Prostate-specific antigen: concepts for staging prostate cancer and monitoring response to therapy

Real-world comparison of Docetaxel versus new hormonal agents in combination with androgen-deprivation therapy in metastatic hormone-sensitive prostate cancer descrying PSA Nadir ≤ 0.05 ng/ml as marker for treatment response

PROPOSE

Using Docetaxel chemotherapy or new hormonal agents (NHT) to intensify upfront systemic therapy resulted in improved survival rates compared to androgen deprivation monotherapy (ADT). Hence, combination therapies have become the new standard of care (SOC) in metastatic hormone-sensitive prostate cancer (mHSPC). However, head-to-head trails comparing different therapies as well as treatment-guiding biomarkers are still lacking. Thus, the aim of the present study was to compare clinical outcomes of Docetaxel versus NHT therapy in the real-world setting as well as to elaborate biomarkers predicting clinical outcome.

METHODS

We retrospectively assessed overall-survival (OS), progression-free survival 1 and 2 (PFS1/2) and time to progression (TTP) in 42 patients treated by either ADT + NHT or ADT + Docetaxel. In addition, we investigated clinical prognostic biomarkers.

RESULTS

Our survival analysis revealed 3-year OS of 89.4% in the NHT group compared to 82.4% in the Docetaxel group. 3-year PFS1 was 59.6% in the NHT group compared to 32.2% in the Docetaxel group and the TTP was 53.8% vs 32.2% (pOS = 0.189; pPFS1 = 0.082; pTTP = 0.055). In addition, castration-resistance occurred more often in the Docetaxel group (78.6% vs 25%, p = 0.004). Interestingly, a PSA-Nadir ≤ 0.05 ng/ml during therapy was associated with increased survival rates (p < 0.001) while PSA levels at primary diagnosis had no influence on therapy outcome. Furthermore, a thyroid-stimulating hormone (TSH) increase during therapy was associated with improved clinical outcome (p = 0.06).

CONCLUSION

We observed a trend towards a higher benefit of NHT as first-line treatment compared to Docetaxel in men with mHSPC. Of note, a PSA-Nadir ≤ 0.05 ng/ml or a TSH-increase during therapy were predictors for therapy response.

Modeling Androgen Deprivation Therapy-Induced Prostate Cancer Dormancy and Its Clinical Implications

Treatment-induced tumor dormancy is a state in cancer progression where residual disease is present but remains asymptomatic. Dormant cancer cells are treatment-resistant and responsible for cancer recurrence and metastasis. Prostate cancer treated with androgen-deprivation therapy (ADT) often enters a dormant state. ADT-induced prostate cancer dormancy remains poorly understood due to the challenge in acquiring clinical dormant prostate cancer cells and the lack of representative models. In this study, we aimed to develop clinically relevant models for studying ADT-induced prostate cancer dormancy. Dormant prostate cancer models were established by castrating mice bearing patient-derived xenografts (PDX) of hormonal naïve or sensitive prostate cancer. Dormancy status and tumor relapse were monitored and evaluated. Paired pre- and postcastration (dormant) PDX tissues were subjected to morphologic and transcriptome profiling analyses. As a result, we established eleven ADT-induced dormant prostate cancer models that closely mimicked the clinical courses of ADT-treated prostate cancer. We identified two ADT-induced dormancy subtypes that differed in morphology, gene expression, and relapse rates. We discovered transcriptomic differences in precastration PDXs that predisposed the dormancy response to ADT. We further developed a dormancy subtype-based, predisposed gene signature that was significantly associated with ADT response in hormonal naïve prostate cancer and clinical outcome in castration-resistant prostate cancer treated with ADT or androgen-receptor pathway inhibitors.

IMPLICATIONS

We have established highly clinically relevant PDXs of ADT-induced dormant prostate cancer and identified two dormancy subtypes, leading to the development of a novel predicative gene signature that allows robust risk stratification of patients with prostate cancer to ADT or androgen-receptor pathway inhibitors.

