Believe me, it is a huge and terrifying deal.
Cancer spreads, and not every trace is always found at the time of surgery.
It can also recur, hence the belt and braces approach to mop up any possible undetected cells.
My Mum had mastectomy which completely removed the cancer, but was advised to have the chemo for those very reasons.
She didn’t think “oh it’s not a huge deal, I don’t actually have cancer now” In fact she was absolutely terrified and it was awful to see how scared she was.
She wasn’t actually given the all clear for another 5 years, despite the tumour being removed at the time of surgery,
This will be an enormous deal for Kate, William and their family.