We do not, in general, make treatment decisions based on age. What is more important is how you are physically doing when you are diagnosed; a 45-year-old woman with end-stage complications from diabetes may be less able to handle chemotherapy than a 70-year-old woman in good health.
That is, your ability to perform your own activities of daily living and take care of your own needs (sometimes called a performance status) can tell your doctor more than merely focusing attention to your age.
The various treatments, from surgery to radiation to chemotherapy, all have risks and a balanced consideration of the benefits and the risks of treatment are always required.
At 58, I am still young in that I have/want another 30 years ahead of me. I want aggressive treatment balanced with minimal long-term side effects.
It takes asking question after question of your doctors to learn ALL you can. This is a case of knowing what questions to ask. There is nothing you can’t ask your doctors!