Hello and thank you for your post.

Some types of chemotherapy can affect the nails on your hand and feet, this could be why your toe nails look like this. What should happen is that the old nail will grow out and be replaced by a new one. However, if you are worried do get it checked out when you are next in contact by your hospital team.  Particularly if the nails become painful, red and swollen as this could be a sign of infection, if this happens contact your breast care nurse or GP for advice.

I hope this has been helpful and that you will be okay.

Take care,

Caroline