Nuclear roundness factor measurement for assessment of prognosis of patients with prostatic carcinoma. II. Standardization of methodology for histologic sections.

A nuclear shape descriptor, nuclear roundness factor, predicted outcome in patients with prostatic carcinoma whereas standard pathological grading by Gleason's architectural pattern did not. The inability of others to duplicate those successes warranted a reevaluation of the technique for NRF measurement. We previously described our digitization system and measured the perimeter and area of a microscopic circle similar in size to prostatic carcinoma nuclei with a reproducibility and accuracy of greater than 95%. We have applied our improved system to nuclear contour digitization and standardized our method for NRF measurement. In order to calculate accurately the NRF for prostatic carcinoma, the histologic section must have been reviewed by a pathologist and 150 nuclei traced after random selection. NRF measurement reproducibility within and between observers exceeded 90%. This system for NRF measurement successfully predicted outcome in 13 of 15 patients with stages A2, B1, and B2 prostatic carcinoma. Our success with a carefully tested and improved system for NRF determination warrants further evaluation of NRF for assessment of prognosis of patients with prostatic carcinoma.