An approach to the individualization of cancer therapy--determination of DNA, SH-groups and micronuclei.

Localization and histo-pathology are the basis for the decision, which modality of therapy is used to treat a tumour today. The great variety of biological factors in human tumours is generally largely neglected. The variety of such factors is shown by measuring the DNA content in tumour cell lines, their distribution in the cell generation cycle and the content of bound SH-groups in the cell nuclei. Further the micronuclei which are an expression of cytogenetic damage and which can be used as an indicator of cell loss have been determined. These parameters have been studied in primary and secondary tumours in the brain as well as in rectal adenocarcinoma. It was found that primary brain-tumours had only diploid and tetraploid cell lines while in almost 50 per cent of metastases in the brain and of the rectum adenocarcinoma aneuploid cell lines appeared. These latter cell populations had a higher number of cells in S-phase. The cells in the primary brain-tumours had less micronuclei and appeared as comparatively stable cell lines. Also a difference in the content of nuclear SH-groups could be demonstrated between primary brain-tumours and brain-metastases. In one recurrent tumour, which could be compared with the original tumour, the amount of bound nuclear SH-groups increased by a factor of about 15. In several cases biopsies from adenocarcinoma of the rectum could be studied before and after preoperative radiotherapy. In aneuploid tumours the reduction of the tumour cell line could be demonstrated, at the same time the number of micronuclei increased. However this was not consistent in all investigated cases.