Jan Jobsen

Clinical Behavior and Molecular Landscape of Stage I p53-Abnormal Low-Grade Endometrioid Endometrial Carcinomas

Abstract Purpose: The clinical significance of the p53-abnormal (p53abn) molecular subtype in stage I low-grade endometrioid endometrial carcinoma (EEC) is debated. We aimed to review pathologic and molecular characteristics, and outcomes of stage I low-grade p53abn EEC in a large international cohort. Experimental Design: Previously diagnosed stage I p53abn EC (POLE–wild-type, mismatch repair–proficient) low-grade EEC from Canadian retrospective cohorts and PORTEC-1&2 trials were included. Pathology review was performed by six expert gynecologic pathologists blinded to p53 status. IHC profiling, next-generation sequencing, and shallow whole-genome sequencing was performed. Kaplan–Meier method was used for survival analysis. Results: We identified 55 stage I p53abn low-grade EEC among 3,387 cases (2.5%). On pathology review, 17 cases (31%) were not diagnosed as low-grade EEC by any pathologists, whereas 26 cases (47%) were diagnosed as low-grade EEC by at least three pathologists. The IHC and molecular profile of the latter cases were consistent with low-grade EEC morphology (ER/PR positivity, patchy p16 expression, PIK3CA and PTEN mutations) but they also showed features of p53abn EC (TP53 mutations, many copy-number alterations). These cases had a clinically relevant risk of disease recurrence (5-year recurrence-free survival 77%), with pelvic and/or distant recurrences observed in 12% of the patients. Conclusions: A subset of p53abn EC is morphologically low-grade EEC and exhibit genomic instability. Even for stage I disease, p53abn low-grade EEC are at substantial risk of disease recurrence. These findings highlight the clinical relevance of universal p53-testing, even in low-grade EEC, to identify women at increased risk of recurrence.

Clinical and Molecular Characteristics of High-Risk, Recurrent, or Metastatic Endometrial Cancer That Is Human Epidermal Growth Factor Receptor 2–Low

PURPOSE Recent success of human epidermal growth factor receptor 2 (HER2)–targeted antibody-drug-conjugate trastuzumab-deruxtecan in HER2-low and HER2-positive tumors has sparked interest in examining the HER2 status of tumors not traditionally associated with HER2 amplification. Despite the increasing number of systemic treatment options, patients with advanced endometrial cancer (EC) still face a poor prognosis. This study evaluates HER2-low status in over 800 EC, correlating HER2 with both molecular and clinical features. METHODS HER2 status was determined by immunohistochemistry (IHC) and dual in situ hybridization (DISH) on four studies of previously classified high-risk EC (PORTEC-3 and Medical Spectrum Twente cohort), recurrent or metastatic EC (DOMEC), and a primary stage IV cohort. EC was classified as HER2-negative (IHC 0), HER2-low (IHC 1+/2+ without amplification), or HER2-positive (IHC 3+ or DISH-confirmed amplification). Survival analysis was performed using the Kaplan-Meier method. Cox proportional hazards models assessed the independence of any prognostic impact of HER2 status. RESULTS HER2 status was determined in 806 EC: 74.8% were HER2-negative, 17.2% HER2-low, and 7.9% HER2-positive. HER2-low was found across all molecular classes and histotypes. The highest rates of HER2-low and HER2-positive tumors were in recurrent or metastatic EC (35.6% and 15.6%), followed by primary stage IV EC (29.9% and 12.4%) and high-risk EC (14.2% and 6.8%). HER2 status had no independent prognostic value. CONCLUSION A quarter of high-risk, metastatic, or recurrent EC exhibited HER2 overexpression. The presence of HER2 overexpression in all clinical and molecular categories highlights the need for broad testing and offers treatment options for a wide range of patients.

