PSA doubling time versus PSA velocity to predict high-risk prostate cancer: data from the Baltimore Longitudinal Study of Aging

Modeling strategies to analyse longitudinal biomarker data: An illustration on predicting immunotherapy non-response in non-small cell lung cancer

Serum tumor markers acquired through a blood draw are known to reflect tumor activity. Their non-invasive nature allows for more frequent testing compared to traditional imaging methods used for response evaluations. Our study aims to compare nine prediction methods to accurately, and with a low false positive rate, predict progressive disease despite treatment (i.e. non-response) using longitudinal tumor biomarker data. Bi-weekly measurements of CYFRA, CA-125, CEA, NSE, and SCC were available from a cohort of 412 advanced stage non-small cell lung cancer (NSCLC) patients treated up to two years with immune checkpoint inhibitors. Serum tumor marker measurements from the first six weeks after treatment initiation were used to predict treatment response at 6 months. Nine models with varying complexity were evaluated in this study, showing how longitudinal biomarker data can be used to predict non-response to immunotherapy in NSCLC patients.

68Ga-PSMA11 PET/CT for biochemically recurrent prostate cancer: Influence of dual-time and PMT- vs SiPM-based detectors

•

⁶⁸Ga-PSMA11 PET/CT showed high detection rates for recurrent prostate cancer.

•

Standard and new generation PET/CT performed equally on a per-patient basis.

•

Delayed imaging revealed no additional lesions.

•

SiPM-based PET/CT identified more prostate cancer lesions.

•

PSMA positivity rate increased with higher PSA levels and higher PSA velocity.

Objectives

⁶⁸Ga-PSMA11 PET/CT is excellent for evaluating biochemically recurrent prostate cancer (BCR PC). Here, we compared the positivity rates of dual-time point imaging using a PET/CT scanner (DMI) with silicon photomultiplier (SiPM) detectors and a PET/CT scanner (D690) with photomultiplier tubes (PMT), in patients with BCR PC.

Methods

Fifty-eight patients were prospectively recruited and randomized to receive scans on DMI followed by D690 or vice-versa. Images from DMI were reconstructed using the block sequential regularized expectation maximization (BSREM) algorithm and images from D690 were reconstructed using ordered subset expectation maximization (OSEM), according to the vendor's recommendations. Two readers independently reviewed all images in randomized order, recorded the number and location of lesions, as well as standardized uptake value (SUV) measurements.

Results

Twenty-eight patients (group A) had DMI as first scanner followed by D690, while 30 patients (group B) underwent scans in reversed order. Mean PSA was 30±112.9 (range 0.3–600.66) ng/mL for group A and 41.5 ± 213.2 (range 0.21–1170) ng/mL for group B (P = 0.796). The positivity rate in group A was 78.6% (22/28 patients) vs. 73.3% (22/30 patients) in group B. Although the performance of the two scanners was equivalent on a per-patient basis, DMI identified 5 additional sites of suspected recurrent disease when used as first scanner. The second scan time point did not reveal additional abnormal uptake.

Conclusions

The delayed time point in ⁶⁸Ga-PSMA11 PET/CT did not show a higher positivity rate. SiPM-based PET/CT identified additional lesions. Further studies with larger cohorts are needed to confirm these results.

Precision Medicine Approach in Prostate Cancer

Prostate cancer is the most prevalent type of cancer and the second cause of death in men worldwide. Various diagnostic and treatment procedures are available for this type of malignancy, but High-grade or locally advanced prostate cancers showed the potential to develop to lethal phase that can be causing dead. Therefore, new approaches are needed to prolong patients' survival and to improve their quality of life. Precision medicine is a novel emerging field that plays an essential role in identifying new sub-classifications of diseases and in providing guidance in treatment that is based on individual multi-omics data. Multi-omics approaches include the use of genomics, transcriptomics, proteomics, metabolomics, epigenomics and phenomics data to unravel the complexity of a disease-associated biological network, to predict prognostic biomarkers, and to identify new targeted drugs for individual cancer patients. We review the impact of multi-omics data in the framework of systems biology in the era of precision medicine, emphasising the combination of molecular imaging modalities with highthroughput techniques and the new treatments that target metabolic pathways involved in prostate cancer.

Prostate-specific antigen patterns in US and European populations: comparison of six diverse cohorts

OBJECTIVE

To determine whether there are differences in prostate-specific antigen (PSA) levels at diagnosis or changes in PSA levels between US and European populations of men with and without prostate cancer (PCa).

