A central registry is performing survival analysis and is examining the ratio of observed survival in a cohort of cancer patients to the expected survival in a comparable group of cancer-free persons. This is referred to as:

The term that describes the comparison of observed survival in a cohort of cancer patients to the expected survival of a similar group of cancer-free individuals is known as relative survival. This statistical measure is crucial in epidemiology and oncology because it allows researchers to determine the impact of cancer on survival by excluding the effects of other causes of mortality that may also affect the general population.

Relative survival provides a clearer picture of the prognosis for cancer patients by essentially isolating the survival impact attributable specifically to the cancer diagnosis. By calculating relative survival, it can effectively account for the background mortality rates in the general population, allowing for a more precise understanding of patient outcomes.

In contrast, the other terms refer to different aspects of survival analysis. Cause-specific survival focuses on survival rates considering only the deaths due to cancer, while observed or all-cause survival includes all deaths regardless of cause, and net survival emphasizes the survival attributable specifically to a disease, typically accounting for background mortality as well. However, in the context of this question, relative survival is the most appropriate term for the described analysis.