Young Age on Starting Prostate-specific Antigen Testing Is Associated with a Greater Reduction in Prostate Cancer Mortality: 24-Year Follow-up of the Göteborg Randomized Population-based Prostate Cancer Screening Trial.

BACKGROUND: The risk of death from prostate cancer (PC) depends on age, but the age at which to start prostate-specific antigen (PSA) screening remains uncertain. OBJECTIVE: To study the relationship between risk reduction for PC mortality and age at first PSA screening. DESIGN, SETTING, AND PARTICIPANTS: The randomized Göteborg-1 trial invited men for biennial PSA screening between the ages of 50 and 70 yr (screening, n = 10 000) or no invitation but exposure to opportunistic PSA testing (control, n = 10 000). INTERVENTION: Regular versus opportunistic PSA screening or no PSA. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We modeled the nonlinear association between starting age and the absolute risk reduction in PC mortality in three settings: (1) intention-to-screen (randomized arms); (2) historical control (screening group and 1990-1994 registry data); and (3) attendees only (screening attendees and matched controls). We tested whether the effect of screening on PC mortality depends on the age at starting screening by comparing survival models with and without an interaction between trial arm and age (intention-to-screen and attendees only). RESULTS AND LIMITATIONS: Younger age on starting PSA testing was associated with a greater reduction in PC mortality. Starting screening at age 55 yr approximately halved the risk of PC death compared to first PSA at age 60 yr. The test of association between starting age and the effect of screening on PC mortality was slightly greater than the conventional level of statistical significance (p = 0.052) for the entire cohort, and statistically significant among attendees (p = 0.002). This study is limited by the low number of disease-specific deaths for men starting screening before age 55 yr and the difficulty in discriminating between the effect of starting age and screening duration. CONCLUSIONS: Given that prior screening trials included men aged up to 70 yr on starting screening, our results suggest that the effect size reported in prior trials underestimates that of currently recommended programs starting at age 50-55 yr. PATIENT SUMMARY: In this study from the Göteborg-1 trial, we looked at the effect of prostate-specific antigen (PSA) screening in reducing men's risk of dying from prostate cancer given the age at which they begin testing. Starting at a younger age reduced the risk of prostate cancer death by a greater amount. We recommend that PSA screening should start no later than at age 55 yr.

Impact of recent screening on predicting the outcome of prostate cancer biopsy in men with elevated prostate-specific antigen: data from the European Randomized Study of Prostate Cancer Screening in Gothenburg, Sweden.

BACKGROUND: Risk models to predict prostate cancer on biopsy, whether they include only prostate-specific antigen (PSA) or other markers, are intended for use in all men of screening age. However, the association between PSA and cancer probably depends on a man's recent screening history. METHODS: The authors examined the effect of prior screening on the ability to predict the risk of prostate cancer by using a previously reported, 4-kallikrein panel that included total PSA, free PSA, intact PSA, and human kallikrein-related peptidase 2 (hK2). The study cohort comprised 1241 men in Gothenburg, Sweden who underwent biopsy for elevated PSA during their second or later visit for the European Randomized Study of Screening for Prostate Cancer. The predictive accuracy of the 4-kallikrein panel was calculated. RESULTS: Total PSA was not predictive of prostate cancer. The previously published 4-kallikrein model increased predictive accuracy compared with total PSA and age alone (area under the curve [AUC], 0.66 vs 0.51; P < .001) but was poorly calibrated and missed many cancers. A model that was developed with recently screened men provided important improvements in discrimination (AUC, 0.67 vs 0.56; P < .001). Using this model reduced the number of biopsies by 413 per 1000 men with elevated PSA, missed 60 of 216 low-grade cancers (Gleason score < or =6), but missed only 1 of 43 high-grade cancers. CONCLUSIONS: Previous participation in PSA screening dramatically changed the performance of statistical models that were designed to predict biopsy outcome. A 4-kallikrein panel was able to predict prostate cancer in men who had a recent screening history and provided independent confirmation that multiple kallikrein forms contribute important diagnostic information for men with elevated PSA. Cancer

A panel of kallikrein markers can reduce unnecessary biopsy for prostate cancer: data from the European Randomized Study of Prostate Cancer Screening in Göteborg, Sweden.

