Which of the following is NOT included as a method for cancer prevention?

Radiation therapy is primarily a treatment modality used to target and destroy cancer cells rather than a preventative measure against the development of cancer. It is typically employed after a cancer diagnosis to shrink tumors or eliminate remaining cancer cells post-surgery.

In contrast, chemoprevention involves the use of natural or synthetic substances to reduce the risk of cancer development at an early stage, while gene alteration may refer to interventions aimed at modifying genetic predispositions to cancer. Lifestyle avoidance encompasses behavioral changes, such as maintaining a healthy diet, avoiding tobacco use, and engaging in regular physical activity, to lower cancer risk.

Thus, while chemoprevention, gene alteration, and lifestyle changes are proactive strategies aimed at minimizing the risk of cancer, radiation therapy is not designed with prevention in mind, focusing instead on treatment once cancer has already manifested.