The survival date of diagnosis recode is calculated using the month, day, and year of the Date of Diagnosis [390]. If the Date of Diagnosis [390] has complete month and day information, the Surv-Date Dx Recode will be the same as the Date of Diagnosis [390]. If the day or month is unknown or not available, the values are imputed by the survival program used to derive the seven survival variables. The survival program is available from your standard setter or NAACCR.

Example 1

Date of diagnosis: 20111199

Date of Last Contact: 20111120

Surv-Date of DX Recode: 20111110

Note: The recoded value is the mid-point between 11/1 and 11/20.

Example 2

Date of diagnosis: 2011

Date of Last Contact: 20111120

Surv-Date of DX Recode: 20110611

Note: The recoded value is the mid-point between 20110101 and 20111120.

The Surv-Date DX Recode is needed to be able to match to a lifetable entry to obtain expected survival. If a case is diagnosed in January 2000, the first 12 months of expected survival will be from the 2000 life table. If a case is diagnosed in December 2000, only one month will be from the 2000 life table and then the 2001 life table is used.

Additional information about the survival algorithm and what specific values are assigned in given missing date situations are available here: http://seer.cancer.gov/survivaltime/.