Evaluation of prostatic specific antigen and digital rectal examination as screening tests for prostate cancer.

BACKGROUND: The 11,811 first visits and 46,751 annual follow-up visits performed since 1988 were analyzed in order to assess the efficacy of serum prostatic specific antigen (PSA) and digital rectal examination (DRE) for diagnosis of prostate cancer. METHODS: At first visit, screening included DRE and measurement of PSA using 3.0 ng/ml as upper limit of normal, demonstrated as optimal value in the course of the study. Transrectal echography of the prostate (TRUS) was performed only if PSA and/or DRE was abnormal. For elevated PSA, biopsy was performed only if PSA was above the value predicted from prostatic volume measured by TRUS. At follow-up visits, it was decided during the course of the study to use PSA alone. RESULTS: PSA was above 3.0 ng/ml in 16.6% and 15.6% of men at first and follow-up visits, respectively. Prostate cancer was found in 2.9% of men invited for screening at first visit and in only 0.4% of men at follow-up visits for a 7.1-fold decrease at follow-up visits done up to 11 years. PSA alone allowed to find 90.5% and 90. 0% of cancers at first and follow-up visits, respectively, compared to 41.1% and 25.0% by DRE alone. In the presence of normal PSA, 344 and 1,919 DREs are needed to find one prostate cancer at first and follow-up visits, respectively. A significant improvement in stage of the disease is found at follow-up (215 cancers) compared to first visits (337 cancers). Comparison made between men invited for screening and those who were not invited but screened showed no significant difference in terms of incidence and prevalence of prostate cancer as well as diagnosis of cancer as a function of age or as a function of PSA, DRE, and TRUS data. The cost for finding one case of prostate cancer is estimated at Can $2,420 and Can $7, 105 (first and follow-up visits, respectively, when PSA is used as prescreening). CONCLUSIONS: PSA used as prescreening and followed by DRE and TRUS when PSA is abnormal is highly efficient in detecting prostate cancer at a localized (potentially curable) stage since 99% of the cancers diagnosed were at such a localized stage, thus practically eliminating the diagnosis of metastatic and noncurable prostate cancer. The approach used is highly reliable, sensitive, efficient, and acceptable by the general population. The detection of clinically nonsignificant cancer is an exception.

Screening decreases prostate cancer death: first analysis of the 1988 Quebec prospective randomized controlled trial.

BACKGROUND: The 46,193 men aged 45 to 80 years registered in the electoral roll of Quebec City and its Metropolitan area were randomized in November 1988 between screening and no screening in a study aimed of assessing the impact of prostate cancer screening on cause-specific death. METHODS: At first visit, screening included measurement of serum prostatic specific antigen (PSA) using 3.0 ng/ml as upper limit of normal and a digital rectal examination (DRE). Transrectal echography of the prostate (TRUS) was performed only if PSA and/or DRE was abnormal and biopsy was then done, only if PSA was above the predicted PSA value. At follow-up visits, PSA alone was used as prescreening. RESULTS: 137 deaths due to prostate cancer occurred between 1989 and 1996, inclusively, in the 38,056 unscreened men while only 5 deaths were observed among the 8,137 screened individuals. The prostate cancer death rates during the eight-year period were 48.7 and 15 per 100,000 man-years in the unscreened and screened groups, respectively, for a 3.25 odds ratio in favor of screening and early treatment (P < 0.01). CONCLUSIONS: If PSA screening is started at the age of 50 years (or 45 years in the higher risk population), annual or biannual PSA alone is highly efficient to identify the men who are at high risk of having prostate cancer. Coupled with treatment of localized disease, this approach demonstrates, for the first time, that early diagnosis and treatment permits a dramatic decrease in deaths from prostate cancer.

Determination of prostate gland volume by transrectal ultrasound: correlation with radical prostatectomy specimens.

Seventy six patients underwent transrectal ultrasound examination of the prostate prior to radical prostatectomy. All radical specimens were weighed and measured when freshly excised. Corresponding measurements calculated using transrectal ultrasound dimensions were retrospectively compared with those of the freshly excised glands. Estimation of gland volume by ultrasound measurement, utilizing the prolate ellipse formula [Width x Height x Length) x 0.70 was applied to a control group of 19 patients, and a close correlation (r = 0.77) between ultrasound estimated volume and actual weight was shown. A modified prolate ellipse formula, using the factor of 0.70, appears to be a more reliable means of estimating gland volume with transrectal ultrasound than the original formula [Width x Height x Length) x 0.523).