ESA 50A Question regarding cancer treatment

My son is recovering from and will probably have to restart chemotherapy for leukaemia very soon He's been on ESA for about 3 years in the support group IB. He's just had an ESA50A form arrive. He has a great haematologist and clinical support nurse on his side. Does he just tick the boxes that he has cancer and is on chemotherapy then get his consultant or nurse specialist to fill in page 18 without filling in all the other questions? (as it says you can). That is what he did last time.

He does have chronic fatigue, joint and bone pain limiting his walking and everyday care with ongoing depression that were part of his claim for PIP. He is also has Asperger's to add to the mix as well with all the limitations with social skills and difficulty articulating his feelings. In light of his PIP award I don't want him to misrepresent himself.

Do the departments dealing with ESA and PIP cross reference their information?

Any advice gratefully received.

Thank you. Will probably include all the other info with reference to his recent PIP claim where the descriptors fit.

My son heard yesterday that his ESA has been renewed and he is to remain in the support group. He did send in a fully completed form with additional evidence as well as the cancer specialist nurse filling in the part about ongoing/recovering from chemotherapy. Just so relieved that he hasn't got to have a F2F assessment.