Using prostate-specific antigen to eliminate the staging radionuclide bone scan

Management of bone metastasis in prostate cancer

Progression of bone metastases is the primary cause of death in prostate cancer, and skeletal-related events (SREs), including pathologic fractures, spinal cord compression, radiation, or surgery to bone can impair patients' quality of life. Over the past decade, the development of cytotoxic agents, androgen-receptor-axis-targeted therapies (ARATs), and radioligand therapies has prolonged overall survival of prostate cancer patients with bone metastases and reduced the risk of SREs. The use of bone-modifying agents has also contributed to the reduced risk of SREs. Initial use of a cytotoxic agent, docetaxel, or an ARAT agent with androgen deprivation therapy (ADT) is the current approach to metastatic castration-sensitive prostate cancer. However, there is no consensus on the optimal medication for upfront use in combination with ADT, or on specific patient selection. Recently, next-generation imaging modalities, such as whole-body magnetic resonance imaging and prostate-specific membrane antigen-positron emission tomography have been utilized to detect bone metastases at an early stage. In addition, metastasis-directed therapy, such as stereotactic body radiation therapy, has been attempted. In the future, patients with bone metastatic prostate cancer will be divided into subgroups and their treatment options will be tailored to their specific characteristics.

Biochemical Recurrence in Prostate Cancer and Temporal Association to Bone Metastasis

Case series

Patient: Male, 78 • Male, 65

Final Diagnosis: Bone metastasis from prostate cancer recurrence

Symptoms: Joint pain

Medication: —

Clinical Procedure: —

Specialty: Uro-Oncology

Bone scan is of doubtful value as a first staging test in the primary presentation of prostate cancer

Purpose. To determine whether axial MR imaging could replace bone scan as the primary staging test in newly diagnosed CaP. Material and Methods. We reviewed retrospectively all bone scans (n = 1201) performed in newly diagnosed CaP patients from 2000 to 2010 in a single tertiary academic center. We recorded patient age, ethnicity, PSA at diagnosis, TNM stage, Gleason score, alkaline phosphatase, bone scan results and axial imaging if available. Results. Mean patient age was 72 years (41–96), mean PSA and alkaline phosphatase were 268.9 ng/mL and 166 IU/L, respectively. Patients were divided in four groups according to possible bony metastases on bone scan. Group 1: Negative, no metastases demonstrated. Group 2: Positive, metastases only in pelvis and/or lumbar spine. Group 3: Positive, widespread metastases including pelvis and lumbar spine. Group 4: Positive, distant metastases without pelvic or lumbar spine abnormalities. Group 4 patients were analyzed in detail, two had possible disease that was detected only outside the pelvic and lumbar spine, unfortunately follow up images were insufficient to confirm the nature of the lesions. Conclusions. Although bone scan is a useful investigation to confirm and monitor metastasic CaP, our data suggests that axial MR imaging is an adequate primary staging study in untreated disease. Bone scan is unnecessary if CT or MRI of the pelvis and abdomen are clear of metastases.

Operational characteristics of (11)c-choline positron emission tomography/computerized tomography for prostate cancer with biochemical recurrence after initial treatment

PURPOSE

We examined the performance of (11)C-choline positron emission tomography/computerized tomography for its ability to delineate prostate cancer distribution and extent after initial therapy.

MATERIALS AND METHODS

A consecutive series retrospective review was performed of all patients with prostate cancer who were evaluated using (11)C-choline positron emission tomography/computerized tomography from September 2007 to November 2010 at the Mayo Clinic. Statistical analysis was performed to determine the sensitivity, specificity, positive predictive value, negative predictive value and prostate specific antigen threshold for the detection of recurrent lesions.

RESULTS

In the study period 176 patients with biochemical recurrence after primary treatment failure underwent (11)C-choline positron emission tomography/computerized tomography. Using patient based analysis (11)C-choline positron emission tomography yielded a sensitivity, specificity, positive predictive value and negative predictive value of 93%, 76%, 91% and 81%, respectively. Of the 176 positron emission tomography/computerized tomography scans performed 56 (32%) were deemed clinically useful as defined by the ability to identify lesions not delineated using conventional imaging, thereby prompting changes in clinical management. The optimal prostate specific antigen for lesion detection was 2.0 ng/ml. On multivariate analysis prostate specific antigen at positron emission tomography (HR 1.37, p = 0.04) and clinical stage at initial diagnosis of prostate cancer (HR 5.19, p = 0.0035) were significant predictors of positive (11)C-choline positron emission tomography/computerized tomography.

CONCLUSIONS

(11)C-choline positron emission tomography/computerized tomography performs well in men with biochemical recurrence after primary treatment failure. The optimal prostate specific antigen value for lesion detection is approximately 2.0 ng/ml. We found that (11)C-choline positron emission tomography/computerized tomography substantially enhances the rate of prostate cancer lesion detection by approximately 32% beyond what can be garnered using conventional imaging techniques and at a lower prostate specific antigen value.

Can early implementation of salvage radiotherapy for prostate cancer improve the therapeutic ratio? A systematic review and regression meta-analysis with radiobiological modelling

PURPOSE

For prostate cancer that is thought to be locally recurrent after prostatectomy, the optimal timing, dose and techniques for salvage radiotherapy (SRT) have not been established. Here we perform a systematic review of published reports including regression meta-analysis and radiobiologic modelling to identify predictors of biochemical disease control and late toxicity.

METHODS

We performed a review of published series reporting treatment outcomes following SRT. Studies with at least 30 patients, median PSA before SRT of less than 2.0 ng/mL, and median follow-up of greater than 36 months were identified. Univariate and multivariate analyses were performed to test Gleason Score, SRT dose, SRT timing, pre-SRT PSA, whole pelvic irradiation and androgen deprivation therapy as predictors of 5-year biochemical progression-free survival (bPFS) and severe (grade≥3) late GI and GU toxicity. bPFS and toxicity data were fit to tumour control probability and normal tissue complication probability models, respectively.

RESULTS

Twenty-five articles met the inclusion criteria for this analysis. Five-year bPFS ranged from 25% to 70%. Severe late GI toxicity rates were 0% to 9%, and severe late GU toxicity rates were 1-11%. On multivariate analysis, bPFS increased with SRT dose by 2.5% per Gy and decreased with pre-SRT PSA by 18.3% per ng/mL (p<0.001). Late GI and GU toxicity increased with SRT dose by 1.2% per Gy (p=0.012) and 0.7% per Gy (p=0.010), respectively. Radiobiological models demonstrate the interaction between pre-SRT PSA, SRT dose and bPFS. For example, an increase in pre-SRT PSA from 0.4 to 1.0 ng/mL increases the SRT dose required to achieve a 50% bPFS rate from 60 to 70Gy. This could increase the rate of severe late toxicity by approximately 10%.

CONCLUSION

Biochemical control rates following SRT increase with SRT dose and decrease with pre-SRT PSA. Severe late GI and GU toxicity rates also increase with SRT dose. Radiobiological models suggest that the therapeutic ratio of SRT may be improved by initiating treatment at low PSA levels.

