are diagnosed with favorable prognostic risk prostate cancer, and who are willing to undergo conservative, expectant management until treatment is warranted due to progression of the disease. Lifestyle interventions in patients who choose AS is an emerging area of research, and several studies are ongoing with results pending. New intervention studies will increase our knowledge of the etiology of prostate cancer and help determine whether dietary factors can influence prostate carcinogenesis after diagnosis in AS patients. The considerable amount of epidemiologic and experimental data relating components of the diet with prostate cancer risk suggest that diet or lifestyle interventions could potentially lengthen the period of active surveillance before treatment management is necessary, and further research is warranted to study the direct effects on secondary clinical outcomes.

Treatment choice and quality of care for men with localized prostate cancer

BACKGROUND

Variations in patterns of care and treatment outcomes suggest differences in the quality of care for men treated for localized prostate cancer.

OBJECTIVE

We sought to compare adherence with quality indicators for prostate cancer care among men treated with radical prostatectomy or external beam radiation therapy.

RESEARCH DESIGN AND SUBJECTS

We sampled 5230 men diagnosed in 2000 or 2001 with early-stage prostate cancer from 984 facilities reporting to the National Cancer Data Base. Our analytic cohort includes 2604 men (from 770 facilities) treated with radical prostatectomy or external beam radiation.

MAIN OUTCOME MEASURE

Subject-level compliance with the RAND quality indicators for localized prostate cancer care, stratified by treatment. We applied sampling weights to obtain national estimates of quality indicator adherence.

RESULTS

The weighted samples represent 24,547 and 27,125 men treated with radical prostatectomy or external beam radiation therapy, respectively. Compliance with several quality indicators approached 100% in both treatment groups; however treatment-specific variations were noted. Men receiving radiation were less likely than those undergoing surgery to be treated in facilities with a board-certified urologist (odds ratio [OR] = 0.4, 95% confidence interval [95% CI] = 0.2-0.8). Adherence with process of care indicators was appreciably higher among radiation subjects, including documentation of clinical stage (OR = 7.5, 95% CI = 4.8-11.9), pretherapy assessment of urinary (OR = 2.8, 95% CI = 1.9-4.2) and sexual (OR = 1.6, 95% CI = 1.2-2.2) function, and discussion of treatment options (OR = 1.8, 95% CI = 1.1-2.9).

CONCLUSIONS

Documented compliance with process of care quality indicators among men with localized prostate cancer appears superior for those treated with external beam radiation compared with those treated surgically.

11C-Choline positron-emission tomography/computed tomography and transrectal ultrasonography for staging localized prostate cancer

OBJECTIVE

To evaluate and compare the role of (11)C-choline positron emission tomography (PET) and transrectal ultrasonography (TRUS) in the preoperative staging of clinically localized prostate cancer.

PATIENTS AND METHODS

Fifty-five consecutive patients with biopsy-confirmed prostate cancer had TRUS and (11)C-choline PET as a part of their clinical staging programme before radical retropubic prostatectomy (RP). The PET images were prospectively interpreted by a consensus decision of two nuclear medicine physicians and one radiologist with special expertise in the field. The TRUS was done by one experienced urologist. The criteria evaluated prospectively in each patient were extracapsular extension (ECE), seminal vesicle invasion (SVI) and bladder neck invasion (BNI). The results were compared with the histopathological findings after RP.

RESULTS

At pathology, 32 patients were classified pT2, 16 as pT3a and three had pT3b lesions. In four patients the histopathological examination showed pT4 with BNI. The overall accuracy of PET in defining local tumour stage (pT2 and pT3a-4) was 70%; the overall accuracy by TRUS was 26%. PET was more sensitive than TRUS for detecting ECE (pT3a) and SVI (pT3b) in advanced stages, and in pT4 stages. The sensitivity and positive predictive value (PPV) (95% confidence interval) in stages pT3a-pT4 for PET were 36 (17-59)% and 73 (39-89)%. The sensitivity and PPV in stages pT3a-pT4 for TRUS were 14 (3-35)% and 100 (29-100)%.

CONCLUSIONS

(11)C-choline PET and TRUS tended to understage prostate cancer. This series shows the current limited value of TRUS and PET for making treatment decisions in patients with clinically localized prostate cancer, especially if a nerve-sparing RP is considered. Treatment decisions should not be based on TRUS and (11)C-choline PET findings alone. In future studies, the combination of metabolic and anatomical information of PET and endorectal magnetic resonance imaging should be evaluated, as this might optimize the preoperative staging in prostate cancer.

Radiation therapy in prostate cancer

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

Long-term prostate cancer control using palladium-103 brachytherapy and external beam radiotherapy in patients with a high likelihood of extracapsular cancer extension

OBJECTIVES

To report the long-term biochemical control rates with brachytherapy-based treatment for patients with prostate cancer at high risk of extracapsular cancer extension.

