Suppressed Immune System
The immune system enables your body to distinguish its own healthy cells from abnormal or foreign cells and organisms, and sends out specialized cells to fight infection and disease, including cancer. The immune system can be weakened or suppressed by certain cancers, anti-rejection drugs for organ transplants, and the human immunodeficiency virus (HIV) that causes AIDS. The risk for developing melanoma is directly related to the degree to which the immune system is suppressed. For example, individuals who have undergone organ transplants and are taking anti-rejection medication are at 3 times the risk for developing melanoma.