SUBJECTS AND METHODS

We analysed repeated measures of PSA from six clinically and geographically diverse cohorts of men: two cohorts with PSA-detected PCa, two cohorts with clinically detected PCa and two cohorts without PCa. Using multilevel models, average PSA at diagnosis and PSA change over time were compared among study populations.

RESULTS

The annual percentage PSA change of 4-5% was similar between men without cancer and men with PSA-detected cancer. PSA at diagnosis was 1.7 ng/mL lower in a US cohort of men with PSA-detected PCa (95% confidence interval 1.3-2.0 ng/mL), compared with a UK cohort of men with PSA-detected PCa, but there was no evidence of a different rate of PSA change between these populations.

CONCLUSION

We found that PSA changes over time are similar in UK and US men diagnosed through PSA testing and even in men without PCa. Further development of PSA models to monitor men on active surveillance should be undertaken in order to take advantage of these similarities. We found no evidence that guidelines for using PSA to monitor men cannot be passed between US and European studies.

Evaluating serum insulin-like growth factor 1 and insulin-like growth factor binding protein 3 as markers in prostate cancer diagnosis

BACKGROUND

Prostate-specific antigen (PSA) lacks specificity and sensitivity in discriminating prostate cancer (PCa) from benign prostatic hyperplasia (BPH) when the total PSA (tPSA) level is between 4 and 10 ng/mL. It remains to be investigated if additional tumor-associated molecules may improve the PCa diagnostic accuracy. The aim of the present study was to investigate whether serum levels of insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3) and their combinations with PSA may enhance the diagnosis of PCa.

METHODS

Serum tPSA and free PSA (fPSA) levels were measured using an automated chemiluminescence-based method. IGF1 and IGFBP3 levels were evaluated by radioimmunoassays in a prospectively and consecutively enrolled subset of 149 patients with tPSA ≤10 ng/mL made up of patients with benign prostatic hyperplasia (BPH; n = 113) and PCa (n = 36).

RESULTS

IGF1 and IGFBP3 serum levels did not significantly differ between the PCa and BPH groups. No important correlation was found between the IGF molecules and PSA isoforms in both groups. Statistical analysis of the combination of markers indicated that only the free/total PSA ratio (f/tPSA%) was informative and independent in predicting the presence of PCa, considering that for high values of this percentage (17%) the probability of finding PCa decreased. Receiver operating characteristics areas under the curve (AUC) for IGF1 and IGFBP3 were not informative (AUC ~0.5 in both cases) contrary to the AUC for f/tPSA% (AUC = 0.689, p = 0.0002).

CONCLUSIONS

The present study showed that neither IGF1 and IGFBP3 alone nor in combination with PSA enhance the diagnostic performance of PSA in PCa.

Expectant management for men with early stage prostate cancer

Since the dissemination of prostate-specific antigen screening, most men with prostate cancer are now diagnosed with localized, low-risk prostate cancer that is unlikely to be lethal. Nevertheless, nearly all of these men undergo primary treatment with surgery or radiation, placing them at risk for longstanding side effects, including erectile dysfunction and impaired urinary function. Active surveillance and other observational strategies (ie, expectant management) have produced excellent long-term disease-specific survival and minimal morbidity for men with prostate cancer. Despite this, expectant management remains underused for men with localized prostate cancer. In this review, various approaches to the expectant management of men with prostate cancer are summarized, including watchful waiting and active surveillance strategies. Contemporary cancer-specific and health care quality-of-life outcomes are described for each of these approaches. Finally, contemporary patterns of use, potential disparities in care, and ongoing research and controversies surrounding expectant management of men with localized prostate cancer are discussed.

Development, validation and evaluation of an instrument for active monitoring of men with clinically localised prostate cancer: systematic review, cohort studies and qualitative study

Background

Active surveillance [(AS), sometimes called active monitoring (AM)],is a National Institute for Health and Care Excellence-recommended management option for men with clinically localised prostate cancer (PCa). It aims to target radical treatment only to those who would benefit most. Little consensus exists nationally or internationally about safe and effective protocols for AM/AS or triggers that indicate if or when men should move to radical treatment.

Objective

The aims of this project were to review how prostate-specific antigen (PSA) has been used in AM/AS programmes; to develop and test the validity of a new model for predicting future PSA levels; to develop an instrument, based on PSA, that would be acceptable and effective for men and clinicians to use in clinical practice; and to design a robust study to evaluate the cost-effectiveness of the instrument.

