Relationship among initial serum prostate specific antigen, prostate specific antigen progression and prostate cancer detection at repeat screening visits

PURPOSE: We evaluated the probability of positive serum PSA (3 ng/ml or greater) and CaP detection at annual followup visits in men with negative initial PSA (less than 3 ng/ml) to optimize the re-screening schedule. MATERIALS AND METHODS: Data on 5,387 men 45 to 80 years old with negative PSA and no CaP diagnosis at the first screening visit were obtained from the Laval University Prostate Cancer Screening Program database. Accelerated failure time regressions were fitted to time from baseline to positive PSA and to time from positive PSA to CaP detection. The models were combined to estimate the cumulative probability of positive PSA followed by CaP detection at re-screening. RESULTS: The 5-year cumulative probability of detecting CaP at annual visits in men with baseline PSA up to 1.5 ng/ml remained below 0.8%, while it was 1.3%, 4.8% and 8.3% in men with PSA 1.5 to less than 2, 2 to less than 2.5 and 2.5 to less than 3 ng/ml, respectively. Time to positive PSA significantly decreased with increasing baseline PSA and age, while the time between positive PSA and CaP detection depended only on age. Men with PSA below 1.0 ng/ml could wait for 4 to 5 years before being re-tested, while men with PSA between 1.0 and 1.5 ng/ml should be screened every second year and men with PSA 1.5 ng/ml or greater should be screened every year. CONCLUSIONS: The proposed retesting schedule using current PSA and age decreases the number of visits by 38.1%, while delaying the detection of only 2.4% of CaPs that would have been detected using annual PSA testing.     

Predictors of subsequent prostate cancer in men with a prostate specific antigen of 2.6 to 4.0 ng/ml and an initially negative biopsy

PURPOSE: Almost 75% of men with a prostate specific antigen (PSA) of 2.6 to 4.0 ng/ml have no evidence of prostate cancer on biopsy. Deciding whether and when to repeat the biopsy is challenging. We determined if patient specific variables might identify men at increased risk for the subsequent detection of prostate cancer. MATERIALS AND METHODS: We analyzed the records of 24,893 men from a community based prostate cancer screening study. Our study group consisted of 1,202 men with PSA 2.6 to 4.0 ng/ml and a previously negative prostate biopsy. Patient specific variables were analyzed for their value in predicting a future diagnosis of prostate cancer. RESULTS: Of 1,011 men with adequate followup 136 (13.5%) were subsequently diagnosed with prostate cancer. Mean followup +/- SD in men without prostate cancer was 72 +/- 36 months. Prostate cancer was subsequently diagnosed in 35% of men with high grade prostatic intraepithelial neoplasia (HGPIN) on initial biopsy (p <0.0001), in 18% with abnormal or suspicious digital rectal examination (DRE) (p = 0.02) and 16% with an annual PSA velocity of 0 ng/ml (p = 0.002). Multivariate analysis identified HGPIN, initial PSA 3.6 to 4.0 ng/ml, abnormal DRE, family history of prostate cancer and annual PSA velocity 0 ng/ml as predictors of prostate cancer. CONCLUSIONS: Men with a PSA of 2.6 to 4.0 ng/ml and negative biopsy should be advised to undergo repeat biopsy if they have HGPIN, initial PSA 3.6 to 4.0 ng/ml, abnormal DRE, a family history of prostate cancer or a PSA velocity of 0 ng/ml or greater.     

Prevalence of prostate specific antigen testing for prostate cancer in elderly men

