@June1952 and @arpie, Thank you very much for your thoughtful messages and information. Yes, my recurrence risk is high, with anything under 25% considered to be low. Although no lymph nodes are affected, the tumor size was 2.4 cm, which is not small. My oncologist is very kind and I trust him.
However, I have been contemplating whether the uncertain 10% benefit from chemotherapy is worthwhile, especially considering the side effects. These side effects not only reduce my immune system's ability to fight but also damage internal organs like the digestive system and liver. I guess that I'm struggling with the idea of attacking my own system for an uncertain treatment outcome. If it works, that would be great, but if it doesn't, it could leave me even more vulnerable. I understand that no treatment is perfect or 100% effective, but I still worry. Maybe I'm overthinking it. It is very comforting to receive your kind messages and encouragement. Thanks again.