How come laryngeal cancer patients clear their throat so much?

Lesions+hoarseness: This is probably due to the fact that there are growing lesions in the throat, and the haorseness that the patient experiences from them. Many of these cancers also involve the laryngeal nerve, so this can also affect throat function. So the throat must be cleared as lesions can interfere with breathing, hoarseness occurs and is remedied by clearing the throat, and nerve issue can limit clearing.