QPOLE: A Quick, Simple, and Cheap Alternative for POLE Sequencing in Endometrial Cancer by Multiplex Genotyping Quantitative Polymerase Chain Reaction

Molecular classification of metastatic and recurrent endometrial endometrioid carcinoma: prognostic relevance among low- and high-stage tumours

AIMS

Molecular classification according to The Cancer Genome Atlas (TCGA) improves endometrial endometrioid carcinoma (EEC) prognostication and has specific treatment implications; however, original data were skewed towards low-grade and low-stage tumours. Herein, we molecularly classify EECs metastatic at the time of diagnosis or with subsequently documented recurrent/metastatic disease to examine correlation with clinical outcomes.

METHODS

TCGA categories include POLE-mutated, microsatellite instability (MSI), p53 abnormal (p53 abnl) and no specific molecular profile (NSMP). POLE targeted sequencing at exons 9, 11, 13 and 14 and immunohistochemistry (IHC) for PMS2, MSH6 and p53 were performed to establish molecular classification.

RESULTS

The distribution in our cohort of 141 EECs was similar to that generally reported in EEC, with nine POLE-mutated (6%), 45 MSI (32%), 16 p53 abnl (11%) and 71 NSMP (50%), with similar distributions between low- and high-stage cohorts. We demonstrate that when stratified by molecular subtype, disease-specific survival from the time of high-stage (stages III-IV) presentation or time of recurrence in low-stage (stages I-II) disease among metastatic and/or recurrent EEC is strongly associated with TCGA classification (high-stage P = 0.02, low-stage P = 0.017). Discordant molecular classification between primary and metastatic/recurrent tumours occurred in four of 105 (3.8%) patients, two related to PMS2/MSH6 IHC and two related to p53 IHC.

CONCLUSIONS

We demonstrate that molecular classification is prognostically relevant not only at the time of diagnosis, but also at the time of recurrence and in the metastatic setting. Rare subclonal alterations occur and suggest a role for confirming TCGA classification in recurrent/metastatic tumours.

Is p53 immunohistochemistry alone useful for delineating adjuvant endometrial treatment in low-middle-income countries?

OBJECTIVE

Endometrial cancer (EC) treatment changed substantially with the introduction of molecular classification. Low-middle income (LMIC) countries will face barriers to including molecular classification to guide treatment. This study aims to analyse the value of p53 immunohistochemistry to delineate adjuvant treatment in FIGO stages I and II.

METHODS

Patients with EC treated between 2010 and 2016 were retrospectively evaluated. Patients included in this analysis must have reviewed FIGO stage I/II high-grade histologies (endometrioid grade 3, serous, clear cell, carcinosarcoma, mixed and undifferentiated). Samples were subjected to p53 immunohistochemistry. Recurrence-free and overall survival were analysed using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression was performed for multivariable analysis.

RESULTS

From 2010 to 2016, 265 patients met the inclusion criteria. Patients with aberrant p53 (71.4 %) were associated with older age (59.7 % vs 77.8 % with more than 60 years), relapse (12.5 vs 29.6 %) and death (22.2 vs 46.7 %). The pattern of relapse was not different, with most being at extrapelvic sites (55.5 % vs 62.3 % for p53 wild type and aberrant, respectively). The median overall survival was not reached versus 92.2 months for p53 wild type and aberrant, respectively (p = 0.003). In multivariate analysis, chemotherapy decreased death (p = 0.014) in p53 aberrant tumours, a benefit not seen in the wild-type cohort (p = 0.22).

CONCLUSION

This retrospective analysis corroborates the finding of worse outcomes for p53 aberrant tumours in stage I/II EC and the benefit of more aggressive adjuvant treatment (systemic therapy and radiotherapy). Although not ideal as a sole molecular marker, p53 immunohistochemistry could complement the classical anatomopathological features and be part of the decision-making process with patients in LMIC.

