SEER*Stat Survival Exercise 2: Period Survival

This exercise illustrates period survival statistics, which use only the most recent interval survival estimate of cases diagnosed in different calendar years (cross-sectional estimate of survival). Create a table with 5-year relative survival estimates for regional stage female breast cancer, calculated using the period method for 2010. Use 3-years of data per survival cohort. Use the SEER 18 registries and display annual statistics in the summary pages. Include the standard life (period) and period contributor tables in the output.

For more information about period survival and an overview of cancer survival statistics, see Cohort Definition Using Diagnosis YearExternal Web Site Policy on the Surveillance Research Program web site.

Key Points and Reminders

  • SEER*Stat allows the calculation of period survival estimates for multiple years. The default and maximum estimate year will be the same as the last year of diagnosis minus one in the data.
  • When producing period survival statistics, you cannot use the year of diagnosis variable in case selections or in the table specifications. SEER*Stat will automatically select cases for the correct years of diagnosis based on the period year estimate, the maximum years of survival, and number of years of survival per cohort specified on the Parameters tab. In this exercise, we are calculating 5-year period survival using 3 year cohorts for 2010. The first interval (one year) will use cases diagnosed in 2008-2010, the second interval (two year) will use cases diagnosed in 2007-2009, and so forth until you have 5 years of survival. This analysis will therefore use 2004-2010 diagnoses.
    • The database used in this exercise contains cases diagnosed from 1973 through 2011, with registries contributing cases from varying years of diagnosis depending on when they joined and began contributing data to the SEER program. All 18 registries contribute cases for the years 2004-2010.
  • Because each period table is comprised of intervals obtained from various contributing life tables, SEER*Stat provides the option of displaying the contributing life tables. Please note that all period parameters are specified in years, but the computations are done monthly (in 12-month increments).
  • Starting with the November 2013 data submission, there are new default expected survival life tables. The new life tables are for 1970-2009 by individual year for ages 0-99. The previous default life tables had a maximum age of 119 and were provided for years 1970-2007. With the new expected life tables, all patients with an age at diagnosis greater than 99 will be excluded from the analysis. See the Expected Survival Life Tables on the SEER website for more information.
  • Starting with SEER*Stat 8.1.4, there's a new option on the Parameters tab for censoring cases when their attained age exceeds the expected rate table max. This option will default to on for November 2013 and later databases.

Step 1:  Create a New Survival Session

  • Start SEER*Stat.
  • From the File menu select New > Survival Session or use the Survival button on the toolbar.

Step 2:  Select a Database (Data Tab)

  • It is extremely important that you select the database as the first step. The other choices you will make in this session will be based on variables in the selected database. The correct database must be selected in order to see the correct list of variables in selection statements, table statements, and the dictionary editor.
  • On the Data Tab select "Incidence - SEER 18 Regs Research Data + Hurricane Katrina Impacted Louisiana Cases, Nov 2013 Sub (1973-2011 varying)"

Step 3:  Choose the Statistics to Display (Statistic Tab)

  • In the Cancer Survival Measures box, select Relative Survival.
  • Check the Period Survival box. When you enable this selection, a message dialog will appear warning you that the interval parameters have been changed to annual intervals.
  • In the Cum Expected Method box, Ederer II should be selected.
  • In the Expected Survival Table drop down box, make sure "U.S. 1970-2009 by individual year (White, Black, Other (AI/API), Ages 0-99, All races for Other Unspec 1991+ and Unknown)" is selected.

Step 4:  Defining the Analysis Cohort (Selection Tab)

  • Specific click-by-click instructions for creating individual selection statements were given in previous tutorials (see Frequency Exercise 1a). Use those techniques to create three selection statements. Be sure to consider the following before making your selections:

    • Selection statements reduce the number of records included in an analysis based on specific variables. If no selection statements are made on the Selection Tab, all records in the database will be included. In this exercise, we want to calculate survival for regional stage female breast cancer. Therefore, we need a statement selecting based on stage, sex, and cancer site.
  • The Cases in Research Database option in the Standard Case Selections box will be checked by default. This will exclude the July through December 2005 cases from Louisiana.
  • Select Edit next to the Case Selection box to open the Case Selection window.
  • Using the controls at the top of the Case Selection window, you will create a search statement. The variables are listed in categories in the Variable box on the top left of the screen. The Selection Statement should read:
    {Race, Sex, Year Dx, Registry, County.Sex} = ' Female'
    And {Site and Morphology.Site recode ICD-O-3/WHO 2008} = 'Breast'
    AND {Stage - LRD (Summary and Historic).Summary stage 2000 (1998+)} = 'Regional'
  • When finished, click the OK button.

Step 5:  Set the Parameters (Parameters Tab)

  • Use the default setting for all parameters.
  • Check Standard Life (Period) and Period Contributors (Std Life) boxes in the Display section, and use the default Cumulative Summary settings.

Step 6:  Edit Settings on the Output Tab

  • Skip to the Output tab because there are no Table variables for this exercise.
  • Enter a title for your results matrix.
  • Use the default settings for the options on the Output tab.

Step 7:  Execute SEER*Stat

  • Use the Execute button or select Execute from the Session menu to execute the session. (Execute Offline is a 3rd option available and has been explained in previous exercises.)
  • You will receive a variable warning dialog instructing you to use caution when using the Summary stage 2000 (1998+) variable. This variable is coded for breast cancer for 1998+, therefore the warning does not apply for this analysis. Click OK to close the dialog and execute the session.
  • A dialog will display the progress of the job. When the job completes a new window will open containing the output table or matrix.

Learn More...

  • The SEER Program strives to make all Localized/Regional/Distant (L/R/D) stage variables consistent for all cancer sites for the appropriate years. However, there are certain site/year combinations where this is not possible. To see which cancer sites were affected by the stage adjustments, click on the "For More Information..." link located on the warning dialog that appears when you execute this session. This link is also available on the selection dialog and within the dictionary editor when working with the Summary stage 2000 (1998+) variable.

Step 8:  The Results Matrix

  • Use the Save As command on the File menu to save the matrix. Enter "Survival Exercise 2" as the filename. SEER*Stat will assign the "ssm" extension to indicate that this is a "SEER*Stat Survival Matrix" file.
  • Compare your results to this SEER*Stat matrix file: Exercise Matrix 2 Results.
  • The results matrix consists of multiple pages of output. Use the drop down list on the toolbar to select a different page to view.
  • The Survival Results Matrix section of the help system contains more information about the SEER*Stat matrix and its features.