Predictors of metastatic disease in men with biochemical failure following radical prostatectomy

Role of 11C-choline PET/CT in the re-staging of prostate cancer patients with biochemical relapse and negative results at bone scintigraphy

AIM

to evaluate the utility of (11)C-choline PET/CT in prostate cancer (PC) patients who have demonstrated a biochemical recurrence and a negative bone scintigraphy (BS).

MATERIALS AND METHODS

123 consecutive PC patients (mean age 67.6 years; range 54-83) with a biochemical relapse (mean PSA value 3.3ng/mL; range 0.2-25.5) after radical prostatectomy (RP) were included in our retrospective study. Patients underwent a BS that resulted negative and a (11)C-choline PET/CT within 4 months from BS (range: 1 day to 4 months; mean: 2.5 months). Validation of results was established by: (1) a positive biopsy, (2) a positive subsequent BS, CT or MR and (3) a normalization of (11)C-choline uptake after systemic therapy or a progression of the disease.

RESULTS

(11)C-choline PET/CT was positive in 42/123 patients (34.1%). (11)C-choline PET/CT detected lesions in: bone (10 patients), lymph-nodes (20 patients), bone and lymph nodes (7 patients), bone and lung (1 patient), lymph-nodes and lung (1 patient), local relapse (3 patients). Overall, (11)C-choline PET/CT showed a total of 30 unknown bone lesions in 18/123 (14.6%) patients.

CONCLUSION

(11)C-choline PET/CT showed a better sensitivity than BS in patients with biochemical relapse after RP: (11)C-choline PET/CT detected unknown bone lesions in 18/123 (14.6%) patients.

ACR Appropriateness Criteria® posttreatment follow-up of prostate cancer

Although prostate cancer can be effectively treated, recurrent or residual disease after therapy is not uncommon and is usually detected by a rise in prostate-specific antigen. Patients with biochemical prostate-specific antigen relapse should undergo a prompt search for the presence of local recurrence or distant metastatic disease, each requiring different forms of therapy. Various imaging modalities and image-guided procedures may be used in the evaluation of these patients. Literature on the indications and usefulness of these radiologic studies and procedures in specific clinical settings is reviewed. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Clinical Indications of C-Choline PET/CT in Prostate Cancer Patients with Biochemical Relapse

Several studies investigated the potential role of imaging modalities in prostate cancer patients in case of biochemical recurrence. However, the role of molecular imaging has not been well established yet. Considering the results of the literature and of our own experience, we tried to summarize the potential applications of (11)C-choline PET/CT in prostate cancer patients in case of biochemical relapse for the detection of lymph node and distant recurrence.

Influence of PSA, PSA velocity and PSA doubling time on contrast-enhanced 18F-choline PET/CT detection rate in patients with rising PSA after radical prostatectomy

PURPOSE

To evaluate the accuracy of contrast-enhanced (18)F-choline PET/CT in restaging patients with prostate cancer after radical prostatectomy in relation to PSA, PSA velocity (PSAve) and PSA doubling time (PSAdt).

METHODS

PET/CT was performed in 49 patients (age range 58-87 years) with rising PSA (mean 4.13 ng/ml) who were divided in four groups according to PSA level: ≤1 ng/ml, 1 to ≤2 ng/ml, 2 to ≤4 ng/ml, and >4 ng/ml. PSAve and PSAdt were measured. PET and CT scans were interpreted separately and then together.

RESULTS

PET/CT diagnosed relapse in 33 of the 49 patients (67%). The detection rates were 20%, 55%, 80% and 87% in the PSA groups ≤1, 1 to ≤2, 2 to ≤4 and >4 ng/ml, respectively. PET/CT was positive in 7 of 18 patients (38.9%) with a PSA ≤2 ng/ml, and in 26 of 31 (83.9%) with a PSA >2 ng/ml. PET/CT was positive in 7 of 25 patients (84%) with PSAdt ≤6 months, and in 12 of 24 patients (50%) with PSAdt >6 months, and was positive in 26 of 30 patients (86%) with a PSAve >2 ng/ml per year, and in 7 of 19 patients (36.8%) with PSAve ≤2 ng/ml per year. PET alone was positive in 31 of 49 patients (63.3%), and of these 31 patients, CT was negative in 14 but diagnosed bone lesions in 2 patients in whom PET alone was negative. CT with the administration of intravenous contrast medium did not provide any further information.

CONCLUSION

Detection rate of (18)F-choline imaging is closely related to PSA and PSA kinetics. In particular, (18)F-choline PET/CT is recommended in patients with PSA >2 ng/ml, PSAdt ≤6 months and PSAve >2 ng/ml per year. CT is useful for detecting bone metastases that are not (18)F-choline-avid. The use of intravenous contrast agent seems unnecessary.

The natural history of metastatic progression in men with prostate-specific antigen recurrence after radical prostatectomy: long-term follow-up

OBJECTIVE

To describe metastasis-free survival (MFS) in men with prostate-specific antigen (PSA) recurrence following radical prostatectomy, and to define clinical prognostic factors modifying metastatic risk.

PATIENTS AND METHODS

We conducted a retrospective analysis of 450 men treated with prostatectomy at a tertiary hospital between July 1981 and July 2010 who developed PSA recurrence (≥0.2 ng/mL) and never received adjuvant or salvage therapy before the development of metastatic disease. We estimated MFS using the Kaplan-Meier method, and investigated factors influencing the risk of metastasis using Cox proportional hazards regression.

RESULTS

Median follow-up after prostatectomy was 8.0 years, and after biochemical recurrence was 4.0 years. At last follow-up, 134 of 450 patients (29.8%) had developed metastases, while median MFS was 10.0 years. Using multivariable regressions, two variables emerged as independently predictive of MFS: PSA doubling time (<3.0 vs 3.0-8.9 vs 9.0-14.9 vs ≥15.0 months) and Gleason score (≤6 vs 7 vs 8-10). Using these stratifications of Gleason score and PSA doubling time, tables were constructed to predict median, 5- and 10-year MFS after PSA recurrence. In different patient subsets, median MFS ranged from 1 to 15 years.

CONCLUSIONS

In men undergoing prostatectomy, MFS after PSA recurrence is variable and is most strongly influenced by PSA doubling time and Gleason score. These parameters serve to stratify men into different risk groups with respect to metastatic progression. Our findings may provide the background for appropriate selection of patients, treatments and endpoints for clinical trials.

