Association of health insurance status with presentation, treatment and outcomes in soft tissue sarcoma

Abstract

Background: Numerous studies across a variety of malignancies have demonstrated that health insurance status is associated with differences in clinical presentation, type of treatments received, and survival. The effect of insurance status on the management of soft tissue sarcoma is unknown. We assessed the association of insurance on (a) stage at diagnosis, (b) receipt of neoadjuvant/adjuvant radiation therapy, and (c) overall survival (OS) in patients with soft tissue sarcoma.

Methods: The study cohort was identified from the National Cancer Database (NCDB) and consisted of patients with stage I-IV soft tissue sarcoma of various histologies diagnosed from 2004 to 2015. The patients were stratified by age (<65 and ≥65 years) and by insurance status (commercial, Medicare, Medicaid and uninsured). Using multivariable logistic regression analysis, we evaluated the association between insurance status and (a) stage at diagnosis (Stage I-III vs IV), and (b) receipt of neoadjuvant/adjuvant radiation therapy in patients with locally advanced disease. The association of insurance status on OS was assessed using Kaplan-Meier and multivariable Cox proportional hazards analyses. A propensity score matched survival analysis was performed to account for measured confounders.

Results: 49 754 patients were identified of whom 23 677 (48%) had commercial insurance, 20 867 (42%) had Medicare, 3229 (6%) had Medicaid, and 1981 (4%) were uninsured. In patients <65 years, those with Medicaid (OR = 1.74, 95% CI: 1.57-1.93, P < .001) and the uninsured (OR = 1.71, 95% CI: 1.51-1.94, P < .001) were more likely to present with stage IV vs Stage I-III disease. Furthermore, among patients with locally advanced disease treated with limb sparing surgery, those with Medicaid (OR = 0.87, 95% CI: 0.77- 0.98, P = .021) and the uninsured (OR = 0.73, 95% CI: 0.63-0.85, P < .001) were less likely to receive neoadjuvant or adjuvant radiotherapy as compared to those with commercial insurance. Lastly, having Medicaid (HR = 1.26, 95% CI: 1.17-1.34, P < .001) and no insurance (HR = 1.30, 95% CI: 1.20-1.41, P < .001) was associated with worse OS compared to having commercial insurance, a finding which remained significant after propensity score matching. In contrast, in patients ≥65 years, there were no statistically significant differences between those with Medicare and commercial insurance with regards to disease presentation, receipt of radiotherapy, or survival.

Conclusions: In a large modern cohort identified from the NCDB, commercial insurance status in patients <65 years was associated early diagnosis, receipt of neoadjuvant/adjuvant radiation therapy, and overall survival for patients with soft tissue sarcoma. Further efforts are warranted to understand disparities in care based on health insurance in the United States.

Keywords: insurance; medicaid; medicare; radiation therapy; soft tissue sarcoma; survival.

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) diagram of the patient cohort; NCDB, National Cancer Database; STS, Soft Tissue Sarcoma

Figure 2

Overall survival as a function of insurance status in patients < 65 years (log rank P < .001)