{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T06:15:09Z","timestamp":1788243309319,"version":"build-2803163510"},"reference-count":25,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:p>A 74-year-old man with nodular melanoma of the right lateral neck presented with nodal and hepatic metastases at staging. He declined guideline-directed therapy and instead pursued lifestyle modifications alongside self-administered ivermectin and fenbendazole. On serial imaging, his disease initially demonstrated reduced metabolic activity and size without new sites of involvement, paralleled by a decline in tumor-informed ctDNA (Signatera) from 2.04 to 0.18 MTM\/mL. Both subsequently worsened, with ctDNA rising to 0.93 MTM\/mL and the dominant axillary nodal mass increasing in size and avidity. The tumor carried a mutational burden of at least 50 mutations\/Mb, placing it at the extreme upper end of the immunogenic spectrum, and spontaneous immune-mediated regression is at least as plausible an explanation as any effect of the patient\u2019s interventions. The discussion contextualizes the growing popularity of antiparasitic repurposing in oncology, the absence of clinical evidence supporting efficacy, and the need for safety counseling given the reported toxicities of such drugs.<\/jats:p>","DOI":"10.3389\/fonc.2026.1907192","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T05:35:08Z","timestamp":1788240908000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Metastatic melanoma with initial ctdna decline and radiographic response during self-directed antiparasitic use: treatment effect or spontaneous regression?"],"prefix":"10.3389","volume":"16","author":[{"given":"Ricky","family":"Cheng","sequence":"first","affiliation":[{"name":"University of Florida College of Medicine","place":["Gainesville, FL, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel V.","family":"Araujo","sequence":"additional","affiliation":[{"name":"Division of Hematology and Oncology, University of Florida College of Medicine","place":["Gainesville, FL, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,1]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1003466","article-title":"Improved survival with ipilimumab in patients with metastatic melanoma","volume":"363","author":"Hodi","year":"2010","journal-title":"N Engl J Med"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/j.esmoop.2024.103978","article-title":"Bespoke ctDNA for longitudinal detection of molecular residual disease in high-risk melanoma patients","volume":"9","author":"Genta","year":"2024","journal-title":"ESMO Open"},{"key":"B3","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1016\/j.ejso.2013.09.026","article-title":"Spontaneous regression of metastatic melanoma \u2013 clinical evidence of the abscopal effect","volume":"40","author":"Bramhall","year":"2014","journal-title":"Eur J Surg Oncol EJSO"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1097\/CAD.0000000000000526","article-title":"Spontaneous regression of Malignant melanoma \u2013 is it based on the interplay between host immune system and melanoma antigens","volume":"28","author":"Cervinkova","year":"2017","journal-title":"Anti-Cancer Drugs"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1097\/CMR.0b013e328307ee4c","article-title":"Spontaneous regression of metastases from Malignant melanoma: a case report","volume":"18","author":"Kalialis","year":"2008","journal-title":"Melanoma Res"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1053\/clon.2001.9315","article-title":"Spontaneous regression of metastatic Malignant melanoma of the parotid gland and neck lymph nodes: a case report and a review of the literature","volume":"13","author":"King","year":"2001","journal-title":"Clin Oncol (R Coll Radiol)"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1038\/s41588-018-0312-8","article-title":"Tumor mutational load predicts survival after immunotherapy across multiple cancer types","volume":"51","author":"Samstein","year":"2019","journal-title":"Nat Genet"},{"key":"B8","unstructured":"NCCN clinical practice guidelines in oncology: melanoma: cutaneous. 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