Methods

A systematic review was conducted to investigate how PSA is currently used to monitor men in worldwide AM/AS studies. A model for PSA change with age was developed using Prostate testing for cancer and Treatment (ProtecT) data and validated using data from two PSA-era cohorts and two pre-PSA-era cohorts. The model was used to derive 95% PSA reference ranges (PSARRs) across ages. These reference ranges were used to predict the onset of metastases or death from PCa in one of the pre-PSA-era cohorts. PSARRs were incorporated into an active monitoring system (AMS) and demonstrated to 18 clinicians and 20 men with PCa from four NHS trusts. Qualitative interviews investigated patients’ and clinicians’ views about current AM/AS protocols and the acceptability of the AMS within current practice.

Results

The systematic review found that the most commonly used triggers for clinical review of PCa were PSA doubling time (PSADT) < 3 years or PSA velocity (PSAv) > 1 ng/ml/year. The model for PSA change (developed using ProtecT study data) predicted PSA values in AM/AS cohorts within 2 ng/ml of observed PSA in up to 79% of men. Comparing the three PSA markers, there was no clear optimal approach to alerting men to worsening cancer. The PSARR and PSADT markers improved the modelc-statistic for predicting death from PCa by 0.11 (21%) and 0.13 (25%), respectively, compared with using diagnostic information alone [PSA, age, tumour stage (T-stage)]. Interviews revealed variation in clinical practice regarding eligibility and follow-up protocols. Patients and clinicians perceive current AM/AS practice to be framed by uncertainty, ranging from uncertainty about selection of eligible AM/AS candidates to uncertainty about optimum follow-up protocols and thresholds for clinical review/radical treatment. Patients and clinicians generally responded positively to the AMS. The impact of the AMS on clinicians’ decision-making was limited by a lack of data linking AMS values to long-term outcomes and by current clinical practice, which viewed PSA measures as one of several tools guiding clinical decisions in AM/AS. Patients reported that they would look to clinicians, rather than to a tool, to direct decision-making.

Limitations

The quantitative findings were severely hampered by a lack of clinical outcomes or events (such as metastases). The qualitative findings were limited through reliance on participants’ reports of practices and recollections of events rather than observations of actual interactions.

Conclusions

Patients and clinicians found that the instrument provided additional, potentially helpful, information but were uncertain about the current usefulness of the risk model we developed for routine management. Comparison of the model with other monitoring strategies will require clinical outcomes from ongoing AM/AS studies.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Overexpression of HER-2/neu in patients with prostatic adenocarcinoma

BACKGROUND

Prostatic adenocarcinoma is one of the main causes of cancer death, and its timely diagnosis and preventing its progression dramatically helps improve life indexes. Given the high disease recurrence rate, today, research is more inclined toward exploring causes of recurrence and development, and innovation of modern treatment methods. Several studies have explored over-expression of human epidermal growth factor receptor 2 (HER-2/neu) in prostatic cancer so far, with different results. Thus, it was decided to investigate HER-2/neu overexpression in patients with prostatic adenocarcinoma in Iran.

MATERIALS AND METHODS

A sample size of 40 patients with prostate cancer entered the study, using a cross-sectional, non-randomized sampling method. Parameters studied included patient age at surgery, Gleason score, serum prostatic specific antigen (PSA) before surgery, and positive sample rate after immunohistochemical staining to investigate HER-2/neu overexpression.

RESULTS

In terms of HER-2/neu receptor staining rate, of 40 slides, 16 (40%) scored 0, 13 (32.5%) 1+, 7 (17.5%) 2+, and 4 (10%) 3+. In total 27.5% of slides showed HER-2/neu overexpression. In terms of age, an inverse correlation was found (-0.181), but without significance (p=0.263). In terms of serum PSA, the correlation coefficient was 0.449 (p=0.004). With respect to Gleason score, the coefficient was 0.190 (p=0.240).

CONCLUSIONS

In this study, HER-2/neu overexpression occurred in 27.5% of prostate cancer cases, which is a relatively high figure, compared to similar studies elsewhere. While, we failed to reveal any relationship between HER-2/neu expression status with progression and prognosis of disease, it was demonstrated that the serum PSA level was significantly higher in cases with increased receptor expression.

Management of men with a suspicion of prostate cancer after negative initial prostate biopsy results

INTRODUCTION

For men with elevated prostate-specific antigen (PSA), appropriate management after negative prostate biopsy remains controversial. After determining PSA kinetics, subsequent follow-up was considered.

