Cancer doesn’t run in my family, so when I noticed a small swelling on my collar bone in March 2020, I just shrugged it off. I travel a lot for work, and I carry a heavy tote with a computer around. I figured my left shoulder was just injured from the straps. I had no idea it was actually a symptom of Hodgkin lymphoma. I was only 32.

But the lump didn’t go away, even after several months. Then, the intense itching started. That...