DNA ploidy and thymidine-labeling index (TLI) have been introduced as progn
ostic indicators to characterize the biological behavior of breast cancer f
or the selection of patients eligible for adjuvant therapy. The aim of this
study was to evaluate the prognostic significance and correlation between
ploidy status, TLI and other common histopathologic parameters such as hist
otype, stage, grading lymph node metastasis, hormone receptors and recurren
ce. DNA ploidy and TLI were assessed for 68 breast cancer patients, 27 to 8
5 yeats of age. DNA histograms, analyzed with static cytometry, were: diplo
id in 21(31%) and non diploid in 47 (70%). High TLI values were observed in
16 cases (24 %), medium values in 46 cases (68%) and low values in 6 cases
(8,5%). DNA ploidy and TLI showed a statistically significant correlation,
as independent parameters, with recurrence (respectively, p=0.0267 and p<0
.0001). Therefore, DNA ploidy and TLI may be considered additional prognost
ic parameters to be utilized besides all the other clinical-pathologic data
for the assessment of these lesions, and to plan therapeutic strategies.