Which survival measure is used to measure the excess mortality associated with a cancer diagnosis?

• A. Observed all-cause survival
• B. Net survival
• C. Cause-specific survival
• D. Relative survival

Answer: (B)

Net survival focuses on mortality caused by cancer by modeling survival in a hypothetical world where other causes of death are removed. This directly expresses the excess mortality linked to a cancer diagnosis because it asks: what would survival look like if cancer were the only threat to life? In practice, this is estimated by comparing observed survival to the expected survival in a similar, cancer-free population, which isolates the effect of the cancer itself.

Observed all-cause survival includes deaths from any cause, so it doesn’t separate cancer-related mortality. Cause-specific survival depends on accurately identifying deaths attributable to cancer, which can be imperfect. Relative survival is a way to estimate net survival by comparing observed survival with expected survival in the general population, but the metric that represents cancer-attributable excess mortality in itself is net survival.