BACKGROUND: Prostate-specific antigen (PSA) is widely used to detect prostate cancer. The low positive predictive value of elevated PSA results in large numbers of unnecessary prostate biopsies. We set out to determine whether a multivariable model including four kallikrein forms (total, free, and intact PSA, and human kallikrein 2 (hK2)) could predict prostate biopsy outcome in previously unscreened men with elevated total PSA. METHODS: The study cohort comprised 740 men in Göteborg, Sweden, undergoing biopsy during the first round of the European Randomized study of Screening for Prostate Cancer. We calculated the area-under-the-curve (AUC) for predicting prostate cancer at biopsy. AUCs for a model including age and PSA (the 'laboratory' model) and age, PSA and digital rectal exam (the 'clinical' model) were compared with those for models that also included additional kallikreins. RESULTS: Addition of free and intact PSA and hK2 improved AUC from 0.68 to 0.83 and from 0.72 to 0.84, for the laboratory and clinical models respectively. Using a 20% risk of prostate cancer as the threshold for biopsy would have reduced the number of biopsies by 424 (57%) and missed only 31 out of 152 low-grade and 3 out of 40 high-grade cancers. CONCLUSION: Multiple kallikrein forms measured in blood can predict the result of biopsy in previously unscreened men with elevated PSA. A multivariable model can determine which men should be advised to undergo biopsy and which might be advised to continue screening, but defer biopsy until there was stronger evidence of malignancy.

Results of a randomized, population-based study of biennial screening using serum prostate-specific antigen measurement to detect prostate carcinoma.

BACKGROUND: The purpose of the current study was to evaluate the effectiveness of a prostate carcinoma screening program in which serum prostate-specific antigen (PSA) levels were measured. METHODS: From a group of 20,000 men born between January 1, 1930, and December 31, 1944, 10,000 men were randomized into a screening group and 10,000 were randomized into a control group. Patients in the screening group were invited to undergo initial PSA testing between 1995 and 1996 and then were invited to receive testing every second year thereafter for 8 years (for a total of 4 PSA tests). Men with PSA levels > or =3 ng/mL (or > or =2.54 ng/mL, in the third and fourth screening rounds) were invited to undergo clinical investigation, which included sextant biopsy of the prostate. By linking to the regional cancer registry, the authors were able to obtain the true and expected incidence rates for the screening and control groups. RESULTS: The screening participation rate was high (73%). A total of 884 malignancies have been detected to date, with 640 having been detected in the screening group. There was an early and marked shift toward more favorable disease stage and grade for malignancies detected on repeat screening. In the fourth screening round, only 2 of 82 detected malignancies were classified as advanced disease. Of the 227 screen-detected tumors on which surgery was performed, only 20 (8.8%) had small volume (<0.2 cm3). Forty-three interval malignancies were detected, but only five were accompanied by symptoms. At 8 years, the cumulative disease incidence rate among screening participants was 7.3%, compared with 2.4% in the control arm. The incidence rate observed in the screening population corresponds to the cumulative incidence rate observed in the Swedish male population at age 72 years. CONCLUSIONS: Biennial PSA screening was very successful in diagnosing prostate carcinoma at an early stage, when curative treatment typically is effective. In addition, the results regarding interval malignancies were favorable. Thus, decreased mortality should be observed on long-term follow-up. The lead time associated with screening appears to fall within the range described in earlier studies involving frozen sera (i.e., 5-9 years).

The risk of finding focal cancer (less than 3 mm) remains high on re-biopsy of patients with persistently increased prostate specific antigen but the clinical significance is questionable.

PURPOSE: We evaluated the significance of focal prostate cancer found in sextant biopsies in men participating in a biennial prostate specific antigen (PSA) based screening program. MATERIALS AND METHODS: In 1995, 10000 men 50 to 65 years old were randomized to biennial screening with PSA testing. Sextant biopsies were recommended when total PSA was 3 ng/ml or greater at screening rounds 1 and 2, and 2.54 ng/ml or greater at subsequent screening rounds. Focal cancer was defined as total a core cancer length of less than 3 mm in the biopsy specimen. Low volume cancer was defined as a total tumor volume of less than 0.5 cm in the radical retropubic prostatectomy specimen. RESULTS: The number of men who underwent biopsy and the number of cancers detected in the 5 possible sets of biopsies were 1725 and 402, 706 and 124, 307 and 36, 103 and 9, and 13 and 0, respectively. The risk of detecting focal cancer was 7.9%, 10.2%, 7.5%, 5.8% and 0%, respectively, but the relative ratio (focal-to-all cancers) increased 34%, 58%, 64%, 67% and, not applicable, respectively. In men with a total core cancer length of less than 10 mm there was no correlation between core cancer length and total tumor volume, as measured in the prostatectomy specimen. Two-thirds of men with a total core cancer length of less than 3 mm had a tumor volume of greater than 0.5 cm, while the risk of low volume cancer was less than 5% only in men with a total core cancer length of greater than 10 mm. CONCLUSIONS: In a repeat PSA based screening program sextant biopsies are of little or no value for predicting tumor volume.