Androgen deprivation therapy influences the uptake of 11C-choline in patients with recurrent prostate cancer: the preliminary results of a sequential PET/CT study

PURPOSE

The influence of androgen deprivation therapy (ADT) on (11)C-choline uptake in patients with prostate cancer (PC) has not yet been clarified. The aim of our study was to investigate this issue by means of sequential (11)C-choline positron emission tomography (PET)/CT in patients with recurrent PC.

METHODS

We retrospectively studied 14 recurrent PC patients (mean age 67 years, range 55-82) during follow-up after radical prostatectomy (RP) with rising serum prostate-specific antigen (PSA) levels. All patients had undergone at least two consecutive (11)C-choline PET/CT scans: the first (11)C-choline PET/CT before commencing ADT and the second (11)C-choline PET/CT after 6 months of ADT administration.

RESULTS

The mean serum PSA level before ADT was 17.0 ± 44.1 ng/ml. After 6 months of ADT administration the PSA value significantly decreased in comparison to baseline (PSA = 2.4 ± 3.1 ng/ml, p < .025). Moreover, before starting ADT, 13 of 14 patients had positive (11)C-choline PET/CT for metastatic spread, while after 6 months of ADT administration in 9 of 14 patients (11)C-choline PET/CT became negative.

CONCLUSION

These preliminary results suggest that ADT significantly reduces (11)C-choline uptake in androgen-sensitive PC patients.

Detection of recurrent prostate carcinoma with anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid PET/CT and 111In-capromab pendetide SPECT/CT

PURPOSE

To compare the diagnostic performance of the synthetic amino acid analog radiotracer anti-1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid (anti-3-(18)F-FACBC) with that of indium 111 ((111)In)-capromab pendetide in the detection of recurrent prostate carcinoma.

MATERIALS AND METHODS

This prospective study was approved by the institutional review board and complied with HIPAA guidelines. Written informed consent was obtained. Fifty patients (mean age, 68.3 years ± 8.1 [standard deviation]; age range, 50-90 years) were included in the study on the basis of the following criteria: (a) Recurrence of prostate carcinoma was suspected after definitive therapy for localized disease, (b) bone scans were negative, and (c) anti-3-(18)F-FACBC positron emission tomography (PET)/computed tomography (CT) and (111)In-capromab pendetide single photon emission computed tomography (SPECT)/CT were performed within 6 weeks of each other. Studies were evaluated by two experienced interpreters for abnormal uptake suspicious for recurrent disease in the prostate bed and extraprostatic locations. The reference standard was a combination of tissue correlation, imaging, laboratory, and clinical data. Diagnostic performance measures were calculated and tests of the statistical significance of differences determined by using the McNemar χ(2) test as well as approximate tests based on the difference between two proportions.

RESULTS

For disease detection in the prostate bed, anti-3-(18)F-FACBC had a sensitivity of 89% (32 of 36 patients; 95% confidence interval [CI]: 74%, 97%), specificity of 67% (eight of 12 patients; 95% CI: 35%, 90%), and accuracy of 83% (40 of 48 patients; 95% CI: 70%, 93%). (111)In-capromab pendetide had a sensitivity of 69% (25 of 36 patients; 95% CI: 52%, 84%), specificity of 58% (seven of 12 patients; 95% CI: 28%, 85%), and accuracy of 67% (32 of 48 patients; 95% CI: 52%, 80%). In the detection of extraprostatic recurrence, anti-3-(18)F-FACBC had a sensitivity of 100% (10 of 10 patients; 95% CI: 69%, 100%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 100% (17 of 17 patients; 95% CI: 80%, 100%). (111)In-capromab pendetide had a sensitivity of 10% (one of 10 patients; 95% CI: 0%, 45%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 47% (eight of 17 patients; 95% CI: 23%, 72%).

CONCLUSION

anti-3-(18)F-FACBC PET/CT was more sensitive than (111)In-capromab pendetide SPECT/CT in the detection of recurrent prostate carcinoma and is highly accurate in the differentiation of prostatic from extraprostatic disease.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102023/-/DC1.

Treatment of men with rising prostate-specific antigen levels following radical prostatectomy

Approximately one-third of patients who undergo radical prostatectomy for prostate cancer will develop a detectable prostate-specific antigen (PSA) level within 10 years. Biochemical recurrence of disease is defined as a rising PSA level in the absence of clinical or radiographic evidence of disease. Management of PSA recurrence is controversial, as prostate cancer may take an indolent course, or it may aggressively develop into metastatic disease. The only potentially curative treatment for biochemical failure after prostatectomy is salvage radiotherapy. Noncurative treatment options include hormone therapy or clinical trials of a novel systemic agent. This article will address management options for a rising PSA level after prostatectomy, as well as ongoing studies exploring molecular biomarkers as prognostic tumor markers and potential targets for prostate cancer therapy.

Increases in quantitative D-dimer levels correlate with progressive disease better than circulating tumor cell counts in patients with refractory prostate cancer

Changes in quantitative D-dimer levels, circulating tumor cell (CTC) counts, and prostate-specific antigen (PSA) levels were measured in 28 patients with refractory castration-resistant prostate cancer to assess their concordance during the course of therapy and their relationship with risk of progressive disease. A significant correlation was identified between changes in PSA and both CTC counts and D-dimer levels (r = 0.67 and 0.58, respectively; P < .001). In addition, there was a significant correlation between changes in CTC count and D-dimer level (r = 0.62; P < .001). A significantly stronger concordance between these biomarkers was noted for increasing values (sensitivity, 72%-77.8%) compared with decreasing values (specificity, 43.8%-71.4%). Notably, increases in PSA and D-dimer levels, not CTC counts, were associated with increased risks for progressive disease (P < .024). Increases in quantitative D-dimer levels correlate with progressive disease better than CTC counts in patients with refractory prostate cancer.

Long-term overall survival and metastasis-free survival for men with prostate-specific antigen-recurrent prostate cancer after prostatectomy: analysis of the Center for Prostate Disease Research National Database

OBJECTIVE

• To describe metastasis-free survival (MFS) and overall survival (OS) among men with prostate-specific antigen (PSA)-recurrent prostate cancer after radical prostatectomy who did not receive additional therapy until metastasis, using a multicentre database capturing a wide ethnic mix.

PATIENTS AND METHODS

• A retrospective analysis of the Center for Prostate Disease Research National Database (comprised of five US military hospitals and one civilian centre) was performed for patients with PSA relapse (≥ 0.2 ng/mL) after radical prostatectomy who had no additional therapy until the time of radiographic metastatic disease. • We investigated factors influencing metastasis and all-cause mortality using univariate and multivariate Cox regression analysis.

