Colon cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study

Abstract

Background: In the first CONCORD study (2008), 5-year survival for patients diagnosed with colon cancer between 1990 and 1994 in the United States was among the highest in the world (60%), but there were large racial disparities in most participating states. The CONCORD-2 study (2015) enabled the examination of survival trends between 1995 and 2009 for US states by race and stage.

Methods: The authors analyzed data from 37 state population-based cancer registries, covering approximately 80% of the US population, for patients who were diagnosed with colon cancer between 2001 and 2009 and were followed through 2009. Survival up to 5 years was corrected for background mortality (net survival) using state-specific and race-specific life tables and age-standardized using the International Cancer Survival Standard weights. Survival is presented by race (all, black, white), stage, state, and calendar period (2001-2003 and 2004-2009) to account for changes in methods used to collect stage.

Results: Five-year net survival increased by 0.9%, from 63.7% between 2001 and 2003 to 64.6% between 2004 and 2009. More black than white patients were diagnosed with distant-stage disease between 2001 and 2003 (21.5% vs 17.2%) and between 2004 and 2009 (23.3% vs 18.8%). Survival improved for both blacks and whites, but 5-year net survival was 9-10% lower for blacks than for whites both between 2001 and 2003 (54.7% vs 64.5%) and between 2004 and 2009 (56.6% vs 65.4%). The absolute difference between blacks and whites decreased by only 1% during the decade.

Conclusions: Five-year net survival from colon cancer increased slightly over time. Survival among blacks diagnosed between 2004 and 2009 had still not reached the level of that among whites diagnosed between 1990 and 1994, some 15 to 20 years earlier. These findings suggest a need for more targeted efforts to improve screening and to ensure timely, appropriate treatment, especially for blacks, to reduce this large and persistent disparity in survival. Cancer 2017;123:5014-36. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Keywords: cancer registries; colon cancer; disparities; population-based survival.

Figure 1

Colon cancer: 5-year age-standardized net survival (%) for patients (15-99 years) diagnosed during 2001-2003 and 2004-2009, and absolute change (%): states grouped by US Census Region. Note: States are ranked within Census Region by the survival estimate for 2004-2009. Note: Dark colors – states affiliated with the National Program of Cancer Registries (NPCR); pale colors – states affiliated with the Surveillance, Epidemiology and End Results (SEER) Program. * Registries affiliated with both federal surveillance programs. Change (%) not plotted because at least one calendar period estimate was not age-standardized.

Figure 2

Colon cancer: 5-year age-standardized net survival (%) for patients (15-99 years), by state, race and calendar period of diagnosis. Note: the pooled (US) survival estimates for each calendar period are shown by the horizontal (solid) line with corresponding 95.0% and 99.8% control limits (dotted lines).