Prostate cancer

Prostate cancer is biologically and clinically a heterogeneous disease and its imaging evaluation will need to be tailored to the specific phases of the disease in a patient-specific, risk-adapted manner. We first present a brief overview of the natural history of prostate cancer before discussing the role of various imaging tools, including opportunities and challenges, for different clinical phases of this common disease in men. We then review the preclinical and clinical evidence on the potential and emerging role of positron emission tomography with various radiotracers in the imaging evaluation of men with prostate cancer.

The detection rate of [11C]choline-PET/CT depends on the serum PSA-value in patients with biochemical recurrence of prostate cancer

PURPOSE

An increase of the serum PSA-level is a sensitive in vitro marker for recurrent prostate cancer. However, it remains difficult to differentiate between local, regional or distant recurrent disease. The aim of this study was to assess the relationship between the detection rate of [(11)C]Choline-PET/CT and the serum PSA-level in patients with a biochemical recurrence of prostate cancer with the view towards localisation of recurrent disease.

METHODS

Sixty-three patients (mean age, 68.8 +/- 6.9; range, 45-83 years) with biochemical recurrence after primary therapy for prostate cancer were included in the analysis. Mean PSA-levels were 5.9 +/- 9.7 ng/ml (range, 0.2-39 ng/ml; median, 2.15). Of the 63 patients, 17 were under anti-androgen therapy at the time of [(11)C]Choline PET/CT. Patients underwent a [(11)C]Choline-PET/CT study after injection of 656 +/- 119 MBq [(11)C]Choline on a Sensation 16 Biograph PET/CT scanner.

RESULTS

Of the 63 patients, 35 (56%) showed a pathological [(11)C]Choline uptake. The detection rate of [(11)C]Choline-PET/CT showed a relationship with the serum PSA-level: The detection rate was 36% for a PSA-value <1 ng/ml, 43% for a PSA-value 1-<2 ng/ml, 62% for a PSA-value 2-<3 ng/ml and 73% for a PSA-value >or=3 ng/ml. Anti-androgen therapy did not show a significant effect on the detection rate of [(11)C]Choline-PET/CT (p = 0.374).

CONCLUSION

As an important result our study shows that even for PSA-values <1.0 ng/ml the detection efficiency of [(11)C]Choline-PET/CT is 36%. Furthermore, the detection rate of [(11)C]Choline-PET/CT shows a positive relationship with serum PSA-levels in patients with biochemical recurrence of prostate cancer after primary therapy. Therefore, in these patients, [(11)C]Choline PET/CT allows not only to diagnose but also to localise recurrent disease with implications on disease management (localised vs systemic therapy).

Diagnostic and therapeutic use of radioisotopes for bony disease in prostate cancer: Current practice

Nuclear medicine techniques continue to be important non-invasive imaging tools assisting the diagnosis, monitoring and--in some cases--treatment of prostate cancer. Bone scintigraphy was the premier modality to have an extensive role in the staging of prostate cancer and has remained an integral tool for over three decades in the assessment of newly diagnosed disease or in follow-up staging. Therapeutic treatment and palliation of disseminated disease, particularly in the skeleton, has also been successful with several radioisotopes including strontium-89 chloride. Despite advances in nuclear medicine techniques and molecular imaging technology such as positron emission tomography and radioimmunoscintigraphy, bone scintigraphy still remains the gold standard in the assessment of osseous metastatic disease in prostate cancer. Thus, it is important to continually review the modalities that have remained important over time and not just to focus on newer technologies. This article summarizes the current diagnostic and therapeutic use of radioisotopes for bony disease in prostate cancer with particular reference to radionuclide bone scintigraphy and positron emission tomography.

Die Skelettszintigraphie beim neu diagnostizierten Prostatakarzinom

BACKGROUND

The indication for a radionuclide bone scan in patients with newly diagnosed, untreated prostate cancer remains controversial.

PATIENTS AND METHODS

In this retrospective study we examined 406 patients who had received a staging bone scan irrespective of their PSA serum level and histology. We evaluated different guidelines and recommendations with respect to their usefulness. The costs were calculated according to EBM and GOA. We evaluated the classification systems of bone metastases according to Soloway, Crawford, and Rigaud.

RESULTS

The bone scan was positive in 41 (10%) of 406 patients. The EAU guidelines turned out to be useful with respect to both clinical value and cost efficiency. The Rigaud classification of bone metastases predicted outcome better than the Soloway or Crawford classification.

CONCLUSIONS

The EAU guidelines from 2005 are a useful tool to decide whether to perform a bone scan in patients with newly diagnosed, untreated prostate cancer. A bone scan should be performed if PSA levels exceed 20 ng/ml in patients with a G1/G2 histology, and in patients with G3 histology and locally advanced disease irrespective of PSA level. Bone scan metastases should be classified according to Rigaud.

Prostate Cancer Imaging—What the Urologic Oncologist Needs to Know

Appropriate imaging for prostate cancer patients depends on the clinical disease state of the patient and the question being asked. For patients who do not have a cancer diagnosis, ultrasound is the standard approach, in combination with a sextant biopsy. In the future, contrast-enhanced ultrasound and MR imaging-directed biopsy may improve biopsy yield and decrease biopsy number. For clinically localized disease, endorectal coil MR imaging and bone scanning may play a role in patients who have risk factors for extracapsular extension, but more data are needed to define the role of MR spectroscopy and lymphtrophic nanoparticle MR imaging. In the rising prostate-specific antigen (PSA) setting after definitive local therapy, endorectal coil MR imaging may help define local recurrence, whereas bone scanning can be useful in the setting of higher PSA or rapid PSA velocity.

Prostate-specific antigen-based serial screening may decrease prostate cancer-specific mortality

OBJECTIVES

To compare the preoperative characteristics, postoperative prostate-specific antigen (PSA) doubling time (DT), and prostate cancer-specific mortality (PCSM) estimates after PSA failure in men diagnosed during a screening study versus a community referral population. A PSA-DT of less than 3 months is a surrogate endpoint for PCSM.

METHODS

From 1988 to 2002, 1492 of 9637 patients with clinically localized prostate cancer underwent radical prostatectomy and experienced PSA failure. They were either participating in a screening study (n = 841) or attended 1 of 44 community-based practices (n = 611). The distributions of PSA, Gleason score, tumor stage, and PSA-DT were compared using chi-square metric. The estimates of PCSM after PSA failure were compared using Gray's P value.

RESULTS

Compared with the community population, the annually screened men experiencing PSA failure had a lower PSA level at diagnosis (5.1 versus 9.5 ng/mL, P <0.0001), were less likely to have Gleason score 7 to 10 cancer (25.1% versus 42.1%, P <0.0001), and were more likely to have low-risk disease (64.5% versus 23.8%, P <0.0001). Furthermore, the screened cohort had a reduction (P <0.0001) in the proportion with a PSA-DT of less than 3, 3 to 5.99, and 6 to 11.99 months and a significant increase in the proportion with a PSA-DT of 12 months or longer. After a median follow-up of 4.5 and 4.1 years after PSA failure in the screened and community cohorts, respectively, the PCSM estimates were lower (P = 0.0002) in the screened cohort (10-year estimate 3.6% [95% confidence interval 1.3 to 5.8] versus 11.3% [95% confidence interval 5.9 to 17.4]).

