Before you start reading, take this helpful quiz on infiltrating/invasive ductal carcinoma as a preview to this FAQ.
Q. I’ve learned I have IDC, which the doctor called infiltrating ductal carcinoma. But someone else called it invasive ductal carcinoma. Are they the same thing?
A. Yes, they are. And here’s what’s going on: atypical cells–cells that, for an unknown reason, mutated as they grew–have collected in the ducts in your breast. Ducts are the tiny tubes that carry milk from the lobules, where it’s made, to the nipple. At some point, these atypical cells broke through the duct wall, and started moving into the surrounding tissue. This is when your cancer crossed the line from DCIS–ductal carcinoma in situ–to invasive (infiltrating) ductal carcinoma–IDC.
Q. So what suddenly made these cells move into the rest of my breast, rather than just continue to collect?
A. Excellent question. And researchers would love to know the answer: if they knew WHY cells suddenly start to move and migrate, they might be able to figure out how to stop them. Right now, their best guess is not that the cells themselves suddenly became more aggressive, but that that something around the cells–a hormone, other cells–gave them the “go ahead” to move. But that’s still a theory; research continues.
Q. How many women get this particular type of breast cancer? Is it one of the common ones?
A. Yes. In fact, infiltrating or invasive ductal carcinoma is the most common type of breast cancer; 70% of women with breast cancer have this diagnosis. And 80% of women with invasive breast cancer have IDC. So you’ve got lots of company.
Q. What will my treatment be like for infiltrating/invasive ductal carcinoma?
A. While some breast cancer is difficult to detect, IDC is fairly straightforward: it’s characterized by a lump in the breast, which is probably what caused you to call the doctor in the first place. This lump, made up of cancerous cells surrounded by scar tissue caused by the cancer, is what the radiation oncologist took a sample of–a biopsy–to see if it contained cancer cells. In your case, it did.