Hormone receptor status and mitotic activity as risk factors for recurrence and death in female breast carcinoma

Abstract

The estrogen (ER) and progesterone (PR) receptor status, volume corrected mitotic index (M/V index) and other classical prognostic factors were related to disease outcome in a series of 281 women with breast cancer followed up for over 8 years. The M/V index predicted recurrence only in ER+ or PR+ patients (p = 0.002-0.006). Similarly, the recurrence-free survival was related to M/V index only in ER+ (p = 0.0005) or PR+ (p less than 0.0001) patients. In survival analysis, ER+ (p = 0.0037) and PR+ (p less than 0.0001) patients were accurately divided into different prognostic groups by the M/V index, whereas in ER- and in PR-tumours the M/V index had only suggestive predictive value (p = 0.06-0.5). In N-tumours the M/V index predicted recurrence-free survival only in ER+ (p = 0.0228) and in PR+ (p = 0.0087) tumours. In survival analysis of N-tumours, the M/V index predicted cancer-related survival in ER+ (p = 0.0102) and in PR+ (p = 0.0014) tumours. In ER-/PR-, N-tumours, none of the variables tested had any prognostic value. The present results suggest that adjuvant hormone treatment might be indicated in ER+ or PR+ tumours with a M/V index greater than 10, regardless of the axillary lymph node status. The prognosis of ER+ or PR+ tumours with a M/V index less than 10 is favourable, the risk of recurrence being of the order of 15% only during the 10-year follow-up. Thus, the expensive and distressing adjuvant treatments could be omitted for these women with an inherently favourable disease outcome.