CONCLUSIONS

Patients diagnosed by annual prostate cancer screening appeared more likely to experience an indolent PSA recurrence and less likely to die of prostate cancer after PSA recurrence compared with patients referred from the community.

The role of fluorodeoxyglucose, 18F-dihydroxyphenylalanine, 18F-choline, and 18F-fluoride in bone imaging with emphasis on prostate and breast

Diagnostic imaging has played a major role in the evaluation of patients with bone metastases. The imaging modalities have included bone scintigraphy, computed tomography, magnetic resonance imaging, and most recently PET/CT, which can be performed with different tracers, including fluorodeoxyglucose (FDG), 18F-fluoride, 18F-choline (FCH), and 18F-DOPA (dihydroxyphenylalanine). For most tumors the sensitivity of FDG in detecting bone metastases is similar to bone scintigraphy; additionally it can be used to monitor the response to chemotherapy and hormonal therapy. 18F-Fluoride may provide a more sensitive "conventional" bone scan and is superior for FDG nonavid tumors, but, nevertheless, FDG in "early disease" often has clear advantages over 18F-fluoride. Although more data need to be obtained, it appears that FCH is highly efficient in preoperative management regarding N and M staging of prostate cancer once metastatic disease is strongly suspected or documented. For neuroendocrine tumors and in particular in medullary thyroid cancer, DOPA is similar to 18F-fluoride in providing high quality information regarding the skeleton. Nevertheless, prospective studies with large patient groups will be essential to define the exact diagnostic role of FCH and DOPA PET in different clinical settings.

Nuclear Medicine Studies of the Prostate, Testes, and Bladder

During the last decade, there has been a significant advancement in imaging of urologic diseases. Transrectal ultrasound (TRUS), computerized tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) are still experiencing new developments in urology. Despite these many technological advances, the initial diagnostic procedure for a patient with suspected prostate cancer (PC) is multiple site blind prostate biopsies. There is a need for a noninvasive metabolic imaging modality to direct the site of biopsy to decrease the sampling error. MRS seems promising but as it is a costly and more time-consuming test, further studies are needed to evaluate its clinical utility. Currently, PET does not play any role to direct biopsy. Acetate and choline appear to be better tracers than FDG for the detection of a prostate lesion, however, further well-organized studies are needed before any of these agents can be used clinically. Incidental detection of intense focal uptake in the prostate during whole body PET scanning should be evaluated with prostate-specific antigen (PSA) and TRUS-guided biopsy. Although FDG is inferior to other tracers for primary staging, it may be useful in selected patients with suspected high-grade cancer. The role of ProstaScint scan is still controversial for detection of recurrent PC. This study may be helpful for evaluating nodal metastases when PSA is elevated and bone scan is negative. Bone scan remains the study of choice when bone metastases are suspected (PSA>15-20 ng/mL+/-bone pain). Acetate and choline provide better accuracy than FDG in the detection of local soft tissue disease, nodal involvement, and distant metastases. High FDG uptake may be indicative of more aggressive and possibly androgen-independent disease. PET/CT with any of the above PET tracers will most likely be preferred to the PET scan alone due to better localization of a hot lesion in PET/CT. Nuclear medicine studies also have been used to evaluate acute scrotum and testicular neoplasms. Scrotal scintigraphy has lost its popularity to Doppler ultrasound in the evaluation of the acute scrotum. In testicular tumors, FDG-PET appears to be superior to conventional imaging modalities in initial staging, detection of residual/recurrence, and monitoring treatment response. Tumor markers after treatment occasionally are elevated and cannot locate the site of recurrence, FDG-PET can play a very important role in this regard. Nuclear medicine studies also have been used to evaluate diseases of the urinary bladder. Radionuclide cystography is more sensitive and has less than 1/20 the radiation exposure of the conventional contrast enhanced micturating cystourethrogram (MCU). However, the utility of FDG-PET in the evaluation of bladder cancer seems to be limited to the evaluation of distant metastases. 11C-Methionine and choline may be a better option for local and nodal disease due to their negligible excretion in the urine.

PSA outcome following radical prostatectomy for patients with localized prostate cancer stratified by prostatectomy findings and the preoperative PSA level

PURPOSE

Algorithms have been developed to predict time to biochemical failure (BF) following radical prostatectomy (RP) for patients with clinically localized prostate cancer. The purpose of this study was to validate an algorithm based on prostatectomy findings and to evaluate whether the preoperative serum prostate specific antigen (PSA) enhances the predictive ability of the algorithm.

MATERIALS AND METHODS

Between 1988 and 2002, 2417 patients underwent RP for clinically localized prostate cancer at one of 2 large university hospitals. Patients were retrospectively stratified into 4 risk groups based upon prostatectomy grade, stage, and margin status, and were then dichotomized by the preoperative PSA level (cut point 10 ng/mL). Cox regression multivariable analyses were performed to evaluate the ability of the risk group and preoperative PSA level to predict time to BF (PSA more than 0.2 ng/mL) following RP.

RESULTS

The preoperative PSA level (P < 0.0001) and risk group (P < 0.0001) were significant predictors of time to BF following RP. Estimates of the BF rates 7 years following RP were 13%, 30%, 51%, and 72% for groups 1-4, respectively (pairwise P values <or=0.0002). Further stratification within each risk group using the preoperative PSA level with a cut point at 10 ng/mL revealed BF rates of 8% versus 35%, 25% versus 54%, 31% versus 73%, and 63% versus 86% for risk groups 1-4, respectively (all P values <0.0001).

CONCLUSIONS

An algorithm to predict BF based on prostatectomy findings has been validated, and the addition of the preoperative PSA level improved its ability to identify high risk patients who may benefit from entry into adjuvant treatment trials.

Predictors of short postoperative prostate-specific antigen doubling time for patients diagnosed during PSA era

OBJECTIVES

To determine the preoperative and postoperative predictors of a short prostate-specific antigen (PSA) doubling time (PSADT) after radical prostatectomy for patients diagnosed during the PSA era.

METHODS

Between 1989 and 2003, 1785 men underwent radical prostatectomy for 2002 American Joint Committee on Cancer (AJCC) Stage T1c or T2 prostate cancer. Of these men, 205 had documented PSA failure. The PSADT was calculated by assuming first-order kinetics and using a minimum of two detectable postoperative PSA measurements after a previous undetectable level. Multivariable logistic regression analyses were performed to determine the significant preoperative and postoperative predictors of a PSADT of less than 6 months.

RESULTS

Patients with a greater biopsy Gleason score (P = 0.006), greater preoperative risk group (P = 0.002), greater prostatectomy Gleason score (P = 0.0006), greater 2002 AJCC pathologic stage (P = 0.01), or shorter time to postoperative PSA failure (P = 0.04) were more likely to have a shorter PSADT. Using multivariable analysis, high-risk disease (P = 0.0001) was the only preoperative factor that remained an independent significant predictor of a PSADT of less than 6 months. Of the postoperative factors, a prostatectomy Gleason score of 8 to 10 (P = 0.002), 2002 AJCC pathologic Stage T3b (P = 0.03), and time to PSA failure of less than 2 years (P = 0.05) remained significant independent predictors of a PSADT of less than 6 months.

