PIP is awarded for the limitations that result from a condition, not the conditions themselves so don't assume he would not qualify, have a look at our PIP Claim guide by following the Guides link at the top of the page.
Providing your husband's GP has issued a Fit Note and he finished receiving SSP then he can make an immediate claim for New Style ESA, he may even automatically qualify if he is receiving chemo or radiotherapy.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems