This fact sheet is for men who've been diagnosed with high grade prostate intraepithelial neoplasia (PIN) or atypical small acinar proliferation (ASAP) after having a prostate biopsy. It explains what PIN and ASAP are and how they might be monitored.

Last updated: August 2017
To be reviewed: May 2019


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  • Capodice, J. L. et al. Zyflamend in men with high-grade prostatic intraepithelial neoplasia: results of a phase I clinical trial. J Soc Integr Oncol 7, 43–51 (2009).
  • Carver, B. S. et al. Race is not a predictor of prostate cancer detection on repeat prostate biopsy. The Journal of Urology 172, 1853–1855 (2004).
  • Clouston, D. & Bolton, D. In situ and intraductal epithelial proliferations of prostate: definitions and treatment implications. Part 2: intraductal carcinoma and ductal adenocarcinoma of prostate. BJU Int. 110 Suppl 4, 22–24 (2012).
  • De Nunzio, C. et al. The number of cores positive for high grade prostatic intraepithelial neoplasia on initial biopsy is associated with prostate cancer on second biopsy. J. Urol. 181, 1069–1074; discussion 1074–1075 (2009).
  • Dickinson, S. I. Premalignant and malignant prostate lesions: pathologic review. Cancer Control 17, 214–222 (2010).
  • Epstein, J. I. & Herawi, M. Prostate needle biopsies containing prostatic intraepithelial neoplasia or atypical foci suspicious for carcinoma: implications for patient care. J. Urol. 175, 820–834 (2006).
  • Fleshner, N. E. et al. Progression from high-grade prostatic intraepithelial neoplasia to cancer: a randomized trial of combination vitamin-E, soy, and selenium. J. Clin. Oncol. 29, 2386–2390 (2011).
  • Fowler, J. E., Jr, Bigler, S. A., Lynch, C., Wilson, S. S. & Farabaugh, P. B. Prospective study of correlations between biopsy-detected high grade prostatic intraepithelial neoplasia, serum prostate specific antigen concentration, and race. Cancer 91, 1291–1296 (2001).
  • Heidenreich, A. et al. EAU guidelines on prostate cancer. Part 1: screening, diagnosis, and treatment of clinically localised disease. Eur. Urol. 59, 61–71 (2011).
  • Laurila, M. et al. Detection rates of cancer, high grade PIN and atypical lesions suspicious for cancer in the European Randomized Study of Screening for Prostate Cancer. Eur. J. Cancer 46, 3068–3072 (2010).
  • Lee, M. C. et al. Multifocal high grade prostatic intraepithelial neoplasia is a risk factor for subsequent prostate cancer. J. Urol. 184, 1958–1962 (2010).
  • Maccagnano, C. et al. Prostate saturation biopsy following a first negative biopsy: state of the art. Urol. Int. 89, 126–135 (2012).
  • Marshall, J. R. et al. Phase III trial of selenium to prevent prostate cancer in men with high-grade prostatic intraepithelial neoplasia: SWOG S9917. Cancer Prev Res (Phila) 4, 1761–1769 (2011).
  • Mason, T. E. et al. Association of CD14 variant with prostate cancer in African American men. The Prostate n/a–n/a (2009). doi:10.1002/pros.21060
  • Merrimen, J. L. et al. Multifocal high grade prostatic intraepithelial neoplasia is a significant risk factor for prostatic adenocarcinoma. J. Urol. 182, 485–490; discussion 490 (2009).
  • Merrimen, J. L., Jones, G. & Srigley, J. R. Is high grade prostatic intraepithelial neoplasia still a risk factor for adenocarcinoma in the era of extended biopsy sampling? Pathology 42, 325–329 (2010).
  • Montironi, R., Mazzucchelli, R., Lopez-Beltran, A., Scarpelli, M. & Cheng, L. Prostatic intraepithelial neoplasia: its morphological and molecular diagnosis and clinical significance. BJU Int. 108, 1394–1401 (2011).
  • Montironi, R. et al. Atypical foci suspicious but not diagnostic of malignancy in prostate needle biopsies (also referred to as ‘atypical small acinar proliferation suspicious for but not diagnostic of malignancy’). Eur. Urol. 50, 666–674 (2006).
  • Ploussard, G. et al. High-grade prostatic intraepithelial neoplasia and atypical small acinar proliferation on initial 21-core extended biopsy scheme: incidence and implications for patient care and surveillance. World J Urol 27, 587–592 (2009).
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  • Sakr, W. A. et al. Age and racial distribution of prostatic intraepithelial neoplasia. Eur. Urol. 30, 138–144 (1996).
  • Sakr, W. A. et al. Epidemiology of high grade prostatic intraepithelial neoplasia. Pathol. Res. Pract. 191, 838–841 (1995).
  • Thompson, I. M. et al. Finasteride Decreases the Risk of Prostatic Intraepithelial Neoplasia. The Journal of Urology 178, 107–110 (2007).
  • Toremifene for the prevention of prostate cancer in men with high grade prostatic intraepithelial neoplasia: results of a double-blind, placebo controlled, phase IIB clinical trial. Medify at
  • Wang, Y. et al. Evidence for an association between prostate cancer and chromosome 8q24 and 10q11 genetic variants in African American men: the Flint Men’s Health Study. Prostate 71, 225–231 (2011).
  • Zanardi, S. et al. Phase I-II trial of weekly bicalutamide in men with elevated prostate-specific antigen and negative prostate biopsies. Cancer Prev Res (Phila) 2, 377–384 (2009).
  • Zynger, D. L. & Yang, X. High-grade Prostatic Intraepithelial Neoplasia of the Prostate: The Precursor Lesion of Prostate Cancer. Int J Clin Exp Pathol 2, 327–338 (2008).

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