FLOW CYTOMETRIC DNA CONTENT-ANALYSIS OF ULTRAVIOLET LIGHT-INDUCED SQUAMOUS-CELL CARCINOMAS - A COMPARATIVE-STUDY OF SQUAMOUS-CELL CARCINOMAS OF THE LIP AND THOSE ARISING FROM OTHER SITES OF SUN-DAMAGED SKIN

The development of squamous cell carcinoma (SCC) of the lip is conside red to be mainly related to excessive sun exposure. However, its highe r metastatic rate is distinct from that of SCCs arising from other sit es of sun-damaged skin. Flow cytometric DNA content analysis, using pa raffin-embedded specimens, was performed on 15 SCCs of the lip and 32 SCCs arising from other sites of sun-damaged skin. A significantly low er incidence of DNA-aneuploidy was observed in SCCs of the lip (2/15) than in those of sun-damaged skin (15/32) (p<0.05). The mean age of pa tients with SCC of the lip (66.7 +/- 11.6 years; mean rt SD) was signi ficantly lower than that of the other patients (78.1 +/- 11.1 years) ( p<0.01), There was no significant difference between the mean diameter size of tumors on the lip (19.5 +/- 5.7 mm) and that of tumors on oth er sites of sun-damaged skin (30.7 +/- 20.5 mm). These results suggest that additional carcinogenic factors besides ultraviolet light may be involved in the development of SCC of the lip.