Disparities in the quality of definitive radiation therapy for patients with locally advanced cervical cancer (059)

Abstract

<b>Objectives:</b> To examine disparities and patterns of definitive radiation therapy administration for patients with locally advanced cervical cancer (LACC) and their impact on overall survival. <b>Methods:</b> Black and non-Hispanic White (NHW) patients diagnosed between 2004 and 2015 with locally advanced cervical cancer (FIGO 2009 stage IB2-IVA), who had no history of another tumor, did not undergo hysterectomy, received external beam radiation therapy of at least 45 Gy, and had at least one month of follow-up, were identified in the National Cancer Database. We examined three quality metrics described in the National Comprehensive Cancer Network (NCCN) guidelines; utilization of radio-sensitizing chemotherapy (defined as chemotherapy administered within two weeks from radiotherapy initiation), receipt of brachytherapy, and completion of radiation treatment within eight weeks from initiation. Clinical-pathologic characteristics were compared with the Chi-square test. Overall survival was evaluated with Cox models after controlling for a priori selected confounders. <b>Results:</b> A total of 9940 patients with LACC were identified; 2242 (22.6%) were Black, and 7698 (77.4%) were NHW. Black patients were more likely to have squamous cell histology (91.3% vs 84.7%, p<0.001), medical comorbid conditions (17.1% vs 14.5%, p<0.001), government-issued insurance (55% vs 46.2%, p<0.001), and be managed at academic facilities (55.6% vs 42.3%, p<0.001). Stage distribution (49.5% vs 47.2% stage III-IVA, p=0.06) and patient age (median 52 years for both groups) were comparable between Black and NHW patients. However, Black patients were more likely to receive all treatment at the reporting facility (79.3% vs 71.7%, p<0.001) and reside within a short distance (<12.5 miles) from the treatment facility (69.3% vs 47.2%, p<0.001). In the present cohort, 5432 (54.6%) patients completed treatment within eight weeks, 8794 (88.5%) received radio-sensitizing chemotherapy, and 6453 (64.9%) received brachytherapy. All three-quality metrics were met for 2981 patients (30%). Black patients were less likely to have treatment that fulfilled all three-quality metrics (26% vs 31.2%, p<0.001) even after controlling for histology, age, insurance, comorbid conditions, and disease stage (OR: 0.82, 95% CI: 0.73-0.91). Patients who received guideline conformant radiation therapy had better OS after controlling for age, comorbid conditions, disease stage, histology, and insurance (HR: 0.67, 95% CI: 0.63-0.72). A survival advantage for patients receiving guideline conformant radiation therapy was present for both WNH (HR: 0.69; 95% CI: 0.64-0.75) and Black patients (HR: 0.60, 95% CI: 0.51-0.71). <b>Conclusions:</b> Approximately one in three patients with LACC received definitive radiotherapy that met all quality metrics and had superior outcomes even after controlling for confounders. Black patients were less likely to receive guideline conformant radiotherapy than WNH, even though they reside closer to treatment facilities and are more likely to present to academic institutions.