Yes, they sure are.
Some cancer patients don’t grow their lost hair back.
Some (a friend of my parents) hair falls out, only to come back thicker and a different color!
Everyone can react differently. I like her (Jennifer’s) gray hair better than her brownish color. Makes her eyes really stand out, I think.
I didn’t have chemo, but had voluntary surgery removing lymph nodes on my throat. So I have lymphademia and scars, not pretty. Plus teeth damage.