PATIENTS AND METHODS

A total of 115 cases with negative repeat biopsy were followed by evaluating PSA kinetics and ratio of percent free PSA (F/T) and by performing second repeat biopsy.

RESULTS

Eighteen cancer cases were diagnosed. Shorter PSA doubling times and faster velocities were found in cancer cases compared with cases without cancer. We observed a clear decrease in F/T among cancer cases.

CONCLUSIONS

To avoid unnecessary repeat biopsies, cases with a suspicion of cancer after negative biopsy can be divided into two groups: one that requires additional biopsies and one with an average change in PSA of <1 ng/ml/year and no change in F/T, which is recommended for surveillance as stable disease without biopsy over a specified time period.

Clinical characteristics and prostate-specific antigen kinetics of prostate cancer detected in repeat annual population screening in Japan

OBJECTIVES

To clarify the present status regarding repeat examination in the annual population screening system in Japan, and to analyze the clinical characteristics and prostate-specific antigen kinetics of prostate cancer detected in this setting.

METHODS

We summarized the annual individual data of prostate-specific antigen-based population screening in Kanazawa, Japan, and analyzed the prostate cancer detection rates at first and repeat screening. The clinical characteristics were compared between patients detected at first and repeat screening. The patients were classified according to favorable or unfavorable clinical characteristics of cancer, and prostate-specific antigen kinetics were compared between the two groups.

RESULTS

From 2000 to 2011, 19 620 men participated in this screening program, and a total of 59 019 screenings were carried out. The total annual numbers of examinees increased, and the annual rates of first examinees gradually decreased. The annual detection rates of cancer at total screening decreased in the second year. The annual detection rate at first screening was not different from that in the first year. The rate of patients with favorable cancer features was significantly higher among patients detected at repeat screening than at first screening. The rates of patients with high prostate-specific antigen velocity and low prostate-specific antigen doubling time were significantly higher in unfavorable than favorable cancer patients in repeat screening.

CONCLUSIONS

Repeat population screening could contribute to early detection of prostate cancer, and it seems that prostate-specific antigen kinetics might predict the cancer characteristics in repeat screening.

A longitudinal study of PSA and its influential factors in a cohort of Chinese men with initial PSA levels less than 4 ng ml(-1)

To evaluate the longitudinal change in prostate-specific antigen (PSA) and the influence of initial PSA on the PSA change. We retrospectively analysed health examination data collected at Beijing Hospital from March 2007 to November 2011. Men with an initial PSA levels less than 4 ng ml(-1) and an annual PSA test for 5 years were enrolled into the study. The men were separated into four groups by the initial PSA level (0-0.99, 1-1.99, 2-2.99 and 3-3.99 ng ml(-1)), and the difference in PSA change among the four groups was analysed. A total of 1330 men were enrolled into the study. The mean age, initial PSA and PSA velocity (PSAV) were 58.17 ± 14.63 (range 24-91) years, 1.18 ± 0.79 (range 0-4) ng ml(-1) and 0.04 ± 0.25 (range -1.34-2.02) ng ml(-1) year(-1). Pearson's correlation analysis showed no correlation between initial PSA and PSAV (r=-0.036, P=0.189). The PSAV of the 0-0.99, 1-1.99, 2-2.99 and 3-3.99 ng ml(-1) initial PSA groups was 0.03 ± 0.11, 0.07 ± 0.32, 0.03 ± 0.34 and -0.01 ± 0.43 ng ml(-1) year(-1), respectively (P=0.06). As the initial PSA increased, the percentage of having a PSAV over 0.75 ng ml(-1) year(-1) and a negative PSAV both significantly increased. Males with a baseline PSA of 0-0.99, 1-1.99, 2-2.99 and 3-3.99 ng ml(-1) had a 1.88%, 6.16%, 16.30% and 57.81% chance, respectively, that their PSA would increase above 4.0 ng ml(-1) over the following 4 years (P<0.0001). The PSAV has no correlation with the initial PSA level. However, as the initial PSA increases, the chance that males will have an abnormal PSA or PSAV in the future increases.

Long-term prostate-specific antigen velocity in improved classification of prostate cancer risk and mortality

BACKGROUND

It remains unclear whether adding long-term prostate-specific antigen velocity (PSAV) to baseline PSA values improves classification of prostate cancer (PCa) risk and mortality in the general population.

OBJECTIVE

To determine whether long-term PSAV improves classification of PCa risk and mortality in the general population.

