Double Duty: Complete Pathologic Response of Two Colonic Primaries with Mosaicism of a Novel <i>MLH1</i> Mutation to Neoadjuvant Pembrolizumab

Beatrice Preti; Laila Schenkel; Matthew Cecchini; Tommaso Romagnoli; Michael Susmoy Sanatani; Karissa French; Patrick Colquhoun; Mark David Vincent

doi:10.3390/curroncol30100653

Current Oncology (Oct 2023)

Double Duty: Complete Pathologic Response of Two Colonic Primaries with Mosaicism of a Novel <i>MLH1</i> Mutation to Neoadjuvant Pembrolizumab

Beatrice Preti,
Laila Schenkel,
Matthew Cecchini,
Tommaso Romagnoli,
Michael Susmoy Sanatani,
Karissa French,
Patrick Colquhoun,
Mark David Vincent

Affiliations

Beatrice Preti: Division of Medical Oncology, Department of Oncology, Western University, London, ON N6A 3K7, Canada
Laila Schenkel: Division of Molecular Diagnostics, Western University, London, ON N6A 3K7, Canada
Matthew Cecchini: Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
Tommaso Romagnoli: Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
Michael Susmoy Sanatani: Division of Medical Oncology, Department of Oncology, Western University, London, ON N6A 3K7, Canada
Karissa French: Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
Patrick Colquhoun: Department of Surgery, Western University, London, ON N6A 3K7, Canada
Mark David Vincent: Division of Medical Oncology, Department of Oncology, Western University, London, ON N6A 3K7, Canada

DOI: https://doi.org/10.3390/curroncol30100653
Journal volume & issue: Vol. 30, no. 10
pp. 9039 – 9048

Abstract

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We present a fascinating case of a 57-year-old male with a novel mutation in MLH1 (MLH1:c.1288G > T, p.(Glu430*)), who presented with two synchronous colonic tumours, initially deemed unresectable, and experienced a complete pathological response on neoadjuvant pembrolizumab. Extensive genetic testing revealed post-zygotic mosaicism from the novel mutation.

Published in Current Oncology

ISSN: 1198-0052 (Print); 1718-7729 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Medicine: Internal medicine: Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Website: https://www.mdpi.com/journal/curroncol

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