  Working in the light-cone gauge, we find a simple procedure to calculate the
autonomous one-loop Q^2 evolution of the twist-three part of the nucleon g_T(x,
Q^2) structure function in the large-N_c limit. Our approach allows us to
investigate the possibility of a similar large-N_c simplification for other
higher-twist evolutions. In particular, we show that it does not occur for the
twist-four part of the f_4(x, Q^2), g_3(x, Q^2) and h_3(x, Q^2) distributions.
We also argue that the simplification of the twist-three evolution does not
persist beyond one loop.
