Oncology Certified Nurse (OCN) Nursing Practice Test

How do carcinogens contribute to the development of cancer?

1. They help repair DNA

2. They activate tumor suppressor genes

3. They cause genetic mutations

4. They enhance immune response

The correct answer is: They cause genetic mutations

Carcinogens contribute to the development of cancer primarily by causing genetic mutations. These are substances or exposures that can initiate or promote the process of carcinogenesis. When a carcinogen interacts with cellular components, particularly DNA, it can lead to alterations such as point mutations, deletions, or insertions that disrupt normal cellular function. Mutations caused by carcinogens can affect important genes, including oncogenes and tumor suppressor genes. Oncogenes, when mutated, can promote unchecked cell division, while mutations in tumor suppressor genes can impair the cell’s ability to control the cell cycle and repair DNA. Over time, the accumulation of these mutations can lead to uncontrolled cell growth and the formation of tumors, ultimately resulting in cancer. The other options do not accurately describe the role of carcinogens in cancer development. For instance, rather than enhancing immune response or repairing DNA, carcinogens have a detrimental impact on cellular integrity and functionality. Activating tumor suppressor genes would typically counteract the oncogenic process rather than promote it. Thus, the correct understanding of carcinogens lies in their capacity to induce genetic mutations, which is a fundamental mechanism in the initiation and progression of cancer.