DNA-PLOIDY AND S-PHASE FRACTION IN PRIMARY MELANOMAS AND THEIR REGIONAL METASTASES

Flow cytometric analysis of DNA ploidy and S-phase fraction was perfor med on the primary melanomas and the first metastases from 55 melanoma patients with regional lymph node metastases or in transit metastases . The frequency of aneuploidy was significantly higher in metastases t han in the primary tumour (p = 0.009), suggesting a higher growth pote ntial in melanoma metastases than in the primary tumours. In 18 patien ts with reliable S-phase determinations from both primary tumour and m etastasis there was no significant difference in mean S-phase fraction between primary melanomas and metastases. Skin metastases localized i n dermis and subcutis had a significantly (p = 0.012) higher mean S-ph ase fraction than lymph node metastases.