DESIGN, SETTING, AND PARTICIPANTS

We studied 503 men aged 30-80 yr, with and without PCa, who had repeated PSA measurements over 20 yr and up to 28 yr before PCa diagnosis. These were selected from among 7455 men in the Copenhagen City Heart Study, a prospective, general population study with follow-up from 1981 through 2010. Results were subsequently applied to all 1 351 441 men aged 40-80 yr living in Denmark from 1997 through 2006.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

PCa risk and mortality were assessed using Cox regression. Improvement in risk classification was assessed using the net reclassification index (NRI).

RESULTS

Age-adjusted hazard ratios for PCa risk and mortality were 2.7-5.3 and 2.3-3.4, respectively, for long-term PSAV when added to models already including baseline PSA values. For PCa risk and mortality, adding long-term PSAV to models already including baseline PSA values and age yielded continuous NRIs of 98-99% and 56-106%, respectively. Used on a nationwide scale (eg, for men aged 60-64 yr), long-term PSAV >0.35 versus ≤ 0.35 ng/ml per year appropriately reclassified 128 of 10 000 men with PCa and 8095 of 10 000 men with no PCa. Correspondingly, inappropriately reclassified were 49 of 10 000 men with PCa and 1658 of 10 000 men with no PCa.

CONCLUSIONS

Long-term PSAV in addition to baseline PSA value improves classification of PCa risk and mortality. Applying long-term PSAV nationwide, the ratio of appropriately to inappropriately classified men would typically be 5:1.

Prostate-specific antigen velocity versus prostate-specific antigen doubling time for prediction of 11C choline PET/CT in prostate cancer patients with biochemical failure after radical prostatectomy

PURPOSE

We previously showed that prostate-specific antigen (PSA) doubling time (PSADT) is a significant predictor of 11C choline positron emission tomography/computed tomography (PET/CT) findings in prostate cancer (PCa) patients. This study compared PSA velocity (PSAV) and PSADT to predict 11C choline PET/CT findings.

MATERIALS AND METHODS

PSAV and PSADT were retrospectively calculated in 170 PCa patients with biochemical failure after radical prostatectomy, who underwent 11C choline PET/CT for restaging of disease.

RESULTS

Median PSA was 1.25 ng/mL (range: 0.23-48.6 ng/mL), and median PSAV was 0.99 ng/mL/y (range: 0.11-98.9 ng/mL/y). Patients with positive 11C choline PET/CT (n = 75) had significantly (P < 0.05) higher PSAV than patients with negative 11C choline PET/CT (n = 95) (6.93 ± 13.08 vs. 1.23 ± 2.03 ng/mL/y). The percent of patients with positive 11C choline PET/CT was 21% for PSAV <1 ng/mL/y, 56% for PSAV between 1 and 2 ng/mL/y, and 76% for PSAV >2 ng/mL/y. The quality of fitting (r2) of PSA values according to the exponential function (PSADT) was significantly (P < 0.05) better than the quality of fitting according to the linear function (PSAV) in the entire sample and in all anatomic regions. At multivariate analysis, trigger PSA, PSADT but not PSAV obtained the statistical significance (P < 0.05).

CONCLUSIONS

PSAV can be used to stratify the risk of positive 11C choline PET/CT in PCa patients with biochemical failure. Patients with PSAV >1 ng/mL/y should be selected to increase the positive detection rate of 11C choline PET/CT. The greater statistical power of PSADT compared with PSAV could be related to the better capability of fitting time-dependent changes in PSA values, thereby better reflecting the natural growth of recurrent PCa.

Differentiation of lethal and non lethal prostate cancer: PSA and PSA isoforms and kinetics

Prostate-specific antigen (PSA) testing for the early diagnosis of prostate cancer has led to a decrease in cancer mortality. However, the high prevalence of low-grade prostate cancer and its long natural history, competing causes of death in older men and treatment patterns of prostate cancer, have led to dramatic overtreatment of the disease. Improved markers of prostate cancer lethality are needed to reduce the overtreatment of prostate cancer that leads to a reduced quality of life without extending life for a high proportion of men. The PSA level prior to treatment is routinely used in multivariable models to predict prostate cancer aggressiveness. PSA isoforms and PSA kinetics have been associated with more aggressive phenotypes, but are not routinely employed as part of prediction tools prior to treatment. PSA kinetics is a valuable marker of lethality post treatment and routinely used in determining the need for salvage therapy.