Molecular Classification Predicts Response to Radiotherapy in the Randomized PORTEC-1 and PORTEC-2 Trials for Early-Stage Endometrioid Endometrial Cancer

PURPOSE The molecular classification of endometrial cancer (EC) has proven to have prognostic value and is predictive of response to adjuvant chemotherapy. Here, we investigate its predictive value for response to external beam radiotherapy (EBRT) and vaginal brachytherapy (VBT) in early-stage endometrioid EC (EEC). METHODS Data of the randomized PORTEC-1 trial (n = 714) comparing pelvic EBRT with no adjuvant therapy in early-stage intermediate-risk EC and the PORTEC-2 trial (n = 427) comparing VBT with EBRT in early-stage high-intermediate-risk EC were used. Locoregional (including vaginal and pelvic) recurrence-free survival was compared between treatment groups across the four molecular classes using Kaplan-Meier's methodology and log-rank tests. RESULTS A total of 880 molecularly classified ECs, 484 from PORTEC-1 and 396 from PORTEC-2, were included. The majority were FIGO-2009 stage I EEC (97.2%). The median follow-up was 11.3 years. No locoregional recurrences were observed in EC with a pathogenic mutation of DNA polymerase-ε ( POLEmut EC). In mismatch repair–deficient (MMRd) EC, locoregional recurrence-free survival was similar after EBRT (94.2%), VBT (94.2%), and no adjuvant therapy (90.3%; P = .74). In EC with a p53 abnormality (p53abn EC), EBRT (96.9%) had a substantial benefit over VBT (64.3%) and no adjuvant therapy (72.2%; P = .048). In EC with no specific molecular profile (NSMP EC), both EBRT (98.3%) and VBT (96.2%) yielded better locoregional control than no adjuvant therapy (87.7%; P < .0001). CONCLUSION The molecular classification of EC predicts response to radiotherapy in stage I EEC and may guide adjuvant treatment decisions. Omitting radiotherapy seems to be safe in POLEmut EC. The benefit of radiotherapy seems to be limited in MMRd EC. EBRT yields a significantly better locoregional recurrence-free survival than VBT or no adjuvant therapy in p53abn EC. VBT is the treatment of choice for NSMP EC as it is as effective as EBRT and significantly better than no adjuvant therapy for locoregional tumor control.

Prognostic refinement of NSMP high-risk endometrial cancers using oestrogen receptor immunohistochemistry

Abstract Background Risk-assessment of endometrial cancer (EC) is based on clinicopathological factors and molecular subgroup. It is unclear whether adding hormone receptor expression, L1CAM expression or CTNNB1 status yields prognostic refinement. Methods Paraffin-embedded tumour samples of women with high-risk EC (HR-EC) from the PORTEC-3 trial ( n  = 424), and a Dutch prospective clinical cohort called MST ( n  = 256), were used. All cases were molecularly classified. Expression of L1CAM, ER and PR were analysed by whole-slide immunohistochemistry and CTNNB1 mutations were assessed with a next-generation sequencing. Kaplan–Meier method, log-rank tests and Cox’s proportional hazard models were used for survival analysis. Results In total, 648 HR-EC were included. No independent prognostic value of ER, PR, L1CAM, and CTNNB1 was found, while age, stage, and adjuvant chemotherapy had an independent impact on risk of recurrence. Subgroup-analysis showed that only in NSMP HR-EC, ER-positivity was independently associated with a reduced risk of recurrence (HR 0.33, 95%CI 0.15–0.75). Conclusions We confirmed the prognostic impact of the molecular classification, age, stage, and adjuvant CTRT in a large cohort of high-risk EC. ER-positivity is a strong favourable prognostic factor in NSMP HR-EC and identifies a homogeneous subgroup of NSMP tumours. Assessment of ER status in high-risk NSMP EC is feasible in clinical practice and could improve risk stratification and treatment.

External-Beam Radiation Therapy Compared With Vaginal Brachytherapy After Surgery for Stage I Endometrial Cancer

RATIONALE: External-beam radiation therapy uses high-energy x-rays to kill tumor cells. Implant radiation therapy uses radioactive material placed directly into or near a tumor to kill tumor cells. Giving external-beam radiation therapy or implant radiation therapy after surgery may kill any tumor cells that remain after surgery. Sometimes, after surgery, the tumor may not need more treatment until it progresses. In this case, observation may be sufficient. It is not yet known whether radiation therapy is more effective than observation when given after surgery in treating stage I endometrial cancer. PURPOSE: This randomized phase III trial is studying external-beam radiation therapy or implant radiation therapy to see how well they work compared with observation in treating patients who have undergone surgery for stage I endometrial cancer.