RESULTS

• There were a total of 346 men who underwent radical prostatectomy between May 1983 and November 2008 and fulfilled the entry criteria. All patients had information on survival and 190 men had information on metastasis. Among patients with survival data (n= 346), 10-year OS was 79% after a median follow-up of 8.6 years from biochemical recurrence. • Among men with metastasis data (n= 190), 10-year MFS was 46% after a median follow-up of 7.5 years. • In Cox regressions, four clinical factors (Gleason score, pathological stage, time to PSA relapse and PSA doubling time), as well as age, were predictive of OS and/or MFS in univariate analysis, although only PSA doubling time (≥ 9 vs 3-8.9 vs <3 months) remained independently predictive of these outcomes in multivariate analysis (P < 0.001).

CONCLUSIONS

• This multicentre multi-ethnic dataset shows that OS and MFS can be extensive for men with PSA-recurrent prostate cancer, even in the absence of further therapy before metastasis. • This unique patient cohort, the second largest of its type after the Johns Hopkins cohort, confirms that PSA doubling time is the strongest determinant of OS and MFS in men with PSA-recurrent disease. • Longer follow-up and more events will be required to determine whether other variables may also contribute to these outcomes.

Screening, risk assessment, and the approach to therapy in patients with prostate cancer

The major challenge in prostate cancer is to identify patients at higher risk of death and to distinguish them from those more likely to die from other causes. Stratification of patients into risk groups can be used to guide management decisions at each disease stage. This review discusses the measures, tools, and nomograms available for risk assessment in prostate cancer. For patients with localized hormone-sensitive disease, the choice is between active surveillance and radical treatment, with focal therapy an emerging option. Current guidelines recommend treatment of patients with a life expectancy ≥10 years, although active surveillance is being used with increasing frequency for low-risk patients, even with a long life expectancy. A number of risk stratification methods have been devised to assess the risk of biochemical recurrence (BCR) after treatment, with prostate-specific antigen (PSA) level, Gleason score, clinical stage, and tumor mass/volume all shown to be predictive of BCR. Among men with BCR after treatment, PSA doubling time (PSADT) was the best predictor of further progression. Although studies in patients with castration-resistant prostate cancer have shown that PSA level and PSADT are associated with a risk of developing metastatic disease, there is currently no clear surrogate for disease progression or overall survival for this patient group and no standard second- or third-line therapy after progression on first-line chemotherapy. The use of newly developed risk-stratification models and markers of disease progression should assist in the earlier identification of disease progression, allowing the optimal treatment of such patients.

Measurements of cancer extent in a conservatively treated prostate cancer biopsy cohort

The optimal method for measuring cancer extent in prostate biopsy specimens is unknown. Seven hundred forty-four patients diagnosed between 1990 and 1996 with prostate cancer and managed conservatively were identified. The clinical end point was death from prostate cancer. The extent of cancer was measured in terms of number of cancer cores (NCC), percentage of cores with cancer (PCC), total length of cancer (LCC) and percentage length of cancer in the cores (PLC). These were correlated with prostate cancer mortality, in univariate and multivariate analysis including Gleason score and prostate-specific antigen (PSA). All extent of cancer variables were significant predictors of prostate cancer death on univariate analysis: NCC, hazard ration (HR) = 1.15, 95% confidence interval (CI) = 1.04-1.28, P = 0.011; PPC, HR = 1.01, 95% CI = 1.01-1.02, P < 0.0001; LCC, HR = 1.02, 95% CI = 1.01-1.03, P = 0.002; PLC, HR = 1.01, 95% CI = 1.01-1.02, P = 0.0001. In multivariate analysis including Gleason score and baseline PSA, PCC and PLC were both independently significant P = 0.004 and P = 0.012, respectively, and added further information to that provided by PSA and Gleason score, whereas NNC and LCC were no longer significant (P = 0.5 and P = 0.3 respectively). In a final model, including both extent of cancer variables, PCC was the stronger, adding more value than PLC (χ² (1df) = 7.8, P = 0.005, χ² (1df) = 0.5, P = 0.48 respectively). Measurements of disease burden in needle biopsy specimens are significant predictors of prostate-cancer-related death. The percentage of positive cores appeared the strongest predictor and was stronger than percentage length of cancer in the cores.

Salvage radiotherapy for patients with PSA relapse following radical prostatectomy: issues and challenges

A progressively rising level of serum prostate specific antigen (PSA) after radical prostatectomy (RP) invariably indicates the recurrence of prostate cancer. The optimal management of patients with post-RP PSA relapse has remained uncertain due to a wide variability in the natural course of post-RP PSA relapse and the inability to separate a recurrent disease confined to the prostate bed from that with occult distant metastasis. Management uncertainty is further compounded by the lack of phase III clinical studies demonstrating which therapeutic approach, if any, would prolong life with no significant morbidity. Radiotherapy has been the main therapeutic modality with a curative potential for patients with post-RP PSA relapse. This review article depicts issues and challenges in the management of patients with post-RP PSA relapse, presents the literature data for the efficacy of salvage radiotherapy, either alone or in combination of androgen ablation therapy, and discusses future directions that can optimize treatment strategies.

[(11)C]choline PET/CT in prostate cancer patients with biochemical recurrence after radical prostatectomy

OBJECTIVE

To evaluate [(11)C]choline positron emission tomography/computed tomography ([(11)C]choline PET/CT) for the detection of a biochemical recurrence of prostate cancer after radical prostatectomy.

METHODS

Retrospective analysis of [(11)C]choline PET/CT performed in 41 consecutive prostate cancer patients with a rising PSA. The mean time to biochemical relapse was 24 months. PSA levels were determined at time of examination, and patients received either a targeted biopsy or surgery. Histopathology reports served as reference for the evaluation of the [(11)C]choline PET/CT findings.

RESULTS

Mean PSA in [(11)C]choline PET/CT positive patients was 3.1 ng/ml (median 2.2 ng/ml, range 0.5-11.6 ng/ml) and 0.86 ng/ml in [(11)C]choline PET/CT negative patients (median 0.83 ng/ml, range 0.41-1.40 ng/ml). Six of 12 patients with PSA < 1.5 ng/ml [(11)C]choline PET/CT revealed a pathological uptake. Histopathology was positive in 6/12 patients in this group. At PSA levels ranging from 1.5 to 2.5 ng/ml all [(11)C]choline PET/CT were positive (n = 16), a positive histology was found in 12/16 patients (75%) and at PSA 2.5-5 ng/ml [(11)C]choline PET/CT was positive in 8/8 patients, confirmed by histology in 7/8 patients. Finally, at PSA higher than 5 ng/ml [(11)C]choline PET/CT identified 5/5 patients positive all confirmed by histology. The sensitivity of [(11)C]choline PET/CT for the detection of recurrence at PSA < 2.5 ng/ml was 89% with a positive predictive value of 72%.

