Treatment Patterns And Outcomes Among Patients With Advanced Cutaneous Squamous Cell Carcinoma (Cscc) In A Us Community Oncology Setting.

e21033 Background: Advanced CSCC is a term that encompasses the locally advanced (laCSCC) and metastatic (mCSCC) condition. For advanced CSCC patients who receive conventional anticancer systemic treatment, there are limited data regarding treatment patterns and clinical outcomes. Methods: This was a retrospective, observational study of adult patients with laCSCC and mCSCC who initiated first-line (1L) systemic treatment from 1/1/2008 to 12/31/2015, with follow-up to 9/30/2017. Data were abstracted from the US Oncology Network’s iKnowMedSM electronic health record database, supplemented by chart review. ECOG performance status (PS) of 0 or 1 was required for inclusion. Exclusion criteria included tumor of unknown primary site, treatment with an anti-PD-1/anti-PD-L1 agent, participation in clinical trial, and concurrent primary cancer. Duration of therapy (DOT) and overall survival (OS) were analyzed by Kaplan-Meier method. Response rate was calculated as the proportion of patients who achieved physician assessed-response. Results: 82 patients met inclusion criteria (17 laCSCC and 65 mCSCC). Median age at start of 1L treatment was 75y; 85% were male, 79% Caucasian, 88% of patients had an ECOG PS of 1, 90% had prior surgery, 84% prior radiotherapy, and 8.5% had prior organ transplant. The most common 1L regimens were carboplatin + paclitaxel (27% of patients) and cetuximab monotherapy (24%). Median 1L DOT was 2.4 mo for the overall population; 4.1 mo for laCSCC, 2.3 mo for mCSCC. Physician-assessed response rate for 1L therapy was 18.3% overall; 17.6% for laCSCC, and 18.5% for mCSCC. Median OS from the start of 1L treatment was 15.3 mo (95% CI, 10.4-21.0) overall; 16.2 mo for laCSCC, and 15.3 mo for mCSCC. Only 24 patients (29%) received 2L therapy. Conclusions: This is the largest retrospective data set regarding advanced CSCC patients treated with conventional chemotherapy. Efficacy was low in both laCSCC and mCSCC. These data provide historic benchmarks for outcomes in advanced CSCC patients prior to the FDA approval of cemiplimab-rwlc.