CONCLUSIONS

High-risk disease preoperatively and a prostatectomy Gleason score of 8 to 10, seminal vesicle invasion, or a time to PSA failure of less than 2 years postoperatively were significant independent indicators of developing a postoperative PSADT of less than 6 months. For these men, trials studying systemic therapy in addition to radical prostatectomy are needed.

2-[18F]fluoro-2-deoxyglucose positron emission tomography for the detection of disease in patients with prostate-specific antigen relapse after radical prostatectomy

EXPERIMENTAL DESIGN

Retrospective cohort study in 91 patients with prostate-specific antigen (PSA) relapse following prostatectomy, imaged with 2-[18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) in a tertiary care cancer center between February 1997 and March 2003. Comparison was made with magnetic resonance imaging (n = 64), bone scan (n = 56), and computed tomography (n = 37). The standard of reference included biopsy or clinical and imaging follow-up. We calculated sensitivity and specificity of PET and correlated PET findings with PSA values, other clinical parameters, and conventional imaging, when available.

RESULTS

PET was true positive in 28 of 91 (31%) patients, showing isolated disease in the prostate bed (n = 3) or metastatic disease with (n = 2) or without (n = 23) simultaneous disease in the prostate bed. In detail, PET identified lesions in the prostate bed (n = 5, all true positives), bones (n = 22; 20 true positives, 2 false positives), lymph nodes (n = 7; 6 true positives, 1 likely false positive), and one liver metastasis. Mean PSA was higher in PET-positive than in PET-negative patients (9.5 +/- 2.2 versus 2.1 +/- 3.3 ng/mL). PSA of 2.4 ng/mL and PSA velocity of 1.3 ng/mL/y provided the best tradeoff between sensitivity (80%; 71%) and specificity (73%; 77%) of PET in a receiver operating curve analysis. Combination with other clinical parameters in a multivariate analysis did not improve disease prediction. There were only two patients in whom other imaging studies showed isolated local recurrence or metastatic disease.

CONCLUSIONS

FDG-PET detected local or systemic disease in 31% of patients with PSA relapse referred for this test. There is a link to tumor burden and tumor biology in that the probability for disease detection increased with PSA levels.

Predictors of prostate cancer-specific mortality after radical prostatectomy or radiation therapy

PURPOSE

We evaluated predictors of prostate cancer-specific mortality (PCSM) after prostate-specific antigen (PSA) failure after radical prostatectomy (RP) or radiation therapy (RT).

PATIENTS AND METHODS

A total of 1,159 men with clinically localized prostate cancer treated with RP (n = 498) or RT (n = 661) developed PSA failure, and they formed the study cohort. Competing risk regression analyses were used to evaluate whether previously identified predictors of time to metastasis, including post-treatment PSA doubling time (PSA-DT), Gleason score, and interval to PSA failure, could also predict time to PCSM after PSA failure. The cumulative incidence method was used to estimate PCSM after PSA failure.

RESULTS

A post-RP PSA-DT of less than 3 months (hazard ratio [HR], 54.9; 95% CI, 16.7 to 180), a post-RT PSA-DT of less than 3 months (HR, 12.8; 95% CI, 7.0 to 23.1), and a biopsy Gleason score of 8 to 10 (HR, 6.1; 95% CI, 3.4 to 10.7) for patients treated with RT were significantly associated with PCSM. Post-RP estimated rates of PCSM 5 years after PSA failure were 31% (95% CI, 17% to 45%) v 1% (95% CI, 0% to 2%) for patients with PSA-DT of less than 3 months v > or = 3 months. Post-RT estimated rates of PCSM 5 years after PSA failure were 75% (95% CI, 59% to 92%) v 35% (95% CI, 24% to 47%) for patients with a biopsy Gleason score of > or = 8 v < or = 7, respectively, and PSA-DT of less than 3 months; these rates were 15% (95% CI, 0.8% to 28%) v 4% (95% CI, 1% to 6%), respectively, for patients with a PSA-DT > or = 3 months.

CONCLUSION

Patients at high risk for PCSM after PSA failure can be identified based on post-RP PSA-DT or post-RT PSA-DT and biopsy Gleason score. These parameters may be useful in identifying patients for a randomized trial evaluating hormonal therapy with or without docetaxel.

Cintilografia óssea no câncer de próstata

Este estudo propõe-se a revisar os aspectos de indicação da cintilografia óssea no estadiamento e acompanhamento dos pacientes com câncer de próstata. Os autores fazem um levantamento da literatura e analisam os critérios de indicação do exame, comparando-o com outras modalidades propedêuticas na avaliação desses pacientes. As aplicações da cintilografia óssea no câncer de próstata são estabelecidas segundo os novos parâmetros descritos na literatura, levando em conta, ainda, a relação custo/benefício.

Pattern of prostate-specific antigen (PSA) failure dictates the probability of a positive bone scan in patients with an increasing PSA after radical prostatectomy

PURPOSE

Physicians often order periodic bone scans (BS) to check for metastases in patients with an increasing prostate-specific antigen (PSA; biochemical recurrence [BCR]) after radical prostatectomy (RP), but most scans are negative. We studied patient characteristics to build a predictive model for a positive scan.

PATIENTS AND METHODS

From our prostate cancer database we identified all patients with detectable PSA after RP. We analyzed the following features at the time of each bone scan for association with a positive BS: preoperative PSA, time to BCR, pathologic findings of the RP, PSA before the BS (trigger PSA), PSA kinetics (PSA doubling time, PSA slope, and PSA velocity), and time from BCR to BS. The results were incorporated into a predictive model.

RESULTS

There were 414 BS performed in 239 patients with BCR and no history of androgen deprivation therapy. Only 60 (14.5%) were positive for metastases. In univariate analysis, preoperative PSA (P = .04), seminal vesicle invasion (P = .02), PSA velocity (P < .001), and trigger PSA (P < .001) predicted a positive BS. In multivariate analysis, only PSA slope (odds ratio [OR], 2.71; P = .03), PSA velocity (OR, 0.93; P = .003), and trigger PSA (OR, 1.022; P < .001) predicted a positive BS. A nomogram for predicting the bone scan result was constructed with an overfit-corrected concordance index of 0.93.

CONCLUSION

Trigger PSA, PSA velocity, and slope were associated with a positive BS. A highly discriminating nomogram can be used to select patients according to their risk for a positive scan. Omitting scans in low-risk patients could reduce substantially the number of scans ordered.