Performance and Impact of Prostate Specific Membrane Antigen-Based Diagnostics in the Management of Men with Biochemical Recurrence of Prostate Cancer and its Role in Salvage Lymph Node Dissection

Up to 50% of patients initially treated for prostate cancer in a curative intent experience biochemical recurrence, possibly requiring adjuvant treatment. However, salvage treatment decisions, such as lymph node dissection or radiation therapy, are typically based on prostate specific antigen (PSA) recurrence. Importantly, common imaging modalities (e.g., computed tomography [CT], magnetic resonance imaging, and bone scan) are limited and the detection of recurrent disease is particularly challenging if PSA is low. Prostate specific membrane antigen (PSMA) positron-emission tomography/computed tomography (PET/CT) is a novel and promising imaging modality which aims to overcome the incapability of early identification of distant and regional metastases. Within this review, we summarize the current evidence related to PSMA-PET/CT in prostate cancer men diagnosed with biochemical recurrence after local treatment with curative intent. We discuss detection rates of PSMA-PET/CT stratified by PSA-levels and its impact on clinical decision making. Furthermore, we compare different image-fusion techniques such as PSMA-PET vs. F-/C-Choline-PET scans vs. PSMA-single photon emission computed tomography/CT. Finally, we touch upon the contemporary role of radio-guided-PSMA salvage lymphadenectomy.

Diagnosis and Treatment Monitoring of a Patient with Gastrointestinal Stromal Tumor by Next-Generation Sequencing and Droplet Digital Polymerase Chain Reaction Assay of a PDGFRA Mutation in Plasma-Derived Cell-Free Tumor DNA

In patients with a suspected malignancy, standard-of care management currently includes histopathologic examination and analysis of tumor-specific molecular abnormalities. Herein, we present a 77-year-old patient with an abdominal mass suspected to be a gastrointestinal stromal tumor (GIST) but without the possibility to collect a tumor biopsy. Cell-free DNA extracted from a blood sample was analyzed for the presence of mutations in GIST-specific genes using next generation sequencing. Furthermore, liquid biopsies were used to monitor the levels of mutant DNA copies during treatment with a tumor-specific mutation droplet digital PCR assay that correlated with the clinical and radiological response. Blood-based testing is a good alternative for biopsy-based testing. However, it should only be applied when biopsies are not available or possible to obtain because overall, in only 50%-85% of the cell-free plasma samples is the known tumor mutation detected.

CDC6 mRNA Expression Is Associated with the Aggressiveness of Prostate Cancer

BACKGROUND

Cell division cycle 6 (CDC6) is an essential regulator of DNA replication and plays important roles in the activation and maintenance of the checkpoint mechanisms in the cell cycle. CDC6 has been associated with oncogenic activities in human cancers; however, the clinical significance of CDC6 in prostate cancer (PCa) remains unclear. Therefore, we investigated whether the CDC6 mRNA expression level is a diagnostic and prognostic marker in PCa.

METHODS

The study subjects included 121 PCa patients and 66 age-matched benign prostatic hyperplasia (BPH) patients. CDC6 expression was evaluated using real-time polymerase chain reaction and immunohistochemical (IH) staining, and then compared according to the clinicopathological characteristics of PCa.

RESULTS

CDC6 mRNA expression was significantly higher in PCa tissues than in BPH control tissues (P = 0.005). In addition, CDC6 expression was significantly higher in patients with elevated prostate-specific antigen (PSA) levels (> 20 ng/mL), a high Gleason score, and advanced stage than in those with low PSA levels, a low Gleason score, and earlier stage, respectively. Multivariate logistic regression analysis showed that high expression of CDC6 was significantly associated with advanced stage (≥ T3b) (odds ratio [OR], 3.005; confidence interval [CI], 1.212-7.450; P = 0.018) and metastasis (OR, 4.192; CI, 1.079-16.286; P = 0.038). Intense IH staining for CDC6 was significantly associated with a high Gleason score and advanced tumor stage including lymph node metastasis stage (linear-by-linear association, P = 0.044 and P = 0.003, respectively).

CONCLUSION

CDC6 expression is associated with aggressive clinicopathological characteristics in PCa. CDC6 may be a potential diagnostic and prognostic marker in PCa patients.

