{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T00:44:50Z","timestamp":1792802690591,"version":"4.5.0"},"reference-count":44,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2024,11,14]],"date-time":"2024-11-14T00:00:00Z","timestamp":1731542400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Agencia Nacional de Investigaci\u00f3n y Desarrollo (ANID, Chile)","award":["1191743"],"award-info":[{"award-number":["1191743"]}]},{"name":"Agencia Nacional de Investigaci\u00f3n y Desarrollo (ANID, Chile)","award":["ACT210079"],"award-info":[{"award-number":["ACT210079"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Breast cancer is the most common cancer among women and a leading cause of cancer-related deaths. PIK3CA gene mutations, which are often present in advanced HR+ breast cancer, can be targeted by alpelisib. However, data on PIK3CA mutations in Chile are limited. Here, we aim to assess the mutational status of PIK3CA in metastatic breast cancer tissues from Chilean patients and describe their clinicopathological characteristics and survival outcomes. We analyzed 102 formalin-fixed, paraffin-embedded metastatic breast cancer samples from 96 patients diagnosed at three Chilean hospitals between 2007 and 2023. PIK3CA mutations were identified using targeted sequencing, and clinicopathological data were collected. We evaluated associations between mutational status, clinicopathological features, and survival. The median age at diagnosis was 56 years. The most common metastatic sites were liver (29.4%), bone (17.6%), and lung\/pleura (16.7%). Most patients were HR+ HER2\u2212 (83.3%), with 57.3% showing HER2-low status. PIK3CA mutations were present in 40.6% of patients, mainly in exons 7, 9, and 20. No significant associations were found between PIK3CA mutations and clinicopathological characteristics or survival. Our study reveals a high frequency of PIK3CA mutations in HR+ metastatic breast cancer, consistent with global data. The majority of mutations are targetable with alpelisib. The proportion of HER2-low status patients suggests potential benefits from novel HER2-targeted therapies. These findings highlight the need for routine molecular diagnostics in Chile to improve personalized treatment and address economic and access challenges.<\/jats:p>","DOI":"10.3390\/ijms252212246","type":"journal-article","created":{"date-parts":[[2024,11,14]],"date-time":"2024-11-14T08:06:32Z","timestamp":1731571592000},"page":"12246","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Molecular Analysis of PIK3CA in Metastatic Hormone Receptor-Positive Breast Cancer in Chile: Clinical and Pathological Insights"],"prefix":"10.3390","volume":"25","author":[{"given":"Carla","family":"Araya","sequence":"first","affiliation":[{"name":"Cl\u00ednica Alemana Facultad de Medicina, Universidad del Desarrollo, Santiago 7650567, Chile"},{"name":"Doctorado en Ciencias e Innovaci\u00f3n en Medicina, Universidad del Desarrollo, Santiago 7610658, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B\u00e1rbara","family":"Mino","sequence":"additional","affiliation":[{"name":"Cl\u00ednica Alemana Facultad de Medicina, Universidad del Desarrollo, Santiago 7650567, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8662-695X","authenticated-orcid":false,"given":"Patricio","family":"Le Cerf","sequence":"additional","affiliation":[{"name":"Servicio de Anatom\u00eda Patol\u00f3gica, Hospital Dr. S\u00f3tero del R\u00edo, Santiago 7610658, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fancy","family":"Gaete","sequence":"additional","affiliation":[{"name":"Servicio de Anatom\u00eda Patol\u00f3gica, Hospital Dr. Luis Tisn\u00e9 B, Santiago 7930426, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2567-0521","authenticated-orcid":false,"given":"Ricardo","family":"Armisen","sequence":"additional","affiliation":[{"name":"Instituto de Ciencias e Innovaci\u00f3n en Medicina, Universidad del Desarrollo, Santiago 7610658, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel E.","family":"Carvajal-Hausdorf","sequence":"additional","affiliation":[{"name":"Cl\u00ednica Alemana Facultad de Medicina, Universidad del Desarrollo, Santiago 7650567, Chile"},{"name":"Doctorado en Ciencias e Innovaci\u00f3n en Medicina, Universidad del Desarrollo, Santiago 7610658, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"229","DOI":"10.3322\/caac.21834","article-title":"Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries","volume":"74","author":"Bray","year":"2024","journal-title":"CA Cancer J. 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