Prognostic value of DNA ploidy and S-phase fraction in relation to estrogen receptor content and clinicopathological variables in primary breast cancer.

Tumors from 472 women with primary breast cancer were analyzed by flow cytometry. Divided into four categories, DNA ploidy showed significant association with disease recurrence and mortality. When allowance was made for its correlation with nodal status and estrogen receptor (ER) content, DNA ploidy did not add prognostic information. S-phase fraction was estimated in 290 DNA histograms. In contrast, it was significantly related to recurrence and mortality when controlling for nodal status, tumor size and ER content. When the follow-up was divided into two periods DNA ploidy and S-phase fraction showed association with disease recurrence in the first period only (less than 2.5 years), while the association with mortality was valid for both periods. Light scatter was measured in 234 samples. A low light scatter variability for the stemline nuclei was related to a high recurrence rate during the early follow-up period. In conclusion, DNA flow cytometry adds prognostic information concerning breast cancer patients.