Analysis of repeated biopsy results within 1 year after a noncancer diagnosis

Objectives. A prostate biopsy data base derived from patients referred to p rivate practice urologists was analyzed for the cancer diagnosis rates of t he "initial" biopsy and the repeated biopsy performed within 1 year for tho se patients with a noncancer diagnosis. Methods. A retrospective analysis assessed 132,426 prostate biopsies receiv ed and processed by a single pathology laboratory between March 1994 and Se ptember 1998; none had had a previous biopsy processed at this laboratory. Prostate cancer was diagnosed in 50,521 of the patients (38.2%). The remain ing 81,905 patients (61.8%) had a noncancer diagnosis of either no evidence of malignancy (NEM), high-grade prostatic intraepithelial neoplasia (HGPIN ), small acinar glands suspicious for cancer (suspicious), or suspicious wi th HGPIN (Susp-HGPIN). We identified 6380 (7.8%) of these "noncancer" patie nts who underwent a repeated biopsy within 1 year. Results. The incidence of NEM, HGPIN, suspicious, and Susp-HGPIN biopsy dia gnoses in the "noncancer" patients (81,905) was 55.3%, 3.7%, 2.5%, and 0.3% , respectively. The rate at which these "noncancer" patients (81,905) under went a repeated biopsy was 4.80% for patients with a diagnosis of NEM, 26.6 % for HGPIN, 40.4% for suspicious, and 47.5% for Susp-HGPIN. The overall ca ncer diagnosis rate in the repeated biopsy patient sample (6380) was 25.7%. When stratified by the initial biopsy diagnosis, the cancer diagnosis rate for the repeated biopsies was 19.8%, 22.6%, 40.0%, and 53.1%, for the pati ents with NEM, HGPIN, suspicious, and Susp-HGPIN, respectively. The repeate d biopsy diagnosis rates did not vary dramatically when analyzed at 3-month intervals during the 1-year period. Also, a strong correlation (79%) was o bserved between the number of tissue samples obtained at the initial and re peated biopsy procedures. In a subset of patients with free and total prost ate-specific antigen (PSA) results obtained before the repeated biopsy (n = 813), we were able to construct a multivariate logistic regression algorit hm using the patients' age, initial biopsy diagnosis, total PSA, and free/t otal PSA ratio that could predict the likelihood of cancer on the repeated biopsy with an accuracy of 70%. Conclusions. Men who have an initial noncancerous biopsy diagnosis remain a t risk of prostate cancer, especially if the initial diagnosis was suspicio us or Susp-HGPIN. These data suggest that the initial biopsy strategy needs to be improved and/or expanded to increase the overall cancer detection ra te in the primary biopsy. In addition, combining factors such as the initia l biopsy diagnosis, family history, digital rectal examination results, pro state gland volume, age, total PSA, and free/total PSA ratio could provide valuable information for predicting the likelihood of cancer. UROLOGY 55: 5 53-559, 2000. (C) 2000, Elsevier Science Inc.