Frontline Therapy Shows 3-Fold OS Improvement vs BSC in Unresectable Advanced or Metastastic ESCC

In real-world practices, patients with unresectable advanced recurrent or metastatic esophageal squamous cell carcinoma (ESCC) treated in the first-line setting showed a median overall survival (mOS) of 10.2 months, which was more than double that of the patients who received best supportive care (BSC) patients of 3.4 months.¹

These findings show that by deploying more effective treatments in the first-line setting, the mOS among treatment-eligible patients may be extended.

Currently, the first-line treatment guidelines for this patient population recommend combining platinum-based chemotherapy and fluoropyrimidines with taxanes or irinotecan. Because of this, investigators wanted to examine the treatment patterns and survival outcomes among real-world first-line treated patients with unresectable advanced recurrent or metastatic ESCC in the United States to better understand patient characteristics and mOS of these patients who received first-line chemotherapy or BSC.

In a real-world, observational, retrospective analysis, recurrent and unresectable de novo patients with ESCC who were diagnosed between January 1, 2012, and December 31, 2020, were identified using the Flatiron database. Descriptive statistics of patient demographics, clinical characteristics, and treatment patterns over the index and post-index periods were created and Kaplan-Meier survival curves were used to estimate the mOS for both patients treated in the first line and with BSC.

Patients included were those aged 18 years and older who had 1 or more outpatient medical records with primary ICD-10 diagnostic code for esophageal cancer and an ESCC histology. Those excluded were patients who had another primary cancer diagnosis on or before the initial esophageal cancer diagnosis date or who had received checkpoint inhibitor immunotherapy or other immunotherapy agents.

A total of 1456 patients were identified with esophageal cancer, including 402 (27.6%) who met inclusion and exclusion criteria who were also identified as patients with advanced or metastatic ESCC. There were 327 patients (22.5%) who were identified as de novo and 75 (5.2%) who had recurrent disease.

In the first-line treated and BSC cohorts enrolled in the study, findings showed that most of the patients were male (70.6% vs 64.6%), White (56.7% vs 52.2%), and around 80% of patients had stage IV disease. Additionally, of the 61.7% treated patients and 48.8% of patients given BSC had an index date which occurred in the last 4 years of the study.

For the 289 patients who had recurrent or de novo ESCC and received first-line treatment, a total of 117 (40.5%) were administered carboplatin and paclitaxel and 67 (23.2%) received fluorouracil, leucovorin, and oxaliplatin (FOLFOX). Then, 124 patients (42.9%) ended up going on to second-line treatment and 28 (22.6%) of those patients were given FOLFOX and another 20 (16.1%) were given carboplatin and paclitaxel.

When patients finished receiving first-line therapy, 54 patients (43.5%) moved on and were given third-line therapy in which the most common regiment was pembrolizumab monotherapy (12.9%, n = 7) followed by the combination of fluorouracil, leucovorin, and irinotecan, also known as FOLFIRI (11.1%, n = 6).

Overall findings concluded that the mOS of all patients treated in the first-line was 10.2 months (8.7-12.3) while the mOS for patients receiving BSC was 3.4 months (2.5-4.4). For the 91 (80.5%) patients who died in the post-index period and received BSC, the mOS was 2.7 months (2.3-3.5).

Regarding treatment-related survival by line of treatment, the mOS from the start of first-line therapy was 8.2 months (7.0-10.2; n = 289). For the 165 (57.1%) of patients who did not move on to second-line treatment, the mOS was 7.0 months (6.0-8.0) and only 38 (23.0%) survived the post-index observation period. Then, the mOS from the start of second-line treatment was 6.8 months (5.5-9.8) for the 124 patients. Seventy of these patients did not proceed to the third line and had a median survival of 12.5 months (9.4-14.9). Additionally, only 21 of these patients (30.0%) survived the post-index observation. For the 53 patients who started third-line therapy, the mOS was 5.9 months (4.8-10.7).

There was similar mOS for the first-line treated patients and BSC patients aged 65 years and older and those younger than 65. Additionally, females seemed to have a longer survival time than males (12.5 vs 9.6) and patients with recurrent ESCC had a longer mOS compared with stage IV, 4A, and 4B de novo patients, both in the first-line treated and BSC patient populations.

Reference:

Navaratnam P, Friedman HS, Zhang Y, et al. Patient demographics, clinical characteristics, treatment patterns, and survival outcomes associated with first-line treated unresectable advanced, metastatic and recurrent esophageal squamous cell carcinoma in the U.S. Presented at: 2022 International Society for Pharmacoeconomics and Outcomes Research; May 15-18, 2022. Washington, DC.