PURPOSE: We investigated the prevalence and outcome of PSA testing for prostate cancer screening or diagnosis in elderly men 75 years or older at our academic medical center. MATERIALS AND METHODS: A cross-sectional study design was used to identify all men 75 years or older who underwent a PSA test through the family medicine or internal medicine service at our institution between January 1, 1998 and June 30, 2004. All patients with a suspected (PSA less than 0.1 ng/ml) or confirmed prior diagnosis of prostate cancer were excluded. The prevalence of PSA testing was then compared to that in younger age groups (45 to 54, 55 to 64 and 65 to 74 years). We then examined the frequency and nature of further evaluation and treatment performed in men following the PSA test. RESULTS: The 8,787 male patients who were 75 years or older generated a total of 82,672 visits in the 5.5-year period. Of these patients 505 (5.7%) underwent at least 1 PSA test. The prevalence of PSA testing in the younger age groups was 10.3% (1,769 of 17,175) in patients 45 to 54 years old, 14.9% (2,052 of 13,772) in those 55 to 64 years old and 11.8% (1,258 of 10,661) in those 65 to 74 years old (chi-square test p <0.001). Of these patients 98 of 343 (28.6%) with PSA between 0.1 and 4 ng/ml were referred to a urologist at our institution and 3 underwent biopsy. None had a prostate cancer diagnosis. Of the 162 patients with PSA more than 4 ng/ml 84 (51.9%) were referred to a urologist. Only 10 of the 84 patients (11.9%) who were referred to a urologist underwent prostate biopsy. Six of the 10 men (60%) were diagnosed with prostate cancer, including 1 with a Gleason 6 tumor, 1 with a Gleason 7 tumor and 4 who were found to have tumors with a Gleason score of 8 or greater. All patients received androgen deprivation therapy, except 1 who received local external beam radiation therapy. An additional patient was diagnosed by biopsy of a vertebral lesion and he received hormone therapy. At a median followup of 51 months (range 28 to 72) 4 of 7 men (57%) were alive with disease. CONCLUSIONS: PSA testing for prostate cancer screening and diagnosis appear to decrease with advancing age. A small but significant proportion of men who are 75 years or older continue to undergo PSA testing. Abnormal PSA results do not always result in further evaluation and therapy for prostate cancer in elderly men. The establishment of firm guideline recommendations regarding PSA testing and further evaluation for prostate cancer in elderly men, perhaps based on individualized geriatric assessment, may be helpful.     

Relationship between initial prostate specific antigen level and subsequent prostate cancer detection in a longitudinal screening study

PURPOSE: Previous studies of archived blood samples from nonscreened populations have shown an association between the prostate specific antigen (PSA) and the subsequent detection of prostate cancer. In the current study we evaluated the relationship between the initial screening PSA and the subsequent risk of prostate cancer detected in a prospective, longitudinal screening study. We also examined the relationship between initial PSA and the clinicopathological features of the cancers detected. MATERIALS AND METHODS: Between May 1991 and November 2001 we enrolled 26,111 volunteers in our PSA and digital rectal examination based prostate cancer screening study. The men were followed biannually or annually depending on the results of previous screening tests. The chi-square and Kruskal-Wallis tests were used to compare the clinical stage, pathological stage and Gleason score of subsequently detected prostate cancers as well as the time to cancer detection in different initial screening PSA strata. RESULTS: The initial screening PSA stratum was strongly associated with the subsequent detection of prostate cancer as well as the clinicopathological stage and grade of the cancers detected. CONCLUSIONS: Even in the lower PSA ranges initial screening serum PSA can help identify men at increased risk for subsequent prostate cancer detected in a longitudinal screening study.     

Clinical value of prostate specific antigen based parameters for the detection of prostate cancer on repeat biopsy: the usefulness of complexed prostate specific antigen adjusted for transition zone volume

PURPOSE: To our knowledge the indications for repeat prostate needle biopsy in men whose previous transrectal ultrasound guided biopsy results revealed no evidence of cancer have not yet been defined. We identified the most effective method for detecting prostate cancer on repeat biopsy. MATERIALS AND METHODS: One or more systematic repeat prostate biopsies were performed in 144 consecutive patients, including 86 with prostate specific antigen (PSA) levels between 4 and 10 ng./ml. at repeat biopsy. Men in whom cancer was detected on repeat biopsies were compared with their counterparts in terms of digital rectal examination findings, PSA based parameters and an atypical prostate on initial prostate biopsy. RESULTS: Prostate cancer was detected on repeat biopsy in 39 of the 144 patients and in 19 on subset analysis of 86. Serum PSA levels at repeat biopsy did not differ significantly in patients with and without prostate cancer. According to receiver operating characteristics analysis the alpha1-antichymotrypsin-PSA complex adjusted for transition zone volume had the greatest area under the curve values, that is 0.756 for all 144 patients and 0.768 for the subset analysis of 86. Multiple logistic regression analysis of the subset of 86 patients showed that alpha1-antichymotrypsin-PSA complex adjusted for transition zone volume was the only significant independent predictor of cancer. CONCLUSIONS: alpha1-Antichymotrypsin-PSA complex adjusted for transition zone volume was the most powerful predictor of cancer in men who had undergone previous negative prostate biopsies. This parameter may be used to avoid more unnecessary repeat biopsies with an acceptable decrease in sensitivity.     

