DNA-PLOIDY LEVEL ASSESSMENTS IN 83 HUMAN BRAIN METASTASES - RELATIONSHIP TO THE SURVIVAL OF 35 PATIENTS

The nuclear DNA content (DNA ploidy) level was determined in a series of 83 human brain metastases, for which 35 complete clinical follow-up s were available. The DNA ploidy level determination was carried out b y means of DNA histogram types. The results show that certain brain me tastases were diploid, while others exhibited aneuploidy levels rangin g from low to very high. The present study also shows that a significa nt proportion, i.e. 18%, of the 83 brain metastases, exhibited very hi gh levels of aneuploidy, i.e. hypertetraploidy, hyperpentaploidy and o ctoploidy. We had previously observed that this feature appeared only rarely, i.e. in less than 2% of primary nervous tumours. Furthermore, the present study shows that DNA ploidy level in brain metastases is r elated significantly (P < 0.001) to patient survival. Indeed, while 9/ 13 (69%) patients with diploid brain metastases survived longer than 9 months, none (0%) of the 22 patients with aneuploid brain metastases survived longer than the 9 months following the diagnosis of their bra in metastases.