Cloning efficiency. A possible prognostic indicator in squamous cell carcinoma of the head and neck

Abstract

Seventy‐three squamous cell carcinomas arising in the head and neck region were cultured using the soft agar clonogenic system. Thirty‐six (49%) demonstrated clonal growth. The cloning efficiency was variable, ranging from 0.001% to 1.67% (median, 0.004%). Statistically significant correlations of high cloning efficiency with advanced local class, increased stage, and decreased survival were observed. There was no correlation between cloning efficiency and T‐class or modified Jakobsson's histologic grade. A cloning efficiency of ≧0.005% was associated with a high likelihood of death from disease or the development of recurrent disease. For head and neck squamous cell carcinomas, the cloning efficiency in soft agar appears to be a potentially useful prognostic indicator.