Clinicopathological features of prostate cancers detected after an initial diagnosis of 'atypical glands suspicious for cancer'

Background: A diagnosis of 'atypical glands suspicious for cancer' (ATYP) in prostate needle biopsy is associated with approximately a 40-50% risk of detecting prostate cancer in subsequent biopsies. Pathological characteristics of prostate cancer following an initial diagnosis of ATYP are rarely studied. Design: We studied prostate biopsies with an initial diagnosis of ATYP. Number of ATYP foci, presence of concomitant high grade prostatic intraepithelial neoplasia (HGPIN), date and diagnosis of repeat biopsies were recorded. When radical prostatectomy was performed for confirmed prostate cancer, Gleason score, tumour volume, extraprostatic extension, seminal vesicle invasion, lymph node status, and surgical margins of resection status were also recorded. Results: Between 1992 and 2009, 239 patients biopsied at our institution carried a diagnosis of ATYP and underwent repeat follow-up biopsies. The mean time interval between first biopsy and last repeat biopsy was 14.4 months; the average number of follow up biopsies was 1.4. Most cases (85.3%) had a single focus of ATYP; in 14.6%, ATYP involved more than one biopsy core. Concomitant HGPIN was present in 56.9% of cases. Final repeat follow-up diagnoses were: prostate cancer in 122 (51.0%), ATYP in 15 (6.3%), HGPIN in 35 (14.6%), and benign prostatic tissue in 67 (28.0%) cases. Of 122 patients with prostate cancer detected in repeat follow-up biopsies, 51 underwent radical prostatectomy and two had only a pelvic lymph node dissection, one of which revealed metastatic prostate cancer. One patient presented with metastatic prostate cancer in a cervical lymph node. Radical prostatectomy Gleason score was 6 in 25 patients (49.0%), 7 in 19 (37.2%),8 in five (9.8%), and undetermined in two (3.9%) cases. Extraprostatic extension was present in seven of 47 (14.9%), and seminal vesicle invasion in three of 51 (5.9%) cases. Tumour volume was low in 42.8%, medium in 49.0%, and extensive in 8.2% of cases. Of the total 53 prostate cancers analysed (51 radical prostatectomy and 2 lymph node metastases), 37 (69.8%) were pathologically significant cancer, 14 (26.4%) were potentially pathologically insignificant, and two were undetermined. Conclusion: Most prostate cancers detected following an initial diagnosis of ATYP are clinically significant. Patients with a diagnosis of ATYP should be followed up aggressively.