{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T17:47:40Z","timestamp":1774806460249,"version":"3.50.1"},"posted":{"date-parts":[[2026,3,13]]},"group-title":"Oncology","reference-count":5,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T00:00:00Z","timestamp":1773360000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,3,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Immune checkpoint inhibitors (ICI) have improved outcomes in Merkel cell carcinoma (MCC). Population analyses suggest improved survival following the 2017 approval of ICI, but registry data lack treatment-level information including type of systemic therapy and initiation timepoint to directly estimate the benefit attributable to immunotherapy. This study compared Merkel Cell Carcinoma-specific survival between patients treated with first-line ICI versus cytotoxic chemotherapy.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Patients were identified from the Seattle Merkel Cell Carcinoma Registry. Among 1,517 patients with MCC, 463 received first-line systemic therapy with either ICI or chemotherapy. Propensity scores were estimated using logistic regression including AJCC 8th stage, age, sex, MCPyV status, and immunosuppression. One-to-one nearest-neighbor matching produced balanced cohorts of 133 ICI-treated and 133 chemotherapy-treated patients. Merkel Cell Carcinoma-specific survival from therapy initiation was analyzed using Kaplan-Meier and Cox proportional hazards models with follow-up administratively censored at five years.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Baseline clinical characteristics were comparable between matched cohorts. ICI therapy was associated with significantly improved Merkel Cell Carcinoma-specific survival compared with chemotherapy (log-rank p&lt;0.0001). Five-year Merkel Cell Carcinoma-specific survival was 56.8% (95% CI 46.8-65.6) for ICI versus 23.9% (95% CI 16.9-31.6) for chemotherapy. In multivariable stage-stratified Cox analysis, ICI remained independently associated with improved Merkel Cell Carcinoma-specific survival (HR 0.32, 95% CI 0.21-0.50; p&lt;0.0001), while immunosuppression was associated with worse Merkel Cell Carcinoma-specific survival (HR 2.03, 95% CI 1.10-3.74; p=0.0228).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>ICI therapy was associated with substantially improved MCC-specific survival compared with chemotherapy.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.03.05.26347615","type":"posted-content","created":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T13:50:22Z","timestamp":1773669022000},"source":"Crossref","is-referenced-by-count":0,"title":["Immunotherapy Significantly Improves Merkel Cell Carcinoma-Specific Survival: A Single-Cohort Propensity Score-Matched Analysis"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2783-5265","authenticated-orcid":false,"given":"Sophia Z.","family":"Shalhout","sequence":"first","affiliation":[{"name":"Division of Surgical Oncology, Department of Otolaryngology-Head and Neck Surgery, Mike Toth Head and Neck Cancer Research Center, Mass Eye and Ear, Boston, Massachusetts"},{"name":"Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-1950-2643","authenticated-orcid":false,"given":"Angela","family":"Fragano","sequence":"additional","affiliation":[{"name":"Division of Surgical Oncology, Department of Otolaryngology-Head and Neck Surgery, Mike Toth Head and Neck Cancer Research Center, Mass Eye and Ear, Boston, Massachusetts"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriella","family":"Chefitz","sequence":"additional","affiliation":[{"name":"Dermatology Branch, National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2297-0003","authenticated-orcid":false,"given":"Tom W.","family":"Andrew","sequence":"additional","affiliation":[{"name":"Translation and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK"},{"name":"Department of Plastic and Reconstructive Surgery, Royal Victoria Infirmary, Newcastle Upon Tyne Hospital NHS Foundation Trust (NuTH), Newcastle upon Tyne, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2697-268X","authenticated-orcid":false,"given":"Kristina","family":"Lachance","sequence":"additional","affiliation":[{"name":"Department of Dermatology, University of Washington, Seattle, WA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1092-1594","authenticated-orcid":false,"given":"Rima","family":"Kulikauskas","sequence":"additional","affiliation":[{"name":"Department of Dermatology, University of Washington, Seattle, WA, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2784-963X","authenticated-orcid":false,"given":"Paul","family":"Nghiem","sequence":"additional","affiliation":[{"name":"Department of Dermatology, University of Washington, Seattle, WA, USA"},{"name":"Fred Hutch Cancer Center, Seattle, Washington, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0090-9914","authenticated-orcid":false,"given":"Isaac","family":"Brownell","sequence":"additional","affiliation":[{"name":"Dermatology Branch, National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, Maryland, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"54368","reference":[{"key":"2026032910415968000_2026.03.05.26347615v1.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaad.2025.03.006"},{"key":"2026032910415968000_2026.03.05.26347615v1.2","doi-asserted-by":"publisher","DOI":"10.1038\/s41571-018-0103-2"},{"key":"2026032910415968000_2026.03.05.26347615v1.3","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1603702"},{"key":"2026032910415968000_2026.03.05.26347615v1.4","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2407417"},{"key":"2026032910415968000_2026.03.05.26347615v1.5","doi-asserted-by":"publisher","DOI":"10.1136\/bmjonc-2024-000654"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.03.05.26347615","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T17:42:11Z","timestamp":1774806131000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.64898\/2026.03.05.26347615"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,13]]},"references-count":5,"URL":"https:\/\/doi.org\/10.64898\/2026.03.05.26347615","relation":{},"subject":[],"published":{"date-parts":[[2026,3,13]]},"subtype":"preprint"}}