Totally agree @arpie. I had 2 very widespread invasive lobular tumours (plus a small sneaky ductal tumour) that hadn't shown up on previous mammograms and only one was partially visible when I had the mammogram and ultrasound that finally confirmed my diagnosis - I was only alerted to the possibility of breast cancer when I had an inverted nipple.
Lobular cancers are notoriously difficult to pick up via mammogram as they often don't look like a lump or mass. My GP had mentioned that my previous mammograms had shown I had dense/ lumpy breast tissue but there was no discussion about increased risk, despite my mum also having had the disease. I had been having mammograms since I was in my early 40s as I was worried about developing bc, and paid for private mammograms every couple of years - clearly I needn't have bothered :(
