Provider-based research networks may improve early access to innovative colon cancer treatment for African Americans treated in the community

Abstract

Background: African American (AA) patients with colon cancer (CC) experience worse outcomes than whites partly due to differential treatment. The National Cancer Institute's Community Clinical Oncology Program (CCOP), a provider-based research network, adopts and diffuses innovative CC treatments quickly. The authors hypothesized that CCOP participation would lessen racial differences in the receipt of oxaliplatin, an innovative treatment for CC, among patients with stage III CC in the community.

Methods: Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, the authors performed a population-based retrospective cohort study of AA and white individuals aged ≥66 years who were diagnosed with AJCC stage III CC from 2003 through 2005. Generalized estimating equations were used to calculate the odds of receiving an oxaliplatin-containing regimen. Predicted probabilities of oxaliplatin receipt for race-CCOP combinations were calculated. The absolute difference in oxaliplatin receipt between races was estimated using the interaction contrast ratio.

Results: Of 2971 included individuals, 36% received oxaliplatin, 29.5% were CCOP-affiliated, and 7.6% were AA. On multivariate analysis, early diffusion of oxaliplatin was not found to be associated with race or CCOP participation. The probability of receiving oxaliplatin for AAs participating in a CCOP (0.46) was nearly double that of AAs who were not participating in a CCOP (0.25; P <.05). For white individuals, the probabilities of receiving oxaliplatin did not differ by CCOP participation. For oxaliplatin receipt, the joint effects assessment suggested a greater benefit of CCOP participation among AAs (interaction contrast ratio, 1.7).

Conclusions: Among older patients with stage III CC, there is a differential impact of race on oxaliplatin receipt depending on CCOP participation. AAs treated by CCOPs were more likely to receive oxaliplatin than AAs treated elsewhere. Provider-based research networks may facilitate early access to innovative treatment for AAs with stage III CC.

Keywords: End Results (SEER) program; Surveillance, Epidemiology; aged; colon cancer; colonic neoplasms/therapy; community-institutional relations; health care disparities; oxaliplatin.

Figure 1

Cohort Selection from Surveillance, Epidemiology, and End Results-Medicare data 5-FU,5-Fluorouracil; AA,African American; CA,Caucasian American; CCOP,Community Clinical Oncology Program

Figure 2

Probability of Receiving Oxaliplatin-containing Regimen, by Race and CCOP Interaction CCOP,Community Clinical Oncology Program