Positron emission tomography for prostate, bladder, and renal cancer

Prostate cancer, renal cancer, bladder, and other urothelial malignancies make up the common tumors of the male genitourinary tract. For prostate cancer, common clinical scenarios include managing the patient presenting with 1) low-risk primary cancer; 2) high-risk primary cancer; 3) prostate-specific antigen (PSA) recurrence after apparently successful primary therapy; 4) progressive metastatic disease in the noncastrate state; and 5) progressive metastatic disease in the castrate state. These clinical states dictate the appropriate choice of diagnostic imaging modalities. The role of positron emission tomography (PET) is still evolving but is likely to be most important in determining early spread of disease in patients with aggressive tumors and for monitoring response to therapy in more advanced patients. Available PET tracers for assessment of prostate cancer include FDG, 11C or 18F choline and acetate, 11C methionine, 18F fluoride, and fluorodihydrotestosterone. Proper staging of prostate cancer is particularly important in high-risk primary disease before embarking on radical prostatectomy or radiation therapy. PET with 11C choline or acetate, but not with FDG, appears promising for the assessment of nodal metastases. PSA relapse frequently is the first sign of recurrent or metastatic disease after radical prostatectomy or radiation therapy. PET with FDG can identify local recurrence and distant metastases, and the probability for a positive test increases with PSA. However, essentially all studies have shown that the sensitivity for recurrent disease detection is higher with either acetate or choline as compared with FDG. Although more data need to be gathered, it is likely that these two agents will become the PET tracers of choice for staging prostate cancer once metastatic disease is strongly suspected or documented. 18F fluoride may provide a more sensitive bone scan and will probably be most valuable when PSA is greater than 20 ng/mL in patients with high suspicion or documented osseous metastases. Several studies suggest that FDG uptake in metastatic prostate cancer lesions reflects the biologic activity of the disease. Accordingly, FDG can be used to monitor the response to chemotherapy and hormonal therapy. Androgen receptor imaging agents like fluorodihydrotestosterone are being explored to predict the biology of treatment response for progressive tumor in late stage disease in castrated patients. The assessment of renal masses and primary staging of renal cell carcinoma are the domain of helical CT. PET with FDG may be helpful in the evaluation of "equivocal findings" on conventional studies, including bone scan, and also in the differentiation between recurrence and posttreatment changes. The value of other PET tracers in renal cell carcinoma is under investigation. Few studies have addressed the role of PET in bladder cancer. Because of its renal excretion, FDG is not a useful tracer for the detection of primary bladder tumors. The few studies that investigated its role in the detection of lymph node metastases at the time of primary staging were largely disappointing. Bladder cancer imaging with 11C choline, 11C methionine, or 11C- acetate deserves further study.

Impact of the Percentage of Positive Prostate Cores on Prostate Cancer–Specific Mortality for Patients With Low or Favorable Intermediate-Risk Disease

Purpose

We investigated whether pretreatment factors predicted time to prostate cancer–specific mortality (PCSM) after conventional-dose and conformal radiation therapy (CRT).

Patients and Methods

Between 1988 and 2002, 421 patients with low (prostate-specific antigen [PSA] level ≤ 10 ng/mL and biopsy Gleason score ≤ 6) or favorable intermediate-risk (PSA > 10 to 15 ng/mL or biopsy Gleason score 3 + 4, but not both factors) disease underwent CRT (median dose, 70.4 Gy). Cox regression multivariable analysis was performed to determine whether the PSA level, Gleason score, T category, or the percentage of positive cores (% PC) predicted time to PCSM after CRT. After a median follow-up of 4.5 years, 117 (28%) patients have died.

Results

The % PC was the only significant predictor (Cox P ≤ .03). The relative risk of PCSM after CRT for patients with ≥ 50% as compared with less than 50% PC was 10.4 (95% CI, 1.2 to 87; Cox P = .03), 6.1 (95% CI, 1.3 to 28.6; Cox P = .02), and 12.5 (95% CI, 1.5 to 107; Cox P = .02) in men with a PSA ≤ 10 and Gleason score ≤ 6, PSA ≤ 10 and Gleason score ≤ 7, and PSA ≤ 15 and Gleason score ≤ 6, respectively. By 5 years after CRT, 5% to 9% compared with less than 1% (log-rank P ≤ .01) of these patients experienced PCSM if they had ≥ 50% compared with less than 50% PC, respectively.

Conclusion

CRT dose-escalation techniques, the addition of hormonal therapy, or both should be considered in the management of patients with low or favorable intermediate-risk disease and ≥ 50% PC.

Intermediate End Point for Prostate Cancer-Specific Mortality Following Salvage Hormonal Therapy for Prostate-Specific Antigen Failure

BACKGROUND

Whether the prostate-specific antigen (PSA) response to salvage hormonal therapy can act as an intermediate end point for prostate cancer-specific mortality (PCSM) remains unclear. Therefore, we evaluated whether PSA response, defined as the absolute value of the ratio of the rate of PSA change after salvage hormonal therapy to the rate of PSA change before salvage therapy, is associated with the time to PCSM following salvage hormonal therapy.

METHODS

A single-institution and two pooled multi-institution databases containing baseline, treatment, and follow-up information on men who received salvage hormonal therapy for PSA failure following surgery or radiation therapy from January 1, 1988, to January 1, 2002, formed the study (n = 199) and validation cohorts (n = 1255), respectively. The ability of PSA response and its constituents (i.e., pre-salvage hormonal therapy PSA slope and post-salvage hormonal therapy PSA slope) to predict time to PCSM following salvage hormonal therapy was assessed using Cox regression analysis. For illustrative purposes, PSA response was analyzed as a dichotomous variable with a breakpoint for the ratio of PSA response of 1. All statistical tests were two-sided.

RESULTS

PSA response was statistically significantly associated with time to PCSM following salvage hormonal therapy in both the study (P(Cox) =.0014) and validation (P(Cox)<.001) cohorts; however, its constituents were not (pre-salvage hormonal therapy PSA slope: P(Cox-study) =.97, P(Cox-validation) =.57; post-salvage hormonal therapy PSA slope: P(Cox-study) =.27, P(Cox-validation) =.31). Patients with a PSA response that was less than or equal to 1 had a statistically significantly shorter time to PCSM than patients with a PSA response of greater than 1 in both the study (hazard ratio [HR] = 3.6, 95% confidence interval [CI] = 1.3 to 10.3; P(Cox) =.01) and validation (HR = 12.8, 95% CI = 6.2 to 26.3; P(Cox)<.001) cohorts.

CONCLUSION

The PSA response to salvage hormonal therapy can serve as an intermediate end point for PCSM in patients with a rising PSA level following surgery or radiation therapy.

Broadening the criteria for avoiding staging bone scans in prostate cancer: a retrospective study of patients at the Royal Marsden Hospital

OBJECTIVE

To determine if it is possible to exclude staging bone scans in a greater proportion of patients if more consideration is given to T stage and Gleason score, as recent guidelines from the National Institute of Clinical Excellence state that routine staging bone scans for prostate cancer are unnecessary in patients with a prostate specific antigen level (PSA) of < 10 ng/mL and Gleason scores of < 8.

PATIENTS AND METHODS

We identified a cohort of consecutive patients with untreated prostate cancer who had a staging isotope bone scan between 1 January 1995 and 31 December 2000, who were not on hormone therapy, who had their PSA estimated within 30 days of the scan, and who had histologically confirmed prostate cancer on biopsy reviewed at the Royal Marsden. Data were analysed according to Gleason score, major Gleason grade, clinical T-stage and PSA level.