CONCLUSION

[(11)C]choline PET/CT is useful for re-staging of prostate cancer in patients with rising PSA even at levels below 1.5 ng/ml. Our study confirms results from other published studies on [(11)C]choline PET/CT in prostate cancer relapse.

Potential surrogate endpoints for prostate cancer survival: analysis of a phase III randomized trial

BACKGROUND

The identification of surrogate endpoints for prostate cancer-specific survival may shorten the length of clinical trials for prostate cancer. We evaluated distant metastasis and general clinical treatment failure as potential surrogates for prostate cancer-specific survival by use of data from the Radiation Therapy and Oncology Group 92-02 randomized trial.

METHODS

Patients (n = 1554 randomly assigned and 1521 evaluable for this analysis) with locally advanced prostate cancer had been treated with 4 months of neoadjuvant and concurrent androgen deprivation therapy with external beam radiation therapy and then randomly assigned to no additional therapy (control arm) or 24 additional months of androgen deprivation therapy (experimental arm). Data from landmark analyses at 3 and 5 years for general clinical treatment failure (defined as documented local disease progression, regional or distant metastasis, initiation of androgen deprivation therapy, or a prostate-specific antigen level of 25 ng/mL or higher after radiation therapy) and/or distant metastasis were tested as surrogate endpoints for prostate cancer-specific survival at 10 years by use of Prentice's four criteria. All statistical tests were two-sided.

RESULTS

At 3 years, 1364 patients were alive and contributed data for analysis. Both distant metastasis and general clinical treatment failure at 3 years were consistent with all four of Prentice's criteria for being surrogate endpoints for prostate cancer-specific survival at 10 years. At 5 years, 1178 patients were alive and contributed data for analysis. Although prostate cancer-specific survival was not statistically significantly different between treatment arms at 5 years (P = .08), both endpoints were consistent with Prentice's remaining criteria.

CONCLUSIONS

Distant metastasis and general clinical treatment failure at 3 years may be candidate surrogate endpoints for prostate cancer-specific survival at 10 years. These endpoints, however, must be validated in other datasets.

[The natural history of metastatic prostate cancer]

Prostate cancer is a pathology which progress with successive stages directly dependant on hormonosensitivity. When metastasis occur, cell modifications and biologic transformations lead to disease diffusion. PSA is useful to practically follow the evolution of the prostate cancer but it is probably the molecular biology which probably will be necessary to get prognostic and predictive markers of metastasis power. At each step of the metastatic cascade, it is possible to imagine a specific targeted therapy for this disease which is today non curable.

Prostate-specific antigen doubling time is a reliable predictor of imageable metastases in men with biochemical recurrence after radical retropubic prostatectomy

OBJECTIVES

To examine the incidence of imageable metastases at the time of biochemical recurrence after radical prostatectomy and to determine whether prostate-specific antigen doubling time (PSADT) reliably predicts these imageable metastases.

METHODS

Between October 2000 and October 2005, 1112 men underwent open radical retropubic prostatectomy by a single surgeon. All men were advised to undergo bone scintigraphy and an abdominal/pelvic imaging study at the time of biochemical recurrence. We ascertained the sensitivity, specificity, and positive and negative predictive values of a PSADT cut-point of 3 months to predict the presence of imageable metastases.

RESULTS

Seventy-four (6.7%) men developed a biochemical recurrence and imageable metastases were demonstrable in 7 cases. Imageable metastases were identified in 11.3% and 7.5% of men undergoing bone scans and abdominal/pelvic imaging, respectively. Extracapsular extension, and older age positive surgical margins, and PSADT were associated with a significantly greater risk of exhibiting imageable metastases. The sensitivity, specificity, and positive and negative predictive values of a PSADT cut-point of 3 months for predicting imageable metastasis were 100%, 98.0%, 87.5%, and 100%, respectively.

CONCLUSIONS

A relatively small proportion of men at the time of developing biochemical recurrence after radical prostatectomy exhibit imageable metastasis. The 100% sensitivity and negative predictive value of a PSADT cut-point of 3 months strongly suggests that PSADT can be used as an excellent proxy for imageable metastasis. Omitting routine bone scintigraphy and body imaging at the time of biochemical recurrence minimizes the costs, inconvenience, and anxiety associated with these studies.

[PSA and follow-up after treatment of prostate cancer]

A first serum total PSA assay is recommended during the first three months after treatment. When PSA is detectable, PSA assay should be repeated three months later to confirm this elevation and to estimate the PSA doubling time (PSADT). In the absence of residual cancer, PSA becomes undetectable by the first month after total prostatectomy: less than 0.1 ng/ml (or less than 0.07 ng/ml) for the ultrasensitive assay method and less than 0.2 ng/ml for the other methods. In the presence of residual cancer, PSA either does not become undetectable or increases after an initial undetectable period. A consensus has been reached to define recurrence as PSA greater than 0.2 ng/ml confirmed on two successive assays. After external beam radiotherapy, PSA can decrease after a mean interval of one to two years to a value less than 1 ng/ml (predictive of recurrence-free survival). Biochemical recurrence after radiotherapy is defined by an increase of PSA by 2 ng or more above the PSA nadir, whether or not it is associated with endocrine therapy. After endocrine therapy, the PSA nadir is correlated with recurrence-free survival. PSA is decreased for a mean of 18 to 24 months followed by a rise in PSA, corresponding to hormone-independence. The time to recurrence or the time to reach the nadir and the PSA doubling time after local therapy with surgery or radiotherapy have a diagnostic value in terms of the site of recurrence, local or metastatic and a prognostic value for survival and response to complementary radiotherapy or endocrine therapy. A PSADT less than eight to 12 months is correlated with a high risk of metastatic recurrence and 10-year mortality. The histological and biochemical characteristics in favour of local recurrence are Gleason score less or equal to seven (3+4), elevation of PSA after a period greater than 12 months and PSADT greater than 10 months. In other cases, recurrence is predominantly metastatic. The risk of demonstrating metastasis in the case of biochemical recurrence after total prostatectomy and before endocrine therapy depends on the PSA level and the PSADT. No consensus has been reached concerning the indication for complementary investigations by bone scan and abdominopelvic CT in patients with biochemical recurrence after treatment of localized cancer without endocrine therapy. However, when PSADT greater than six months, the risk of metastasis is less than 3% even for PSA greater than 30 ng/ml. When PSADT less than six months and PSA greater than 10 ng/ml, the risk of metastasis is close to 50%.

