my friend's aunt is of 60years old. she has been diagnosed with colon cancer since 1 weak it is of stage two. doctor has told to get chemotherapy done. so wil it be cured

She was suffering from stomach ache since months so she was diagnosed with gall stones. So she was getting surgery for the same. But during surgery doctors noticed about small polyps and finally diagnosed with colon cancer after investigations. So now it has been said to get chemotherapy done. So wanted to know about this. Whether wil it be cured after chemotherapy.? And is there any severe side effects? And what diet has to be given to her. She is diabetic since 25 years.