Preliminary Results of Clinical Evaluation of the Free/Total Prostate-Specific Antigen Ratio in a Multicentric Study

Aims and Background

The free/total (F/T) prostate-specific antigen (PSA) ratio is probably the most promising tool proposed to increase the specificity of PSA in the diagnosis of prostate cancer. The aim of the present study was to evaluate the clinical value of the F/T ratio in 138 patients with benign hyperplasia, 101 with untreated prostate cancer, and 176 apparently healthy men.

Methods

We used a new immunometric assay of free PSA (FPSA-RIACT, CIS Diagnostici, Italy) which has shown good analytical performance; sample handling and storage under routine conditions did not affect the antigen stability.

Results

The diagnostic efficiency of the F/T ratio was significantly better than that of total PSA. In patients with total PSA ranging from 4 to 10 ng/ml, at a specificity level of 95% total PSA showed a sensitivity of 7%, whereas the sensitivity of F/T increased to 70%. Using the F/T ratio as a decision tool in association with total PSA and considering all cases candidate to biopsy (total PSA greater than 3.79 ng/ml corresponding to the 95% level), we demonstrated a 35% reduction of total biopsies that would have been required on the basis of total PSA alone.

Conclusions

The determination of the percentage of F/T serum PSA significantly improves the specificity of the marker, particularly in the 4-10 ng/ml dose range where unnecessary prostate biopsies can be reduced.

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.

Imaging metastatic bone disease from carcinoma of the prostate

Imaging bone metastases from prostate cancer presents several challenges. The lesions are usually sclerotic and appear late on the conventional X-ray. Bone scintigraphy is the mainstay of lesion detection, but is often not suitable for assessment of treatment response, particularly because of a ‘flare’ phenomenon after therapy. Magnetic resonance imaging is increasingly used in assessment, and newer techniques allow quantitation. In addition to ¹⁸F-fluorodeoxyglucose (¹⁸FDG), newer PET isotopes are also showing promise in lesion detection and response assessment. This article reviews the available imaging modalities for evaluating prostatic bony metastases, and links them to the underlying pathological changes within bone lesions.

Why did he die?

The true reason why cancer patients die is not absolutely clear. The decreasing rate of postmortem examinations in this group of patients is discussed. Understanding how cancer cells kill people can elucidate therapeutic approaches that might benefit our patients. Finally, the author pledges to support research to understand the reason why many of our patients die.

Cancer of the prostate

Prostate carcinoma, with about 190,000 new cases occurring each year (15% of all cancers in men), is the most frequent cancer among men in northern and western Europe. Causes of the disease are essentially unknown, although hormonal factors are involved, and diet may exert an indirect influence; some genes, potentially involved in hereditary prostate cancer (HPC) have been identified. A suspect of prostate cancer may derive from elevated serum prostate-specific antigen (PSA) values and/or a suspicious digital rectal examination (DRE) finding. For a definitive diagnosis, however, a positive prostate biopsy is requested. Treatment strategy is defined according to initial PSA stage, and grade of the disease and age and general conditions of the patient. In localized disease, watchful waiting is indicated as primary option in patients with well or moderately differentiated tumours and a life expectancy <10 years, while radical prostatectomy and radiotherapy (with or without hormone-therapy) could be appropriate choices in the remaining cases. Hormone-therapy is the treatment of choice, combined with radiotherapy, for locally advanced or bulky disease and is effective, but not curative, in 80-85% of the cases of advanced disease. Patients who develop a hormone-refractory prostate cancer disease (HRPC) have to be evaluated for chemotherapy because of the recent demonstration of improved overall survival (2-2.5 months) and quality of life with docetaxel in more than 1,600 cases.

Production of monoclonal and polyclonal antibodies against prostate-specific antigen, a prostate cancer serum marker

