title: Assessing mutant p53 in primary high-grade serous ovarian cancer using immunohistochemistry and massively parallel sequencing.
abstract: The tumour suppressor p53 is mutated in cancer, including over 96% of high-grade serous ovarian cancer (HGSOC). Mutations cause loss of wild-type p53 function due to either gain of abnormal function of mutant p53 (mutp53), or absent to low mutp53. Massively parallel sequencing (MPS) enables increased accuracy of detection of somatic variants in heterogeneous tumours. We used MPS and immunohistochemistry (IHC) to characterise HGSOCs for TP53 mutation and p53 expression. TP53 mutation was identified in 94% (68/72) of HGSOCs, 62% of which were missense. Missense mutations demonstrated high p53 by IHC, as did 35% (9/26) of non-missense mutations. Low p53 was seen by IHC in 62% of HGSOC associated with non-missense mutations. Most wild-type TP53 tumours (75%, 6/8) displayed intermediate p53 levels. The overall sensitivity of detecting a TP53 mutation based on classification as 'Low', 'Intermediate' or 'High' for p53 IHC was 99%, with a specificity of 75%. We suggest p53 IHC can be used as a surrogate marker of TP53 mutation in HGSOC; however, this will result in misclassification of a proportion of TP53 wild-type and mutant tumours. Therapeutic targeting of mutp53 will require knowledge of both TP53 mutations and mutp53 expression.
authors.affiliation: Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, NSW 2065 Australia.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Cole
authors.affiliation: Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, NSW 2065 Australia.
authors.forename: Trisha
authors.initials: T
authors.lastname: Dwight
authors.affiliation: Department of Anatomical Pathology, Royal North Shore Hospital and University of Sydney, NSW 2065 Australia.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Gill
authors.affiliation: Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, NSW 2065 Australia.
authors.forename: Kristie-Ann
authors.initials: KA
authors.lastname: Dickson
authors.affiliation: Hunter New England Local Health District, Royal North Shore Hospital, University of Sydney, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Anatomical Pathology, Royal North Shore Hospital and University of Sydney, NSW 2065 Australia.
authors.forename: Adele
authors.initials: A
authors.lastname: Clarkson
authors.affiliation: Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St Leonards, Australia.
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Gard
authors.affiliation: Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St Leonards, Australia.
authors.forename: Jayne
authors.initials: J
authors.lastname: Maidens
authors.affiliation: Mater Private and Royal North Shore Hospitals, Sydney, NSW, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Valmadre
authors.affiliation: Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, NSW 2065 Australia.
authors.forename: Roderick
authors.initials: R
authors.lastname: Clifton-Bligh
authors.affiliation: Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, NSW 2065 Australia.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Marsh
mesh_terms: D045744:Cell Line, Tumor; D005260:Female; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007150:Immunohistochemistry; D009154:Mutation; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis* / Q000235:genetics*
chemical_list: D016159:Tumor Suppressor Protein p53