Serum Prostate-Specific Antigen Hemodilution Among Obese Men Undergoing Screening in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Tria

(Cancer Epidemiol Biomarkers Prev 2009;18(3):748–51)

Background: Previous studies have shown an inverse relationship between prostate-specific antigen (PSA) concentration and body mass index (BMI). It has been recently proposed that this relationship may be explained by the larger plasma volume of obese men diluting a fixed amount of PSA (hemodilution effect). We examined this hypothesis in a cohort of men enrolled in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.

Methods: Of 38,349 men ages 55 to 74 years randomized in PLCO to receive annual PSA and digital rectal examination screening, 28,380 had a baseline PSA, complete demographic information, and no prostate cancer diagnosis within 6 years from baseline. Self-reported height and weight were used to calculate BMI and to estimate plasma volume. PSA mass was estimated as PSA concentration times plasma volume. Multivariable linear regression models were used to investigate the relationship between PSA concentration, plasma volume, PSA mass, and BMI.

Results: PSA concentration significantly decreased with increasing BMI (P < 0.001); mean PSA values were 1.27, 1.25, 1.18, and 1.07 ng/mL among normal (BMI, 18.5-25), overweight (BMI, 25-30), obese (BMI, 30-35), and morbidly obese (BMI, >35) men, respectively. However, plasma volume also increased with increasing BMI and PSA mass showed no association with BMI, with mean values of 3.78, 3.95, 3.97, and 3.82 μg across the four BMI categories (P = 0.10).

Conclusions: This study confirms earlier findings that the inverse relationship between PSA concentration and BMI may be explained by a hemodilution effect. These findings could have implications for prostate cancer screening in large men.

PSA Doubling Time as a Predictive Factor on Repeat Biopsy for Detection of Prostate Cancer

imbo M, Tomioka S, Sasaki M, Shima T, Suzuki N, Murakami S, Nakatsu H, Shimazaki J.
1Department of Urology, Asahi General Hospital, Asahi.

OBJECTIVE: Detection of prostate cancer needs a biopsy of the prostate. Suspecting cancer from an increase in Prostate Specific Antigen (PSA) has a high negative rate at an initial prostate biopsy. Cases with negative initial biopsy may be the candidates of subsequent biopsy. For lowering unnecessary repeat biopsy, the use of predictive factors before a repeat biopsy is applied for indication.

METHODS: Seventy-seven cases with negative initial prostate biopsy received a repeat biopsy and factors for the detection of cancer were examined.

RESULTS: Prostate Specific Antigen doubling time distinguished a part of cancer cases. Its sensitivity of 30, 50 and 70 months was 36.6%, 30.4% and 10%, respectively. Cancer case did not show PSA doubling time of >100 months in general. Values of PSA transition zone density, %Free/total PSA and PSA velocity were similar between cancer and no cancer cases.

CONCLUSIONS: Prostate Specific Antigen doubling time was one of the predictive factors for the detection of prostate cancer and was valuable for avoiding unnecessary repeat biopsy in some cases.

Prostate-specific antigen in vaginal fluid after exposure to known amounts of semen and after condom use: comparison of self-collected and nurse-colle

BACKGROUND: Prostate-specific antigen (PSA) in vaginal fluid indicates exposure to semen , and was used to assess condom effectiveness, although validity and reliability have not been fully evaluated. Our objective was to compare PSA in self-collected samples with samples collected by a nurse.

METHODS: We conducted two studies, each with 100 women aged 18-48 years. In the first, a nurse exposed each participant to her partner's semen (10, 100 and 1000 microl), and nurse and participant collected samples. In the second, each participant sampled before and after using two male condoms (MC) and two female condoms (FC); a nurse collected another sample afterwards.

RESULTS: PSA concentration increased with semen exposure, but was lower in nurse-collected samples. Both procedures were sensitive, almost 100% after exposure to 100-1000 microl of semen . PSA detection rates with MC and FC were 13% and 28% in self-collected samples, 8% and 9% in nurse-collected samples. Concordance between sample types was 93% with the MC (95% CI: 89%; 96%), 78% with the FC (95% CI: 72%; 84%). PSA decay between sampling times may explain higher values in self-collected samples.

CONCLUSIONS: PSA is a highly sensitive surrogate endpoint for condom effectiveness studies. Self-collected and nurse-collected samples are equivalent, but sample collection timing is critical

Bahamondes L, Diaz J, Marchi NM, Castro S, Villarroel M, Macaluso M.
Department of Obstetrics and Gynaecology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil.

Painkillers May Prevent Prostate Problems

By: Sylvia Booth Hubbard

Over-the-counter painkillers like Advil and aspirin may help men stave off prostate problems, according to two new studies. However, medical experts are quick to warn men not to self-medicate, and especially not to take more than recommended dosages.

The preventive painkillers fall into the general class of drugs called “non-steroidal anti-inflammatory drugs” or NSAIDs. Ibuprofen is one, and well-known brands include Advil, Motrin, and Nuprin. Other members of the NSAIDs class are naproxen (brand name “Aleve”) and aspirin.

“Our data suggest if men are taking these [medications] for another problem, it might prevent urological problems as well,” Mayo Clinic epidemiologist Jennifer St. Sauver told HealthDay News. St. Sauver’s study showed that men who took NSAIDs on a daily basis reduced the enlargement of their prostate glands by about 50 percent. Such enlargement, called “benign prostatic hyperplasia” or BPH, is common in men over forty, affecting about 50 percent of men by age 50, and about 75 percent by age 80.

