What Causes Sharp Pain While Swallowing When Diagnosed With Stage-3 Breast Cancer?

i have stage 3c breast cancer but before i was diagnosed i was worried about my throat sometimes only when swallowing liquid it would cause a sharp quick pain deep in my throat and now i can tell there is something faint not a pain deep in my throat but i can swallow food no problem and only rarely if i touch e outside of my throat not even hard its a sharp pain for a but second or two most of the time if i do same touch i feel nothing its not consistent and i have had a pet scan which showed my body but i do feel something in my throat