What is a key indicator of malignant cells compared to benign ones?

Malignant cells are characterized by their ability to invade surrounding tissues and spread to distant sites in the body, a process known as metastasis. This invasive capability is a significant indicator of malignancy because it reflects the cells' altered growth behaviors and loss of normal regulatory mechanisms that govern cell division and tissue organization.

Unlike benign tumors, which typically remain localized and grow slowly without invading adjacent tissues or spreading to other parts of the body, malignant cells display aggressive growth patterns. They can often penetrate the extracellular matrix, facilitating invasion into nearby tissues and the bloodstream or lymphatic system, which can lead to the formation of secondary tumors in other organs.

The ability to invade and spread is associated with various molecular and genetic changes in malignant cells, such as increased mobility, altered adhesion properties, and changes in the expression of genes related to invasion and metastasis. This unique feature is crucial for distinguishing between malignant and benign neoplasms and plays a fundamental role in determining the severity of cancer and its treatment approach.