The other study was led by Dr. Eric A. Singer, who is chief resident in urology at the University of Rochester Medical Center in New York. Singer’s team found that NSAIDs lowered PSA (prostate specific antigen) levels by about 10 percent. PSA, which is produced by the cells of the prostate gland and is normally present in small amounts, is frequently elevated by disorders of the prostate, including prostate cancer. Some of the men in Singer’s study took acetaminophen (brand name “Tylenol”), which also apparently reduced PSA levels. However, not enough men in the study took it to be statistically significant.

Both St. Sauver and Singer speculated that NSAID’s anti-inflammatory action was the probable role-player in helping prevent prostate problems. Both researchers also caution men that NSAIDs can trigger kidney ailments, liver toxicity, and other health problems. “We are certainly not telling men to take NSAIDs to reduce PSA or cancer risk,” Singer said. “Talk to your health-care provider about prostate health and prostate cancer screening, and make sure your doctor knows what medications you are taking.”
According to the American Cancer Society, close to 200,000 men in the U.S. are diagnosed with prostate cancer every year, and one in six men develop it at some point in their life.

Prognostic significance of 5-year PSA value for predicting prostate cancer recurrence

PURPOSE: To analyze the prognosis and outcomes of patients who remain free of biochemical failure during the first 5 years after treatment.

METHODS AND MATERIALS: Between 1991 and 2002, 742 patients with prostate cancer were treated with brachytherapy alone (n = 306), brachytherapy and hormonal therapy (n = 212), or combined implantation and external beam radiotherapy (with or without hormonal therapy; n = 224). These patients were free of biochemical failure (American Society for Therapeutic Radiology and Oncology [ASTRO] definition) during the first 5 post-treatment years and had a documented 5-year prostate-specific antigen (PSA) value. The median follow-up was 6.93 years.

RESULTS: The actuarial 10-year freedom from PSA failure rate was 97% using the ASTRO definition and 95% using the Phoenix definition. The median 5-year PSA level was 0.03 ng/mL (range, 0-3.6). The 5-year PSA value was 0.01-0.10 in 31.1%, >0.10-0.2 in 10.2%, >0.2-0.5 in 7.82%, and >0.5 in 3.10%. The 5-year PSA value had prognostic significance, with a PSA value of or=0.2 ng/mL (n = 81; p < .0001). The treatment regimen had no effect on biochemical failure. None of the 742 patients in this study developed metastatic disease or died of prostate cancer.

CONCLUSION: The results of this study have shown that the prognosis for patients treated with brachytherapy and who remain biochemically free of disease for >or=5 years is excellent and none developed metastatic disease during the first 10 years after treatment. The 5-year PSA value is prognostic, and patients with a PSA value <0.2 ng/mL are unlikely to develop subsequent biochemical relapse

Stock RG, Klein TJ, Cesaretti JA, Stone NN.
Department of Radiation Oncology, Mount Sinai Hospital, New York, NY 10029, USA

Characteristics and outcome of prostate cancer with PSA <4 ng/ml at diagnosis: a population-based study

Division of Radiation Oncology, Geneva University Hospitals, Geneva, Switzerland.

This population-based study aims to assess prognosis of prostate cancer diagnosed with prostate-specific antigen (PSA) levels <4 ng/ml in routine care. Materials and methods We compared prostate cancer patients with low PSA values (n=59) with other prostate cancer patients (n=1330) by logistic regression and the Cox model using data from the Geneva Cancer Registry. Results Patients with low PSA values more frequently had early-stage and well differentiated tumours. Nevertheless, 35% presented with aggressive tumour characteristics or metastases. After adjustment for other prognostic factors, prostate cancer-specific mortality was similar for both groups (hazard ratio: 1.1; 95%CI: 0.6-2.2). Conclusion We conclude that cancer with low PSA values at diagnosis is not indolent.

Strategy for sensitive and specific detection of molecular forms of PSA based on 2DE and kinetic analysis: A step towards diagnosis of prostate canc

Clin Chim Acta. 2008 Dec 3.
Kumar V, Hassan MI, Singh AK, Dey S, Singh TP, Yadav S.

BACKGROUND: Prostate specific antigen (PSA) present in human seminal fluid exists in many isoforms due to different sequence, glycosylation pattern and polypeptide length. Its presence in various stages of cancer has already been reported. METHODS: We identified 8 forms of Prostate specific antigen followed by purification of 3 forms. We compared their binding affinities to designed synthetic peptides, by using surface plasmon resonance (SPR). PSA forms were purified using various chromatographic procedures and characterized by 2D gel electrophoresis (2DE), matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The heterogeneity of purified PSA was demonstrated by 2DE analysis. The peptides were designed on the basis of cleavage map of insulin-like growth factor binding protein 3 (IGFBP-3) subsequently, these peptides showed the binding affinities in the range of 10(-5) to 10(-12) M. Out of 7 peptides, VLLH showed maximum affinity to intact PSA, while FLSYK showed maximum affinity to cleaved forms of PSA. On the other hand, FLSYK in the presence of zinc showed higher affinity to intact PSA. These peptides showed higher affinity to PSA compared to zinc, which is a known inhibitor of PSA. CONCLUSIONS: This study reports purification and characterization of 3 forms of PSA simultaneously. Furthermore, we have reported specific peptides for different forms of PSA which are either responsible for prostate cancer (PCa) or benign prostatic hyperplasia (BPH). Our study aids the existing information on categorizing the molecular heterogeneity of PSA