how effective is radiation and chemotherapy without surgery?

[Jugganaut Returns]

my grandpa just got out of surgery for cancer they found in his chest and heart. the said they can operate because it is too severe. they are going to try radiation and chemo. can that fix the problem without surgery?
im sorry for the bad grammar. i meant to say they cannot operate because the cancer is too severe.

[tinmuning]

Sometimes, radiotherapy and chemotherapy are done prior to surgery in hopes of decreasing the size of the tumor so if surgery has to be done later on, it won't be as radical since the tumor is smaller.

You mentioned that the cancer is situated in the chest area, we all know that that area contain a lot of vital organs like the heart and lungs so the doctors would want the tumor to shrink in size as small as possible so when they do surgery, there's a relatively low risk to damage the adjacent vital structures.