Screening for prostate cancer in high risk populations

PURPOSE: Black men and men with a family history of prostate cancer are at higher risk for this disease and may have an earlier age of onset. Consequently, screening at a younger age has been recommended for high risk men, however, there are limited data on actual screening results in young, high risk populations. MATERIALS AND METHODS: In men 50 years old or older we compared screening results in 1,224 black men, 1,227 men with a positive family history and 63 men who were both with those of 15,964 nonblack men with no known family history. In high risk men in their forties we also evaluated the percent with abnormal screening tests, the positive predictive value of screening tests, cancer detection rates and the prognostic features of tumors detected. RESULTS: In men 50 years old or older prostate cancer detection rates were 6.4% for controls compared with 10.3%, 10.5% and 17.5%, respectively, for the high risk groups. Among high risk men screened in their forties 8% had suspicious screening tests and approximately 55% who underwent a biopsy had cancer detected. Of tumors detected 80% were organ confined and all but 1 were of moderate Gleason grade 5 years old or older. Only 1 tumor (7%) fulfilled the published criteria for a possibly harmless cancer. CONCLUSIONS: Black men and men with a family history of prostate cancer are at a 75% to 80% higher risk for prostate cancer. On initial screening of high risk men in their fourth decade only 8% have positive screening tests; however, approximately 55% of these men have tumors, most of which are medically important with favorable prognostic features.     

Comparative analysis of complexed prostate specific antigen, free prostate specific antigen and their ratio in detecting prostate cancer

PURPOSE: We evaluate the diagnostic use of total, free and complexed serum prostate specific antigen (PSA), and their ratios for enhancing the specificity in detecting prostate cancer. MATERIALS AND METHODS: A total of 354 nonconsecutive men undergoing prostate biopsy were eligible for this retrospective and prospective study. Cancer was found in 122 of these 354 men (34%). Receiver operating characteristics curve analyses were used to calculate and compare the performance of total PSA (Hybritech, San Diego California and Bayer, Tarrytown, New York), complexed PSA (Bayer), percent complexed PSA and percent free PSA. In addition, sensitivity and specificity were calculated and compared. RESULTS: The area under the receiver operating characteristics curve was highest for percent free PSA, followed by percent complexed PSA, complexed PSA and the 2 total PSA assays (Hybritech and Bayer). The cutoff value of 3.45 ng./ml. for complexed PSA detected the same number of cancers and resulted in 1 additional false-positive case compared with a Hybritech total PSA threshold of 4.0 ng./ml. At sensitivities of 80% to 95%, there were no significant differences for detection comparing the corresponding specificities between Hybritech total PSA and complexed PSA for all 354 men. Complexed PSA alone did not enhance the overall diagnostic accuracy compared with percent free PSA in the Hybritech total PSA range between 4.01 and 6.00 ng./ml., between 6.01 and 10.00 ng./ml., and between 2.50 and 6.00 ng./ml. At sensitivities of 80% to 95% specificity of percent complexed PSA was almost identical to that of percent free PSA except for the Hybritech total PSA range less than or equal to 4.00 ng./ml. CONCLUSIONS: This study suggests complexed PSA is equivalent to total PSA for the early detection of prostate cancer. Percent free PSA outperforms complexed PSA and percent complexed PSA performed equivalently to percent free PSA in all total PSA ranges analyzed between 2.5 and 10 ng./ml.     

Long-term effects of finasteride on prostate specific antigen levels: results from the prostate cancer prevention trial

PURPOSE: Studies have shown that finasteride decreases prostate specific antigen (PSA) by approximately 50% during the first 12 months of use. We estimated the long-term effects of finasteride on PSA in men with and without a prostate cancer diagnosis at the end of the study. MATERIALS AND METHODS: We analyzed serial PSA in participants in the Prostate Cancer Prevention Trial who had an end of study biopsy (928 with cancer and 8,620 with negative biopsy) or an interim diagnosis of prostate cancer (671). Linear mixed effects regression models were fit to longitudinal PSA values beginning 1 year after randomization. RESULTS: In subjects with no cancer in the end of study biopsy PSA in the finasteride arm showed a median annual decrease of 2% [corrected] after year 1, while PSA in the control arm showed an annual increase of 3% (p <0.001). In end of study cases PSA increased annually by 6% (placebo) and 7% (finasteride). In those with interim diagnoses PSA increased by 11% (placebo) and 15% (finasteride) each year prior to diagnosis. Cases with high grade disease (Gleason 7 and above) had greater PSA increases than cases with low grade disease (p <0.001). CONCLUSIONS: In men who have been receiving finasteride for more than 1 year time varying adjustment factors may be needed to determine whether PSA is in the normal range. In the Prostate Cancer Prevention Trial cohort the adjustment factor required to preserve median PSA increased from 2 at 24 months to 2.5 at 7 years after the initiation of finasteride.     

