My great grandmother died in 1900, in her forties, of cancer. Various types of cancer have always been around. I had an ovarian tumor at the age of 22 that the doctors told me straight-up might be cancer. It’s not a ‘modern’ disease, though bad health habits and poor nutrition may be making it more common in recent decades.
It’s not modern but was rare prior. None of my grandparents had cancer and only one other family member has had it. Yes, nutrition, x-rays/radiation, chemicals, medications—including vaccines have increased the prevalence.