A patient's race/ethnicity does not explain the underuse of appropriate adjuvant therapy in colorectal cancer.
BACKGROUND
To improve colorectal cancer outcomes, appropriate adjuvant therapy (chemotherapy, radiation therapy) should be given. Numerous studies have demonstrated underuse of adjuvant therapy in colorectal cancer. The current study examines variables associated with underuse of adjuvant therapy.


METHODS
Three population-based databases were linked: California Cancer Registry, California Patient Discharge Database, 2000 Census. All colorectal cancer patients diagnosed from 1994 to 2001 were studied. Patient characteristics (age, gender, race/ethnicity, comorbidities, payer, diagnosis year, socioeconomic status) were used in five multivariate regression analyses to predict receipt of chemotherapy for Stage III colon cancer, and receipt of chemotherapy and radiation therapy for Stages II, III rectal cancer.


RESULTS
The overall cohort was 18,649 Stage III colon cancer and Stages II, III rectal cancer patients. Mean age was 68.9 years, 50 percent male, 74 percent non-Hispanic white, 6 percent black, 11 percent Hispanic, 9 percent Asian, and 65 percent had no significant comorbid disease. Receipt of chemotherapy was 48 percent for Stage III colon cancer, 48 percent for Stage II rectal cancer, and 66 percent for Stage III rectal cancer. Receipt of radiation therapy was 52 percent for Stage II rectal cancer and 66 percent for Stage III rectal cancer. In all five models, low socioeconomic status predicted underuse of chemotherapy or radiation therapy (P < 0.016). Race/ethnicity was not statistically associated with underuse in any of the models.


CONCLUSIONS
Most literature identifies race/ethnicity as the reason for disparate receipt of adjuvant therapy in colorectal cancer. Using a more robust database of three population-based sources, our analysis demonstrates that socioeconomic status is a more important predictor of (in)appropriate care than race/ethnicity. Explicit measures to improve care to the poor with colorectal cancer are needed.
McGory
Marcia L
ML
Department of Surgery, David Geffen School of Medicine, University of California Los Angeles, Center for Health Sciences, Box 956904, Los Angeles, California, 90095-6904, USA. mmcgory@mednet.ucla.edu
Zingmond
David S
DS
Sekeris
Evan
E
Bastani
Roshan
R
Ko
Clifford Y
CY
D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000473:pathology / Q000628:therapy*; D015897:Comorbidity; D019992:Databases as Topic; D005260:Female; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy / Q000706:statistics & numerical data*; D011203:Poverty; D044469:Racial Groups; D012042:Registries; D012044:Regression Analysis; D012737:Sex Factors; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology