Development of ploidy and cell proliferation in serial samples of ascites from patients with ovarian carcinoma

Repeated samples of ascites were obtained from 14 ovarian carcinoma patients over a period of 10 to 360 days. The samples were studied by means of flow-cytometry and monoclonal antibodies specific for bromodeoxyuridine. Ploidy and proliferation of tumor cell populations were measured to establish the significance of these properties in the development of the tumors. Ploidy was mostly a stable feature while the proportion of S-phase values increased significantly over the passage of time. This increase is discussed in relation to the expression of selective processes towards more aggressive tumor cell lines and to the development of chemoresistance.