Marián Švajdler

Refined criteria for p53 expression in ovarian mucinous tumours are highly concordant with TP53 mutation status, but p53 expression/TP53 status lack prognostic significance

In gynecological neoplasms, immunohistochemical (IHC) expression of p53 is generally an accurate predictor of TP53 mutation status if correctly interpreted by the pathologist. However, the literature concerning cut-offs, frequency and prognostic significance of p53 staining in ovarian mucinous tumours is limited and heterogeneous. We performed an analysis of 123 primary ovarian mucinous tumours including mucinous borderline tumours (MBT), mucinous carcinomas (MC), and tumours with equivocal features between MBT and MC. We assessed p53 expression for the three recognised patterns of aberrant staining in ovarian carcinoma [overexpression ('all'), null and cytoplasmic] but using a recently suggested cut-off for aberrant overexpression in ovarian mucinous tumours (strong nuclear p53 staining in ≥12 consecutive tumour cells) and correlated the results with next generation sequencing (NGS) in all qualitatively sufficient cases (92/123). Aberrant p53 expression was present in 25/75 (33.3%) MBT, 23/33 (69.7%) MC (75% of MC with expansile invasion and 61.5% with infiltrative invasion), and 10/15 (66.7%) tumours equivocal between MBT and MC. Regarding the 92 tumours with paired IHC and mutation results, 86 showed concordant results and six cases were discordant. Three discordant MBT cases showed aberrant expression but were TP53 wild-type on sequencing. Three cases had normal p53 expression but contained a TP53 mutation. Overall, IHC predicted the TP53 mutation status with high sensitivity (94.1%) and specificity (92.7%). The accuracy of IHC was 93.5% with a positive predictive value of 94.1% and a negative predictive value of 92.7%. When comparing MC cases with wild-type TP53 versus those with TP53 mutation, there were no significant differences concerning disease-free survival, local recurrence-free survival, or metastases-free survival (p>0.05). In the MBT subgroup, there were no events for survival analyses. In conclusion, using an independent large sample set of ovarian mucinous tumours, the results of our study confirm that the suggested refined cut-off of strong nuclear p53 staining in ≥12 consecutive tumour cells reflect high accuracy, sensitivity and specificity for an underlying TP53 mutation but the TP53 mutation status has no prognostic significance in either MC or MBT.

TRPS1 expression in 451 tubo-ovarian tumours: a potential prognostic marker for high-grade serous carcinoma.

Trichorhinophalangeal syndrome type 1; transcriptional repressor GATA binding 1 (TRPS1), a member of the GATA transcription factor family, functions primarily as a transcriptional repressor. TRPS1 is frequently utilised as a diagnostic marker for breast carcinoma, although its specificity is lower than previously believed. Moreover, TRPS1 is expressed in various solid tumours originating from the skin, salivary glands, soft tissues, prostate, urothelium, and female genital tract. The current study evaluated the diagnostic and prognostic significance of TRPS1 in 451 primary tubo-ovarian tumours. The cohort included 94 high-grade serous carcinomas (HGSCs), 81 low-grade serous carcinomas (LGSCs), 31 micropapillary serous borderline tumours (mSBTs), 92 clear cell carcinomas (CCCs), 52 endometrioid carcinomas (ECs), 31 mucinous carcinomas (MCs), and 70 mucinous borderline tumours (MBTs). Immunohistochemical analysis was performed using tissue microarrays following standardised protocols. Clinical data were analysed to determine the prognostic relevance of TRPS1 expression. TRPS1 expression was detected in 47% of HGSCs, 44% of ECs, 35% of CCCs, 19% of LGSCs, and 29% of mSBTs with complete negativity in MC/MBT. TRPS1-negative HGSC cases had higher recurrence rates than those with positive staining. Furthermore, TRPS1 expression significantly correlated with improved metastasis-free survival in HGSC cases. These findings suggest that TRPS1 may serve as an independent prognostic marker for HGSC. Despite varying expression rates across primary tubo-ovarian carcinomas, the routine use of TRPS1 in the differential diagnosis seems to be limited, ​as other robust immunohistochemical markers are available for distinguishing the individual subgroups. Further research is needed to clarify the specific functions and clinical implications of TRPS1 in tubo-ovarian cancer.

Advantages of next-generation sequencing (NGS) in the molecular classification of endometrial carcinomas – our experience with 270 cases

Molecular classification of endometrial carcinomas (EC) divides these neoplasms into four distinct subgroups defined by a molecular background. Given its proven clinical significance, genetic examination is becoming an integral component of the diagnostic procedure. Recommended diagnostic algorithms comprise molecular genetic testing of the POLE gene, whereas the remaining parameters are examined solely by immunohistochemistry. The aim of this study is to share our experiences with the molecular classification of EC, which has been conducted using immunohistochemistry and next-generation sequencing (NGS) at our department. This study includes all cases of EC diagnosed at Šikl's Department of Pathology and Biopticka Laboratory Ltd. from 2020 to the present. All ECs were prospectively examined by immunohistochemistry (MMR, p53), fol lowed by NGS examination using a customized Gyncore panel (including genes POLE, POLD1, MSH2, MSH6, MLH1, PMS2, TP53, PTEN, ARID1A, PIK3CA, PIK3R1, CTNNB1, KRAS, NRAS, BRCA1, BRCA2, BCOR, ERBB2), based on which the ECs were classified into four molecularly distinct groups [POLE mutated EC (type 1), hypermutated (MMR deficient, type 2), EC with no specific molecular profile (type 3), and TP53 mutated ("copy number high", type 4)]. The cohort comprised a total of 270 molecularly classified ECs. Eighteen cases (6.6%) were classified as POLE mutated EC, 85 cases (31.5%) as hypermutated EC (MMR deficient), 137 cases (50.7%) as EC of no specific molecular profile, and 30 cases (11.1%) as TP53 mutated EC. Twelve cases (4.4%) were classified as "multiple classifier" endometrial carcinoma. ECs of no specific molecular profile showed multiple genetic alterations, with the most common mutations being PTEN (44% within the group of NSMP), fol lowed by PIK3CA (30%), ARID1A (21%), and KRAS (9%). In comparison with recommended diagnostic algorithms, NGS provides a more reliable classification of EC into particular molecular subgroups. Furthermore, NGS reveals the complex molecular genetic background in individual ECs, which is especially significant within ECs with no specific molecular profile. These data can serve as a springboard for the research of therapeutic programs committed to targeted therapy in this type of tumor.