{"entity":{"id":"pten-alteration","kind":"biomarker","name":"PTEN alteration (sequencing) and PTEN loss (IHC)","aka":["PTEN loss","PTEN deficiency","PTEN-deficient","PTEN alteration","PTEN deletion","PTEN mutation","PTEN IHC loss","PTEN null"],"tldr":"PTEN can be lost by mutation or deletion (read by sequencing) or as absent protein on a stain. Both readouts select capivasertib: alterations in breast cancer, and protein deficiency in metastatic hormone-sensitive prostate cancer.","summary":"PTEN loss removes the brake on PI3K signalling. In breast cancer capivasertib with fulvestrant is labelled for tumours with PIK3CA, AKT1 or PTEN alterations by FoundationOne CDx (CAPItello-291); in prostate cancer, following CAPItello-281, the 2026 label adds capivasertib with abiraterone for metastatic androgen pathway modulation-naive or -sensitive prostate cancer selected on PTEN deficiency in tumour tissue by the VENTANA PTEN (SP218) RxDx Assay (P250031, 12 June 2026). The IHC rule is loss of PTEN staining in tumour cells with retained stromal staining; the sequencing rule is a deleterious mutation or homozygous deletion.","asOf":"2026-09-23","links":[{"label":"TRUQAP prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d698c106-2322-401e-b738-cbd83c843ecf"}],"tags":["biomarker","pi3k"],"related":["pik3ca-hotspot-mutation","akt1-e17k"],"cancers":["breast-hr-positive","prostate-mhspc","prostate","endometrial","glioblastoma"],"sections":[],"technologies":[],"targets":[],"drugs":["capivasertib","abiraterone","foundationone-cdx"],"companies":[],"institutions":[],"pathways":[],"terms":["pten-loss","ihc"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"pten","measurement":"sequencing-variant","scoringRule":{"text":"Sequencing: a deleterious PTEN mutation or deletion in tumour tissue or plasma. Immunohistochemistry: absence of PTEN staining in tumour cells with retained staining in adjacent stroma, on the VENTANA PTEN (SP218) RxDx Assay for prostate cancer.","quote":"PTEN protein Loss/Deficient","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools","sourceLabel":"FDA: List of FDA-Authorized Companion Diagnostic Devices"},"thresholds":[{"value":"PTEN alteration (with PIK3CA and AKT1 as the qualifying set)","drugId":"capivasertib","cancerId":"breast-hr-positive","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d698c106-2322-401e-b738-cbd83c843ecf","quote":"with one or more PIK3CA/AKT1/PTEN -alterations as detected by an FDA-approved test","status":"current"},{"value":"PTEN deficiency in tumour tissue (IHC)","drugId":"capivasertib","cancerId":"prostate-mhspc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d698c106-2322-401e-b738-cbd83c843ecf","quote":"Select patients for the treatment of metastatic androgen pathway modulation-naïve or -sensitive (mAPMN/S) prostate cancer with TRUQAP based on PTEN deficiency in tumor tissue","status":"current"}],"tests":["foundationone-cdx","foundationone-liquid-cdx","tempus-xt","caris-mi-profile"],"assays":["foundationone-cdx-panel"],"companionDiagnostics":[{"device":"FoundationOne CDx","maker":"Foundation Medicine","companyId":"foundation-medicine","drugs":["capivasertib","fulvestrant"],"indication":"Breast Cancer - Tissue","pma":"P170019/S048 (11/16/2023)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"VENTANA PTEN (SP218) RxDx Assay","maker":"Ventana Medical Systems (Roche Tissue Diagnostics)","drugs":["capivasertib"],"indication":"Metastatic hormone-sensitive prostate cancer (mHSPC) - Tissue","pma":"P250031 (06/12/2026)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"}],"forPatient":"PTEN loss means the PI3K growth pathway is running without its brake. In hormone-receptor-positive breast cancer it qualifies you for capivasertib with fulvestrant after hormone therapy; in newly metastatic hormone-sensitive prostate cancer a PTEN-deficient stain qualifies you for capivasertib added to abiraterone. Ask which test was used, because the breast indication uses sequencing and the prostate one a stain."},"route":"/biomarkers/pten-alteration/","neighbours":{"biomarker":[{"id":"akt1-e17k","kind":"biomarker","name":"AKT1 E17K mutation","route":"/biomarkers/akt1-e17k/"},{"id":"pik3ca-hotspot-mutation","kind":"biomarker","name":"PIK3CA mutation","route":"/biomarkers/pik3ca-hotspot-mutation/"}],"cancer":[{"id":"endometrial","kind":"cancer","name":"Endometrial cancer","route":"/cancers/endometrial/"},{"id":"glioblastoma","kind":"cancer","name":"Glioma & glioblastoma","route":"/cancers/glioblastoma/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"prostate-mhspc","kind":"cancer","name":"Metastatic hormone-sensitive prostate cancer","route":"/cancers/prostate-mhspc/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"drug":[{"id":"abiraterone","kind":"drug","name":"Abiraterone acetate","route":"/drugs/abiraterone/"},{"id":"capivasertib","kind":"drug","name":"Capivasertib","route":"/drugs/capivasertib/"},{"id":"foundationone-cdx","kind":"drug","name":"FoundationOne CDx / Liquid CDx","route":"/drugs/foundationone-cdx/"}],"term":[{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"},{"id":"pten-loss","kind":"term","name":"PTEN loss","route":"/terms/pten-loss/"}],"target":[{"id":"pten","kind":"target","name":"PTEN","route":"/targets/pten/"}]}}