PCN9 TREATMENT PATTERNS AND SURVIVAL IN UNRESECTABLE ADVANCED ESOPHAGEAL SQUAMOUS CELL CANCER IN THE SURVEILLANCE, EPIDEMIOLOGY, AND END RESULTS (SEER) MEDICARE LINKED DATA

Abstract

Esophageal squamous cell cancer (ESCC) is a leading cause of cancer death worldwide. Treatment options are limited for patients who cannot undergo surgery. The study objective was to understand patterns of care, overall survival, and duration of treatment (DoT) in Medicare patients with unresectable ESCC in the United States. This was a retrospective cohort study using SEER data linked with Medicare claims. Patients aged ≥66 years with a primary, pathologically confirmed diagnosis of unresectable advanced or metastatic ESCC between 2010–2015 were included, and were followed through 2016. Outpatient systemic treatment was identified using Medicare claims. First-line, second-line, and third-line therapies were inferred based on changes and gaps in treatment. Patients were followed until death, end of follow-up, second primary cancer, or switch to managed care. The Kaplan-Meier estimator was used to estimate unadjusted median survival and DoT. This study identified 756 ESCC patients. Mean age was 75 years, 64% were male, 71% white, 52% had TNM Stage T4b or M1, and 79% had no mobility limitation indicators at diagnosis. Mean follow-up time from diagnosis was 15.6 months and 75% of patients died during follow-up. Of all diagnosed patients, 459 (61%) received first-line treatment, 104 (14%) received second-line, and 26 (3.4%) received third-line. Median survival was 11.5 months (95% CI 10.3-14.1) for first-line, 5.7 months (95% CI 5.0-8.5) for second-line, and 5.3 months (95% CI 2.5-19.0) for third-line patients. DoT (first to last dose) by line was 1.4, 1.6, and 1.4 months. Paclitaxel plus carboplatin (n=206, 45%) was the most common first-line regimen; docetaxel or paclitaxel monotherapy (n=21, 20%) was the most common second-line regimen. Patients with ESCC have poor overall survival, and few receive second- or third-line treatment. These results highlight the need for more effective treatment options in second-line and later lines of treatment.