Help!! cancer diagnosis question?

I found out by accident yesterday that my mum aged 50, could possibly have cancer. before Christmas my mum presumed she had mastitis and went to see her local GP, he agreed that he also thought it was mastitis and prescribed antibiotics. After completing the course my mum realised that her nodes in her neck were swollen so went back to the GP who yet again prescribed another course of antibiotics...yet again this didn't work and my mum realised that this was something more than mastitis as did the doctor. Her GP then sent her last week to the hospital for tests ( not sure what but I'm presuming a biopsy & blood tests etc )...anyway the upshot is, she's been told to return on Thursday of next week and to bring someone with her...Please if you've been through this sort of thing could you explain why she needs someone there with her for the results...maybe my mind is running on overdrive, I'm not even supposed to know about this, my dad told me by accident because my mum doesn't want to worry me until necessary so for now I have to act normally for her sake. I'm 37 so not a child and would just like a heads up on what to expect as I'm guessing that the hospital asking her to have someone with her for the results means it's not likely to be good news...thanks in anticipation of replies x