QUANTITATIVE HISTOPATHOLOGY IN LYMPH NODE-NEGATIVE BREAST-CANCER - PROGNOSTIC-SIGNIFICANCE OF MITOTIC COUNTS

Reliable prognostic factors are needed to improve the stratification o f patients with lymph node-negative breast cancer to different therapy modalities. We investigated the prognostic value of quantitative hist opathology in a retrospective study of 98 ''low-risk'' breast cancer p atients (T1+2hT0M0) with a median follow-up of 9 years. An interactive video system and stereological and morphometric techniques were used to obtain estimates of four nuclear features (mean volume, mean profil e area, volume fraction, and profile density), and two mitotic counts [mitotic profile frequency (MF) and mitotic profile density (MD)]. All measurements were performed in fields of vision sampled systematicall y from the whole tumour area of a routine histological section. Histol ogical grade, histological type, and oestrogen receptor (ER) status wa s reassessed, whereas tumour diameter and age at diagnosis were record ed from the files. We found that all quantitative histopathological va riables and ER status were correlated with histological grade. Single- factor prognostic analyses showed a highly significant value of MF (2p =0.001) and a marginally significant value of MD (2p=0.09), whereas no other variable approached statistical significance (2p greater than o r equal to 0.25). In a multivariate Cox analysis, MF was the only para meter of significant independent prognostic value (2p=0.03). Thus, the prognostic value of nuclear features found in previous studies could not be reproduced, whereas the marked value of mitotic counts for pred iction of the outcome in patients with breast cancer was confirmed. Mi totic counts are easily obtained and may be of clinical value for iden tification of high-risk cases among patients with lymph node-negative breast cancer.