Current applications for prostate-specific antigen doubling time

OBJECTIVE

To review the current status of prostate-specific antigen doubling time (PSADT) as it pertains to the evolution of prostate cancer (PCa), specifically assessing its role in the following four stages: before diagnosis, prior to definitive treatment, following treatment including salvage therapy after recurrence, and lastly, after onset of androgen-insensitive PCa.

METHODS

We searched PubMed literature for current articles on PSADT using the key words listed for this review and, where possible, selected those with significant levels of evidence that were deemed relevant, seminal, or controversial. We summarized the data regarding PSADT as a marker for diagnosis and disease characterization, as well as a predictor of progression, response to treatment, and mortality.

RESULTS

PSADT may offer an advantage in providing a more dynamic picture of tumor behavior, providing clues regarding the relative aggressiveness of the underlying pathology. Evidence points toward a role for PSADT in the management of PCa, specifically in active surveillance, disease recurrence after treatment, and in androgen-independent PCa. PSADT is an important prognostic factor that may serve as an auxiliary end point for cancer-specific survival; however, optimal cut-off points denoting risk remain debatable.

CONCLUSIONS

PCa management requires risk stratification with a combination of variables, PSADT being one of the most reliable predictors. It is now a parameter included in many predictive nomograms and in treatment guidelines for expectant management and salvage therapy.

[(11)C]choline uptake with PET/CT for the initial diagnosis of prostate cancer: relation to PSA levels, tumour stage and anti-androgenic therapy

PURPOSE

The accuracy of positron emission tomography (PET)/CT with [(11)C]choline for the detection of prostate cancer is not well established. We assessed the dependence of [(11)C]choline maximum standardized uptake values (SUV(max)) in the prostate gland on cell malignancy, prostate-specific antigen (PSA) levels, Gleason score, tumour stage and anti-androgenic hormonal therapy.

METHODS

In this prospective study, PET/CT with [(11)C]choline was performed in 19 prostate cancer patients who subsequently underwent prostatectomy with histologic sextant analysis (group A) and in six prostate cancer patients before and after anti-androgenic hormonal therapy (bicalutamide 150 mg/day; median treatment of 4 months; group B).

RESULTS

In group A, based on a sextant analysis with a [(11)C]choline SUV(max) cutoff of 2.5 (as derived from a receiver-operating characteristic analysis), PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 72, 43, 64, 51 and 60%, respectively. In the patient-by-patient analysis, no significant correlation was detected between SUV(max) and PSA levels, Gleason score or pathological stage. On the contrary, a significant (P < 0.05) negative correlation was detected between SUV(max) and anti-androgenic therapy both in univariate (r (2) = 0.24) and multivariate (r (2) = 0.48) analyses. Prostate [(11)C]choline uptake after bicalutamide therapy significantly (P < 0.05) decreased compared to baseline (6.4 +/- 4.6 and 11.8 +/- 5.3, respectively; group B).

CONCLUSION

PET/CT with [(11)C]choline is not suitable for the initial diagnosis and local staging of prostate cancer. PET/CT with [(11)C]choline could be used to monitor the response to anti-androgenic therapy.

Evaluation of [11C]-choline positron-emission/computed tomography in patients with increasing prostate-specific antigen levels after primary treatment for prostate cancer

OBJECTIVE

To evaluate [(11)C]-choline positron-emission tomography (PET)/computed tomography (CT) for detecting clinical recurrence after primary treatment for prostate cancer.

PATIENTS AND METHODS

In all, 50 patients with prostate cancer who had had initial therapy (radical prostatectomy in 40, external beam radiation in three and interstitial brachytherapy in seven) had PET/CT using [(11)C]-choline in the presence of an increased or increasing prostate-specific antigen (PSA) level. The mean (range) time to biochemical progression was 22 (2-136) months. Current PSA levels were determined in all patients at the time of examination. The results were correlated with the histopathology reports after targeted biopsy or surgery, and with the clinical follow-up.

RESULTS

The mean (median, range) PSA level in patients with positive PET/CT was 3.62 (2.42, 0.5-13.1) ng/mL, and that in patients with a negative scan was 0.90 (0.95, 0.41-1.40) ng/mL. PET/CT was positive in seven of 13 patients with a PSA level of <1.5 ng/mL, and histology was positive in this group in nine. In 17 patients with PSA levels of 1.5-2.5 ng/mL PET/CT was positive in all and the histology was positive in 13; in 11 men with a PSA level of 2.5-5 ng/mL PET/CT was positive in all 11 and the histology was positive in 10; in nine men with PSA levels of >5 ng/mL PET/CT identified all as positive and the histology was positive in eight. The sensitivity at a PSA level of <2.5 ng/mL of PET/CT for detecting recurrence was 91% (95% confidence interval, 71-99%) with a specificity of 50% (16-84)%.

CONCLUSION

[(11)C]-choline PET/CT seems to be useful for re-staging prostate cancer after curative therapy and with increasing PSA levels; this was verified by histological examination. We recommend this method at PSA levels of <2.5 ng/mL.

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).

Prostate specific antigen recurrence after definitive therapy

PURPOSE

We estimate that approximately 70,000 men yearly have prostate specific antigen-only recurrence after failed definitive therapy. The ideal salvage therapy for these men is not clear. Treatment must be individualized based on the patient risk of progression, the likelihood of success and the risks involved with the therapy. However, to do so the risks and benefits of the various options must be known. Therefore, we provide a comprehensive overview of the natural history and treatment options for men with prostate specific antigen-only recurrence.

MATERIALS AND METHODS

A literature review and overview of prostate specific antigen-only recurrence after failed definitive therapy was done.

