Cancer Causes & Control

, Volume 24, Issue 6, pp 1231–1242

The effect of multiple primary rules on population-based cancer survival

  • Hannah K. Weir
  • Christopher J. Johnson
  • Trevor D. Thompson
Original paper

DOI: 10.1007/s10552-013-0203-3

Cite this article as:
Weir, H.K., Johnson, C.J. & Thompson, T.D. Cancer Causes Control (2013) 24: 1231. doi:10.1007/s10552-013-0203-3

Abstract

Purpose

Different rules for registering multiple primary (MP) cancers are used by cancer registries throughout the world, making international data comparisons difficult. This study evaluates the effect of Surveillance, Epidemiology, and End Results (SEER) and International Association of Cancer Registries (IACR) MP rules on population-based cancer survival estimates.

Methods

Data from five US states and six metropolitan area cancer registries participating in the SEER Program were used to estimate age-standardized relative survival (RS%) for first cancers-only and all first cancers matching the selection criteria according to SEER and IACR MP rules for all cancer sites combined and for the top 25 cancer site groups among men and women.

Results

During 1995–2008, the percentage of MP cancers (all sites, both sexes) increased 25.4 % by using SEER rules (from 14.6 to 18.4 %) and 20.1 % by using IACR rules (from 13.2 to 15.8 %). More MP cancers were registered among females than among males, and SEER rules registered more MP cancers than IACR rules (15.8 vs. 14.4 % among males; 17.2 vs. 14.5 % among females). The top 3 cancer sites with the largest differences were melanoma (5.8 %), urinary bladder (3.5 %), and kidney and renal pelvis (2.9 %) among males, and breast (5.9 %), melanoma (3.9 %), and urinary bladder (3.4 %) among females. Five-year survival estimates (all sites combined) restricted to first primary cancers-only were higher than estimates by using first site-specific primaries (SEER or IACR rules), and for 11 of 21 sites among males and 11 of 23 sites among females. SEER estimates are comparable to IACR estimates for all site-specific cancers and marginally higher for all sites combined among females (RS 62.28 vs. 61.96 %).

Conclusion

Survival after diagnosis has improved for many leading cancers. However, cancer patients remain at risk of subsequent cancers. Survival estimates based on first cancers-only exclude a large and increasing number of MP cancers. To produce clinically and epidemiologically relevant and less biased cancer survival estimates, data on all cancers should be included in the analysis. The multiple primary rules (SEER or IACR) used to identify primary cancers do not affect survival estimates if all first cancers matching the selection criteria are used to produce site-specific survival estimates.

Keywords

Cancer survivalMultiple primary rulesSEER Program

Abbreviations

ICD

International Classification of Diseases

IACR

International Association of Cancer Registries

NAACCR

North American Association of Central Cancer Registries

NPCR

National Program of Cancer Registries

SEER

Surveillance, Epidemiology, and End Results

Copyright information

© Springer Science+Business Media Dordrecht (outside the USA) 2013

Authors and Affiliations

  • Hannah K. Weir
    • 1
  • Christopher J. Johnson
    • 2
  • Trevor D. Thompson
    • 1
  1. 1.Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health PromotionCenters for Disease Control and PreventionAtlantaUSA
  2. 2.Cancer Data Registry of IdahoBoiseUSA