How do mutations in DNA repair genes affect cancer progression?

Mutations in DNA repair genes have a significant impact on cancer progression because they lead to an accumulation of mutations within the genome. Normally, DNA repair genes are responsible for correcting errors that occur during DNA replication or in response to DNA damage, thereby maintaining genomic stability. When these genes are mutated, their ability to repair damaged DNA is compromised. This can result in an increased frequency of mutations throughout the cell's lifespan.

As mutations accumulate, they can disrupt normal cellular processes, including those involved in regulating the cell cycle, apoptosis, and other critical pathways. This accumulation can eventually lead to uncontrolled cell growth and the development of cancer. Essentially, the failure to repair DNA damage allows more genetic alterations to persist, some of which may confer a growth advantage to the cells, thereby promoting tumor development and progression.

This understanding highlights the crucial role that DNA repair mechanisms play in cancer prevention and illustrates how deficiencies in these systems can predispose individuals to malignancies.