RESULTS

The natural history after prostate specific antigen-only recurrence is long but variable. Median time from prostate specific antigen-only recurrence after radical prostatectomy to prostate cancer death exceeds 16 years, although some men die within 1 year after PSA recurrence. Rapid prostate specific antigen doubling time is the best prognostic factor for poor outcome. Salvage radiation therapy after radical prostatectomy results in a 45% 4-year prostate specific antigen response rate, although long-term outcomes appear poor. To our knowledge the effect on survival is not known. Salvage radical prostatectomy is rarely performed but in the highly selected patient it may provide some benefit. There are no randomized studies of early vs late hormonal therapy for men with prostate specific antigen-only recurrence. A retrospective study suggested delayed metastasis when therapy was begun early but only in men at high risk. This mirrors other data suggesting that men at high risk may derive significant benefits from early hormonal therapy, whereas men at low risk are unlikely to benefit and may be harmed by hormonal therapy.

CONCLUSIONS

Prostate specific antigen-only recurrence is the most common form of advanced prostate cancer. Optimal salvage treatments and timing of these treatments remain controversial.

Management of asymptomatic rise in prostatic-specific antigen in patients with prostate cancer

Biochemical failure after curative-intent therapies is an increasingly common dilemma confronting patients and physicians. No definition of biochemical failure exists that can be applied to all forms of treatment and that is not to some degree affected by the follow-up interval, pretreatment prognostic factors, or the frequency of prostatic-specific antigen (PSA) testing. Available imaging techniques lack sensitivity in detection of occult micrometastases. Prognostic factors such as tumor characteristics and PSA kinetics should be considered when recommending second-line therapies. For those patients with suspected localized recurrence, second-line treatment with salvage therapies may provide long-term disease control. Hormonal therapy, although most commonly employed for PSA recurrence, is of palliative benefit only. Currently, the most appropriate therapeutic intervention for asymptomatic patients with evidence of biochemical failure remains undefined.

Low nuclear ErbB3 predicts biochemical recurrence in patients with prostate cancer

OBJECTIVE

To further evaluate the association between the cytoplasmic or nuclear localization of ErbB3 with biochemical recurrence (BCR) in patients with prostate cancer and positive surgical margins, as there is a greater risk of BCR for such patients after radical prostatectomy (RP).

PATIENTS AND METHODS

We recently noted that ErbB3, which is normally associated with the plasma membrane, can translocate to the nucleus, an event which appears to be associated with disease progression. We evaluated ErbB3 expression and localization using immunohistochemistry on tissue samples from 55 patients with positive surgical margins after RP; 30 of these 55 (55%) had BCR after 3 years of follow-up. The relationship between ErbB3 nuclear localization and BCR (prostate-specific antigen, PSA, >0.3 ng/mL) after RP was analysed by Kaplan-Meier survival analysis and Cox regression models.

RESULTS

The BCR-free survival probability at 3 years was 0.65 and 0.35 for positive and negative nuclear ErbB3, respectively (Kaplan-Meier, P = 0.029). Patients negative for nuclear ErbB3 had a 2.47-fold increase in BCR frequency in a univariate Cox model (P = 0.008) and it remained an independent prognostic marker when combined with clinical prognostic variables in a multivariate model (P = 0.023).

CONCLUSION

Low nuclear localization of ErbB3 is a predictor of BCR in patients with prostate cancer and positive surgical margins after RP.

[Pathological interpretation of radical prostatectomy]

The examination by the pathologist of the whole prostate gland after radical prostatectomy allows close inspection of the tissue in order to determine the presence or absence of important prognostic pathological parameters, such as the histological grade, extracapsular extension, seminal vesicle invasion, positive surgical margins. Only complete embedding and multiple close steps sectioning of the whole prostate gland allows the more accurate assessment of the margin status. Specimens not sectioned from the whole organ carry the likelihood of missing important adverse pathologic features. The vast majority of departments of pathology in French institutions are used to study radical prostatectomy specimens obtained from the entire prostate gland.

[Pathological stage: pronostic factors in prostate cancer]

Most of prostatic malignancies are adenocarcinomas. Nomograms using pretreatment clinical or pathological features predict the probability of biochemical or clinical relapse after radical prostatectomy. These predictive tools must not be used in decision making for the anticancer treatment. The accurate pathological stage can only be assessed after examination of the radical prostatectomy specimens. Postoperative nomograms can be also used to predict the probability of survival without progression on the basis of pretreatment PSA level, the Gleason score of the biopsy and prostatectomy samples, the histological grading, the presence or absence of positive surgical margins, involvement of seminal vesicles, capsular penetration and lymph-node metastases. Retrospective studies have confirmed that these pathological posttreatment parameters are risk factors for clinical and biochemical progression. These unfavourable parameters, along with the PSA velocity during the year before radical prostatectomy, predict the risk of local relapse and distant dissemination. Scientific consensus exists for prescribing an adjuvant therapy after the initial local treatment for this population of patients with carcinoma of the prostate who are considered at high risk of progression.

Case-Matched comparison of contemporary radiation therapy to surgery in patients with locally advanced prostate cancer

PURPOSE

Few studies critically compare current radiotherapy techniques to surgery for patients with locally advanced prostate cancer, despite an urgent need to determine which approach offers superior cancer control. Our objective was to compare rates of biochemical relapse-free survival (BFS) and surrogates of disease specific survival among men with high risk adenocarcinoma of the prostate as a function of treatment modality.

METHODS AND MATERIALS

Retrospective data from 409 men with prostate-specific antigen (PSA) > or =10 or Gleason 7-10 or Stage > or =T2b cancer treated uniformly at one university between March 1988 and December 2000 were analyzed. Patients had undergone radical prostatectomy (RP), brachytherapy implant alone (BTM), or external beam radiotherapy with brachytherapy boost with short-term neoadjuvant and adjuvant androgen deprivation therapy (BTC). From the total study population a 1:1 matched-cohort analysis (208 patients matched via prostate-specific antigen, Gleason score) comparing RP with BTC was performed as well.

RESULTS

Estimated 4-year BFS rates were superior for patients treated with BTC (BTC 72%, BTM 25%, RP 53%; p < 0.001). Matched analysis of BTC vs. RP confirmed these results (BTC 73%, BTM 55%; p = 0.010). Relative risk (RR) of biochemical relapse for BTM and BTC compared with RP were 2.92 (1.95-4.36) and 0.56 (0.36-0.87), (p < 0.001, p = 0.010). RR for BTC from the matched cohort analysis was 0.44 (0.26-0.74; p = 0.002).

CONCLUSIONS

High-risk prostate cancer patients receiving multimodality radiation therapy (BTC) display apparently superior BFS compared with those receiving surgery (RP) or brachytherapy alone (BTM).

