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Thompson EF, Hoang L, Höhn AK, Palicelli A, Talia KL, Tchrakian N, Senz J, Rusike R, Jordan S, Jamieson A, Huvila J, McAlpine JN, Gilks CB, Höckel M, Singh N, Horn LC. Molecular subclassification of vulvar squamous cell carcinoma: reproducibility and prognostic significance of a novel surgical technique. Int J Gynecol Cancer 2022; 32:977-985. [PMID: 35764349 DOI: 10.1136/ijgc-2021-003251] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES Vulvar squamous cell carcinoma is subclassified into three prognostically relevant groups: (i) human papillomavirus (HPV) associated, (ii) HPV independent p53 abnormal (mutant pattern), and (iii) HPV independent p53 wild type. Immunohistochemistry for p16 and p53 serve as surrogates for HPV viral integration and TP53 mutational status. We assessed the reproducibility of the subclassification based on p16 and p53 immunohistochemistry and evaluated the prognostic significance of vulvar squamous cell carcinoma molecular subgroups in a patient cohort treated by vulvar field resection surgery. METHODS In this retrospective cohort study, 68 cases treated by vulvar field resection were identified from the Leipzig School of Radical Pelvic Surgery. Immunohistochemistry for p16 and p53 was performed at three different institutions and evaluated independently by seven pathologists and two trainees. Tumors were classified into one of four groups: HPV associated, HPV independent p53 wild type, HPV independent p53 abnormal, and indeterminate. Selected cases were further interrogated by (HPV RNA in situ hybridization, TP53 sequencing). RESULTS Final subclassification yielded 22 (32.4%) HPV associated, 41 (60.3%) HPV independent p53 abnormal, and 5 (7.3%) HPV independent p53 wild type tumors. Interobserver agreement (overall Fleiss' kappa statistic) for the four category classification was 0.74. No statistically significant differences in clinical outcomes between HPV associated and HPV independent vulvar squamous cell carcinoma were observed. CONCLUSION Interobserver reproducibility of vulvar squamous cell carcinoma subclassification based on p16 and p53 immunohistochemistry may support routine use in clinical practice. Vulvar field resection surgery showed no significant difference in clinical outcomes when stratified based on HPV status.
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Affiliation(s)
- Emily F Thompson
- Department of Molecular Oncology, BC Cancer Research Center, Vancouver, British Columbia, Canada
| | - Lynn Hoang
- Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Anne Kathrin Höhn
- Division of Gynecologic Pathology, University of Leipzig, Leipzig, Germany
| | - Andrea Palicelli
- Pathology Unit, Azienda Unità Sanitaria Locale - IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Karen L Talia
- Royal Women's Hospital and VCS Foundation, Melbourne, Victoria, Australia
| | - Nairi Tchrakian
- Department of Molecular Oncology, BC Cancer Research Center, Vancouver, British Columbia, Canada.,Barts Health NHS Trust, London, UK
| | - Janine Senz
- Department of Molecular Oncology, British Columbia Cancer Research Center, Vancouver, British Columbia, Canada
| | | | | | - Amy Jamieson
- Department of Gynecology and Obstetrics, Division of Gynecologic Oncology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jutta Huvila
- Department of Pathology, University of Turku, Turku, Finland
| | - Jessica N McAlpine
- Gynecology and Obstetrics, Division Gynecologic Oncology, University of British Columbia, Vancouver, British Columbia, Canada
| | - C Blake Gilks
- Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Michael Höckel
- Leipzig School of Radical Pelvis Surgery, Division of Gynecologic Oncology, University Hospital Leipzig, Leipzig, Germany
| | - Naveena Singh
- Cellular Pathology, Barts Health and NHS Trust and Queen Mary University, London, UK
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