It matters, as the cable length increases so does the capacitance, this acts like a 1st order filer so gradually losses at HF will build up. The cable also has characteristic impedance which is a combination of other factors. The impedance of a coax cable is the square root of (the per unit length inductance divide by the per unit length capacitance. If the terminating connector on the equipment as well as the cable are the same impedance as the cable then all is well, but losses at higher frequencies will still be apparent and length dependant. Impedance mismatches can cause some interesting effects, arguably at only the higher frequencies. It is a shame that manufacturers seldom quote impedance of their input and output sockets, and only a few connector manufacturers do so as well.