Geographic variation and sociodemographic disparity in the use of oxaliplatin-containing chemotherapy in patients with stage III colon cancer

Abstract

This study examined the geographic variation and sociodemographic disparities in the use of oxaliplatin chemotherapy, which has not been widely studied in the past. Our results suggest that chemotherapy use varies across geographic regions. Patterns of use that relate specifically to oxaliplatin-containing chemotherapy can inform providers and researchers how newer regimens are being used as standard chemotherapy in a real-world setting.

Background: According to the National Cancer Comprehensive Network (NCCN), oxaliplatin with 5-fluorouracil and leucovorin (5-FU/LV) is the recommended adjuvant chemotherapy for patients with resected stage III colon cancer. Age and race are considered strong predictors of chemotherapy receipt, whereas geographic disparity has received minimal attention. The purpose of this study was to examine geographic variation and sociodemographic disparity in the use of chemotherapy in patients with stage III colon cancer, focusing specifically on oxaliplatin.

Methods: A retrospective cohort of 4106 Medicare patients was identified from the Surveillance, Epidemiology and End Results (SEER)/Medicare linked database. Descriptive statistics show how oxaliplatin-containing chemotherapy was used in various geographic regions among different age and racial groups. Multiple logistic regression analysis was performed to examine the relationship between receipt of oxaliplatin-containing chemotherapy and geographic region while adjusting for other sociodemographic and tumor characteristics.

Results: Only 49% of the patients with stage III disease received adjuvant chemotherapy within 3 to 6 months of colon cancer-specific surgery. Patients aged 66 to 70 years were 78% more likely to receive chemotherapy than were those aged 80 years and older (P<.001). Patients in less urban regions were approximately 42% less likely to receive oxaliplatin chemotherapy than those residing in a big metro region (odds ratio [OR], 0.58; P=.008).

Conclusion: Chemotherapy use varies across geographic regions, especially for new chemotherapy drugs like oxaliplatin. Further research is needed to identify the causes of this geographic disparity and ways to provide high-quality cancer care to all patients according to their preferences and needs.