title: Effects of Cancer Stage and Treatment Differences on Racial Disparities in Survival From Colon Cancer: A United States Population-Based Study.
abstract: We evaluated differences in treatment of black vs white patients with colon cancer and assessed their effects on survival, based on cancer stage.
  
  
  
  We collected data from the Surveillance, Epidemiology, and End Results-Medicare database and identified 6190 black and 61,951 white patients with colon cancer diagnosed from 1998 through 2009 and followed up through 2011. Three sets of 6190 white patients were matched sequentially, using a minimum distance strategy, to the same set of 6190 black patients based on demographic (age; sex; diagnosis year; and Surveillance, Epidemiology, and End Results registry), tumor presentation (demographic plus comorbidities, tumor stage, grade, and size), and treatment (presentation plus therapies) variables. We conducted sensitivity analyses to explore the effects of socioeconomic status in a subcohort that included 2000 randomly selected black patients. Racial differences in treatment were assessed using a logistic regression model; their effects on racial survival disparity were evaluated using the Kaplan-Meier method and the Cox proportional hazards model.
  
  
  
  After patients were matched for demographic variables, the absolute 5-year difference in survival between black and white patients was 8.3% (white, 59.2% 5-y survival; blacks, 50.9% 5-y survival) (P < .0001); this value decreased significantly, to 5.0% (P < .0001), after patients were matched for tumor presentation, and decreased to 4.9% (P < .0001) when patients were matched for treatment. Differences in treatment therefore accounted for 0.1% of the 8.3% difference in survival between black and white patients. After patients were matched for tumor presentation, racial disparities were observed in almost all types of treatment; the disparities were most prominent for patients with advanced-stage cancer (stages III or IV, up to an 11.1% difference) vs early stage cancer (stages I or II, up to a 4.3% difference). After patients were matched for treatment, there was a greater reduction in disparity for black vs white patients with advanced-stage compared with early-stage cancer. In sensitivity analyses, the 5-year racial survival disparity was 7.7% after demographic match, which was less than the 8.3% observed in the complete cohort. This reduction likely was owing to the differences between the subcohort and the complete cohort in those variables that were not included in the demographic match. This value was reduced to 6.5% (P = .0001) after socioeconomic status was included in the demographic match. The difference decreased significantly to 2.8% (P = .090) after tumor presentation match, but was not reduced further after treatment match.
  
  
  