RESULTS

In all, 420 patients were identified who fulfilled the criteria for inclusion; 67 scans (16%, 95% confidence interval, CI, 13-20%) were positive. Of the 187 scans taken in patients with a PSA level of <or= 20 ng/mL, stage < T4 and Gleason < 8 (with major Gleason grade < 4), two (1%, 0.3-4%) were reported as positive, giving a negative predictive value of 99% (95% CI 98.5-99.5%) for these criteria for avoiding the need for staging bone scans. In 116 patients (28%) with Gleason score 7, of whom 28 (24%) had positive scans, there was a statistically significant association between positive scans and a major Gleason pattern of 4 compared with 3.

CONCLUSIONS

Isotope bone scans are an unnecessary part of staging of prostate cancer if the PSA level is <or= 20 ng/mL, stage < T4 and Gleason score < 8, and should be omitted unless the major Gleason pattern is 4. The present results suggest that by considering the Gleason score and T stage, a larger proportion of patients with prostate cancer than previously thought could avoid a staging bone scan.

MRI of the skeleton in prostate cancer staging

OBJECTIVE

To explore the value of MRI in the detection of bone metastases in newly diagnosed prostate cancer.

MATERIAL AND METHODS

MRI examinations of the axial skeleton in 76 patients with newly diagnosed prostate cancer were reviewed, and the relation of these findings to the serum level of prostate specific antigen (PSA) was examined.

RESULTS

MRI indicated bone metastases in 26/76 patients (34%) in the entire study group, in 4/24 (17%) with serum PSA <20 ng/ml and in 22/52 (42%) with serum PSA >20 ng/ml.

CONCLUSIONS

These results suggest that MRI is a more sensitive indicator of suspected bone metastases than bone scintigraphy in the low range of serum PSA, but less sensitive in the high range. Further studies of MRI and bone scintigraphy in parallel in patients with serum PSA <20 ng/ml are needed to elucidate their relative value in the staging of patients with prostate cancer.

Surrogate end point for prostate cancer-specific mortality after radical prostatectomy or radiation therapy

BACKGROUND

The relationship between prostate-specific antigen (PSA)-defined recurrence and prostate cancer-specific mortality remains unclear. Therefore, we evaluated the hypothesis that a short post-treatment PSA doubling time (PSA-DT) after radiation therapy is a surrogate end point for prostate cancer-specific mortality by analyzing two multi-institutional databases.

METHODS

Baseline, treatment, and follow-up information was compiled on a cohort of 8669 patients with prostate cancer treated with surgery (5918 men) or radiation (2751 men) from January 1, 1988, through January 1, 2002, for localized or locally advanced, non-metastatic prostate cancer. We used a Cox regression analysis to test whether the post-treatment PSA-DT was a prognostic factor that was independent of treatment received. All statistical tests were two-sided.

RESULTS

The post-treatment PSA-DT was statistically significantly associated with time to prostate cancer-specific mortality and with time to all-cause mortality (all P(Cox)<.001). However, the treatment received was not statistically significantly associated with time to prostate cancer-specific mortality after PSA-defined disease recurrence for patients with a PSA-DT of less than 3 months (P(Cox) =.90) and for patients with a PSA-DT of 3 months or more (P(Cox) =.28) when controlling for the specific value of the PSA-DT. Furthermore, after a PSA-defined recurrence, a PSA-DT of less than 3 months was statistically significantly associated with time to prostate cancer-specific mortality (median time = 6 years; hazard ratio = 19.6, 95% confidence interval = 12.5 to 30.9).

CONCLUSION

A post-treatment PSA-DT of less than 3 months and the specific value of the post-treatment PSA-DT when it is 3 months or more appear to be surrogate end points for prostate cancer-specific mortality after surgery or radiation therapy. We recommend that consideration be given to initiating androgen suppression therapy at the time of a PSA-defined recurrence when the PSA-DT is less than 3 months to delay the imminent onset of metastatic bone disease.

Cancer-specific mortality after surgery or radiation for patients with clinically localized prostate cancer managed during the prostate-specific antigen era

PURPOSE

To determine whether pretreatment risk groups shown to predict time to prostate cancer-specific mortality (PCSM) after treatment at a single institution retained that ability in a multi-institutional setting.

PATIENTS AND METHODS

From 1988 to 2002, 7,316 patients treated in the United States at 44 institutions with either surgery (n = 4,946) or radiation (n = 2,370) for clinical stage T1c-2, N0 or NX, M0 prostate cancer made up the study cohort. A Cox regression analysis was performed to determine the ability of pretreatment risk groups to predict time to PCSM after treatment. The relative risk (RR) of PCSM and 95% confidence intervals (CIs) were calculated for the intermediate- and high-risk groups relative to the low-risk group.

RESULTS

Estimates of non-PCSM 8 years after prostate-specific antigen (PSA) failure were 4% v 15% (surgery versus radiation; Plog rank =.002) compared with 13% v 18% (surgery versus radiation; Plog rank =.35) for patients whose age at the time of PSA failure was less than 70 as compared with >or= 70 years, respectively. The RR of PCSM after treatment for surgery-managed patients with high- or intermediate-risk disease was 14.2 (95% CI, 5.0 to 23.4; PCox <.0001) and 4.9 (95% CI, 1.7 to 8.1; PCox =.0037), respectively. These values were 14.3 (95% CI, 5.2 to 24.0; PCox <.0001) and 5.6 (95% CI, 2.0 to 9.3; PCox =.0012) for radiation-managed patients.

CONCLUSION

This study provided evidence to support the prediction of time to PCSM after surgery or radiation on the basis of pretreatment risk groups for patients with clinically localized prostate cancer managed during the PSA era.

