Prognosis Of Breast Cancer

my mum was diagnosed with breast cancer 4 years ago. she had had a standard mammogram which picked it up. 3 years previous she had a clear mammogram. she couldnt feel any lumps herself, but after the mammogram she was called in to say there was something wrong. she was called in for a biopsy. at the biopsy she was told, that she had at least two tumours in same breast and when they pulled the fluid off that she had cancer. they didnt even need to send it off anywhere to tell her this. she then went for a mastectomy ,and they removed her breast and lymph nodes. she was told 22 lymph nodes were cancerous (i dont know how many she had, if any, over and above the 22 ) and it was aggressive. she had chemo then radiation followed by a daily pill (eg. armidex but im unsure). i cant establish the full facts but when she does have a check up they don't take any blood test . she had a premliminay bone scan when diagnosed and was told it wasnt in her bones. she doesnt say much about it,but i have noticed that recently she has left the room feeling sick and my son has told me that she has also been clutching her throat . i really dont have a clue what the prognosis is and am obviously worried