A "Chicken or Egg" Conundrum: Race, Molecular Subtype, and Tumor Location in Prostate Cancer

Utility of Anterior Zone Biopsy in Men Enrolled in Active Surveillance for Prostate Cancer

BACKGROUND

Anterior zone (AZ) disease is present in one-fifth of men with newly diagnosed prostate cancer and has been associated with poor pathologic features. However, anterior targeted biopsies are not a routine part of active surveillance (AS) protocols. Our purpose is to assess the utility of AZ sampling for prostate biopsy in patients undergoing surveillance for low-risk prostate cancer.

METHODS

A prospective data collection of men enrolled in AS between 2006 and 2014 was performed. Patient and disease characteristics were collected, including number of positive cores and Gleason score on all diagnostic and surveillance biopsies. Progression was defined as incident Gleason > 6 in any core and/or receipt of definitive therapy including radical prostatectomy or radiotherapy. Rate of anterior disease and relationship to subsequent disease progression was assessed.

RESULTS

A total of 85 men were included, of which 45% demonstrated progression. Median follow-up was 40 months. Among those undergoing AZ sampling at initial diagnosis, 37% presented with AZ disease. A total of 47% of men with AZ-only disease progressed, whereas 78% of men with AZ and peripheral zone disease progressed. This compares with a 39% rate of progression among men with only peripheral zone disease. Multivariable logistic regression identified increasing body mass index as a significant predictor of disease progression (odds ratio, 5.18; 95% confidence interval, 1.06-25.31; P = .04).

CONCLUSIONS

Over one-third of men enrolled in AS for low-risk prostate cancer had AZ disease on diagnostic biopsy. Progression occurred in the majority of these men. AZ sampling should be considered in biopsy surveillance strategies.

Molecular subtyping of prostate cancer

PURPOSE OF REVIEW

The recent publication of The Cancer Genome Atlas molecular taxonomy of primary prostate cancer highlights the increased understanding of the genomic basis of human prostate cancer, but also emphasizes the complexity and heterogeneity of prostate cancer.

RECENT FINDINGS

Seven molecular subclasses have been defined on the basis of early genomic alterations, which are largely mutually exclusive.

SUMMARY

We review the recent advances in the genomic understanding of human prostate cancer, with focus on molecular subclassification. Broadly, prostate cancer can be classified based upon whether specific genomic rearrangements, such as the Transmembrane Protease, Serine 2-ETS-related gene fusion occur or whether specific alterations such as Speckle-type POZ protein and forkhead box A1 mutations occur. The molecular drivers remain to be identified in a further quarter of human prostate cancers. Depending upon the molecular subclassification and the coincident genomic alterations, specific clinical insights can be gained from this information, including associations with pathologic factors, race, and prognosis, as well as the possibility for future precision therapies.