Markers and meaning of primary treatment failure

BCR is the most clinically used endpoint for identification of treatment failure. Approximately 15% to 53% of patients undergoing primary curative therapy will develop BCR. BCR often precedes clinically detectable recurrence by years. It does not necessarily translate directly into PCa morbidity and mortality, nor does it always reflect the desired endpoint. Furthermore, it has not been validated as a surrogate endpoint, in that interventions that have been shown to alter the PSA level have not been shown to also alter survival. The utility of PSA level as a surrogate endpoint is brought into question by the knowledge that the overall survival rate of patients at 10 years is similar in patients with and without BCR, and that in a significant proportion of men, the only evidence of disease during their lifetime will be a detectable PSA level. The likelihood of developing BCR post-therapy can be predicted by using multiple clinical and pathologic variables. With the development of nomograms that incorporate several markers, the accuracy of prediction has improved. Until recently, the natural history of BCR post-RRP has not been well understood. Pound et al showed the heterogenous and prolonged natural history of BCR. In this large series of men with BCR following RRP, only 34% of men developed metastatic disease. The median time from development of BCR to identification of metastases was 8 years, and the median time from the development of metastatic disease to death was just under 5 years. These data highlight the extremely variable and potentially indolent nature of BCR. The risk of metastatic disease following BCR has been relatively well defined and relates to PSADT and time to PSA recurrence. It generally is accepted that a PSADT of less than 6 to 10 months and a time to PSA recurrence of less than 1 to 2 years relates to a higher risk of developing metastatic disease. Local recurrence, however, remains poorly understood with respect to its true incidence, clinical significance, and natural history. The significance of BCR post-RT remains unclear due to the lack of data on its natural history. Attempts have been made to identify patients at high risk for metastatic progression by looking at time to PSA recurrence and PSADT. A PSADT of less than 6 to 12 months and a time to PSA recurrence of less than 12 months reflects a higher risk of developing metastatic disease. Accurate risk stratification by means of an algorithm similar to that produced by Pound et al has not been performed on a large cohort, thus making risk assessment for an individual patient difficult. The major dilemma for clinicians in the management of BCR is the identification of the site of disease recurrence, which ultimately guides therapy decisions. Clinicopathologic features allow for risk stratification for recurrence, and multiple investigations have attempted to localize the site of recurrence. Time to biochemical progression, Gleason score, and PSADT are predictive of the probability and time to development of metastatic disease, and allow for stratification of patients into different risk groups (see Table 2). TRUS, CT, PET, and DRE all have limited utility in the identification of local recurrence. ProstaScint and MRI have demonstrated encouraging initial results: however, they require further investigation. Bone scintigraphy is of little value for the initial investigation of BCR. In patients with a PSA level of less than 10 ng/mL, the risk of having a positive bone scan is less than 1% and, until the PSA level rises above 40 ng/mL, the risk of having a positive bone scan is less than 5%. Therefore, bone scintigraphy should be reserved for patients with a PSA level greater than 10 to 20 ng/mL or patients with a rapidly rising PSA level. Using new MRI sequences, there is some evidence that MRI is better for the detection of bony metastatic disease; however, this technique requires further investigation. BCR causes anxiety for the patient and the treating doctor, because the best way to manage patients with PSA-only progression is unknown. Currently, there are no validated treatment recommendations for the management of BCR. The information in this review provides the framework for assignment of patients into clinical trials based on different risk categories. Patients at high risk for metastatic progression could be identified early and thus entered into appropriate clinical trials for systemic therapies. Similarly, patients with a low risk of progression could be placed into observation protocols, potentially sparing them from exhaustive and inappropriate investigations.

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.

Investigation of the safety and accuracy of intraoperative gamma probe directed biopsy of bone scan detected rib abnormalities in prostatic adenocarcinoma

PURPOSE

We evaluated the technique of intraoperative gamma probe directed rib biopsy in patients with suspected metastatic prostate adenocarcinoma. This technique can be used to identify accurately the rib in question, reliably obtain sufficient tissue for diagnosis, be performed with minimal patient morbidity and potentially alter the course of therapy.

MATERIALS AND METHODS

From 1996 to 2001, 8 patients with biopsy proved adenocarcinoma of the prostate and suspicious rib lesions on radionuclide bone scanning underwent open rib biopsy as part of the evaluation for metastatic disease. Mean prostate specific antigen in the patient population was 17.1 ng/ml (range 6.1 to 36.5) and clinical stage was T1c to T3c. A new technique of intraoperative gamma probe directed biopsy was used to localize and resect the rib in question. At 6 to 12 hours before the operation each patient received an intravenous injection of 28 mCi. (99m)technetium-oxidronate. The hand held, pencil sized gamma probe in a sterile sleeve was used to localize the area of greatest activity in the target bone and 3 cm. of bone were resected.

RESULTS

Of the 8 patients who underwent the procedure 2 had metastatic prostate cancer on final rib pathological findings. Four of the remaining 5 patients had benign rib lesions (an old rib fracture) and 1 had metastatic lung cancer. The hot spot on bone scan was localized with 100% accuracy using our technique and a pathological diagnosis was made in all cases. Mean operative time was 61 minutes and estimated blood loss was less than 20 ml. in all cases. Seven of the 8 patients were discharged home the same day, while 1 required overnight hospitalization. There was 1 intraoperative complication of inadvertent entry into the pleural cavity, resulting in a small pneumothorax, which was treated with small chest catheter drainage and observation.

CONCLUSIONS

Intraoperative gamma probe directed rib biopsy of suspected metastatic lesions in patients with prostate cancer can be safely and accurately performed with minimal patient morbidity. The information obtained using this technique can be used to tailor treatment decisions for this subset of patients with prostate cancer.

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.

Determinants of prostate cancer-specific survival after radiation therapy for patients with clinically localized prostate cancer

PURPOSE

Identifying pretreatment and posttreatment predictors of time to prostate cancer-specific death (PCSD) after external-beam radiation therapy (RT) was the subject of this study.

PATIENTS AND METHODS

A Cox regression analysis was used to evaluate the ability of the pretreatment risk group to predict time to PCSD for 381 patients who underwent RT for clinically localized prostate cancer. Posttreatment factors analyzed for the 94 patients who experienced prostate-specific antigen (PSA) failure included the time to PSA failure, the posttreatment PSA doubling time (DT), and the timing of salvage hormonal therapy.

RESULTS

Despite the median age of 73 years at diagnosis, 45% of patients with high-risk disease were estimated to die from prostate cancer within 10 years after RT compared with 0% (P =.004) and 6% (P =.05) for patients with low- or intermediate-risk disease, respectively. Predictors of time to PCSD after PSA failure included PSA DT (P =.01) and delayed use of hormonal therapy (P <or=.002). Nearly identical estimates of PCSD and all-cause death after PSA failure were noted for patients with a short PSA DT (ie, <or= 12 months).

CONCLUSION

Prostate cancer was a major cause of death during the first decade after RT for patients with clinically localized but high-risk disease, and the cause of death for patients with a short PSA DT after RT was nearly always prostate cancer. These data provide evidence to propose the hypothesis that a short posttreatment PSA DT may serve as a possible surrogate for PCSD. Prospective validation is needed.

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.

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.

Lower prostate specific antigen outcome than expected following radical prostatectomy in patients with high grade prostate and a prostatic specific antigen level of 4 ng/ml. Or less

PURPOSE

We report the estimates of 10-year prostate specific antigen (PSA) outcome following radical prostatectomy in patients with or without grade 4 or 5 disease in the needle biopsy or prostatectomy specimen stratified by the presenting PSA level.

MATERIALS AND METHODS

From 1989 to 2001, 2,254 patients treated with radical prostatectomy for clinically localized prostate cancer comprised the study cohort. PSA outcome was estimated using the actuarial method of Kaplan and Meier, and was stratified by the presenting PSA level and needle biopsy and prostatectomy Gleason score.

RESULTS

The 10-year estimates of PSA outcome declined significantly (p </=0.002) for patients with biopsy or prostatectomy Gleason score 6 or less as the presenting PSA level increased. This trend was observed for biopsy and prostatectomy Gleason score 7 or higher except for the PSA 4 or less group which did significantly worse (46% versus 62%, p = 0.03) compared to the PSA greater than 4 to 10 ng./ml. group. This finding may be explained by a low serum free testosterone level and the presence of a significantly higher proportion of prostatectomy Gleason score 8 to 10 disease (25% versus 16%, p = 0.03) in the PSA 4 or less versus greater than 4 to 10 ng./ml. group.

