Carcinogenic potency is quantified by which measures?

• A. Maximum tolerated dose, LD50, and NOAEL
• B. Slope factors, relative potency factors, or benchmark dose modeling
• C. Exposure frequency and duration
• D. NOAEL and LOAEL

Answer: (B)

Cancer potency is about how strongly a chemical increases cancer risk per amount of exposure, so the measures used are designed to quantify risk per unit dose. Slope factors express how much cancer risk increases for each extra unit of dose, typically used with low-dose extrapolation to estimate lifetime risk from small exposures. Relative potency factors allow you to compare how potent different carcinogens are by expressing their potencies relative to a reference chemical. Benchmark dose modeling goes further by fitting a dose–response curve to data and estimating a dose that produces a specified increase in cancer risk (the benchmark dose), with confidence limits to reflect uncertainty.

These approaches specifically capture cancer risk per dose, which is why they are the appropriate measures of carcinogenic potency. Other options describe general toxicity or threshold levels (like NOAEL/LOAEL, LD50, or maximum tolerated dose) or focus on exposure frequency and duration, which relate to how much or how long someone is exposed rather than the inherent potency of the carcinogen to cause cancer.