The Epidemiology of Second Primary Cancers
The issue here is twofold. First, I believe that our bodies are constantly fighting off cancerous cells. It is not until the immune surveillance is overwhelmed that cancerous tumors sneak past the immune system and begin to grow. This would indicate that the cancer that first shows up may just be one of many “hidden.” Thus, the idea that a second cancer may arise later fits in with this theory.
Another issue is that chemotherapy is very damaging to the body and destroys the immune system. This would leave the body open to future cancers, especially if the needed lifestyle changes are not made. Likely a combination of the two is what occurs, as many oncologists do not even broach the idea of lifestyle changes with their patients. I have had patients see cardiologists that even go so far as to tell their patients to avoid any supplements because they don’t want it the “interfere” with the treatment.