Posttreatment prostatic-specific antigen doubling time as a surrogate endpoint for prostate cancer-specific survival: An analysis of Radiation Therapy Oncology Group Protocol 92–02

PURPOSE

We evaluated whether posttreatment prostatic-specific antigen doubling time (PSADT) was predictive of prostate cancer mortality by testing the Prentice requirements for a surrogate endpoint.

METHODS AND MATERIALS

We analyzed posttreatment PSA measurements in a cohort of 1,514 men with localized prostate cancer (T2c-4 and PSA level <150 ng/mL), treated and monitored prospectively on Radiation Therapy Oncology Group Protocol 92-02. From June 1992 to April 1995, men were randomized to neoadjuvant androgen deprivation and 65-70 Gy of radiation therapy (n = 761), or in combination with 24 months of adjuvant androgen deprivation (n = 753). Using an adjusted Cox proportional hazards model, we tested if PSADT was prognostic and independent of randomized treatment in this cohort. The endpoints were time to PSADT (assuming first-order kinetics for a minimum of 3 rising PSA measurements) and cancer-specific survival (CSS).

RESULTS

After a median follow-up time of 5.9 years, randomized treatment was a significant predictor for CSS (p(Cox) = 0.002), PSADT <6 months (p(Cox) < 0.001), PSADT <9 months (p(Cox) < 0.001), and PSADT <12 months (p(Cox) < 0.001) but not for PSADT <3 (p(Cox) = 0.4). The significant posttreatment PSADTs were also significant predictors of CSS (p(Cox)< 0.001). After adjusting for T stage, Gleason score and PSA, all of Prentice's requirements were not met, indicating that the effect of PSADT on CSS was not independent of the randomized treatment.

CONCLUSIONS

Prostatic specific antigen doubling time is significantly associated with CSS, but did not meet all of Prentice's requirements for a surrogate endpoint of CSS. Thus, the risk of dying of prostate cancer is not fully explained by PSADT.

Time to Prostate Specific Antigen Recurrence After Radical Prostatectomy and Risk of Prostate Cancer Specific Mortality

PURPOSE

In patients treated with radical prostatectomy who have biochemical recurrence we have previously reported that time from surgery to biochemical recurrence and postoperative prostate specific antigen doubling time are significantly related to the risk of prostate cancer death. We performed a more thorough examination of the association of time from surgery to biochemical recurrence and the risk of prostate cancer death.

MATERIALS AND METHODS

We retrospectively studied the records of 379 patients treated with radical prostatectomy between 1982 and 2000 who had had biochemical recurrence. We examined the association of time from surgery to prostate specific antigen recurrence and prostate specific antigen doubling time, and the risk of prostate cancer death using the Spearman correlation and Cox proportional hazards regression, respectively.

RESULTS

Longer time from surgery to prostate specific antigen recurrence was associated with a slower prostate specific antigen doubling time (Spearman r = 0.36, p < 0.001) and a decreased risk of prostate cancer death (RR 0.76, 95% CI 0.66 to 0.88, p < 0.001). The 15-year actuarial prostate cancer specific survival rate after biochemical recurrence in patients with recurrence at 3 years or less was 41% (95% CI 29 to 53) compared to 87% (95% CI 75 to 93) in patients with recurrence more than 3 years after radical prostatectomy. On multivariate analysis a shorter time from surgery to prostate specific antigen recurrence was associated with an increased risk of prostate cancer death (3 or less vs more than 3 years, RR 2.70, 95% CI 1.37 to 5.31, p = 0.004).

CONCLUSIONS

Earlier prostate specific antigen recurrence is associated with an increased risk of prostate cancer death. These data suggest that perhaps time to prostate specific antigen recurrence may be a reasonable intermediate end point in patients treated with radical prostatectomy, although this must be validated in other studies.

Molecular load of pathologically occult metastases in pelvic lymph nodes is an independent prognostic marker of biochemical failure after localized prostate cancer treatment

PURPOSE

Thirty percent of patients treated with curative intent for localized prostate cancer (PC) experience biochemical recurrence (BCR) with rising serum prostate-specific antigen (sPSA), and of these, approximately 50% succumb to progressive disease. More discriminatory staging procedures are needed to identify occult micrometastases that spawn BCR.

PATIENTS AND METHODS

PSA mRNA copies in pathologically normal pelvic lymph nodes (N0-PLN) from 341 localized PC patients were quantified by real-time reverse-transcriptase polymerase chain reaction. Based on comparisons with normal lymph nodes and PLN with metastases and on normalization to 5 x 10(6) glyceraldehyde-3'-phosphate dehydrogenase mRNA copies, normalized PSA copies (PSA-N) and a threshold of PSA-N 100 or more were selected for continuous and categorical multivariate analyses of biochemical failure-free survival (BFFS) compared with established risk factors.

RESULTS

At median follow-up of 4 years, the BFFS of patients with PSA-N 100 or more versus PSA-N less than 100 was 55% and 77% (P = .0002), respectively. The effect was greatest for sPSA greater than 20 ng/mL, 25% versus 60% (P = .014), Gleason score 8 or higher, 21% versus 66% (P = .0002), stage T3c, 18% versus 64% (P = .001), and high-risk group (50% v 72%; P = .05). By continuous analysis PSA-N was an independent prognostic marker for BCR (P = .049) with a hazard ratio of 1.25 (95% CI, 1.001 to 1.57). By categorical analysis, PSA-N 100 or more was an independent variable (P = .021) with a relative risk of 1.98 (95% CI, 1.11 to 3.55) for BCR compared with PSA-N less than 100.

CONCLUSION

PSA-N 100 or more is a new, independent molecular staging criterion for localized PC that identifies high-risk group patients with clinically relevant occult micrometastases in N0-PLN, who may benefit from additional therapy to prevent BCR.

Biochemical Recurrence after Localized Treatment

The quoted incidence of biochemical recurrence (BCR) after localized treatment varies significantly and depends on numerous well-known prognostic factors; however, it likely occurs in at least 30%-40% of patients who receive localized treatment. Because the clinical significance of BCR is often unclear, and depends in many cases on unknown factors, it is difficult to select the best treatment and determine when best to institute that therapy. This review examines some of the issues associated with BCR and attempts to shed some light on this common but controversial clinical scenario. Some treatment strategies discussed in this article include salvage radiotherapy after radical prostatectomy, salvage therapy after radiotherapy, and hormonal therapy.

Positron emission tomography/computed tomography with F-18-fluorocholine for restaging of prostate cancer patients: meaningful at PSA < 5 ng/ml?

