What characterizes cancer?

Cancer is characterized by the uncontrolled growth of body cells. This means that instead of following the normal cellular processes of growth, division, and death, cancer cells continue to proliferate without the regulatory mechanisms that usually keep cell growth in check. This uncontrolled growth can lead to the formation of tumors and can disrupt the normal functioning of the body by crowding out healthy cells and tissues.

In contrast, normal cell growth is careful and regulated, responding appropriately to the body's needs—this is not characteristic of cancer. Gradual weight loss can be associated with cancer, but it is not a defining characteristic; rather, it is a potential symptom that can occur due to various health issues. Limited tissue repair is not specific to cancer since this can happen in a variety of other conditions as well and is not a fundamental trait of cancer itself. Thus, the defining aspect of cancer is indeed the uncontrolled growth of cells.