The aim of this study was to produce monoclonal and polyclonal antibodies against prostate-specific antigen (PSA), a prostate cancer serum marker. Hyperimmune ICR mice produced polyclonal antibodies (PoAbs) after injection with 0.5 mL of pristane, and were injected with NS-1 myeloma cells 2 weeks later. Hyperimmune Balb/c mice were used for the production of monoclonal antibodies (MAbs). Mice were immunized four times and given a final boost, and their spleen cells were collected and fused with NS-1 myeloma cells under the presence of PEG 1500. The fused cells were then selected in the HAT-RPMIX medium. Anti-PSA antibody-secreting hybridoma cell lines with high titer were cloned by enzyme-linked immunosorbent assay (ELISA) and then subcloned by limiting dilution in 15% fetal bovine serum (FBS) HT-RPMIX medium. Twelve murine hybridoma producing anti-PSA MAbs were obtained and designated C3m1G11, B3m1E5, C3m1E8, C3m1C5, C3m2F4, C3m1F8, C3m2B3, C3m2E6, B3m2B11, B3m2F2, C3m2C7, and C3m2D9. Isotypes of these MAbs were identified as IgG2a heavy chain and kappa light chain. Hitrap Protein A column was used for the purification of polyclonal and monoclonal antibodies. The purity analysis of MAb was performed by capillary electrophoresis.

Prostate cancer

It is a paradigm in cancer treatment that early detection and treatment improves survival. However, although screening measures lead to a higher rate of detection, for small bulk localised prostate cancer it remains unclear whether early detection and early treatment will lead to an overall decrease in mortality. The management options include surveillance, radiotherapy, and radical prostatectomy but there is no evidence base to evaluate the benefits of each approach. Advanced prostate cancer is managed by hormonal therapy. There have been major changes in treatment over the last two decades with the use of more humane treatment and developments in both chemotherapy and radiation. In this article we review the natural history and management of prostate cancer.

ELISA for a complexed antigen with a monoclonal antibody blocking reaction with the free antigen-assay-specific for complexed prostate-specific antigen

We have developed an enzyme-linked immunoassay (ELISA) for serum complexed-antigen (prostate-specific antigen; PSA)(c-PSA) with simultaneous blocking of free-antigen (PSA)(f-PSA). The assay utilizes three different monoclonal antibodies (MAbs) recognising three distinct PSA epitopes. The detection limit was established as 0.19 microg/l (n=20, mean of zero standard+2S.D.) and the average recovery of f-PSA was 98-100%. The within-run and between-day coefficients of variation (CV) ranged from 2.1% to 3.2% and 2.8% to 6.3%, respectively. There was a good correlation between serum c-PSA measured by the present ELISA and PSA-alpha(1)-antichymotrypsin complex (PSA-ACT) concentrations (r=0.991). This method should provide a better tool for discriminating between benign and malignant prostatic disease.

Posttraumatic fibro-osseous lesion of rib

Eleven cases are described of an unusual, benign, fibro-osseous lesion of rib previously reported under a variety of designations, including painless fibro-osseous lesion resembling osteoid osteoma, symmetrical fibro-osseous dysplasia, focal Erdheim-Chester disease, and fibro-osseous pseudotumor. All patients were adults, most of whom were asymptomatic, the lesion discovered by bone scans done to rule out metastatic disease. A single rib was involved in eight patients and multiple ribs in three. A roentgenographic abnormality was apparent in only five patients. Histologically, all lesions showed a bland fibrous stroma in which resided an anastomosing network of bone trabeculae, having a zonal pattern of maturation from metaplastic woven to mature lamellar bone, with or without an associated xanthomatous component. Seven patients had a history of previous trauma, three with fractured ribs. Considering the relative infrequency of solitary rib lesions attributable to metastatic disease, it is proposed that in most cases there is no need for a diagnostic rib resection for these incidentally discovered, posttraumatic reparative lesions.

A highly sensitive enzyme-linked immunoassay for serum free prostate specific antigen (f-PSA)

Monoclonal antibodies (MAbs) were generated against human prostate specific antigen (PSA) to allow development of a sensitive free-PSA (f-PSA) assay. Of a total of 211, 12 could detect only f-PSA, the other 199 MAbs binding to both f-PSA and complex-PSA. In the present study, one MAb (no. 5C6) specific for f-PSA and another (no. 79) reacting with both forms were used to develop an enzyme-linked immunoassay (ELISA) for serum f-PSA. The detection limit was established as 0.008 microg/l (n = 20, mean of zero standard + 3 S.D.) and the average recovery of f-PSA was 93-102%. The within-run and between-day coefficient of variation (CV) varied from 5.4-7.4% and 4.8-6.5%, respectively. The cross-reactivity of the assay to PSA-alpha1-antichymotrypsin complex was determined to be < 0.4%.

