Brother in-law been diagnosed with rare stomach cancer

Looking for advice my brother in law just be diagnosed with rare type of stomach cancer :( he's been off work for while and due starting treatment my question is what benefits can he claim as he can't go back to work not as if he doesn't it's what he works as ground worker    Where does he turn to? He's worked every day 6 days a week for 34 years, any help would be appreciated