Lump on his lower chest-choke

Hello. My boyfriend is experiencing choking most of the time he eats, even swallowing water. If I'm not mistaken it started last year. He is on his early 60s.
But before that, that was long time ago now, that everytime we lie on bed he doesn't want me to put my hand on his lower chest. He said it hurts him. I ignored it thinking that maybe my hand is only heavy. And he always keep telling me that if I want to kill him is simply knock him there and he will die soon.
I worried alot now when he took my hand on his mid lower chest and touched this big lump in there... He said it's hurt and sometimes he can't breath easily. He told me that it's become big now. He didn't tell me before about that lump.
What is it? Is that the other reason why he choke during his meal? Is that cancerous.  
I worried so much. Please let me know what is it. He hates going to the Hospital. So could you please give me some info about that? and maybe from your response he will see the Dc. soon.
Thank you so much !