Stage T1c prostate cancer: defining the appropriate staging evaluation and the role for pelvic lymphadenectomy

A good staging system should be able to accurately reflect the natural history of a malignant disease, to express the extent of the disease at the time of diagnosis, and stratify patients in prognostically distinctive groups. The staging system for prostate cancer, as it is today, fails to fulfill these requirements. Approximately one third of the patients who undergo surgery for complete excision of prostate cancer in fact do not have a localize disease. The incidence of tumor at the inked margin may reach 30% for T1 stage and up to 60% for clinical T2b prostate cancer according to comparison with pathologic examination of resected specimen. Several concepts have been recently proposed as a means of improving the accuracy of the available staging system. In this paper, we review current aspects of clinical and pathological staging of prostate cancer, and the importance of these new concepts on the early stages of prostate cancer.

Comparison of prostate-specific antigen (PSA) measured by four combinations of free PSA and total PSA assays

We compared prostate-specific antigen (PSA) assay systems [i.e., free PSA (f-PSA) and the corresponding total PSA (t-PSA) assay] from four different manufacturers as well as the f-PSA/t-PSA ratios with regard to their ability to discriminate between benign prostate hyperplasia (BPH) and prostate cancer (PCA). ROC analysis showed similar areas under the curves (AUCs) with different assay systems. For the entire patient population the AUCs of the f-PSA/t-PSA ratio were not or slightly increased compared with the sole measurement of t-PSA (t-PSA, 0.792–0.820; f-PSA/t-PSA ratio, 0.685–0.859). In contrast, for only those patients who showed t-PSA concentrations within the diagnostic gray area of 4–25 μg/L t-PSA, the AUCs were greater for the f-PSA/t-PSA ratio than for measurement of t-PSA alone (t-PSA, 0.608–0.647; f-PSA/t-PSA ratio, 0.690–0.806). These results were confirmed by the predictive values of the negative results (NPVs) of the t-PSA assays and the f-PSA/t-PSA ratios (assay thresholds corresponding to a 95% detection limit). Compared with the sole t-PSA measurement there was no mentionable increase in the NPVs due to the f-PSA/t-PSA ratio for the entire patient population, but an increase up to 49% when limited to t-PSA concentrations within 4–25 μg/L. We therefore conclude that the f-PSA/t-PSA ratio may be helpful for differential diagnosis of BPH and PCA within the diagnostic gray area of 4–25 μg/L t-PSA.

Update on the appropriate staging evaluation for newly diagnosed prostate cancer

PURPOSE

Prostate cancer clinical staging methods and decision support tools were reviewed to assess their accuracy to predict pathological staging results and determine what comprises an appropriate clinical staging evaluation.

MATERIALS AND METHODS

The MEDLINE data base was searched and 238 abstracts were obtained. Data were extracted from 142 articles that evaluated the preoperative accuracy of digital rectal examination, prostate specific antigen, prostatic acid phosphatase, systematic biopsy parameters (including Gleason scoring), seminal vesicle biopsy, various imaging studies and pelvic lymphadenectomy versus pathological staging results. The sensitivity, specificity and accuracy rates were calculated and tabulated from the reported data on each method or decision support tools for organ confined, nonorgan confined and lymph node metastatic tumor.

RESULTS

Decision support tools based on logistic regression analysis, which combine several statistically independent staging parameters, had greater accuracy than any single clinical staging method alone. The most accurate decision support tools for clinical staging combined digital rectal examination (T stage), systematic biopsy parameters (including Gleason scoring) and prostate specific antigen.

CONCLUSIONS

The components that comprise the most accurate decision support tools for clinical staging represent an appropriate staging evaluation for the newly diagnosed prostate cancer patient in 1997. Limited use of radiographic imaging and seminal vesicle biopsy may be indicated in select patients to detect bone metastases, and plan pelvic lymphadenectomy and surgical therapy.

Defining the ideal tumor marker for prostate cancer

The ideal tumor marker would function well for detection, screening, staging, prognosis, follow-up, and performance characteristics. Prostate-specific antigen is a remarkably good tool in this respect; however, the translation into improved patient outcomes is still uncertain.