Impact of molecular profile on prognosis and relapse pattern in low and intermediate risk endometrial cancer

INTRODUCTION

The role of molecular classification in patients with low/intermediate risk endometrial cancer (EC) is uncertain. Higher precision in diagnostics will inform the unsettled debate on optimal adjuvant treatment. We aimed to determine the association of molecular profiling with patterns of relapse and survival.

MATERIAL AND METHODS

This retrospective cohort study included patients referred to The Norwegian Radium Hospital, Oslo University Hospital from 2006-2017. Patients with low/intermediate risk EC were molecularly classified as pathogenic polymerase epsilon (POLE)-mutated, mismatch repair deficient (MMRd), p53 abnormal, or no specific molecular profile (NSMP). The main outcomes were time to recurrence (TTR) and cancer-specific survival (CSS).

RESULTS

Of 626 patients, 610 could be molecularly classified. Fifty-seven patients (9%) had POLE-mutated tumors, 202 (33%) had MMRd tumors, 34 (6%) had p53 abnormal tumors and 317 (52%) had NSMP tumors. After median follow-up time of 8.9 years, there was a statistically significant difference in TTR and CSS by molecular groups. Patients with p53 abnormal tumors had poor prognosis, with 10 of the 12 patients with relapse presenting with para-aortic/distant metastases. Patients with POLE mutations had excellent prognosis. In the NSMP group, L1CAM expression was associated with shorter CSS but not TTR.

CONCLUSIONS

The differences in outcome by molecular groups are driven by differences in relapse frequency and -patterns and demand a higher precision in diagnostics, also in patients with low/intermediate risk EC. Tailored adjuvant treatment strategies need to consider systemic treatment for patients with p53 abnormal tumors and de-escalated treatment for patients with POLE mutated tumors.

Moving into the modern era of molecular classification for endometrial cancer

The molecular subtypes of endometrial carcinoma (EC) were first described by The Cancer Genome Atlas (TCGA) a decade ago. Using surrogate approaches, the molecular classification has been demonstrated to be prognostic across EC patients and to have predictive implications. Starting in 2020, the molecular classification has been incorporated into multiple guidelines as part of the risk assessment and most recently into the International Federation of Gynecology and Obstetrics (FIGO) staging. This review article discusses the implementation of the EC molecular classification into clinical practice, the therapeutic implications, and the molecular and clinical heterogeneity of the EC molecular subtypes.

Molecular-based classification of endometrial carcinoma in Northern Thailand: impact on prognosis and potential for implementation in resource-limited settings

BACKGROUND

Endometrial carcinoma is molecularly categorized into four subgroups: polymerase-E exonuclease domain-mutant (POLE-mut), mismatch repair-deficient (MMR-d), p53-abnormal (p53-abn), and no specific molecular profile (NSMP). This classification scheme has been included into clinical recommendation for post-operative risk-based management, although there have been few Asian studies on this topic. The present study aimed to evaluate the prevalence and clinical outcomes of endometrial carcinoma using this classification in Northern Thailand and the feasibility of implementation in resource-limited settings.

METHODS

Endometrial carcinomas from hysterectomy specimens were classified using immunohistochemistry for MMR proteins and p53, as well as POLE mutation testing. Clinicopathological variables and outcomes were analyzed. The costs of the molecular information-based approach were compared to those incurred by the conventional approach (without molecular classification).

RESULTS

Of 138 patients, 52.9% in the NSMP subgroup, 28.2% were in the MMR-d, 13.8% in the p53-abn, and 5.1% in the POLE-mut. After adjusting for other variables, patients with POLE-mut showed the most favorable outcomes, while those with p53-abn had the poorest survival. When estimating the costs for post-operative management, the use of molecular classification resulted in a 10% increase over the conventional approach. However, the cost increased only by 1% if only POLE testing was used to identify patients for treatment omission.

CONCLUSION

In Northern Thailand, endometrial carcinoma had comparable subgroup distribution and prognostic implications to previous reports, supporting the implementation of management guidelines that incorporate molecular information. In resource-limited settings, at least POLE mutation testing in early-stage patients should be considered.