The changing pattern of prostate cancer at the time of diagnosis: Characteristics of screen detected prostate cancer in a population based screening study

Purpose: We describe the clinical and pathological features of prostate can cer diagnosed through serum prostate specific antigen (PSA), digital rectal examination and transrectal ultrasonography in a population based randomiz ed screening study. Materials and Methods: Between November 1993 and June 1997, 20,632 voluntee rs 55 to 76 years old were included in the study. In the screening arm 9,77 6 men underwent digital rectal examination, transrectal ultrasound and seru m PSA determination. Biopsies were taken if the digital rectal examination and/or transrectal ultrasound findings were abnormal or if PSA was 4 ng./ml . or greater. A total of 2,262 men underwent biopsy and 474 cases of prosta te cancer were diagnosed. Results: The pretreatment data were complete in 459 men, of whom 78% had cl inically organ confined disease. Bone or lymph node metastases were seen in 8 cases (1.7%). Of 172 men who underwent radical prostatectomy 2 had lymph node metastases. Overall 66.3% of men treated with radical prostatectomy h ad organ confined disease. Conclusions: Comparison of the characteristics of prostate cancer detected through screening of the general population with those in a population base d cohort of men in which there was no organized screening revealed stage re duction, primarily with regard to number of metastastic cases. Whether this stage reduction will lead to a decrease in disease specific mortality rema ins unknown until the study is completed and the end point of prostate canc er specific mortality is evaluated.