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

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.

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.

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.

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.