Prostate-specific antigen detection by ultrasensitive assay in samples from women

BACKGROUND

The Prostate Specific Antigen (PSA) has been characterized as a specific prostate marker. Recent studies have indicated the existence of a PSA of nonprostatic origin detected in lactating women and breast tumors.

METHODS

We have evaluated the presence of PSA by an ultrasensitive assay (COBAS CORE) in 252 serum and non serum samples from women.

RESULTS

The results demonstrate the presence of PSA in 100% of the breast secretions, 81% of the breast cysts, 80% of the bronchoalveolar lavage fluids and 71% of the cytosols of breast cancer. Likewise, PSA was detected in 14% of the sera evaluated, although the concentrations were always lower than 0.5 ng/ml.

CONCLUSIONS

We conclude that PSA should not continue being considered as the specific prostate tissue marker although, given that the serum concentrations detected are very low, they do appear to interfere to a minimum extent in the usefulness of PSA as a tumor marker.

Acid phosphatase: defining a role in androgen-independent prostate cancer

OBJECTIVES

In multivariable analysis, post-therapy change in prostate-specific antigen (PSA) was shown to be the most significant factor predictive of survival in patients with androgen-independent prostate cancer. To refine the model, we studied the patterns of change in acid phosphatase, alkaline phosphatase, and lactate dehydrogenase after treatment.

METHODS

One hundred seven patients with androgen-independent prostate cancer treated on seven different protocols in Memorial Sloan-Kettering Cancer Center were evaluated. For tumor-specific (acid phosphatase and PSA) and nontumor-specific (alkaline phosphatase and lactate dehydrogenase) enzymes, a minimum 50% or 80% decrease from baseline documented on three separate occasions a minimum of 6 weeks apart was required to categorize a patient as having a decline.

RESULTS

Nineteen patients (18%) had either a 50% decline in acid phosphatase or PSA, of whom 13 (68%) had a decline of both markers. Six (32%) patients showed discordance between the two parameters. Declines in PSA level typically preceded declines in acid phosphatase levels. The median survival of patients showing declines in both markers exceeded that of patients showing declines in PSA alone by 1 year. Although baseline measurements of alkaline phosphatase or lactate dehydrogenase did add additional prognostic information, post-therapy changes did not.

CONCLUSIONS

Post-therapy declines in PSA and acid phosphatase represent reproducible endpoints for clinical trials in androgen-independent disease. The requirement of a repeated and parallel decline in both markers may improve the results observed by monitoring declines in PSA alone. Monitoring the two parameters may allow the development of models that can be used as surrogate endpoints for response and survival in a disease in which reproducible measurements of response are lacking.

Normal range prostate-specific antigen versus age-specific prostate-specific antigen in screening prostate adenocarcinoma

OBJECTIVES

Prostate-specific antigen (PSA) has become the most useful serum tumor marker in the diagnosis and screening of prostate adenocarcinoma. The currently cited reference range of normal (0 to 4.0 ng/mL monoclonal) lacks both the sensitivity and specificity to be universally accepted as a screening test, and alternatives to serum PSA have been proposed, such as PSA density, PSA velocity, and age-adjusted PSA. Age-adjusted PSA takes into account the facts that as men grow older the prostate enlarges and that screening should have maximum sensitivity in younger men and maximum specificity in older men.

METHODS

A population of 4,710 men with no known history of prostate adenocarcinoma underwent 5,629 examinations by transrectal ultrasound of the prostate (TRUS) from 1987 to 1994. This population consists of Mobile Urology Group, Mobile, Alabama, and Emory University, Atlanta, Georgia, patient databases. We have examined our data to determine the sensitivity, specificity, and positive predictive values for normal range PSA (0 to 4 ng/mL) versus age-specific PSA values.

RESULTS

A total of 2040 patients had an abnormal digital rectal examination (DRE) and 3581 procedures were performed for an elevated PSA and a normal DRE. Biopsies were performed in 2,657 patients with 945 (35.6%) positive for cancer. Criteria for biopsy included elevated PSA (more than 4 mg/mL), PSA density more than 0.15 abnormal DRE, or suspicious TRUS. Patients were grouped according to decade: group 1 (ages 40 to 49 years, n = 183), group 2 (ages 50 to 59 years, n = 1018), group 3 (ages 60 to 69 years, n = 2358), and group 4 (ages 70 to 79 years, n = 1687).

