Klin Onkol 1988; 1(4): 121-124.
Summary: The effect of preoperative radiotherapy of rectal cancer was evaluated by DNA flow cytometric analyses in two studies. In the first randomized study aneuploidy was present in 65% (26/40) of non-irradiated rectal cancers but only in 40% (18/45) of preoperatively irradiated tumors. In the second study the biopsies and operative samples were compared in 16 cases. Aneuploid population disappeared after radiotherapy in 37,5% (6) of 16 preoperatively treated patients. No such effect was observed in control group of 9 untreated patients. The results of both studies are consistent showing elimination of aneuploid population after radiotherapy in about 1/3 of rectal cancers. DNA diploid tumors can not be analysed using this method. Whether the response observed in DNA histograms correlates with clinical response and the course of disease needs to be further investigated.
