Interpretation of p53 Immunostaining in Endometrial Carcinoma

The purpose of this website is to allow you to test your ability to interpret p53 immunostaining in endometrial carcinoma. p53 immunostaining has emerged as an important surrogate marker for the Copy-Number High (CNH) molecular subtype of endometrial cancer (1-3); this is the most aggressive of the endometrial cancer molecular subtypes. Almost all serous carcinomas show abnormal p53 immunostaining, and a significant minority of grade 3 endometrioid carcinomas show abnormal p53 immunostaining (4). The grade 3 endometrioid carcinomas with abnormal p53 staining patterns have a worse prognosis than other grade 3 endometrioid carcinomas. Thus, accurate interpretation of p53 immunostaining is important in endometrial carcinoma diagnostics. Because of this recent evolution in the interpretation of p53 immunostaining in endometrial carcinoma (5), we have developed this website to allow you to test your interpretive ability.

This website has 20 scanned slides of endometrial biopsies stained for p53. These tumors were stained independently in another lab, with identical staining results/interpretation, and we also have assessed these tumors for TP53 mutations.

You will be offered a choice of the following options when you review each case:

  1. p53 wild-type/normal
  2. p53 abnormal (overexpression)
  3. p53 abnormal (complete absence)
  4. p53 abnormal (cytoplasmic)
  5. p53 abnormal (heterogeneous p53 staining)

Before proceeding with this quiz, we suggest you review the BAGP/UKNEQAS/CIQC guidelines for interpretation of p53 staining.

When ready to proceed with the 20 slide quiz, click on TEST SET, below.

References

  1. Kommoss S, McConechy MK, Kommoss F, Leung S, Bunz A, et al. Final Validation of the ProMisE Molecular Classifier for Endometrial Carcinoma in a Large Population-based Case Series. Ann Oncol. 2018 Feb 7. [Epub ahead of print] PubMed PMID: 29432521.
  2. Talhouk A, McConechy MK, Leung S, Li-Chang HH, Kwon JS, et al. A clinically applicable molecular-based classification for endometrial cancers. Br J Cancer. 2015 Jul 14;113(2):299-310.
  3. Stelloo E, Nout RA, Osse EM, Jürgenliemk-Schulz IJ, Jobsen JJ, et al. Improved Risk Assessment by Integrating Molecular and Clinicopathological Factors in Early-stage Endometrial Cancer-Combined Analysis of the PORTEC Cohorts. Clin Cancer Res. 2016 Aug 15;22(16):4215-24.
  4. Bosse T, Nout RA, McAlpine JN, McConechy MK, Britton H, et al. Molecular Classification of Grade 3 Endometrioid Endometrial Cancers Identifies Distinct Prognostic Subgroups. Am J Surg Pathol. 2018 Mar 2. [Epub ahead of print] PubMed PMID: 29505428.
  5. Köbel M, Ronnett BM, Singh N, Soslow RA, Gilks CB, McCluggage WG. Interpretation of P53 Immunohistochemistry in Endometrial Carcinomas: Toward Increased Reproducibility. Int J Gynecol Pathol. 2018 Mar 6. [Epub ahead of print] PubMed PMID: 29517499.