The value of S-phase and DNA ploidy analysis as prognostic markers for node-negative breast cancer in the Australian setting

This study aimed to determine the prognostic significance of DNA ploidy and S-phase fraction (SPF) measurements in our laboratory for patients with no de-negative breast cancer. Frozen tumors from axillary node-negative breast cancer patients (n = 50) treated at Westmead Hospital, NSW, between 1988 a nd 1991 were analysed by flow cytometry. The median duration of follow-up f or all patients was 8.4 years. Forty-six specimens provided evaluable DNA h istograms with 43% (n = 20) diploid and 56% (n = 26) aneuploid tumors ident ified. Comparisons of DNA ploidy status and SPF were made with traditional prognostic variables, which included age, menopausal status, tumor size, hi stologic grade and hormone receptor status, Our results showed that there w as no significant difference in disease-free or overall survival between pa tients with diploid and aneuploid tumors. Histologic grade 3 tumors were mo re likely to be aneuploid and had higher SPF than grade 1 or 2 tumors. Pati ents with grade 3 tumors and a high SPF were four times more likely to rela pse than the rest of the population. These results indicate that DNA flow c ytometric analysis in our laboratory provides additional prognostic data th at could be utilised alongside traditional clinical and histopathologic ind icators for predicting outcome for patients.