HISTOPATHOLOGY GRADING IN SMALL BREAST CANCERS LESS-THAN-OR-EQUAL-TO-10MM - RESULTS FROM AN AREA WITH MAMMOGRAPHY SCREENING

Histopathological malignancy grading using the Bloom-Richardson classi fication of ductal cancers was performed for 248 invasive ductal breas t cancers less than or equal to 10mm operated 1978-1985. There were si gnificantly more grade 1 lesions in the prevalence screening round. Gr ade 3 was correlated with aneuploidy, higher S-phase (SPF), and more r eceptor negative tumours. There were also significantly more positive lymph nodes in grade 3 lesions, 18% compared to 5% and 12% respectivel y for grades 1 and 2 (p<0.05). In life table analysis for survival, wh en the high risk group of grade 3 lesions was compared to the grade 1 and 2 lesions combined, five-year disease-free survival was 84.6% vs. 99.1% (p<0.001). With good training and care from the pathologist, mal ignancy grading seems useful for prognostication of eventual recurrenc e and death. In tumours 10mm or smaller only grade 3 lesions need to b e included in follow-up systems and should probably have adjuvant trea tment. Malignancy grading is especially good in small ductal breast ca ncers where grading can always be performed while other prognostic det erminations are hampered by shortage of material. Lymph node positivit y is also low in this group.