Predictors of repeated PSA testing among black and white men from the Maryland Cancer Survey, 2006

INTRODUCTION

Blacks have the highest incidence of and death from prostate cancer in the United States. Screening with prostate-specific antigen (PSA) may decrease mortality. Repeated testing allows for the calculation of PSA velocity (change of PSA over time), which may be a more clinically useful test for prostate cancer than a single PSA measurement. The objective of this study was to examine whether blacks were as likely as whites to report having had repeated PSA testing.

METHODS

The Maryland Cancer Survey 2006 was a population-based, random-digit-dialed statewide survey on cancer screening and risk behaviors of adults aged 40 years or older. We analyzed self-reported information on repeated PSA testing (2 PSA tests in the preceding 3 years) for 1,721 black and white men. We used logistic regression to estimate the effect of race and age on repeated PSA testing, adjusting for other covariates.

RESULTS

Sixty-five percent of men reported ever having had a PSA test; 41% had repeated PSA testing in the past 3 years. Blacks aged 40 to 49 were more likely to report having repeated PSA testing than whites in this age group (adjusted odds ratio [AOR], 3.3; 95% confidence interval [CI], 1.6-6.5). Blacks aged 60 to 69 were less likely to report repeated PSA testing than whites (AOR, 0.4, 95% CI, 0.2-0.8). No difference was seen by race among men aged 50 to 59 and men aged 70 or older. Repeated PSA testing was associated with living in an urban area and with having higher education, health insurance, a family history of prostate cancer, and having discussed cancer screening with a doctor.

CONCLUSION

Self-reported repeated PSA testing differed by age and race, being higher among blacks aged 40 to 49 and lower among blacks aged 60 to 69, compared with whites in their respective age groups.

A novel repeat biopsy nomogram based on three-dimensional extended biopsy

OBJECTIVES

To develop a nomogram based on a cohort examined with 3-dimensional (3D) protocol for diagnosis of prostate cancer on repeat biopsy.

METHODS

Of 4074 consecutive men undergoing prostate biopsy at our institutions between 2000 and 2009, 775 men with at least 1 previous negative biopsy underwent repeat biopsy with a 3D protocol. Men with previous atypical glands or atypical small acinar proliferation and/or without available prostate-specific antigen (PSA) kinetics information were excluded. The remaining 515 men constituted the study cohort. We developed a logistic regression-based nomogram with 70% of the cohort selected randomly; we validated it with the remaining 30%. Predictive accuracy and performance characteristics were assessed using the area under the receiver operating characteristic curve (AUC) and calibration plots, respectively. The threshold probability was evaluated with decision curve analysis.

RESULTS

We developed a novel repeat biopsy nomogram incorporating age, free to total PSA ratio, prostate volume, history of previous extended biopsy, and PSA doubling time. Validation confirmed predictive accuracy with an AUC value of 0.791. Calibration plots showed good agreement. The decision curve of the nomogram was superior to the decision curve of biopsying all men in a range of threshold probability over 0.15. At the threshold of 0.2, the number of unnecessary biopsies could be reduced by 10 per 100, without missing prostate cancer.

CONCLUSIONS

We developed a novel repeat biopsy nomogram based on a cohort examined with 3D protocol. This repeat biopsy nomogram is clinically beneficial, preventing a substantial number of unnecessary biopsies.

Prostate-specific antigen velocity based risk-adapted discontinuation of prostate cancer screening in elderly men

OBJECTIVE

• To evaluate weather prostate-specific antigen (PSA) velocity could be used to stratify patients at risk of death from prostate cancer (PCa) and be useful in aiding decision making regarding PSA screening in elderly men, as previous studies have shown that PSA velocity can predict PCa risk.

PATIENTS AND METHODS

• The cohort included 3,525 patients aged ≥ 75 years with two or more PSA tests before a diagnosis of PCa. Cox proportional hazard model was used to evaluate which variables at time of last PSA measurement were associated with death from PCa. • The rates of death from PCa after diagnosis in different PSA velocity groups were calculated. Kaplan-Meier and log rank test were used to assess the significant difference in death from PCa after diagnosis, stratified by PSA velocity cutoff.

RESULTS

• On multivariate analysis, men with a PSA velocity of PSA velocity ≥ 0.45 ng/mL/year had a 4.8-fold higher risk of death from PCa as compared to men with a PSA velocity of < 0.45 ng/mL/year (p value = 0.013). After a median 6.5 (up to 16.9) years of follow-up from diagnosis, 1.4% of the men with a PSA velocity < 0.45 ng/mL/year had died of PCa as compared to 8.7% of those with a PSA velocity ≥ 0.45 ng/mL/year. • The cumulative rate of death from PCa after diagnosis, stratified by a PSA velocity of 0.45 ng/mL/year, was statistically different (log rank test, P < 0.001).