METHODS

A total of 243 consecutive patients with at least one higher risk factor (Gleason score of 7 or worse, prostate-specific antigen [PSA] level greater than 10 ng/mL, or elevated prostatic acid phosphatase level greater than 2.5 U) who were treated with palladium-103 plus supplemental external beam radiotherapy from 1992 through 1996 were included in this study. Patients received 41 Gy external beam radiotherapy to a limited pelvic field, followed 4 weeks later by a palladium-103 boost. The prescribed minimal palladium-103 dose to the prostate was 80 to 90 Gy. Freedom from biochemical failure was defined as a serum PSA level of 0.2 ng/mL or less at the last follow-up visit.

RESULTS

Of the 243 patients, 41 developed biochemical failure. The overall actuarial freedom from biochemical progression rate at 13 years was 81%, with 198 patients followed up for longer than 5 years. The overall actuarial freedom from failure rate for the 93 patients with a PSA level of 10 ng/mL or greater and Gleason score of 7 or greater was 74% at 5 years and 72% at 10 years. The overall actuarial freedom from failure rate for the 66 patients with elevated prostatic acid phosphatase was 65% at 10 years. The absolute risk of failure decreased progressively with time, falling to 1% by 6 years after treatment. On Cox proportional hazard multivariate analysis, considering each factor as a continuous variable, the strongest predictor of failure was the acid phosphatase level (P <0.0001), followed by Gleason score (P = 0.42) and PSA level (P = 0.15).

CONCLUSIONS

The evidence from this patient group at high risk of extracapsular cancer extension suggests that the relatively high tumor control rates with brachytherapy-based therapy are durable.

Long-term outcomes after treatment with brachytherapy and supplemental conformal radiation for prostate cancer patients having intermediate and high-risk features

BACKGROUND

This study summarizes long-term outcomes from treatment of prostate cancer with increased risk of extracapsular cancer extension (ECE) using brachytherapy-based treatment.

METHODS

A total of 282 consecutive patients were treated from 1992-1996 by 1 author (M.D.). Two hundred forty-three patients had at least 1 higher risk feature for ECE including Gleason Score 7-10 (172), prostate-specific antigen (PSA) above 10 (166), and clinical stages T(2c) (109) and T(3) (107). Using National Comprehensive Cancer Network (NCCN) guidelines, 119 patients had intermediate-risk disease and 124 had high-risk disease. Patients received pelvic 3-dimensional conformal external beam radiation followed by a palladium (Pd)-103 boost. Generous brachytherapy margins were utilized. Biochemical failure was defined using ASTRO Consensus Definition, nadir +2 and PSA >0.2 ng/mL at last follow-up. The nonfailing patient follow-up period was 1-14 years (median, 9.5 years). Biochemical data and original biopsy slides were independently re-reviewed at the University of Washington (by K.W. and L.T., respectively).

RESULTS

Overall actuarial freedom from biochemical progression at 14 years was 81%, including 87% and 72% having intermediate and high-risk disease, respectively. Absolute risk of failure decreased progressively, falling to 1% beyond 6 years after treatment. All failing patients had prostate biopsies without evidence of local recurrence. The strongest predictor of failure was Gleason score (P = .03) followed by PSA (P = .041). Treatment morbidity was limited to temporary RTOG grade 1-2 urinary and gastrointestinal symptoms.

CONCLUSIONS

High tumor control rates are possible with beam radiation followed by Pd-103 brachytherapy. Despite perceptions that brachytherapy is inappropriate for patients at higher risk for ECE, this series strengthens the rationale that brachytherapy-based treatment may be a desirable modality for such patients.

Guidelines for primary radiotherapy of patients with prostate cancer

BACKGROUND AND PURPOSES

The appropriate application of 3-D conformal radiotherapy, intensity modulated radiotherapy or image guided radiotherapy for patients undergoing radiotherapy for prostate cancer requires a standardisation of target delineation as well as clinical quality assurance procedures.

PATIENTS AND METHODS

Pathological and imaging studies provide valuable information on tumour extension. In addition, clinical investigations on patient positioning and immobilisation as well as treatment verification data offer an abundance of information.

RESULTS

Target volume definitions for different risk groups of prostate cancer patients based on pathological and imaging studies are provided. Available imaging modalities, patient positioning and treatment preparation studies as well as verification procedures are collected from literature studies. These studies are summarised and recommendations are given where appropriate.

CONCLUSIONS

On behalf of the European Organisation for Research and Treatment of Cancer (EORTC) Radiation Oncology Group this article presents a common set of recommendations for external beam radiotherapy of patients with prostate cancer.

What constitutes high-risk locally advanced prostate cancer?

