What percentage of women will develop invasive cancer at some point in their lifetime?

• A. 33%
• B. 25%
• C. 50%
• D. 75%

Answer: (A)

Lifetime risk for women to develop invasive cancer is about one in three. This means that by the end of a typical lifespan, roughly 33% of women will have had an invasive cancer at some point. Invasive cancer refers to cancers that have spread beyond their point of origin, unlike non‑invasive (in situ) forms. The figure comes from large population studies that track cancer incidence over many years and calculate the cumulative risk from birth to life expectancy. It encompasses cancers across sites (breast, colorectal, lung, etc.), not just one type. The estimate is a general population figure and can vary by country, ethnicity, and risk factors, but 33% is the standard teaching number. The other options are not aligned with the common epidemiologic data for lifetime risk in women.