Adjuvant chemotherapy and the kinetic refractoriness of minimal residual tumors.

If Skipper's exponential growth and 'log-kill' hypothesis is replaced by one assuming an S-shaped growth curve and a growth inhibition proportional to the product of the growth fraction and the tumor volume, little growth inhibition can be achieved in minimal tumors. This 'kinetic refractoriness' may explain why minimal residual tumors cannot be eradicated by adjuvant chemotherapy.