What is the primary characteristic of cancer?

The primary characteristic of cancer is abnormal and uncontrolled cell division. Cancer cells have lost the regulatory mechanisms that typically control cell growth and division in healthy tissues. This lack of control leads to the excessive proliferation of these cells, which can form tumors and invade surrounding tissues, disrupting normal functions in the body. Unlike normal cells, which have specific checkpoints to regulate their lifecycle and maintain tissue homeostasis, cancer cells bypass these checkpoints, allowing for continuous growth and division. This uncontrolled growth is a fundamental aspect of malignancy and distinguishes cancer from benign conditions where cell growth is regulated. Other options, such as controlled growth, slow progression, or normal cell function, do not accurately encapsulate the essence of cancer biology as they reflect characteristics of healthy cells rather than the aberrations seen in cancerous cells.