Unbiased stereological estimation of the number and volume of nuclei and nuclear size variability in invasive ductal breast carcinomas

Abstract

The application of design-based stereological methods for estimating nuclear features quantitatively in invasive ductal breast cancer is described. Nuclear number, size and size variability are explored in relation to the tumour grade and patient prognosis. The study includes an examination of the efficiency in estimating different nuclear volumes, and two different estimators of the nuclear size variability are contrasted. Forty-two invasive ductal breast carcinomas diagnosed and graded by two pathologists were used. Both 5-microns and 25-microns-thick sections were obtained from paraffin blocks for stereological study. More undifferentiated tumours show significantly larger nuclei than low-grade tumours. The estimates based on the disector method demonstrate a decrease in the number of tumour cell nuclei per unit volume of tissue from grades 1 to 2 and especially from grades 2 to 3. The univariate survival analysis shows a high prognostic value of the nuclear volume estimates. The study shows that an efficient sampling procedure was performed, particularly when estimating volume-weighted mean nuclear volume using the point-sampled intercepts method. This method is more efficient than estimation of the number-weighted mean nuclear volume using the selector method; however, the latter provides paired estimates of volume- and number-weighted mean nuclear volume, as well as an estimate of the coefficient of variation of nuclear volume in the number distribution of the same cells.

Use of the optical disector in canine mammary simple and complex carcinomas

“…Despite the differences in figures between our and human studies, some observations in breast cancers were mirrored to some extension in CMC. For instance, there was no significant association between N V (nuclei, tumor) and histological grade, but a significant negative correlation was noted between the N V (nuclei, tumor) and the volume‐weighted mean nuclear volume [r = −0.34, −0.63, and −0.31 in our study and in the two existing breast cancer estimations, respectively, and ].…”

“…Herein, the optical disector was used to assess the N V (nuclei, tumor) in CMC. Notably, the mean value for CMC (1.6 × 10 6 nuclei/mm 3 ) was higher (but in the same order of magnitude) than that reported for human breast cancer (0.4 × 10 6 nuclei/mm 3 ) . Interspecies differences may underlie such discrepancy, along with eventual technical discrepancies, particularly in the definition of the reference space (e.g., we excluded stromal areas).…”

“…Another interesting finding in both species is that cancers with worst survival outcomes presented a lower N V (nuclei, tumor) . At a first glance, this is an unexpected observation that appears to contradict the traditional concept that highly cellular tumors are associated with poorer prognosis .…”

“…Stereological studies have been performed in human breast cancer and estimates of nuclear volumes (volume and number‐weighted mean nuclear volumes) and of numerical density (N V ) of nuclei and mitotic figures have been correlated with prognosis . In CMC, the use of stereology is still very incipient , but it already started to solve issues related with the subjective assessment of nuclear pleomorphism in grading of CMC .…”

Stereology in Grading and Prognosis of Canine Cutaneous Mast Cell Tumors

“…29,30 Most histological grading schemes rely on the subjective evaluation of morphologic and cytological parameters, which are prone to personal bias and often lead to intra-and interobserver variability. 1,28 In the case of ccMCTs, the most frequently used grading systems are those of Patnaik and Kiupel. The Patnaik system grades ccMCTs as grade I (G1), II (G2), and III (G3) according to the degree of mast cell differentiation, morphology, cellularity, extent of tissue involvement, stromal reaction, and mitotic count.…”