Excluding basal and squamous cell cancers of the skin, prostate cancer is the most common malignancy diagnosed in the United States. With increasing awareness and routine prostate-specific antigen testing, a remarkable migration in the clinical presentation of the disease has occurred in the past 20 years. An increasingly greater proportion of men are diagnosed with clinically organ-confined disease. In parallel, the incidence of men presenting with clinically bulky locoregional or metastatic disease has decreased. Despite the stage migration, when clinical and pathologic parameters are taken into account, a significant number of men with clinically localized prostate cancer do not have truly organ-confined disease. Such men might not to be cured with single modality, locally directed therapies. Thus, prostate cancer represents a disease spectrum with a number of biologic and clinical factors determining disease extent. An overview of some of these aspects of the disease is presented.

Multigene Methylation Analysis for Detection and Staging of Prostate Cancer

PURPOSE

Aberrant gene promoter methylation profiles have been well-studied in human prostate cancer. Therefore, we rationalize that multigene methylation analysis could be useful as a diagnostic biomarker. We hypothesize that a new method of multigene methylation analysis could be a good diagnostic and staging biomarker for prostate cancer.

EXPERIMENTAL DESIGN

To test our hypothesis, prostate cancer samples (170) and benign prostatic hyperplasia samples (69) were examined by methylation-specific PCR for three genes: adenomatous polyposis coli (APC), glutathione S-transferase pi (GSTP1), and multidrug resistance 1 (MDR1). The methylation status of representative samples was confirmed by bisulfite DNA sequencing analysis. We further investigated whether methylation score (M score) can be used as a diagnostic and staging biomarker for prostate cancer. The M score of each sample was calculated as the sum of the corresponding log hazard ratio coefficients derived from multivariate logistic regression analysis of methylation status of various genes for benign prostatic hyperplasia and prostate cancer. The optimal sensitivity and specificity of the M score for diagnosis and for staging of prostate cancer was determined by receiver-operator characteristic (ROC) curve analysis. A pairwise comparison was employed to test for significance using the area under the ROC curve analysis. For each clinicopathologic finding, the association with prostate-specific antigen (PSA) failure-free probability was determined using Kaplan-Meier curves and a log-rank test was used to determine significance. The relationship between M score and clinicopathologic findings was analyzed by either the Mann-Whitney U test, Kruskal-Wallis test, or the Spearman rank correlation test.

RESULTS

The frequency of positive methylation-specific PCR bands for APC, GSTP1, and MDR1 genes in prostate cancer samples was 64.1%, 54.0%, and 55.3%, respectively. In benign prostatic hyperplasia samples, it was 8.7%, 5.8%, and 11.6%, respectively. There was a significant correlation of M score with high pT category (P < 0.001), high Gleason sum (P < 0.001), high preoperative PSA (P = 0.027), and advanced pathologic features. For all patients, the M score had a sensitivity of 75.9% and a specificity of 84.1% as a diagnostic biomarker using a cutoff value of 1.0. In patients with low or borderline PSA levels (<10.0 ng/mL), the M score was significantly higher in prostate cancers than in benign prostatic hyperplasias (2.635 +/- 0.200 and 0.357 +/- 0.121, respectively). ROC curve analysis revealed that the M score had a sensitivity of 65.4% and a specificity of 94.2% when 1.0 was used as a cutoff value. For all patients, M score can distinguish organ-confined (< or =pT(2)) from locally advanced cancer (> or =pT(3)) with a sensitivity of 72.1% and a specificity of 67.8%. Moreover, considering patients with PSA levels of <10 ng/mL, the M score has a sensitivity of 67.1% and a specificity of 85.7%. The ROC curve analysis showed a significant difference between M score and PSA (P = 0.010).

CONCLUSIONS

This is the first report demonstrating that M score is a new method for multigene methylation analysis that can serve as a good diagnostic and staging biomarker for prostate cancer.

Evidence-based medicine, medical decision analysis, and pathology

Recent advances in molecular pathology and other technologies such as proteomics present pathologists with the challenge of integrating the new information generated with high-throughput methods with current diagnostic models based mostly on histopathology and clinicopathologic correlations. Parallel developments in the field of medical informatics and bioinformatics provide the technical and mathematical methods to approach these problems in a rational manner. However, it remains unclear whether pathologists or other medical specialists will become primarily responsible for the development and maintenance of these multivariate and multidisciplinary diagnostic and prognostic models that are hoped to provide more accurate, individualized patient-based information. Evidence-based medicine (EBM) and medical decision analysis (MDA) are relatively new disciplines that use quantitative methods to assess the value of information, differentiate fact from myth, and integrate so-called best evidence into multivariate models for the assessment of prognosis, response to therapy, selection of laboratory tests, and other complex problems that influence individual patient care. We review from an epistemological viewpoint the current approach to information in pathology and describe some of the concepts developed by the practitioners of EBM and MDA.