  We observed significant disparities in treatment and survival of black vs white patients with colon cancer. The disparity in survival appears to have been affected more strongly by tumor presentation at diagnosis than treatment. The effects of treatment differences on disparities in survival were greater for patients with advanced-stage vs early-stage cancer.
authors.affiliation: Division of Population Science, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Yinzhi
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Division of Population Science, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Jesse M
authors.initials: JM
authors.lastname: Civan
authors.affiliation: Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Palazzo
authors.affiliation: Division of Population Science, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina.
authors.forename: Terry
authors.initials: T
authors.lastname: Hyslop
authors.affiliation: Division of Solid Tumor Oncology, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Jianqing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Division of Population Science, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Myers
authors.affiliation: Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
authors.forename: Bingshan
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Binghua
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Division of Solid Tumor Oncology, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Sama
authors.affiliation: Experimental Teaching Center, School of Basic Medicine, Fourth Military Medical University, Xi'an, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Xing
authors.affiliation: Division of Population Science, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania. Electronic address: hushan.yang@jefferson.edu.
authors.forename: Hushan
authors.initials: H
authors.lastname: Yang
mesh_terms: D001741:Black or African American; D000368:Aged; D003110:Colonic Neoplasms / Q000208:ethnology* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D015897:Comorbidity; D005260:Female; D054624:Health Status Disparities; D054625:Healthcare Disparities / Q000208:ethnology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012307:Risk Factors; D018426:SEER Program; D012959:Socioeconomic Factors; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D014481:United States / Q000453:epidemiology; D044465:White People
keywords: CRC; Colorectal Cancer; Outcome; Race
references.citation: N Engl J Med. 2004 Jun 3;350(23):2335-42
references.pmid: 15175435
references.citation: Am J Public Health. 2013 Jul;103(7):e91-9
references.pmid: 23678899
references.citation: J Clin Epidemiol. 2001 Apr;54(4):359-66
references.pmid: 11297886
references.citation: Am J Gastroenterol. 2005 Mar;100(3):515-23; discussion 514
references.pmid: 15743345
references.citation: J Comput Graph Stat. 2008 Dec;17(4):914-924
references.pmid: 25580069
references.citation: J Natl Cancer Inst. 2002 Mar 6;94(5):334-57
references.pmid: 11880473
references.citation: Dis Colon Rectum. 2014 Mar;57(3):295-302
references.pmid: 24509450
references.citation: Arch Surg. 2002 May;137(5):550-4; discussion 554-6
references.pmid: 11982467
references.citation: Cancer. 2007 Aug 1;110(3):660-9
references.pmid: 17582625
references.citation: CA Cancer J Clin. 2004 Mar-Apr;54(2):78-93
references.pmid: 15061598
references.citation: J Natl Cancer Inst. 1995 Nov 15;87(22):1686-93
references.pmid: 7473817
references.citation: J Clin Oncol. 2008 Jul 20;26(21):3523-9
references.pmid: 18640933
references.citation: Gastrointest Endosc. 2000 May;51(5):524-7
references.pmid: 10805835
references.citation: Cancer. 2007 Jun 1;109(11):2161-70
references.pmid: 17455219
references.citation: Cancer. 2007 Feb 1;109(3):612-20
references.pmid: 17186529
references.citation: J Clin Oncol. 2012 Feb 1;30(4):401-5
references.pmid: 22184373
references.citation: J Epidemiol Community Health. 2011 Mar;65(3):211-7
references.pmid: 19959651
references.citation: Am J Manag Care. 2010 Jul;16(7):515-22
references.pmid: 20645667
references.citation: J Natl Cancer Inst. 2013 Dec 4;105(23):1814-20
references.pmid: 24231453
references.citation: Biometrics. 2012 Jun;68(2):628-36
references.pmid: 22008180
references.citation: JAMA. 2013 Jul 24;310(4):389-97
references.pmid: 23917289
references.citation: Ethn Dis. 1998 Winter;8(1):43-51
references.pmid: 9595247
references.citation: Ann Oncol. 2005 May;16(5):767-72
references.pmid: 15817594
references.citation: Am J Gastroenterol. 2009 Mar;104(3):739-50
references.pmid: 19240699
references.citation: J Clin Oncol. 2004 Dec 1;22(23):4753-61
references.pmid: 15570076
references.citation: J Clin Oncol. 2006 May 10;24(14):2179-87
references.pmid: 16682737
references.citation: Cancer. 2008 Feb 15;112(4):900-8
references.pmid: 18181101
references.citation: Cancer. 2004 Jul 1;101(1):66-76
references.pmid: 15221990
references.citation: Gastroenterology. 2001 Mar;120(4):848-56
references.pmid: 11231939
references.citation: Lancet. 2014 Apr 26;383(9927):1490-502
references.pmid: 24225001
references.citation: Nat Commun. 2014;5:4613
references.pmid: 25105248
references.citation: J Natl Compr Canc Netw. 2008 Jul;6(6):536-64
references.pmid: 18597709
references.citation: Cancer. 2008 Dec 15;113(12):3400-9
references.pmid: 18932248
references.citation: J Clin Oncol. 2007 Apr 20;25(12):1539-44
references.pmid: 17442997
references.citation: Am J Clin Oncol. 2015 Apr;38(2):227-33
references.pmid: 25806713
references.citation: J Psychosoc Oncol. 2009;27(1):59-83
references.pmid: 19197679
references.citation: Ann Oncol. 2009 Nov;20(11):1842-7
references.pmid: 19406901
references.citation: Am J Epidemiol. 2011 Oct 1;174(7):828-38
references.pmid: 21836166
references.citation: Cancer Biomark. 2007;3(6):301-13
references.pmid: 18048968
references.citation: J Natl Cancer Inst. 2010 Apr 21;102(8):538-46
references.pmid: 20357245
references.citation: J Clin Oncol. 2005 Jun 1;23(16):3706-12
references.pmid: 15867200
references.citation: Arch Surg. 2004 Feb;139(2):151-5; discussion 156
references.pmid: 14769572
references.citation: Clin Colorectal Cancer. 2015 Mar;14(1):1-10
references.pmid: 25579803
references.citation: Cancer. 2012 Jun 1;118(11):2925-34
references.pmid: 22072441
references.citation: Cancer Epidemiol Biomarkers Prev. 2006 Apr;15(4):792-7
references.pmid: 16614125
references.citation: Cancer. 1998 Jun 15;82(12):2312-20
references.pmid: 9635522
references.citation: J Clin Oncol. 2013 Jun 1;31(16):1928-30
references.pmid: 23589553
references.citation: Oral Oncol. 2015 Jun;51(6):586-92
references.pmid: 25865553
references.citation: J Natl Cancer Inst. 2005 Aug 17;97(16):1211-20
references.pmid: 16106026
references.citation: Cancer Epidemiol Biomarkers Prev. 2008 Aug;17(8):1950-62
references.pmid: 18708384
references.citation: Cancer Epidemiol Biomarkers Prev. 2015 Jul;24(7):1138-43
references.pmid: 25987547