Identification of a low-risk group of stage I breast cancer patients by cytometrically assessed DNA and nuclear texture parameters.

Image cytometrical measurements were performed on Feulgen-stained cells from 329 stage I breast cancers (pT1pN0,M0,R0). For each patient, several DNA (ploidy, S-phase fraction, exceeding rates, 2c deviation index, ploidy balance, entropy, and histogram typing), morphometric (area and radius of nuclei), and textural parameters (mainly co-occurrence and run-length) were calculated. The prognostic value of these parameters was investigated by multivariate Cox regression analysis, considering a distant recurrence-free survival of 8 years as the prognostic criterion. In the multivariate analysis, one DNA parameter (histogram type) and two textural parameters (co-occurrence and variation of the average heterochromatin area) were proven to have independent prognostic value. Using a linear combination of these variables, a prognostic factor was calculated for each individual patient. Patients were stratified using this factor into several groups according to their risk for distant recurrence. Thus, a low-risk group of stage I patients was identified, remaining distant recurrence-free for 8 years. In addition, a group of patients with a worse prognosis and an 8-year recurrence rate of about 26 per cent was identified, compared with the average distant recurrence rate of all stage I patients of 13 per cent. A combination of DNA and textural parameters can provide powerful prognostic information in stage I breast carcinomas and may allow a better selection of patients for different therapy protocols.