Original Contribution
Racial Disparity in Colorectal Cancer: The Role of Equal Treatment Jonathan A. Laryea, M.D.1 • Eric Siegel, M.S.2 • Suzanne Klimberg, M.D.1 1 Department of Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas 2 Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
BACKGROUND: Racial disparity exists in colorectal cancer outcomes. The reasons for this are multifactorial. OBJECTIVE: The aim of this study was to evaluate the role of equal treatment of blacks and whites in the elimination of racial disparity in colorectal cancer outcomes. DESIGN: A retrospective cohort study of 878 patients with colorectal cancer diagnosed between 1998 and 2008 was done at a University tertiary referral center. Demographic variables including age, sex, and race were abstracted. Tumor-specific variables including American Joint Committee on Cancer stage, anatomic tumor location, vital status, and survival were obtained. Treatment-specific variables including surgery, chemotherapy, radiotherapy, and follow-up were also obtained. Racial differences in these variables were studied and their effect on overall survival was determined by using univariate and multivariate analyses. The findings were then compared with previous data from our institution. SETTING: University tertiary referral center. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival and cancer-specific mortality. RESULTS: A total of 878 patients met the inclusion
criteria, 186 (21.2%) of whom were black. Blacks were Funding/Support: This study was supported by a minority mentoring research grant from the Diversity Strategic Planning Working Group of the National Surgical Adjuvant Breast and Bowel Project. Financial Disclosure: None reported. Podium presentation at the meeting of The American Society of Colon and Rectal Surgeons, Phoenix, AZ, April 27 to May 1, 2013. Correspondence: Jonathan A. Laryea, M.D., Division of Colon and Rectal Surgery, Department of Surgery, University of Arkansas for Medical Sciences (UAMS), 4301 W Markham St, slot 520, Little Rock, AR 72205. E-mail: [email protected] Dis Colon Rectum 2014; 57: 295–302 DOI: 10.1097/DCR.0000000000000056 © The ASCRS 2014 Diseases of the Colon & Rectum Volume 57: 3 (2014)
significantly younger at diagnosis in comparison with whites, with a median (quartiles) age of 55 years (28–87) compared with 59 years (23–94) (p = 0.0012). Equal proportions of blacks (78.5%) and whites (79.2%) underwent surgery (p = 0.84), similar proportions of blacks (55.4%) and whites (60.8%) received chemotherapy (p = 0.18), and similar proportions of blacks (17.2%) and whites (20.5%) received radiation therapy (p = 0.31). There was no difference in overall survival or cancer-specific mortality between the 2 racial groups. Univariate analysis showed American Joint Committee on Cancer stage and surgery as the only statistically significant factors for overall survival. On multivariate analysis, stage, surgery, and chemotherapy were the only statistically significant factors. Race was not an independent determinant of survival. CONCLUSIONS: There were no differences in overall survival and cancer-related mortality between blacks and whites, and this may have resulted from identical treatment. The previously noted disparities in treatment and overall survival at our institution have disappeared.
KEY WORDS: Racial disparity; Overall survival; C ancerrelated mortality; Equal treatment.
R
acial disparity in colorectal cancer outcomes is a very well-known phenomenon, but it is poorly understood. Previous studies have shown that blacks have 40% to 50% excess mortality from colorectal cancer in comparison with whites.1–5 Blacks are more likely to present with advanced stages of disease.6–9 The reasons for the racial disparity in colorectal cancer outcomes are multifactorial. Some of the factors include lower socioeconomic status,5,6,10–14 treatment inequalities,15–20 biological factors,21 lack of access to care,21–26 and other unknown factors. However, the disparity still remains even after adjusting for stage, age, sex, and socioeconomic status.5,27 Studies looking at Medicare data have found that blacks with colorectal cancer are as likely to be referred to a medical oncologist as whites. 295
296
However, blacks are less likely to receive adjuvant therapy than whites once they see the oncologist.28,29 Studies from equal-access systems such as the Veterans Affairs Medical Centers have suggested that equal treatment may eliminate the racial disparity in overall survival for colorectal cancer.30 A previous study from our institution showed that blacks had a 40% excess mortality from colorectal cancer in comparison with whites.5 This disparity persisted after adjusting for stage and socioeconomic status. However, blacks were less likely to receive chemotherapy and radiation therapy. Since that publication, a lot of changes have been made in an attempt to eliminate the racial disparity in outcomes. We therefore decided to evaluate the role of equal treatment on the racial disparity in colorectal cancer outcomes.
