Which type of radiation-induced cancer demonstrates a threshold dose-response relationship?

The correct answer is skin cancer, which typically shows a threshold dose-response relationship. In a threshold dose-response relationship, there is a specific dose level below which no effect is observed. This means that a certain amount of radiation exposure is necessary before the risk of developing skin cancer begins to increase.

Skin cells have a regeneration process that allows for some repair from low levels of radiation exposure. However, when the dose of radiation exceeds a certain threshold, the damage to the DNA of skin cells accumulates, leading to an increased risk of malignant transformation and skin cancer development. This type of relationship underscores the importance of limiting exposure to higher doses of radiation to prevent skin cancer.

In contrast, the other types of cancers listed do not exhibit a clear threshold effect. Lung cancer and leukemia, for example, can increase the risk even at low levels of radiation exposure, with the risk appearing to rise progressively without a minimum exposure level necessary to initiate cancer development. Thyroid cancer can also show a dose-response relationship, but the connection is more complex and can occur at lower doses without a definitive threshold.