CONCLUSION

• Men age ≥ 75 years old with a PSA velocity of <0.45 ng/mL/year are unlikely to die of PCa. It may be safe to discontinue PSA screening in these men.

Relationship between initial PSA density with future PSA kinetics and repeat biopsies in men with prostate cancer on active surveillance

The objective of our study is to examine the correlation between PSA density (PSAd) at the time of diagnosis with PSA velocity (PSAV), PSA doubling time and tumour progression, on repeat biopsy, in men with prostate cancer on active surveillance. Data from 102 patients with clinically localized prostate cancer on active surveillance in the period between 1992 and 2007, who had the necessary parameters available, were collected. PSAd was calculated and correlated with PSAV, PSA doubling time (PSADT), Gleason score at diagnosis and local progression on repeated biopsies. PSAV was 0.64 and 1.31 ng ml^–1 per year (P=0.02), PSADT of 192 and 113 months (P=0.4) for PSAd below and above 0.15, respectively. The rate of detecting high Gleason score (⩾7) at diagnosis was 6 and 23% for PSAd below and above 0.15, respectively. A total of 101 patients underwent at least a second biopsy and the incidence of upgrading was 10 and 31% for PSAd below and above 0.15, respectively (P=0.001). Although low PSAd is an accepted measure for suggesting insignificant prostate cancer, our study expands its role to indicate that PSAd <0.15 may be an additional clinical parameter that may suggest indolent disease, as measured by future PSAV and repeat biopsy over time.

Preoperative prostate specific antigen doubling time is not a useful predictor of biochemical progression after radical prostatectomy

PURPOSE

Postoperative prostate specific antigen doubling time may be used as a surrogate for prostate cancer specific mortality in patients with biochemical recurrence after radical prostatectomy. Less is known about the usefulness of preoperative prostate specific antigen doubling time for the initial prediction of prostatectomy outcomes.

MATERIALS AND METHODS

Preoperative prostate specific antigen doubling time was calculated in 1,208 men from a large prostate cancer screening study who were treated with radical prostatectomy. We examined the relationship of prostate specific antigen doubling time with tumor features and biochemical progression-free survival.

RESULTS

Overall prostate specific antigen doubling time was associated with nonorgan confined disease (OR 0.996, 95% CI 0.992-0.999, p = 0.013) but not with biochemical progression (HR 1.000, 95% CI 0.998-1.001, p = 0.66). Using previously published 18 and 36-month thresholds for prostate specific antigen doubling time there was no significant relationship between doubling time and specific adverse pathological features or biochemical progression. Using the concordance index prostate specific antigen doubling time did not enhance the prediction of biochemical progression beyond that achieved by a model with prostate specific antigen, clinical stage and biopsy Gleason score.

CONCLUSIONS

In our series of men with newly diagnosed, clinically localized prostate cancer shorter preoperative prostate specific antigen doubling time was associated with nonorgan confined disease but not with biochemical progression after radical prostatectomy. All calculations of prostate specific antigen kinetics may not be equivalent. Caution should be exercised when using prostate specific antigen doubling time in the pretreatment setting.

Prostate cancer: is PSA velocity useful?

When a patient presents for assessment of prostate cancer risk, do serial measurements of PSA provide more-useful information than determination of a single PSA concentration? The authors of a new systematic review contend that the answer to this question is 'no'. Stacy Loeb cautions against hasty abandonment of PSA kinetics.

Risk factors, prevention and early detection of prostate cancer

Approximately one in six men in the United States will develop prostate cancer during their lifetime. Genetic and environmental variables play a role in determining prostate cancer risk. This article highlights the latest evidence regarding the risk factors for prostate cancer. The current screening strategies using prostate-specific antigen and digital rectal examination are also discussed, as well as the limitations of these protocols and potential methods for improving early detection.

Early Detection of Cancer: Immunoassays for Plasma Tumor Markers

BACKGROUND: Plasma tumor biomarkers are widely used clinically for monitoring response to therapy and detecting cancer recurrence. However, only a limited number of them have been effectively used for the early detection of cancer. OBJECTIVE: To review plasma tumor markers used clinically for the early detection of cancer and to provide expert opinion about future directions. METHODS: Literature review, as well as our expert opinion, of plasma tumor markers that have been widely accepted for the early detection of cancer. RESULTS: In the United States, only prostate specific antigen (PSA), cancer antigen 125 (CA125), and alpha-fetoprotein (AFP) have been clinically used for the early detection of prostate, ovarian, and liver cancers, respectively. Both analytical and clinical issues related to the use of these three markers were discussed. CONCLUSION: Few plasma tumor markers have been used effectively for the early detection of cancer, mainly due to their limited sensitivity and/or specificity. Multiple approaches have been developed to improve the clinical performance of tumor markers for the early detection of cancer. Metrological traceability and antibody specificity are important issues to ensure comparability of immunoassays for the measurement of plasma tumor markers.

