Medical costs of treating breast cancer among younger Medicaid beneficiaries by stage at diagnosis

Background Younger women (aged 18–44 years) diagnosed with breast cancer often face more aggressive tumors, higher treatment intensity, and lower survival rates than older women. In this study, we estimated incident breast cancer costs by stage at diagnosis and by race for younger women enrolled in Medicaid. Methods We analyzed cancer registry data linked to Medicaid claims in North Carolina from 2003 to 2008. We used Surveillance, Epidemiology, and End Results (SEER) Summary 2000 definitions for cancer stage. We split breast cancer patients into two cohorts: a younger and older group aged 18–44 and 45–64 years, respectively. We conducted a many-to-one match between patients with and without breast cancer using age, county, race, and Charlson Comorbidity Index. We calculated mean excess total cost of care between breast cancer and non-breast cancer patients. Results At diagnosis, younger women had a higher proportion of regional cancers than older women (49 vs. 42%) and lower proportions of localized cancers (44 vs. 50%) and distant cancers (7 vs. 9%). The excess costs of breast cancer (all stages) for younger and older women at 6 months after diagnosis were $37,114 [95% confidence interval (CI) = $35,769–38,459] and $28,026 (95% CI = $27,223–28,829), respectively. In the 6 months after diagnosis, the estimated excess cost was significantly higher to treat localized and regional cancer among younger women than among older women. There were no statistically significant differences in excess costs of breast cancer by race, but differences in treatment modality were present among younger Medicaid beneficiaries. Conclusions Younger breast cancer patients not only had a higher prevalence of late-stage cancer than older women, but also had higher within-stage excess costs.