e18015 Background: Since publication of the landmark KEYNOTE-048 Trial, pembrolizumab alone or with platinum-based chemotherapy and 5-fluorouracil (5FU) was established as a standard of care for the frontline treatment of patients with recurrent or metastatic head and neck squamous cell cancer (HNSCC), replacing the EXTREME regimen of Cetuximab with platinum and 5FU. In clinical practice, some clinicians modify the KEYNOTE-048 regimen by substituting a taxane for 5FU (i.e., Paclitaxel + Carboplatin + Pembrolizumab, PCT). Within the Kaiser Permanente Northern California (KPNCAL) network, we identified a cohort of 123 patients who received palliative first-line therapy for metastatic HNSCC to identify practice patterns in a real-world setting within a large health care delivery system. Methods: This is a data-only cohort study of all adult KPNCAL members diagnosed with metastatic HNSCC treated with palliative combination chemotherapy and/or immunotherapy between January 1, 2018 and July 31, 2020. Results: Among a cohort of 123 patients, 28 patients received the EXTREME regimen (platinum + 5FU + cetuximab), 10 received modified EXTREME (platinum + taxane + cetuximab), 14 received platinum + 5FU + pembrolizumab, 9 received platinum + taxane + pembrolizumab and 62 received single agent immunotherapy. From 2018 through mid-2020, there was an apparent shift away from cetuximab based regimens and a concurrent rise in immunotherapy-based regimens. By mid-2020, the majority of patients received an immunotherapy-based regimen (28 patients), while only 5 patients received a cetuximab based regimen (Table). Conclusions: Data from our cohort reported clinical practice patterns within a large multispecialty integrated health-care system in Northern California. Our findings highlight the marked variability in practice patterns within a single health care system for first-line metastatic therapy. While we identified trends away from cetuximab based therapy and toward immunotherapy-based therapy in clinical practice there remained wide practice variations among clinical oncologist treating patients with newly diagnosed metastatic HNSCC. This further emphasizes the need for prospective clinical trials to identify the optimal regimen or to confirm clinical equipoise between regimens among patients with metastatic or recurrent head and neck cancer. [Table: see text]
Practice Patterns for Thoracic Aneurysms in the Stent Graft Era: Health Care System Implications