Breast carcinoma, intratumour heterogeneity and histological grading, using geostatistics

Article type: Research Article

Authors: Sharifi‐Salamatian, Vénus | de Roquancourt, Anne | Rigaut, Jean Paul^;

Affiliations: Laboratoire d'Analyse d'Images en Pathologie Cellulaire (A.I.P.C), Institut Universitaire d'Hématologie, | Laboratoire d'Anatomie Pathologique, Université Paris 7‐Denis Diderot Hôpital Saint‐Louis, 1 avenue Claude Vellefaux, 75475 Paris Cedex 10, France

Note: [] Corresponding author.

Abstract: Tumour progression is currently believed to result from genetic instability. Chromosomal patterns specific of a type of cancer are frequent even though phenotypic spatial heterogeneity is omnipresent. The latter is the usual cause of histological grading imprecision, a well documented problem, without any fully satisfactory solution up to now. The present article addresses this problem in breast carcinoma. The assessment of a genetic marker for human tumours requires quantifiable measures of intratumoral heterogeneity. If any invariance paradigm representing a stochastic or geostatistic function could be discovered, this might help in solving the grading problem. A novel methodological approach using geostatistics to measure heterogeneity is used. Twenty tumours from the three usual (Scarff‐Bloom and Richardson) grades were obtained and paraffin sections stained by MIB‐1 (Ki‐67) and peroxidase staining. Whole two‐dimensional sections were sampled. Morphometric grids of variable sizes allowed a simple and fast recording of positions of epithelial nuclei, marked or not by MIB‐1. The geostatistical method is based here upon the asymptotic behaviour of dispersion variance. Measure of asymptotic exponent of dispersion variance shows an increase from grade 1 to grade 3. Preliminary results are encouraging: grades 1 and 3 on one hand and 2 and 3 on the other hand are totally separated. The final proof of an improved grading using this measure will of course require a confrontation with the results of survival studies.

Keywords: Breast carcinoma, intratumour heterogeneity, grading, geostatistics, ergodicity, paraffin‐embedded sections

Journal: Analytical Cellular Pathology, vol. 20, no. 2-3, pp. 83-91, 2000