According to reports, re-staging of patients suffering from prostate cancer by positron emission tomography (PET) using C-11-choline has failed to produce positive findings at a PSA level of < 5 ng/ml. Hence, the purpose of our study has been to determine whether this is true also for PET/CT using F-18-fluorocholine (FCH PET/CT) or whether it is possible to obtain true positive results by FCH PET/CT even at lower PSA levels.

METHODS

In 34 patients with prostate cancer who had undergone initial therapy (radical prostatectomy n = 31, radiotherapy n = 3), a PET/CT scan was performed using F-18-fluorocholine (FCH) during follow-up in case of demonstrable or rising PSA levels. Current PSA levels were determined in all patients at the time of examination.

RESULTS

Median PSA in FCH positive patients was 6.1 ng/ml (mean PSA 17.1 ng/ml), median PSA in FCH negative patients was 2.3 ng/ml (mean PSA 3.4 ng/ml), respectively (p < 0.05). In eight of 17 examinations (47%) with PSA < 5 ng/ml, at least one FCH-positive focus was detected. So far the findings could be confirmed by correlating imaging methods (CT and/or MR), biopsy/histology and the course of the disease, respectively, in seven of the eight FCH-positive cases with PSA < 5 ng/ml, so that a true positive FCH PET/CT finding was obtained all in all in seven of 17 (41%) examinations with PSA < 5 ng/ml. In four of these seven FCH PET-positive patients with PSA < 5 ng/ml, adjuvant hormonal therapy was administered at the time of the examination or prior to the examination.

CONCLUSION

In re-staging patients with prostate cancer, FCH PET/CT is able to yield true positive findings even at PSA < 5 ng/ml. Therefore, FCH PET/CT should not be restricted to patients with PSA > 5 ng/ml.

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.

Prognostic value of serum markers for prostate cancer

The incidence of prostate cancer has increased dramatically during the last 10-15 years and it is now the commonest cancer in males in developed countries. The increase is mainly caused by the increasing use of opportunistic screening or case-finding based on the use of prostate-specific antigen (PSA) testing in serum. With this approach, prostate cancer is detected 5-10 years before giving rise to symptoms and on average 17 years before causing the death of the patient. While this has led to detection of prostate cancer at a potentially curable stage, it has also led to substantial overdiagnosis, i.e. detection of cancers that would not surface clinically in the absence of screening. A major challenge is thus to identify the cases that need to be treated while avoiding diagnosing patients who will not benefit from being diagnosed and who will only suffer from the stigma of being a cancer patient. It would be useful to have prognostic markers that could predict which patients need to be diagnosed and which do not. Ideally, it should be possible to measure these markers using non-invasive techniques, i.e. by means of serum or urine tests. As it is very useful for both early diagnosis and monitoring of prostate cancer, PSA is considered the most valuable marker available for any tumor. Although the prognostic value of PSA is limited, measurement of the proportion of free PSA has improved the identification of patients with aggressive disease. Furthermore, the rate of increase in serum PSA reflects tumor growth rate and prognosis but, due to substantial physiological variation in serum PSA, reliable estimation of the rate of PSA increase requires follow-up for at least 2 years. Algorithms based on the combined use of free and total PSA and prostate volume in logistic regression and neural networks can improve the diagnostic accuracy for prostate cancer, and assays for minor subfractions of PSA and other new markers may provide additional prognostic information. Markers of neuroendocrine differentiation are useful for the monitoring of androgen-independent disease and various bone markers are useful in patients with metastatic disease.

Prostate cancer relapse after therapy with curative intention: a diagnostic and therapeutic dilemma

Prostate cancer is the most common malignant disease and second in causes of cancer death among men in Western Europe and North America. Despite improved surgical and irradiation techniques tumor relapse after curatively intended therapy is not uncommon. Due to the difficulty in discriminating local and systemic progression, it is often difficult to decide what this means for the patient and what kind of second-line treatment has to be given. Modern imaging techniques (MRI with endorectal coil, Choline-PET-CT, ProstaScint-Scan) are used for diagnosis of prostate cancer relapse. Nevertheless, early detection of local tumor relapse and likewise the detection of disseminated tumor cells often fails. To differentiate between local and systemic progression, prognostic factors of the primary tumor (grading, surgical margins, infiltration of the seminal vesicles, lymph node metastases) and PSA kinetics are used. The time from initial treatment to biochemical relapse and PSA doubling time are of highest prognostic relevance. Local progression allows second-line local treatment with potentially curative results (local irradiation after radical prostatectomy, salvage-surgery / cryotherapy / HIFU after irradiation), while in the case of systemic progress a palliative systemic therapy (hormonal treatment, chemotherapy, bisphosphonates) is indicated. Before deciding on the most appropriate therapy, prognostic factors and the patient's individual situation (co-morbidity, life expectancy, individual wishes) should be taken into account.

Biochemical recurrence after definitive prostate cancer therapy. Part I: Defining and localizing biochemical recurrence of prostate cancer*

PURPOSE OF REVIEW

The introduction of prostate-specific antigen into clinical practice heralded a dramatic shift in the epidemiology of prostate cancer. The diagnosis and treatment of lower stage disease in younger men with fewer competing co-morbidities has resulted in a longer period of post-treatment cancer surveillance and the potential for disease recurrence. Life-long periodic prostate-specific antigen testing for biochemical recurrence is standard of care; however, there is no single definition of biochemical recurrence that reliably predicts clinical recurrence. This review explores the complexities of biochemical recurrence, a thorough understanding of which is crucial to making appropriate treatment decisions after primary treatment. It also evaluates the array of diagnostic tests frequently employed when biochemical recurrence has occurred.

RECENT FINDINGS

There is a disconnection between biochemical recurrence and progression to clinical disease. The definition of biochemical recurrence varies both by the prostate-specific antigen cut-point used and by the primary therapy employed. Furthermore, biochemical recurrence by itself appears not to be as reliable a predictor of eventual clinical recurrence as prostate-specific antigen doubling time. Current imaging modalities are rarely useful in localizing disease when biochemical recurrence is first detected.

SUMMARY

The correct interpretation of biochemical recurrence is crucial to treatment decision-making. New data show that prostate-specific antigen doubling time during prostate-specific antigen recurrence may be a valid surrogate for death from the disease. The potential therefore exists for prostate-specific antigen doubling time to be accepted as a trial endpoint, which might accelerate drug approval by the United States Food and Drug Administration.