This study examined the validity of current US and European guidelines on the management of patients diagnosed with atypical small acinar proliferation (ASAP). Current guidance states that these patients should undergo repeat biopsy within three to six months due to the 30-40% risk of prostate cancer on subsequent biopsy. Two hundred and sixty-four patients across three institutions who were diagnosed with ASAP were followed up for a median of 5.4 years. All underwent repeat biopsy and 34% were subsequently diagnosed with prostate cancer including 8% with high-grade disease. Mean pre-biopsy prostate specific antigen (PSA) was 6.7 in those with positive repeat biopsies compared with 5.8 in those with negative repeat biopsies (p<0.001). In those diagnosed with cancer, the majority (78%) had low-risk disease, 17% had Gleason 7 and 6% had Gleason 8-10. Less than half of the patients diagnosed with prostate cancer underwent radical prostatectomy (36, 40%) and of those who did, histologically Gleason 8-10 disease was found in 11 patients. The findings suggest that for every 13 repeat biopsies, one high-grade cancer was found. The authors suggest that patients diagnosed with ASAP may be better managed along active surveillance lines using PSA / digital rectal examination (DRE) and additional imaging modalities such as MRI. In a climate where overtreatment of low-risk disease is being increasingly recognised, this study has highlighted the need for prospective studies into the management of ASAP.
