Utilization of polyclonal serum prostate specific antigen levels in screening for prostate cancer: a comparison with corresponding monoclonal values

Critical appraisal of prostate-specific antigen in prostate cancer screening: 20 years later

Prostate-specific antigen (PSA) is secreted by all types of prostate epithelial cells and has been used for 2 decades as a biologic marker for prostate cancer (PCa). Since the implementation of PSA screening in the United States, the detection of PCa has increased, accompanied by a decrease in the incidence of high-grade cancer and PCa-specific mortality rates. It has been suggested that these decreases have resulted from the enhanced detection of PCa while still curable. These data have been the impetus for early detection programs, which have recommended the initiation of screening as early as 40 years of age. Despite widespread use, PSA screening remains controversial, principally because of the lack of evidence from randomized controlled trials demonstrating a mortality benefit that could outweigh the concerns of the costs of overdiagnosis and overtreatment. Two ongoing, randomized controlled trials are examining whether screening reduces the risk of PCa-related mortality, and the results of these studies are expected soon. Although it has its limitations, PSA still remains the best-studied marker for the detection of PCa.

The influence of serial prostate-specific antigen (PSA) screening on the PSA velocity at diagnosis

BACKGROUND

A prostate-specific antigen (PSA) velocity (PSAV) >2 ng/mL during the year before diagnosis has been associated with an increased risk of prostate cancer-specific mortality (PCSM) after radical prostatectomy (RP) or radiation therapy. The objective of the current study was to examine whether the proportion of men with a PSAV >2 ng/mL per year has changed significantly during the PSA era.

METHODS

The authors evaluated 1095 men from a prospective prostate cancer screening study who underwent RP between 1989 and 2002. For the purposes of this analysis, clinicopathologic features were compared between men who were treated during the following 3 periods: before 1995, from 1995 to 1998, and after 1998. Logistic regression analysis was used to evaluate for an association between the year of diagnosis and the proportion of men with a PSAV >2 ng/mL per year.

RESULTS

Two hundred sixty-two of 1095 men (24%) had a PSAV >2 ng/mL per year. There was a statistically significant reduction in the proportion of men presenting with a PSAV >2 ng/mL per year over the study period. Specifically, 35% of men presented with a PSAV >2 ng/mL per year in the early period compared with only 22% and 12% in the middle and late periods, respectively (P < .001). Over the studied periods, there also was a significantly greater proportion of men with >2 PSA values obtained before diagnosis (P < .001).

CONCLUSIONS

Men who were screened serially with PSA were less likely to present with a PSAV >2 ng/mL per year. This association lends support to the hypothesis that serial PSA-based screening may lead to a decrease in PCSM.

Prostate cancer detection strategies

Prostate cancer is the most common malignancy in men and, as a result, there has been a nationwide emphasis on screening and detection. With the widespread use of the prostate-specific antigen (PSA), prostate cancer screening effectively detects localized prostate cancer. However, recent reports have identified a significant proportion of prostate cancer in men with low PSA levels. Many of these cancers are higher-grade malignancies. Consequently, PSA may function more effectively as a screening tool when applied over a continuum that is associated with degree of risk, rather than a binary measure. Other markers are currently being investigated. Ideally, a marker will identify the malignancy that is a clinical threat, thereby avoiding intervention for indolent disease. Prevention strategies may be employed for higher-risk patients, and these strategies eventually may be tailored to genetic or other risks.

Do prostatic infarction, prostatic inflammation and prostate morphology play a role in acute urinary retention?

OBJECTIVE

To investigate whether there is a role of prostatic infarction, prostatic inflammation and prostate morphology in acute urinary retention (AUR) etiology.

METHODS

Ninety-eight consecutive male patients who were admitted to our clinic with either AUR or lower urinary tract symptoms (LUTS) were involved in the study. Patient age ranged from 43 to 88 years (median age 70). Group 1 consisted of 53 (54%) patients with AUR, and Group 2 consisted of 45 (46%) patients with LUTS. In Group 1 and Group 2, 58.4% (n:31) and 62.2% (n:28) of the patients underwent transurethral prostate resection, 41.6% (n:22) and 37.8% (n:17) of the patients underwent suprapubic transvesical prostatectomy, respectively. Each patient was asked about the factors: smoking habits, taking previous general anesthesia and preexisting cardiovascular disease such as hypertention and atherosclerotic coronary vascular disease which may lead to AUR via prostatic infarct. Prostatic infarction, prostatic inflammation and prostatic morphology were examined in the patients' specimen.

RESULTS

Mean age, median serum prostate-specific antigen (PSA) level, and prostatic inflammation ratio were significantly higher in Group 1. There were not significant differences between the groups regarding prostate volume, prostatic infarction ratio and a type of prostatic morphology. In the present study, except for taking previous general anesthesia and preexisting cardiovascular disease, only prostatic inflammation was found important contributory factor on AUR. AUR risk was 3.03 times higher in the patients with prostatic inflammation (95%CI 1.28-7.15) (p = 0.01).

CONCLUSIONS

No significant effect of prostatic infarction was found on occurrence of AUR which was more frequent in elderly patients. Prostatic inflammation may have an important risk factor in AUR etiology. Additionally, serum PSA levels were higher in AUR group. No association was found between a type of prostatic morphology and AUR.

Natural history of prostatism: risk factors for acute urinary retention

PURPOSE

We determined the occurrence of and risk factors for acute urinary retention in the community setting.

MATERIALS AND METHODS

A cohort of 2,115 men 40 to 79 years old was randomly selected from an enumeration of the Olmsted County, Minnesota population (55% response rate). Participants completed a previously validated baseline questionnaire that assessed symptom severity, and voided into a portable urometer to measure peak urinary flow rates. A 25% random subsample underwent transrectal sonographic imaging of the prostate to determine prostate volume. Followup was performed through a retrospective review of community medical records to determine the occurrence of acute urinary retention in the subsequent 4 years.

RESULTS

During the 8,344 person-years of followup 57 men had a first episode of acute urinary retention (incidence 6.8/1,000 person-years, 95% confidence interval [CI] 5.2, 8.9). Among men with no to mild symptoms (American Urological Association symptom index score 7 or less) the incidence of acute urinary retention increased from 2.6/1,000 person-years among men 40 to 49 years old to 9.3/1,000 person-years among men 70 to 79 years old. By contrast, rates increased from 3.0/1,000 person-years for men 40 to 49 years old to 34.7/1,000 person-years among men 70 to 79 years old among men with moderate to severe symptoms (American Urological Association symptom index score greater than 7). Men with depressed peak urinary flow rate (less than 12 ml. per second) were at 4 times the risk of acute urinary retention compared with men with urinary flow rates greater than 12 ml. per second (95% CI 2.3, 6.6). Men with an enlarged prostate (greater than 30 ml.) experienced a 3-fold increase in risk (95% CI 1.0, 9.0, p = 0.04).

CONCLUSIONS

Lower urinary tract symptoms, depressed peak urinary flow rates, enlarged prostates and older age are associated with an increased risk of acute urinary retention in community dwelling men. These findings may help to identify men at increased risk of acute urinary retention in whom closer evaluation may be warranted.

PSA and clinical problems relating to prostate cancer

The PSA is the most important tumoral marker for prostate cancer. Not all Authors agree that it plays an important role in screening and diagnosis, classification and prognosis; they agree, instead, about its monitoring the response to therapy. Two personal experiences are presented: in one the PSA values are compared with the prostatic biopsies in 100 patients with suspect rectal exploration; in the other the PSA value, taken at the moment of diagnosis, is compared with the result of the radionuclide bone scan in 43 patients with prostate cancer.