CONCLUSIONS

Patients with Gleason grade 4 or 5 disease in the radical prostatectomy specimen and a presenting PSA of 4 ng./ml. or less may be androgen deficient and have a significantly lower estimate of 10-year PSA outcome then expected based on the presenting PSA level.

Routine bone scans in patients with prostate cancer related to serum prostate-specific antigen and alkaline phosphatase

OBJECTIVE

To evaluate the need for a bone scan as a routine staging procedure in patients with newly diagnosed prostate cancer in relation to serum prostate-specific antigen (PSA) and alkaline phosphatase (ALP) levels, and thus determine whether a reduction of the use of this staging method is possible in patients with a low probability of osseous metastasis.

PATIENTS AND METHODS

The results of bone scans were related retrospectively to levels of serum PSA and ALP in 363 patients with prostate cancer newly diagnosed between 1989 and 1997.

RESULTS

Of 363 consecutive patients, 111 had a positive bone scan. In 19 of 144 (13%, "missed diagnosis") patients with a PSA level of < 20 ng/mL the bone scan was positive. In 125 patients (49%, "false-positives") with a PSA level of > 20 ng/mL the bone scan was negative. A threshold level of 100 U/L for ALP gave a better balance for the number of "false-positives" and "missed diagnosis". ALP values correlated better with an abnormal bone scan than did PSA levels; ALP levels of > 90 U/L indicated a 60% chance for the presence of bone metastases.

CONCLUSION

Patients with newly diagnosed and untreated prostate cancer should undergo bone scintigraphy if there is bone pain or if ALP levels are > 90 U/L. Recent reports discourage the routine use of a bone scan when the serum PSA level is <20 ng/mL. However, the present series suggests there is a greater chance of a positive bone scan in patients with low PSA levels; these findings need further confirmation.

Association of prostate-specific antigen levels and patterns of benign and malignant uptake detected. on bone scintigraphy in patients with newly diagnosed prostate carcinoma

The bone scan patterns of benign and malignant uptake in 432 patients with newly diagnosed prostate carcinoma were reviewed in relation to prostate-specific antigen (PSA) levels determined within 4 months of scintigraphy. Scan results were categorized in terms of likelihood of metastatic disease and anatomical locations of benign and malignant lesions were tabulated. At least one suspect focus was identified in 138 scans (32%), and metastatic bone disease was present in 38 (9%). Metastatic disease prevalence increased from 1% for PSA <20 ng x ml(-1) to 58% for PSA>100 ng x ml(-1). Among patients with PSA>20 ng x ml(-1) (n = 157), 70 (45%) had at least one bone scan finding of concern for metastases and 35 (22%) proved to have metastatic disease. Almost all scans with metastases had either limited disease (< or = 5 suspicious lesions; n = 16; 42%) or extensive metastases (> 20 abnormalities; n = 19; 50%). The majority of patients with limited skeletal metastases had PSA < 100 ng x ml(-1) (11/16; 69%), while almost all patients with extensive skeletal involvement had PSA >100 ng x ml(-1) (17/19; 89%). Among those with limited metastatic disease, most (13/16; 81%) had at least one lesion in the pelvis or sacrum; the next most common sites were in the thoracic and lumbar spine (six each; 38%). In scans with a low to moderate suspicion for bone metastases, the only anatomical site with a significantly higher prevalence of malignant than benign lesions was the pelvis.

The value of serum prostate specific antigen and other parameters in detecting bone metastases in prostate cancer

The cut-off value of serum prostate-specific antigen (PSA) level in prediction of bone metastases and the correlation of serum PSA with the clinical stage, grade, score and the rate of bone metastases have been investigated in cases of prostate cancer (PCa). The study population consisted of 160 patients with histologically proven PCa between April, 1993 and August, 1996. The negative predictive value and the sensitivity were the highest (94%) in patients with a serum PSA value less than 10 ng/ml. We claim that in patients with PSA values less than 10 ng/ml whole body bone scan is not necessary.

The value of a baseline bone scan in patients with newly diagnosed prostate cancer

PURPOSE

This study evaluated the role of bone scans in managing newly diagnosed, untreated prostate cancer.

METHODS

Two hundred seventy consecutive staging bone scans in patients (mean age, 69 years) with newly diagnosed prostate cancer who had serum prostate-specific antigen (PSA) determinations and biopsies between January 1995 and October 1997 were evaluated retrospectively.

RESULTS

The bone scans were positive for metastatic bone disease in 24 patients and negative in 246. Serum PSA levels, the number of positive biopsy cores, the extent of tumor in the prostate gland, and Gleason scores were all significantly correlated with scintigraphic bone metastases (P < 0.0001 for each). Of the 177 patients with PSA levels less than 10 ng/ml, three had bone metastases. Bone metastases were found in 2 of 34 patients with PSA levels of 10.1 to 20 ng/ml, in 3 of 29 patients with PSA values of 20.1 to 50 ng/ml, and in 16 of 30 patients with PSA levels greater than 50.1 ng/ml. Only one patient had a bone metastasis when the prostate cancer involved fewer than 2 biopsy cores (1 of 135) or when disease was confined to one lobe (1 of 131), but the incidence increased significantly when the malignancy involved three or more biopsy cores (20 of 114) or disease was present in both prostate lobes (20 of 118). Four of 160 patients with Gleason scores less than 6 had bone metastases, whereas 20 of 110 patients with Gleason scores greater than 7 had bone metastases.

CONCLUSIONS

The likelihood of bone metastases is low in patients with newly diagnosed, untreated prostate cancer when the initial PSA level was less than 10 ng/ml, the number of positive biopsy cores was less than 2, tumor was confined to one lobe, or the Gleason score was less than 6. However, none of these criteria can be used to exclude metastatic bone disease. A baseline bone scan is an important staging procedure and should be obtained to provide maximum data for clinical management of the disease.

Predictive value of prostate-specific antigen, tumour stage and tumour grade for the outcome of bone scintigraphy in patients with newly diagnosed prostate cancer

OBJECTIVE

In order to evaluate the negative predictive value of a low prostate-specific antigen (PSA) for a positive bone scan, we performed a retrospective study in a patient material from the Umea region in Northern Sweden. We also evaluated whether different tumour grades could influence this predictive value.

MATERIAL AND METHODS

Four-hundred-and-forty-six patients of newly diagnosed prostate cancer were reviewed. We analysed different levels of PSA, tumour grade, tumour stage and combinations of these parameters for their use in making a positive bone scintigraphy (BS) prediction.

RESULTS

Among 214 patients with PSA <20 ng/ml, 9 showed a positive BS. When tumours of grades 2 and 3 were excluded, the number of positive BS predictions decreased to 6. For 350 of these 446 patients, a classification according to TNM was available; 162 of these 350 had a PSA value <20 ng/ml, and when this group comprised only small and well-differentiated tumours (T1-2, G1), only one of the remaining 81 patients had a positive BS result.

CONCLUSIONS

We conclude that in most patients with small and well-differentiated tumours (T1-2, G1) and PSA <20, BS staging need not be carried out.