Making headlines in the lab.

Out of 130 ovarian cancer patients the DNA index of cells from ovarian carcinoma was studied in 56 cases in which cytospin preparations showed the presence of atypical cells. In 24 patients the population had a diploid DNA index (1.0) and in the others the DNA index ranged from 1.2 to 2.0 (tetraploid). No hypodiploid or hypertetraploid populations were detected. Repeated samples from the same patients did not show any significant differences and primary culture did not alter the DNA index. In contrast, cell cycle phase distribution differed greatly from sample to sample, as also the ratio between DNA diploid and DNA aneuploid populations. Primary culture was successful in 57% of the tumours, with a higher percentage of success in DNA aneuploid tumours. After primary culture the ratio between DNA aneuploid cells and DNA diploid cells increased. In relation to the histological gradings of malignancy, DNA aneuploid cells clustered in the highest grade of malignancy. The mean S-phase for tumours with a DNA index of 1.0 was 3.5 and 14.1% for those with DNA index >1. Ovarian carcinomas show a large difference in DNA index between patients even after primary culture. Flow cytometric measurement of DNA content in human cancer cells is becoming a procedure for defining the DNA index and cell cycle distribution of the cell population. This may have several practical applications including prognostic value We applied the cytofluorometric technique to the study of human ovarian tumours with the following aims: (i) to describe the DNA index in ovarian cancers, (ii) to establish the extent to which the DNA index is modified by growing cancer cells in vitro, (iii) to correlate the DNA index with the cytological degree of malignancy. Materials and methods Biopsy material for analysis was obtained from primary surgery, from second look laparotomy, pleural effusion or from ascitic fluid after paracentesis. All patients were classified by FIGO staging as III and IV and by histologically confirmed diagnosis as serous, mucinous, undifferen-tiated, mixed or endometroid ovarian carcinoma (Young et al., 1982). Histological grading of tumours was evaluated in terms of well differentiated (grade 1), moderately differentiated (grade 2) and poorly differentiated (grade 3) (Long & Sommers, 1969) and according to Broders criteria (Broders, 1926; Ozols et al., 1980). As cell suspensions were also used for seeding primary cultures, single cells were obtained from the biopsy material by a sterile procedure. Tumour biopsy specimens were collected in …