I'm under 50. I had cancer and have recently finished treatment. Prior to cancer, I didn't smoke, rarely drank, was at a healthy weight/low BMI, exercised - weight lifting, walked a minimum of 15,000 steps a day. I eat most organic, rarely UPFs. I still got cancer. My cancer is genetic/hereditary. Irregardless of this, one can do all the right things and still get cancer. Cancer is indiscriminating.
What I will say is that my lifestyle put me in a better place to deal with the ravages of chemotherapy and radiotherapy, ditto my age. Had I been overweight, eaten poorly, out of shape, drank, smoke etc, older, I would have found treatment so much harder.
Edited to add that I agree with @TomatoSandwiches, stress plays a huge part. not just in cancer, but in health and wellbeing full stop.