METHODS Patient Population
Approval for this study was obtained from the institutional review board of University of Arkansas for Medical Sciences (UAMS), a university tertiary referral hospital. Data obtained from the UAMS tumor registry included diagnosis date, age at diagnosis, race, sex, tumor site codes, American Joint Committee on Cancer (AJCC) stage group, surgery details, chemotherapy summary, radiotherapy summary, vital status, cancer status, and date of death or last contact. Patients were included for analysis if they were diagnosed between January 1, 1998 and December 31, 2008, were either black or white, and had at least 1 day of follow-up after diagnosis. Statistical Analysis
All statistical analyses used SAS version 9.3 (The SAS institute, Cary, NC). Age was dichotomized as ≥60 versus
Racial Disparity in Colorectal Cancer: The Role of Equal Treatment Jonathan A. Laryea, M.D.1 • Eric Siegel, M.S.2 • Suzanne Klimberg, M.D.1 1 Department of Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas 2 Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
BACKGROUND: Racial disparity exists in colorectal cancer outcomes. The reasons for this are multifactorial. OBJECTIVE: The aim of this study was to evaluate the role of equal treatment of blacks and whites in the elimination of racial disparity in colorectal cancer outcomes. DESIGN: A retrospective cohort study of 878 patients with colorectal cancer diagnosed between 1998 and 2008 was done at a University tertiary referral center. Demographic variables including age, sex, and race were abstracted. Tumor-specific variables including American Joint Committee on Cancer stage, anatomic tumor location, vital status, and survival were obtained. Treatment-specific variables including surgery, chemotherapy, radiotherapy, and follow-up were also obtained. Racial differences in these variables were studied and their effect on overall survival was determined by using univariate and multivariate analyses. The findings were then compared with previous data from our institution. SETTING: University tertiary referral center. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival and cancer-specific mortality. RESULTS: A total of 878 patients met the inclusion
criteria, 186 (21.2%) of whom were black. Blacks were Funding/Support: This study was supported by a minority mentoring research grant from the Diversity Strategic Planning Working Group of the National Surgical Adjuvant Breast and Bowel Project. Financial Disclosure: None reported. Podium presentation at the meeting of The American Society of Colon and Rectal Surgeons, Phoenix, AZ, April 27 to May 1, 2013. Correspondence: Jonathan A. Laryea, M.D., Division of Colon and Rectal Surgery, Department of Surgery, University of Arkansas for Medical Sciences (UAMS), 4301 W Markham St, slot 520, Little Rock, AR 72205. E-mail: [email protected] Dis Colon Rectum 2014; 57: 295–302 DOI: 10.1097/DCR.0000000000000056 © The ASCRS 2014 Diseases of the Colon & Rectum Volume 57: 3 (2014)
significantly younger at diagnosis in comparison with whites, with a median (quartiles) age of 55 years (28–87) compared with 59 years (23–94) (p = 0.0012). Equal proportions of blacks (78.5%) and whites (79.2%) underwent surgery (p = 0.84), similar proportions of blacks (55.4%) and whites (60.8%) received chemotherapy (p = 0.18), and similar proportions of blacks (17.2%) and whites (20.5%) received radiation therapy (p = 0.31). There was no difference in overall survival or cancer-specific mortality between the 2 racial groups. Univariate analysis showed American Joint Committee on Cancer stage and surgery as the only statistically significant factors for overall survival. On multivariate analysis, stage, surgery, and chemotherapy were the only statistically significant factors. Race was not an independent determinant of survival. CONCLUSIONS: There were no differences in overall survival and cancer-related mortality between blacks and whites, and this may have resulted from identical treatment. The previously noted disparities in treatment and overall survival at our institution have disappeared.
KEY WORDS: Racial disparity; Overall survival; C ancerrelated mortality; Equal treatment.
R
acial disparity in colorectal cancer outcomes is a very well-known phenomenon, but it is poorly understood. Previous studies have shown that blacks have 40% to 50% excess mortality from colorectal cancer in comparison with whites.1–5 Blacks are more likely to present with advanced stages of disease.6–9 The reasons for the racial disparity in colorectal cancer outcomes are multifactorial. Some of the factors include lower socioeconomic status,5,6,10–14 treatment inequalities,15–20 biological factors,21 lack of access to care,21–26 and other unknown factors. However, the disparity still remains even after adjusting for stage, age, sex, and socioeconomic status.5,27 Studies looking at Medicare data have found that blacks with colorectal cancer are as likely to be referred to a medical oncologist as whites. 295
296
However, blacks are less likely to receive adjuvant therapy than whites once they see the oncologist.28,29 Studies from equal-access systems such as the Veterans Affairs Medical Centers have suggested that equal treatment may eliminate the racial disparity in overall survival for colorectal cancer.30 A previous study from our institution showed that blacks had a 40% excess mortality from colorectal cancer in comparison with whites.5 This disparity persisted after adjusting for stage and socioeconomic status. However, blacks were less likely to receive chemotherapy and radiation therapy. Since that publication, a lot of changes have been made in an attempt to eliminate the racial disparity in outcomes. We therefore decided to evaluate the role of equal treatment on the racial disparity in colorectal cancer outcomes.
METHODS Patient Population
Approval for this study was obtained from the institutional review board of University of Arkansas for Medical Sciences (UAMS), a university tertiary referral hospital. Data obtained from the UAMS tumor registry included diagnosis date, age at diagnosis, race, sex, tumor site codes, American Joint Committee on Cancer (AJCC) stage group, surgery details, chemotherapy summary, radiotherapy summary, vital status, cancer status, and date of death or last contact. Patients were included for analysis if they were diagnosed between January 1, 1998 and December 31, 2008, were either black or white, and had at least 1 day of follow-up after diagnosis. Statistical Analysis
All statistical analyses used SAS version 9.3 (The SAS institute, Cary, NC). Age was dichotomized as ≥60 versus
