Combined histoarchitectural and cytological biopsy grading improves grading accuracy in low-grade prostate cancer

Abstract

Objectives: Accurate tumor grading on prostate biopsy represents the mainstay for therapy planning. Biopsy undergrading is a persistent diagnostic dilemma with therapeutic relevance. We questioned whether Gleason grading combined with an established alternative grading system incorporating cytological parameters improves grading accuracy.

Methods: Needle biopsies of 968 patients and the corresponding radical prostatectomy specimens were graded according to the Gleason grading system. In addition, all biopsies were graded according to the histo- and cytological grading system of Helpap. Biopsy Gleason grade, as well as the combined Gleason/Helpap grade, was compared with the final Gleason score and the pathological tumor-stage of the corresponding radical prostatectomy.

Results: In biopsy Gleason score 6 cancers, an upgrading was seen in 76.0% of the patients (98/129), and 30.2% of them (39/129) showed non-organ confined disease. In combined biopsy Gleason 6/Helpap 2a patients, a final Gleason score of 6 was found in 22 out of 24 patients (91.7%, P<0.0001), and all 24 patients showed organ-confined disease (pT2a). In biopsy Gleason 6/Helpap 2b cancers, a final Gleason score of 6 was found in just 9 out of 105 patients (8.6%), and the rate of organ-confined disease decreased to 62.8% (66/105, P=0.0001). In higher Gleason grades, combined biopsy grading failed to show a diagnostic benefit over sole Gleason grading.

Conclusion: Combined biopsy Gleason/Helpap grading improves the identification of low-grade/low-stage cancers and might contribute to more precise therapy planning in prostate cancer management.