Effects of systematic 12-core biopsy on the performance of percent free prostate specific antigen for prostate cancer detection

PURPOSE: The performance characteristics of percent free (f) prostate specific antigen (PSA) for differentiating between benign prostatic hyperplasia and prostate cancer were originally established using primarily sextant biopsy. We determined whether the addition of 6 laterally directed cores to the traditional sextant prostate biopsy affects the performance of percent fPSA. MATERIALS AND METHODS: We retrospectively evaluated a cohort of 350 consecutive biopsies in men with negative digital rectal examinations and PSA between 4 and 10 ng/ml who underwent systematic 12 core biopsy (S12C) biopsy at Scott Department of Urology between March 1999 and January 2003. The effects of 6 additional, laterally directed biopsies on the sensitivity, specificity and area under the ROC curve for percent fPSA was evaluated in the 277 men in whom percent fPSA was measured. RESULTS: Cancers detected exclusively in the 6 laterally directed cores were associated with percent fPSA values similar to those in patients with a benign S12C biopsy. This resulted in a modest and yet predictable decrease in the sensitivity of percent fPSA at each biopsy threshold value without affecting specificity. There was a nonstatistically significant decrease in the area under the ROC curve with the addition of 6 laterally directed cores to sextant biopsy (medial sextant cores 0.66 vs S12C 0.60). CONCLUSIONS: The 12 core biopsy strategies have a higher cancer detection rate than sextant biopsies and they are gaining widespread acceptance. The addition of 6 laterally directed cores to traditional sextant biopsy may result in a modest decrease in the sensitivity of percent fPSA at each selected biopsy threshold without affecting specificity.     

Prostate specific antigen testing and digital rectal examination before and during a randomized trial of screening for prostate cancer: European randomized study of screening for prostate cancer, Rotterdam

PURPOSE: Worldwide 2 large-scale randomized screening trials for prostate cancer have been initiated. Determining prostate specific antigen (PSA) involves a simple test that may influence the outcome of these trials if frequently done in the control arm or before study enrollment. We quantified PSA and digital rectal examination before and during the screening trial in Rotterdam, The Netherlands and in the general population. MATERIALS AND METHODS: Trial participants were administered study intake questionnaires on tests done before study participation. Data on PSA from the regional general practice laboratory were correlated with participant data. Various sources were used to quantify PSA tests and digital rectal examinations in the general population. RESULTS: Of men 55 to 74 years old 45% underwent digital rectal examination at 1 time and 13% reported that PSA was tested before trial participation. Each rate increased with age. No statistically significant effect of former PSA testing or digital rectal examination on the cancer detection rate was identified. The rate of PSA determination after initial screening and/or randomization in the control arm was 2-fold that in the screening arm (76 versus 33/1,000 person-years). PSA determination initially decreased in the screening arm but increased rapidly after some time. The number of PSA determinations in the general population was estimated to be 45/1,000 person-years at ages 55 to 69 years. CONCLUSIONS: PSA testing was moderate in the control arm but if different men undergo this test each year, the contamination rate may become rather high. In the final analysis of mortality PSA testing should be considered.     

