THE REPRODUCIBILITY OF NUCLEAR MORPHOMETRIC MEASUREMENTS IN INVASIVE BREAST-CARCINOMA

The intraobserver and interobserver reproducibility of computerized nu clear morphometry was determined in repeated measurements of 212 sampl es of invasive breast cancer. The influence of biological variation an d the selection of the measurement area was also tested. Morphometrica lly determined mean nuclear profile area (Pearson's r 0.89, grading ef ficiency (GE) 0.95) and standard deviation (SD) of nuclear profile are a (Pearson's r 0.84, GE 0.89) showed high reproducibility. In this res pect, nuclear morphometry equals with other established methods of qua ntitative pathology and exceeds the results of subjective grading of n uclear atypia in invasive breast cancer. A training period of eight da ys was sufficient to produce clear improvement in consistency of nucle ar morphometry results. By estimating the sources of variation it coul d be shown that the variation associated with the measurement procedur e itself is small. Instead, sample associated Variation is responsible for the majority of variation in the measurements (82.9% in mean nucl ear profile area and 65.9% in SD of nuclear profile area). This study points out that when standardized methods are applied computerized mor phometry is a reproducible and reliable method of assessing nuclear at ypia in invasive breast cancer. For further improvement special emphas ize should be put on sampling rules of selecting the microscope fields and measurement areas.