PD07.03. Real-World Data on the Management of Double Primary Squamous Cell Carcinoma of the Esophagus and Head and Neck

Abstract

Esophageal Cancer: Adjuvant and Neo-Adjuvant Therapies Esophageal squamous cell carcinoma (ESCC) and head and neck squamous cell carcinoma (HNSCC) frequently develop as double primary cancers through field cancerization, driven by shared risk factors such as alcohol consumption and tobacco smoking. Immune checkpoint inhibitors (ICIs), particularly programmed death-1 (PD-1) inhibitors, have become standard therapies for both ESCC and HNSCC, necessitating a reassessment of treatment strategies for patients with double primary cancers. However, real-world clinical practice regarding PD-1 inhibitor use in this population remains poorly characterized. Therefore, we evaluated treatment patterns and their association with overall survival (OS) using real-world data (RWD) from our institution. We retrospectively analyzed 37 patients with double primary ESCC and HNSCC treated with systemic therapy between 2018 and 2023 using our institutional cancer registry linked to the CyberOncology RWD platform. Treatment patterns, programmed death-ligand (PD-L1) expression, ICI use, and OS were evaluated. Among 37 patients (94.6% male; median age 65.1 years), 62.2% were heavy smokers and 32.4% heavy drinkers. PD-L1 combined positive score was <1 in 17 and ≥20 in 14 of 31 evaluable patients. ICIs were given to 19 (61.3%) with immune-related adverse events in 3 (9.7%), without a difference in 1-year OS. HNSCC was prioritized for treatment in 78.4% of cases, while ESCC remained untreated in 40.5% of cases. After HNSCC chemoradiotherapy (CRT), ESCC was treated by surgery (n=2), CRT (n=1), or endoscopic submucosal dissection (ESD) (n=6); three ESD-treated patients died from HNSCC. One patient developed cervical hemorrhage after HNSCC CRT, delaying surgery for stage I ESCC, leading to fatal progression. Using real-world data, we comprehensively characterized treatment patterns in patients with double primary ESCC and HNSCC. Untreated ESCC did not generally compromise overall survival; however, in selected cases, ESCC could be treated after successful HNSCC therapy, whereas in others, progression of ESCC adversely affected prognosis. These findings highlight the need for individualized treatment strategies that account for the stage of each tumor and the dynamic impact of treatment sequencing in patients with concurrent cancers.