Which of the following belongs to cancer identification fields?

The field that belongs to cancer identification is the date of initial diagnosis. This particular field is crucial for gathering accurate data on cancer cases, as it marks the moment when the cancer is first identified and diagnosed. It serves as a foundational element in tracking patient information and is integral to understanding the timing and progression of the disease.

This date helps tumor registrars determine important aspects such as treatment timelines and outcomes, as well as staging and survival rates for cancer patients. Understanding when a diagnosis occurs is essential for any analysis related to cancer epidemiology and outcomes, thus cementing its role in cancer identification.

While the other options provide valuable information about patient status and demographics, they do not specifically pertain to the identification of cancer cases in the way that the date of initial diagnosis does.