Risk of developing prostate cancer in the future: overview of prognostic biomarkers

In many disease states, the use of biomarkers is a standard method of determining both the presence and the risk of the future development of disease. For several years, total prostate-specific antigen (PSA) levels have been the standard measure for the diagnosis of prostate cancer (PCa) and other prostatic diseases. However, recent data have indicated that PSA can also be used to determine the risk of developing PCa in the future. This evolving use of PSA is supported by clinical trial data from the Baltimore Longitudinal Study of Aging, the European Randomized Study of Screening for Prostate Cancer, and the Malmö Preventive Medicine Study. Data from the European Randomized Study of Screening for Prostate Cancer have demonstrated that men with a PSA level of > or =1.5 ng/mL are at a significantly elevated risk of developing PCa compared with patients with a PSA level <1.5 ng/mL. The Malmö study showed that the PSA level could independently the predict cancer risk as far as 25-30 years into the future. Secondary nonserum risk factors (eg, age, family history, ethnicity) can also offer predictive value for determining the risk of developing future disease. Furthermore, recent investigations of novel biomarkers have yielded promising PCa prognostic candidates, including the PCa gene 3 and early PCa antigen 2. However, PSA remains the most reliable measure in assessing the risk of developing PCa.

Radiation therapy approaches to the treatment of high-risk prostate cancer

Radiation therapy modalities have been shown to offer patients a nonoperative option for definitive treatment of localized prostate cancer as well as options for adjuvant or salvage therapy in high-risk prostate cancer patients. In patients with high-risk, localized disease, radiation therapy with or without adjuvant hormonal therapy is considered an excellent treatment option because of its efficacy within the prostate and among local periprostatic structures, addressing micrometastatic disease. Following radical prostatectomy in patients with high-risk or recurrent disease, radiotherapy can increase oncologic efficacy in both the adjuvant and salvage setting. Continued studies are underway to address ongoing concerns of sparing surrounding tissues unnecessary radiation while administering high-dose radiation to the prostate and targeted periprostatic structures. Newer technologies are using real-time imaging and computer-simulated motion calculation to adjust for physiological organ motion with respect to bony landmarks classically used to map areas of radiation administration.

Prostate-specific antigen (PSA) kinetics in untreated, localized prostate cancer: PSA velocity vs PSA doubling time

OBJECTIVES

To compare the accuracy of prostate-specific antigen (PSA) velocity (PSAV) vs PSA doubling time (DT) for predicting the repeat biopsy results in men with localized prostate cancer on active surveillance (AS), as the utility of PSAV vs PSADT in untreated prostate cancer has not been well studied.

PATIENTS AND METHODS

Eligible patients had favourable-risk localized prostate cancer (T1/2a, PSA level <or=15 ng/mL, Gleason score <or=3 + 4, and percentage positive biopsy cores <or=50%), and consented to AS between 2002 and 2005. Repeat biopsies were taken after 18-24 months, with adverse histology defined as any of: primary Gleason grade >or=4, >50% cores positive, or initial Gleason score 3 + 3 upgraded to >or=3 + 4. Using all PSA values for the 2 years preceding repeat biopsy, the PSAV and PSADT were calculated using linear regression and the log-slope method (DT = ln2/slope), respectively.

RESULTS

In all, 199 patients were assessable; the median PSAV and PSADT were 0.71 ng/mL/year and 5.29 years, respectively. Fifty-three patients (27%) had adverse histology on repeat biopsy. On univariate analyses, PSAV (P < 0.001) and PSADT (P = 0.019) were associated with adverse histology. The area under the receiver operating characteristic curve for predicting adverse histology was 0.70 and 0.63 for PSAV and PSADT, respectively. The mean difference was 0.07 (95% confidence interval 0.03-0.12; P < 0.001).

CONCLUSIONS

PSAV is more accurate than PSADT for predicting adverse histology on repeat biopsies. These data suggest that PSAV should be used in preference to PSADT to describe PSA kinetics in untreated, localized prostate cancer.