%0 Journal Article
%A Garcia-Carbonero, Rocio
%A González Astorga, Beatriz
%A Vidal Tocino, Rosario
%A Contreras Toledo, Débora
%A Pericay, Carles
%A Fernandez Montes, Ana
%A Falcó, Esther
%A González Cordero, Marta
%A Reina Zoilo, Juan José
%A Alonso, Vicente
%A Rodríguez Salas, Nuria
%A Gil-Raga, Mireia
%A Santos, Cristina
%A Páez, David
%A Anton-Pascual, Beatriz
%A Aguilar, Fernando
%A Morales, Pilar
%T Real-world study on microsatellite instability and mismatch repair deficiency testing patterns among patients with metastatic colorectal cancer in Spain
%D 2023
%U https://hdl.handle.net/20.500.13003/19917
%X Clinical practice guidelines recommend that all patients with metastatic colorectal cancer (mCRC) should be tested for mismatch repair deficiency (dMMR) or microsatellite instability-high (MSI-H). We aimed to describe the dMMR/MSI-H testing practice in patients with mCRC in Spanish centers.Multicenter, observational retrospective study that included patients newly diagnosed with mCRC or who progressed to a metastatic stage from early/localized stages.Three hundred patients were included in the study from May 2020 through May 2021, with a median age of 68 years, and two hundred twenty-five (75%) had stage IV disease at initial diagnosis; two hundred eighty-four patients received first-line treatment, and dMMR/MSI-H testing was performed in two hundred fifty-one (84%) patients. The results of the dMMR/MSI-H tests were available in 61 (24%) of 251 patients before the diagnosis of metastatic disease and in 191 (81%) of 236 evaluable patients for this outcome before the initiation of first-line treatment. Among the 244 patients who were tested for dMMR/MSI-H with IHC or PCR, 14 (6%) were MMR deficient. The most frequent type of first-line treatment was the combination of chemotherapy and biological agent, that was received by 71% and 50% of patients with MMR proficient and deficient tumors, respectively, followed by chemotherapy alone, received in over 20% of patients in each subgroup. Only 29% of dMMR/MSI-H tumors received first-line immunotherapy.Our study suggests that a high proportion of patients with mCRC are currently tested for dMMR/MSI-H in tertiary hospitals across Spain. However, there is still room for improvement until universal testing is achieved.Not applicable.
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