CONCLUSIONS

Use of the age-specific range for PSA increases the sensitivity in younger men more likely to benefit from treatment, and decreases the biopsy rate in older patients who may not be candidates for aggressive treatment. Age-adjusted PSA is the most valuable for patients over the age of 70 years of whom 22% would be spared TRUS with biopsy.

Increase of serum prostatic specific antigen and clinical progression in pN + MO prostate cancer

OBJECTIVE

To analyse the increase of serum prostatic specific antigen (PSA) as a means of early detection of progression in hormonally untreated or androgen-deprived patients with T1-T4, pN+ and MO prostate cancer.

PATIENTS AND METHODS

From 1986 to 1992 40 patients with T1-T4 pN+ MO prostate cancer were either deprived of androgen at diagnosis (Group 1, 19 patients) or had no immediate hormone manipulation (Group 2, 21 patients) and were followed at 3-6-monthly intervals when determinations of PSA and routine clinical/radiological examinations were performed. A significant increase in PSA was defined as a > or = 50% increase of the baseline PSA value which was the either the lowest PSA value within 6 months from the start of androgen deprivation (Group 1) or the initial PSA value (Group 2).

RESULTS

By June 1993 22 of the 40 patients had clinically progressed. In 12 patients the progression was preceded by a significant increase in PSA (Group 1, three of four progressing patients; Group 2, nine of 18 progressing patients). A PSA increase of > or = 50% was observed simultaneously with clinical progression in six patients, whereas clinical progression occurred in four patients with no previous or simultaneous significant increase in PSA. In four of nine hormonally untreated patients > or = 1 year elapsed between antecedent PSA increase and clinical progression.

CONCLUSION

In routine clinical practice PSA does not significantly increase (> or = 50% of baseline value and > 10 micrograms/L) before disease progression in about one third of patients with pN+ MO prostate cancer managed with or with no hormone manipulation. Future studies should be carried out to determine whether a lower rate of increase in PSA during follow-up has any clinical significance.

Utility of SPECT imaging for determination of vertebral metastases in patients with known primary tumors

Determining the etiology of a focal lesion seen on bone scan in patients with primary tumors usually requires the use of other imaging procedures or biopsy. Single positron emission computed tomography (SPECT) with high resolution multidetector systems can localize the specific site of a vertebral lesion and in this way potentially differentiate between benign and metastatic disease. SPECT images of the lower thoracic and lumbar spine were reviewed for lesion location and intensity by two experienced interpreters. Follow-up data were adequate to ascertain the cause of 71 lesions seen on SPECT in 29 patients. Twenty-six of these lesions were not seen on planar images. Of the 71 lesions, 44 were benign and 27 metastatic. Of the 15 lesions where the pedicle was involved, 11 were found to metastatic. There were a total of 14 facet lesions, 9 of which were present in vertebra with no lesions at sites other than the facets. All 9 of these isolated facet lesions turned out to be benign. Lesion intensity did not distinguish benign from malignant disease. We conclude that SPECT imaging is useful in determining the etiology of focal lesions seen on bone scan in patients with a known primary tumor referred for evaluation of metastatic disease.

The clinical usefulness of prostate specific antigen: update 1994

In conclusion, PSA is the first prostate specific serum marker of clinical usefulness in urology. It represents a valuable clinical tool that has improved our ability to detect early prostate cancer and to monitor response to therapy. While large PSA screening studies have demonstrated an appreciable increase in the detection of organ confined, potentially curable prostate cancers, no study to date has yet demonstrated that the increased detection rate will decrease the prostate cancer-specific mortality rate. Yet more importantly, no study to date has demonstrated that early diagnosis using PSA will not decrease the prostate cancer specific mortality rate and until such data exist, PSA should be used to aid in early diagnosis and treatment planning for men with prostate cancer. PSA, when combined with other variables such as Gleason score and clinical stage, improves the prediction of pathological stage for prostate cancer. The introduction of PSA velocity and age specific reference ranges should further enhance the clinical usefulness of PSA. New advances in PSA research hold great promise for further improvements in PSA, and truly make it the most important and useful tumor marker for adenocarcinoma of the prostate.