Prostate specific antigen changes as related to the initial prostate specific antigen: data from the prostate, lung, colorectal and ovarian cancer screening trial

PURPOSE: Annual screening with PSA, although of unproven benefit, is currently used for prostate cancer early detection. A large fraction of screened men have low (less than 2 ng/ml) initial PSA. The yield over time of positive PSA screens (ie more than 4 ng/ml) in these men has not been well characterized in large cohorts in the United States. MATERIALS AND METHODS: Men in the screening arm of the PLCO received baseline PSA and annual tests for 5 years. 30,495 of these men had baseline PSA 4 ng/ml or less. We estimated the cumulative probability of converting to PSA greater than 4 at years 1 through 5 as a function of baseline PSA. RESULTS: Among men with baseline PSA less than 1 ng/ml, 1.5% converted by year 5 (95% CI 1.2-1.7). Among men with baseline PSA of 1.0 to 1.99 ng/ml, 1.2% (95% CI 0.9-1.3) and 7.4% (95% CI 6.8-8.1) converted by year 1 and 5, respectively. A total of 33.5% and 79% of men with initial PSA of 2.0 to 2.99 and 3.0 to 4.0, respectively, converted by year 5. Of men with baseline PSA less than 1 ng/ml converting to PSA more than 4 ng/ml, 8% were diagnosed with cancer within 2 years of conversion. About 10% of men with baseline PSA less than 1 ng/ml and negative baseline DRE had a positive DRE within 3 years. CONCLUSIONS: For men choosing PSA screening, screening every 5 years for baseline PSA less than 1 ng/ml and every 2 years for PSA 1 to 2 ng/ml could result in a 50% reduction in PSA tests and in less than 1.5% of men missing earlier positive screens, but with an unknown effect on prostate cancer mortality.     

Percent free prostate specific antigen is not an independent predictor of organ confinement or prostate specific antigen recurrence in unscreened patients with localized prostate cancer treated with radical prostatectomy

PURPOSE: We studied the controversial relationship of percent free prostate specific antigen (PSA) with organ confined prostate cancer and PSA failure after radical prostatectomy. MATERIALS AND METHODS: We tested the characteristics of the percent free PSA monoclonal Immulite DPC Immunoassay (Diagnostic Products Corp., Los Angeles, California) for predicting organ confinement in 698 consecutive unscreened men treated only with radical prostatectomy between 1995 and 2000. In addition, we assessed the ability of percent free PSA to predict post-radical prostatectomy PSA failure, defined as PSA 0.1 ng./ml. or greater, in a subset of 581 men in whom followup was available. All statistical analyses were repeated for stage T1c cancer with PSA between 2 and 10 ng./ml. RESULTS: On univariate analyses percent free PSA achieved significance for predicting organ confined disease at all clinical stages (p <0.001) and for stage T1c cancer with PSA between 2 and 10 ng./ml. (p = 0.012). However, significance dissipated after controlling for total PSA, biopsy Gleason sum and clinical stage (p = 0.135 and 0.851, respectively). In univariate Cox models percent free PSA failed to predict PSA failure across stages (p = 0.341), as well as in stage T1c cancer (p = 0.93). In multivariate analyses controlling for traditional PSA biopsy grade and clinical stage (p <0.001), percent free PSA failed to contribute to predicting PSA failure (p = 0.342). In the stage T1c subset biopsy Gleason sum (p <0.001) and PSA (p = 0.018) remained significant, in contrast to percent free PSA (p = 0.237). CONCLUSIONS: Percent free PSA has no independent, statistically significant association with organ confined status or posttreatment PSA outcome in unscreened patients who undergo radical prostatectomy for localized prostate cancer.     

Use of 2.6 ng/ml prostate specific antigen prompt for biopsy in men older than 60 years

PURPOSE: Since the United States Food and Drug Administration approved the prostate specific antigen (PSA) blood test as an aid to early prostate cancer detection, using a cutoff of 4.0 ng/ml in 1994, this cutoff has been widely adopted to recommend prostate biopsy. There has been recent investigation into lowering the PSA prompt for biopsy, especially in men younger than 60 years. We determined how a lower cutoff would perform in men older than 60 years. MATERIALS AND METHODS: From a prostate cancer screening study we studied 782 consecutive men who underwent prostate biopsy for PSA greater than 2.5 ng/ml or suspicious digital rectal examination. Biopsy results were evaluated as a function of patient age. RESULTS: Clinical and pathological characteristics of cancers detected in the PSA range 2.6 to 4.0 ng/ml were similar regardless of patient age. Overall PSA between 2.6 and 4.0 ng/ml was associated with a cancer detection rate of 16.2% using a sextant biopsy technique. PSA velocity was similar in men with prostate cancer in all age groups. CONCLUSIONS: More than 15% of men with PSA 2.6 to 4.0 ng/ml who are 40 years or older have prostate cancer detected with sextant needle biopsies. PSA velocity, tumor stage, Gleason grade and tumor volume were similar in all age groups.